Individuals and Their Physiology

1. Individuals and Their Physiology

Are we all the same?

Do Now

Challenge: How many bones are in the body? Are there more or less muscles?

How are the structure and function of the musculoskeletal system related to movement of the human body?

Challenge: Predict what would happen if we didn’t have muscles or a skeleton

• B.1.1.1—The human skeleton is divided into an axial component and an appendicular component. These have different primary functions.
• B.1.1.2—Movements occur in one or more planes, and rotations occur along one or more axes.
• B.1.1.3—Anthropometry, the measurement of body segments and proportions of the human body, has applications in many areas of sport and health science.
• B.1.2—The structure of connective tissues and joints are related to their function in enabling movement.
• B.1.4.1—Three different classes of levers, both within and outside the human body, work to create movements.
• A.1.3.1—The cardiovascular system transports nutrients, hormones, gases, heat and waste to perform necessary bodily functions.
• A.1.3.2—The respiratory system enables the exchange of gases between the external environment and the body, to facilitate cellular respiration.
• A.1.1.1—The nervous system senses both internal and external conditions to coordinate the responses of the body’s physiological systems effectively

Individuals and Their Physiology

Syllabus Guidance

Lesson Objectives

Axial

Individuals and Their Physiology

State how the human skeleton is divided

B.1.1.1—The human skeleton is divided into an axial component and an appendicular component. These have different primary functions.

Appendicular

• The human skeleton can be divided into two main parts: the axial skeleton and the appendicular skeleton. Each part has distinct components and functions.
• Axial Skeleton
• The axial skeleton forms the central axis of the body and is primarily responsible for supporting and protecting the organs of the head, neck, and trunk.

2. Appendicular Skeleton

• The appendicular skeleton includes the bones of the limbs and the girdles (shoulder and pelvic) that attach them to the axial skeleton.

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Individuals and Their Physiology

State what each section of the human skeleton is composed of

B.1.1.1—The human skeleton is divided into an axial component and an appendicular component. These have different primary functions.

• Anatomical planes are imaginary lines that divide the body into sections and are used as reference points in anatomy and medicine. Here is a list of the major anatomical planes:

Individuals and Their Physiology

State the anatomical planes

B.1.1.1—The human skeleton is divided into an axial component and an appendicular component. These have different primary functions.

Sagittal Plane:

• Description: Divides the body into left and right parts.

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Frontal (Coronal) Plane:

• Description: Divides the body into anterior (front) and posterior (back) parts.

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Transverse (Horizontal) Plane:

• Description: Divides the body into superior (upper) and inferior (lower) parts.
• Also Known As: Cross-sectional plane or axial plane.

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Frontal

Transverse

Sagittal

Individuals and Their Physiology

State the anatomical planes

B.1.1.1—The human skeleton is divided into an axial component and an appendicular component. These have different primary functions.

Individuals and Their Physiology

Draw the anatomical planes

B.1.1.1—The human skeleton is divided into an axial component and an appendicular component. These have different primary functions.

• Positional Terms Quizlet

Individuals and Their Physiology

Practise the position terms

B.1.1.1—The human skeleton is divided into an axial component and an appendicular component. These have different primary functions.

Individuals and Their Physiology

Describe the purpose of the human skeleton

B.1.1.1—The human skeleton is divided into an axial component and an appendicular component. These have different primary functions.

1. The thumb is ______________ to the pinky finger.
2. The lungs are ______________ to the liver.
3. The ribs are ______________ to the heart.
4. The elbow is ______________ to the shoulder.
5. The mouth is ______________ to the chin.
6. The toes are ______________ to the ankle.
7. The sternum is ______________ to the spine.
8. The kidneys are ______________ to the intestines.
9. The clavicle (collarbone) is ______________ to the ribs.
10. The belly button is ______________ to the hips.
11. The brain is ______________ to the eyes.
12. The ankle is ______________ to the knee.

Individuals and Their Physiology

Practise the position terms

B.1.1.1—The human skeleton is divided into an axial component and an appendicular component. These have different primary functions.

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1. The heart is ______________ to the ribs.
2. The fingers are ______________ to the elbow.
3. The nose is ______________ to the eyes.
4. The skin is ______________ to the muscles.
5. The knee is ______________ to the hip.
6. The stomach is ______________ to the heart.
7. The spine is ______________ to the sternum.
8. The brain is ______________ to the skull.

Individuals and Their Physiology

Practise the position terms

B.1.1.1—The human skeleton is divided into an axial component and an appendicular component. These have different primary functions.

• The heart is posterior/deep to the ribs.
• The fingers are distal to the elbow.
• The nose is medial/inferior to the eyes.
• The skin is superficial to the muscles.
• The knee is distal/ to the hip.
• The stomach is inferior to the heart.
• The spine is posterior to the sternum.
• The brain is deep to the skull.
• The thumb is lateral to the pinky finger.
• The lungs are superior to the liver.

Individuals and Their Physiology

Practise the position terms

B.1.1.1—The human skeleton is divided into an axial component and an appendicular component. These have different primary functions.

1. The ribs are anterior to the heart.
2. The elbow is distal to the shoulder.
3. The mouth is superior to the chin.
4. The toes are disatal to the ankle.
5. The sternum is anterior to the spine.
6. The kidneys are posterior to the intestines.
7. The clavicle (collarbone) is superior to the ribs.
8. The belly button is medial to the hips.
9. The brain is posterior to the eyes.
10. The ankle is distal to the knee.

Individuals and Their Physiology

Practise the position terms

B.1.1.1—The human skeleton is divided into an axial component and an appendicular component. These have different primary functions.

• Objective: blindfold task where students have to collect objects with a blindfold on and their partner can only use positional terminology

Individuals and Their Physiology

Practise the position terms

B.1.1.1—The human skeleton is divided into an axial component and an appendicular component. These have different primary functions.

Individuals and Their Physiology

Describe positional terminology

B.1.1.1—The human skeleton is divided into an axial component and an appendicular component. These have different primary functions.

Individuals and Their Physiology

Describe positional terminology

B.1.1.1—The human skeleton is divided into an axial component and an appendicular component. These have different primary functions.

Challenge: Explain what happens to the thoracic cavity during breathing

• flexion, extension, abduction, adduction, pronation, supination, inversion, eversion, retraction, opposition, reposition, depression, circumduction, plantarflexion, dorsiflexion, horizontal flexion and horizontal extension

Individuals and Their Physiology

Quiz your vocabulary

B.1.1.2—Movements occur in one or more planes, and rotations occur along one or more axes.

Movements of the Body Quizlet

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Flexion & extension

Individuals and Their Physiology

B.1.1.2—Movements occur in one or more planes, and rotations occur along one or more axes.

Abduction & adduction

Individuals and Their Physiology

B.1.1.2—Movements occur in one or more planes, and rotations occur along one or more axes.

Pronation & supination

Individuals and Their Physiology

B.1.1.2—Movements occur in one or more planes, and rotations occur along one or more axes.

Inversion & eversion

Individuals and Their Physiology

B.1.1.2—Movements occur in one or more planes, and rotations occur along one or more axes.

Plantarflexion & dorsiflexion

Individuals and Their Physiology

B.1.1.2—Movements occur in one or more planes, and rotations occur along one or more axes.

Depression & elevation

Individuals and Their Physiology

B.1.1.2—Movements occur in one or more planes, and rotations occur along one or more axes.

Protraction & retraction

Individuals and Their Physiology

B.1.1.2—Movements occur in one or more planes, and rotations occur along one or more axes.

Opposition & reposition

Individuals and Their Physiology

B.1.1.2—Movements occur in one or more planes, and rotations occur along one or more axes.

• flexion, extension, abduction, adduction, pronation, supination, inversion, eversion, retraction, opposition, reposition, depression, circumduction, plantarflexion, dorsiflexion, horizontal flexion and horizontal extension

Individuals and Their Physiology

B.1.1.2—Movements occur in one or more planes, and rotations occur along one or more axes.

1.List 3 fundamental planes

2.Distinguish between adduction and abduction, and inversion and eversion.

3.Outline 3 functions of the skeletal system

4. Identify the plane of movement and the axis of rotation for the following

physical activities:

a. squat

b. push up

c. golf swing

d. surfer

5.Explain why swimwear for competitive swimmers has developed over time

Individuals and Their Physiology

B.1.1.2—Movements occur in one or more planes, and rotations occur along one or more axes.

Create a video to explain the movements that occur in planes or axis.

60 seconds maximum

Individuals and Their Physiology

B.1.1.2—Movements occur in one or more planes, and rotations occur along one or more axes.

Challenge: Include ways to remember each

• Define anthropometric data:
• Describe where anthropometric data is stored:
• Explain how anthropometric data is used in sports using examples:
• Predict changes for athlete performance optimization, injury prevention strategies, and design of sports equipment based on anthropometric data:
• Evaluate the effectiveness of current injury prevention strategies in sports using anthropometric data:
• Design a hypothetical sports shoe based on anthropometric principles:

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Individuals and Their Physiology

Research the influence of anthropometric data on sport performance

B.1.1.3—Anthropometry, the measurement of body segments and proportions of the human body, has applications in many areas of sport and health science.

Challenge: Propose innovative uses of anthropometric data in future sports technology:

• Anthropometric data refers to measurements of the human body, such as height, weight, body fat percentage, and limb lengths.
• Anthropometric data is typically stored in databases maintained by sports organizations, research institutions, or healthcare facilities. It can also be kept in athlete management systems and personal health records.

Individuals and Their Physiology

Research the influence of anthropometric data on sport performance

B.1.1.3—Anthropometry, the measurement of body segments and proportions of the human body, has applications in many areas of sport and health science.

• In sports, anthropometric data helps tailor training programs, select the best athletes for specific roles, and design equipment. For example, basketball players might be chosen based on their height and arm length, while cyclists may benefit from bikes customized to their body dimensions.

Individuals and Their Physiology

Research the influence of anthropometric data on sport performance

B.1.1.3—Anthropometry, the measurement of body segments and proportions of the human body, has applications in many areas of sport and health science.

• In the future, more personalized training plans and sports equipment will be developed based on precise body measurements. Injury prevention strategies could become more effective by identifying and addressing biomechanical imbalances. Sports equipment, like shoes or protective gear, may be custom-fitted to individual athletes to enhance performance and reduce injury risks.

Individuals and Their Physiology

Research the influence of anthropometric data on sport performance

B.1.1.3—Anthropometry, the measurement of body segments and proportions of the human body, has applications in many areas of sport and health science.

• Current injury prevention strategies that use anthropometric data are moderately effective. While they can help predict certain risks, such as the likelihood of stress fractures in runners with certain body types, the integration of real-time monitoring and more personalized data could improve outcomes.

Individuals and Their Physiology

Research the influence of anthropometric data on sport performance

B.1.1.3—Anthropometry, the measurement of body segments and proportions of the human body, has applications in many areas of sport and health science.

Individuals and Their Physiology

State with examples different types of bones

B.1.2—The structure of connective tissues and joints are related to their function in enabling movement.

• I can identify and label the major bones of the human body on the diagram or model.

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Individuals and Their Physiology

B.1.2—The structure of connective tissues and joints are related to their function in enabling movement.

Design a presentation to briefly review the different types of bones (long, short, flat, irregular, sesamoid) with the class.

E.g. Femur - Long Bone - Reason: Provides strength, structure, and facilitates movement.

• What are the functions of the bones you've labeled?
• How does the structure of a particular bone relate to its function in movement?
• Why are some bones categorized as irregular or sesamoid?

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Individuals and Their Physiology

Use your creativity to present bone

B.1.2—The structure of connective tissues and joints are related to their function in enabling movement.

Types of Bones Student Presentation.pptx

Individuals and Their Physiology

Example

B.1.2—The structure of connective tissues and joints are related to their function in enabling movement.

• Using the knowledge of bone types and their functions, design an athlete or a character that specializes in a specific sport or physical activity (e.g., basketball, gymnastics, or swimming).

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• Present your athlete to the class, explaining the importance of specific bones and how they contribute to performance in their chosen sport.

Individuals and Their Physiology

Task: Identify and explain which bones would be most critical for their athlete's success in that sport, focusing on bone type and function.

B.1.2—The structure of connective tissues and joints are related to their function in enabling movement.

Individuals and Their Physiology

Can you find the link between these images?

B.1.2—The structure of connective tissues and joints are related to their function in enabling movement.

• Bones -
• Ligaments –
• Tendons –
• Fascia –
• Joints -

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Individuals and Their Physiology

Discuss what you already know about the following:

B.1.2—The structure of connective tissues and joints are related to their function in enabling movement.

TOK: How do you know this and how do we know this?

• Bones -

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• Ligaments –

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• Tendons –

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• Fascia –

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• Joints -

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Structure: Hard, dense tissue forming the skeleton.

Function: Support the body, protect organs, and allow movement by providing attachment points for muscles.

Structure: Tough, fibrous bands of connective tissue.

Function: Connect bones to other bones and stabilize joints.

Structure: Strong, flexible bands of connective tissue.

Function: Attach muscles to bones, transmitting the force needed for movement.

Structure: Thin layers of connective tissue.

Function: Surround and support muscles, organs, and other structures, reducing friction between them.

Structure: Where two or more bones meet.

Function: Allow movement and flexibility in the skeleton, with types ranging from immovable (like the skull) to freely movable (like the shoulder).

Create a kid's story book to describe and clearly explain the structure and/or function of one or more of the following:

• Bronze: Bones
• Silver: Ligaments
• Silver: Tendons
• Gold: Fascia
• Gold: Joints

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Individuals and Their Physiology

B.1.2—The structure of connective tissues and joints are related to their function in enabling movement.

Challenge: make it 3D, engaging and colourful

• Length: The storybook should be appropriate in length for the age group, typically between 10-20 pages with a mix of text and illustrations.
• References: If scientific facts are included, they should be accurate and, if needed, sourced from reliable references (e.g., simple references at the back of the book for older children).
• Presentation: You will present these to your nominated age group.

Individuals and Their Physiology

Criteria for Assessment

B.1.2—The structure of connective tissues and joints are related to their function in enabling movement.

• 1. Content Understanding (40%)
• Accuracy: The storybook correctly explains the structure and function of the selected topic(s).
• Clarity: Scientific concepts are clearly explained in a way that is easy for children to understand.
• Age-Appropriate Language: The vocabulary and explanations match the reading level of the intended age group.

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Individuals and Their Physiology

Criteria for Assessment

B.1.2—The structure of connective tissues and joints are related to their function in enabling movement.

• 2. Creativity and Engagement (30%)
• Storyline: The book includes a fun and engaging story that captures a child's interest while teaching them about bones, ligaments, tendons, fascia, or joints.
• Characters: Characters (e.g., animals, superheroes, or kids) should be relatable and help explain the scientific concepts in a fun and memorable way.
• Illustrations: Creative and colorful illustrations should enhance understanding and keep the reader engaged.

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Individuals and Their Physiology

B.1.2—The structure of connective tissues and joints are related to their function in enabling movement.

• 3. Educational Value (20%)
• Learning Objectives: The book should have clear learning objectives, such as understanding the role of bones in the body or how ligaments and tendons help with movement.
• Interactive Elements: Includes questions, activities, or prompts to encourage children to think about what they’ve learned.

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Individuals and Their Physiology

B.1.2—The structure of connective tissues and joints are related to their function in enabling movement.

• 4. Design and Presentation (10%)
• Layout: The book is well-organized with a clear flow of information, balancing text and illustrations on each page.
• Visual Appeal: The cover and overall design are appealing and inviting to children.

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Individuals and Their Physiology

B.1.2—The structure of connective tissues and joints are related to their function in enabling movement.

• Bonus (Optional):
• Cultural or Social Relevance: The story includes elements that reflect diversity or teach important social lessons alongside the scientific content.

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Individuals and Their Physiology

B.1.2—The structure of connective tissues and joints are related to their function in enabling movement.

• Fibrous joints are a type of joint where bones are connected by dense, fibrous connective tissue. These joints are generally immovable or allow very limited movement,

Individuals and Their Physiology

Describe the 3 Types of Joints

B.1.2—The structure of connective tissues and joints are related to their function in enabling movement.

Challenge: Can you think of any examples of where immovable joints would be needed?

• Cartilaginous joints are a type of joint where bones are connected by cartilage, allowing for more movement than fibrous joints but less than synovial joints.

Individuals and Their Physiology

Describe the 3 Types of Joints

B.1.2—The structure of connective tissues and joints are related to their function in enabling movement.

Challenge: why is it important to have some movement in these joints?

Individuals and Their Physiology

I can Identify Types of Synovial Joints

B.1.2—The structure of connective tissues and joints are related to their function in enabling movement.

Individuals and Their Physiology

I can Label the Synovial Joint

B.1.2—The structure of connective tissues and joints are related to their function in enabling movement.

Individuals and Their Physiology

Labelling a synovial Joint

B.1.2—The structure of connective tissues and joints are related to their function in enabling movement.

11.2 Movement

Match the structure to it’s function

11.2.U2 Synovial joints allow certain movements but not others.

What is an effort? Fulcrum load?�What is mechanical advantage?

Individuals and Their Physiology

B.1.4.1—Three different classes of levers, both within and outside the human body, work to create movements.

• A lever is a simple machine that consists of a rigid bar pivoting around a fixed point called a fulcrum. Levers are used to make work easier by allowing a small force to move a larger load.

Individuals and Their Physiology

Can you define lever?

B.1.4.1—Three different classes of levers, both within and outside the human body, work to create movements.

Easier simple fulcrum larger small

1.

2.

3.

4.

Challenge: What words don’t I understand?

• In a first-class lever, the fulcrum is positioned between the effort and the load.
• Can you pick which one is a first-class lever?

Individuals and Their Physiology

What is a first class lever?

B.1.4.1—Three different classes of levers, both within and outside the human body, work to create movements.

Challenge: Can you think of an example of a simple first class lever?

• A seesaw. The fulcrum is in the center, with the effort and load on either side.

Individuals and Their Physiology

B.1.4.1—Three different classes of levers, both within and outside the human body, work to create movements.

Challenge: Can you think of an example using the human body?

• The neck. When you nod your head, the neck muscles (effort) work on one side, the joint between the skull and spine acts as the fulcrum, and the weight of the head is the load on the other side

Individuals and Their Physiology

Example in the human body

B.1.4.1—Three different classes of levers, both within and outside the human body, work to create movements.

• A wheelbarrow. The wheel is the fulcrum, the load is in the bucket, and you apply effort by lifting the handles.

Individuals and Their Physiology

In a second-class lever, the load is positioned between the fulcrum and the effort.

B.1.4.1—Three different classes of levers, both within and outside the human body, work to create movements.

Challenge: Can you draw on the fulcrum, load and effort?

Challenge: Can you think of an example using the human body?

• The foot when standing on tiptoes. The ball of the foot acts as the fulcrum, the body’s weight (load) is in the middle, and the calf muscles provide the effort at the heel.

Individuals and Their Physiology

B.1.4.1—Three different classes of levers, both within and outside the human body, work to create movements.

• The arm during a bicep curl. The elbow joint is the fulcrum, the biceps apply the effort in the middle, and the weight of the forearm and hand is the load.

Individuals and Their Physiology

In a third-class lever, the effort is applied between the fulcrum and the load.

B.1.4.1—Three different classes of levers, both within and outside the human body, work to create movements.

• In tongs, the effort is applied between the fulcrum and the load, making it a classic example of a third-class lever.

Individuals and Their Physiology

B.1.4.1—Three different classes of levers, both within and outside the human body, work to create movements.

Individuals and Their Physiology

What are the components of the blood?

A.1.3.1—The cardiovascular system transports nutrients, hormones, gases, heat and waste to perform necessary bodily functions.

Leukocytes

Erythrocytes

Individuals and Their Physiology

A.1.3.1—The cardiovascular system transports nutrients, hormones, gases, heat and waste to perform necessary bodily functions.

Individuals and Their Physiology

Identify red and white blood cells, as seen under the light microscope, on prepared slides and in diagrams and photomicrographs

Individuals and Their Physiology

A.1.3.1—The cardiovascular system transports nutrients, hormones, gases, heat and waste to perform necessary bodily functions.

Individuals and Their Physiology

A.1.3.1—The cardiovascular system transports nutrients, hormones, gases, heat and waste to perform necessary bodily functions.

• What are the properties of each? Why?

Individuals and Their Physiology

Can you identify what these are and where they are found?

Individuals and Their Physiology

Label the artery below

Explain how the structures of arteries, veins and capillaries are adapted for their function

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(Recoil)

(Doesn’t Burst)

(Maintain Pressure)

(Reduce Friction)

https://www.youtube.com/watch?v=4xG2aJa6UyY

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Thick Collagen Layer

Thick Muscle and Elastic Layer

Smooth

Narrow Lumen

1.

2.

3.

4.

Individuals and Their Physiology

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(Recoil)

(Low Pressures = Not going to burst)

(Build up blood to return to the heart)

(No Friction)

https://www.youtube.com/watch?v=4xG2aJa6UyY

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Thin Collagen Layer

Thin Muscle and Elastic Layer

Rough

Wide Lumen

1.

2.

3.

4.

Valves

5.

(prevent backflow)

Individuals and Their Physiology

?

Right atrium

Left atrium

Right ventricle

Left ventricle

Individuals and Their Physiology

Name the main blood vessels to and from the: – heart, limited to vena cava, aorta, pulmonary artery and pulmonary vein – lungs, limited to the pulmonary artery and pulmonary vein

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Left ventricle

Right ventricle

Left atrium

Right atrium

Aorta

1

3

4

5

Vena cava

2

What can you identify?

A - aorta

B - right atrium

C - auricle

D - coronary arteries

E - myocardium

F - apex

6.2 The Blood System

External Features

6.2 S2Recognition of the chambers and valves of the heart and the blood vessels connected to it in dissected hearts or in diagrams of heart structure.

There are 4 coronary arteries which supply the heart itself.

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2 at the front and 2 at the back

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coronary arteries

6.2 The Blood System

Coronary arteries supply heart muscle with oxygen and nutrients.

6.2 S2Recognition of the chambers and valves of the heart and the blood vessels connected to it in dissected hearts or in diagrams of heart structure.

External View

FRONT

BACK

6.2 The Blood System

External View

6.2 S2Recognition of the chambers and valves of the heart and the blood vessels connected to it in dissected hearts or in diagrams of heart structure.

6.2 The Blood System

6.2 S2Recognition of the chambers and valves of the heart and the blood vessels connected to it in dissected hearts or in diagrams of heart structure.

6.2 The Blood System

6.2 S2Recognition of the chambers and valves of the heart and the blood vessels connected to it in dissected hearts or in diagrams of heart structure.

Watch this!

6.2 The Blood System

6.2 S2Recognition of the chambers and valves of the heart and the blood vessels connected to it in dissected hearts or in diagrams of heart structure.

6.2 The Blood System

Left

Right

Right

Left

Atrium

Atrium

Ventricle

Ventricle

6.2 The Blood System

Vena Cava

Atrioventricular Valve (Tricuspid)

Pulmonary Artery

Lungs

6.2 The Blood System

Vena Cava

Atrioventricular Valve (Tricuspid)

Pulmonary Artery

Lungs

Pulmonary Valve (Semilunar)

Atrioventricular Valve (Bicuspid)

Pulmonary Vein

Aortic Valve (Semilunar)

Aorta

• Heart rate refers to how many heart contractions there are per minute.
• Measured in beats per minute (bpm)

Use the data booklet to help identify each of the structures

I understand cardiac function, which includes an understanding of the role of extrinsic factors and how they work with the intrinsic mechanisms controlling heart rate

Individuals and Their Physiology

Use the data booklet to help identify each of the structures

I understand cardiac function, which includes an understanding of the role of extrinsic factors and how they work with the intrinsic mechanisms controlling heart rate

Individuals and Their Physiology

How much blood comes out of your heart per beat?

Individuals and Their Physiology

Do Now

Stroke volume (SV) refers to the amount of blood pumped by the heart per beat

Individuals and Their Physiology

What is stoke volume and how does it vary?

Challenge: once a person reaches their peak intensity, suggest why their stroke volume plateaus

Cardiac Output(CO)=Stroke Volume(SV)×Heart Rate(HR)�L/min = ml x beats

Individuals and Their Physiology

What is cardiac output?

Challenge: Suggest reasons why trained and untrained CO are the same at rest

Individuals and Their Physiology

I can calculate the Cardiac Output of an individual

• Blood pressure measures the force of blood against the walls of your arteries as your heart pumps it around your body. It’s usually recorded with two numbers:
• Systolic Pressure (the first number) measures the pressure when your heart contracts
• Diastolic Pressure (the second number) measures the pressure when your heart relaxes and fills
• Blood pressure is measured in millimeters of mercury (mmHg),
• A normal blood pressure is 120/80 mmHg.

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Individuals and Their Physiology

What is blood pressure?

Define blood pressure, explain its significance in assessing cardiovascular health, and differentiate between systolic and diastolic pressure readings.

• A stethoscope is a medical tool used by doctors to listen to the sounds made by your heart, lungs, and other organs.
• This helps doctors diagnose conditions by hearing abnormal sounds or rhythms.

Individuals and Their Physiology

identify a stethoscope and a sphygmomanometer, describe their functions, and demonstrate how each tool is used to assess heart health and measure blood pressure.

• A sphygmomanometer (blood pressure monitor) is a device used to measure blood pressure.
• It typically consists of a cuff that wraps around your arm, a pump to inflate the cuff, and a gauge to display the pressure.
• When the cuff is inflated, it temporarily stops blood flow in the artery.

Individuals and Their Physiology

identify a stethoscope and a sphygmomanometer, describe their functions, and demonstrate how each tool is used to assess heart health and measure blood pressure.

Individuals and Their Physiology

interpret blood pressure readings, explain what constitutes normal and abnormal levels, and discuss potential health implications related to different blood pressure ranges.

Individuals and Their Physiology

I can plan an investigation of how exercise affects cardiac output

Individuals and Their Physiology

I can plan an investigation of how exercise affects cardiac output

Individuals and Their Physiology

I can plan an investigation of how exercise affects cardiac output

Individuals and Their Physiology

I can plan an investigation of how exercise affects cardiac output

Individuals and Their Physiology

I can plan an investigation of how exercise affects cardiac output

Individuals and Their Physiology

I can plan an investigation of how exercise affects cardiac output

Individuals and Their Physiology

I can plan an investigation of how exercise affects cardiac output

Individuals and Their Physiology

What is qualitative data? How accurate is it compared to qualitative data?

Do Now

Challenge: How can using a RPE chart assist in managing risk?

Which one were you?

• Qualitative Data
• Rate of Perceived Exertion (RPE)
• Quantitative Data
• Average
• Standard Deviation
• Correlation
• Graphing

Individuals and Their Physiology

I can analyse data from an investigation can justify a conclusion on how exercise affects cardiac output

Internal Assessment: Collect, Analyse and Present Experimental Data

Add Gender, Height, Weight, estimated SV and Resting Heart Rate to the spreadsheet

Challenge: Using AI, create a consent form for our experiment based on the listed risks

• Create your own graph between two variables
• Add all appropriate labels

​

Individuals and Their Physiology

I can analyse data from an investigation can justify a conclusion on how exercise affects cardiac output

Internal Assessment: Collect, Analyse and Present Experimental Data

Add Gender, Height, Weight, estimated SV and Resting Heart Rate to the spreadsheet

Challenge: write a conclusion based on the data

• What went well in the experiment?

​

• What didn’t go well in the experiment?

​

• How could the experiment be improved next time?

​

• What future investigations could be conducted?

Individuals and Their Physiology

I can evaluate an investigation on how exercise affects cardiac output

Internal Assessment: Collect, Analyse and Present Experimental Data

• Myogenic refers to a nervous impulse originating in muscle tissue itself.

​

https://www.youtube.com/watch?v=QflNbT23JCE

​

Individuals and Their Physiology

I can describe the myogenic nature of heart muscle.

Understand of the role of extrinsic factors and how they work with the intrinsic mechanisms controlling heart rate

Skeletal

Strong Contractions

Smooth - Involuntary

Cardiac –

Identify each of the 3 types of muscles structures

I understand cardiac function, which includes an understanding of the role of extrinsic factors and how they work with the intrinsic mechanisms controlling heart rate

Individuals and Their Physiology

Challenge: why does cardiac muscle need properties of smooth and skeletal muscle?

Vena Cava

Right Atrium

Left Atrium

Sinoatrial (SA) Node

Atrioventricular (AV) Node

Bundle of His

Purkinje Fibres

Bachmann’s Branch

Use the data booklet to help identify each of the structures

I understand cardiac function, which includes an understanding of the role of extrinsic factors and how they work with the intrinsic mechanisms controlling heart rate

Individuals and Their Physiology

Intrinsic factors include the heart's own regulatory mechanisms, such as the sinoatrial (SA) node, which acts as the heart's natural pacemaker.

• The Sinoatrial Node (SA node) is a specialized myocardial structure that initiates the electrical impulses to stimulate contraction, and is found in the atrial wall of the right atrium.
• 60 – 100 cardiac contractions per minute

Sinoatrial Node (SA Node)

Bachmann’s Branch

Use the data booklet to help identify each of the structures

I understand cardiac function, which includes an understanding of the role of extrinsic factors and how they work with the intrinsic mechanisms controlling heart rate

Individuals and Their Physiology

• The sinoatrial node sends out an electrical impulse that stimulates contraction of the atria (heart muscle tissue)
• This impulse directly causes the atria to contract and stimulates the AV node at the junction between the atrium and ventricle

​

Use the data booklet to help identify each of the structures

I understand cardiac function, which includes an understanding of the role of extrinsic factors and how they work with the intrinsic mechanisms controlling heart rate

Individuals and Their Physiology

• The Atrioventricular Node (AV node) delays the signal, to allow time for the ventricles to fill with blood.
• The AV Node sends signals down the septum via a nerve bundle (Bundle of His).

Atrioventricular Node (AV Node)

Bundle of His

A1.1 Communication

I understand cardiac function, which includes an understanding of the role of extrinsic factors and how they work with the intrinsic mechanisms controlling heart rate

• The contractions of the atria and ventricles must be staggered so blood flows in the correct direction.  When action potential is delayed about 0.12 seconds. Action potential starts at SA node and travels to the AV node.  The fibers in the AV node take longer to become excited. 

​

• ​They have smaller diameter and don’t conduct as quickly, reduced number of Na+ channels in membranes, fewer gap junctions between cells, more non-conductive connective tissue in node.

A1.1 Communication

I understand cardiac function, which includes an understanding of the role of extrinsic factors and how they work with the intrinsic mechanisms controlling heart rate

• The Bundle of His innervates nerve fibres (Purkinje fibres) in the ventricular wall, causing ventricular contraction

Purkinje Fibres

Bundle of His

A1.1 Communication

I understand cardiac function, which includes an understanding of the role of extrinsic factors and how they work with the intrinsic mechanisms controlling heart rate

A1.1 Communication

Challenge: Explain the mechanism of the heart-beat in simple terms but with the correct vocabulary

Oops - I forgot my data booklet

Individuals and Their Physiology

Do Now

Draw and label the heart

Challenge: How would you sort the nervous system?

Individuals and Their Physiology

Do Now

How would you sort these?

Page 37

Central Nervous System (CNS) – Brain and Spine

Peripheral Nervous System – Everything else

Challenge: Justify which is more important

Individuals and Their Physiology

A1.1.1 The nervous system is divided into the central nervous system and the peripheral nervous system.

How would you sort these?

Page 37

Sensory

Peripheral Nervous System (PNS)

Motor

Somatic

- Voluntary movements

Autonomic

Sympathetic

Parasympathetic

‘Fight or Flight’

‘Rest and digest’

Individuals and Their Physiology

A1.1.1 The nervous system is divided into the central nervous system and the peripheral nervous system.

I feel confident in describing how the nervous system broken up.

Page 37

Sensory

Peripheral Nervous System (PNS)

Motor

Somatic

- Voluntary movements

Autonomic

Sympathetic

Parasympathetic

‘Fight or Flight’

‘Rest and digest’

Individuals and Their Physiology

A1.1.1 The nervous system is divided into the central nervous system and the peripheral nervous system.

Describe how the nervous system is organised

A1.1 Communication

Find the link

A1.1.1 The nervous system is divided into the central nervous system and the peripheral nervous system.

‘Fight or Flight’

‘Rest and digest’

https://www.youtube.com/watch?v=3xrW3PH0050

​

Challenge: Justify why respiration is important

Where is this found in the body and how does our body detect changes in this?

Individuals and Their Physiology

I understand cardiac function, which includes an understanding of the role of extrinsic factors and how they work with the intrinsic mechanisms controlling heart rate

Brainstorm what physiological changes would happen in the body?

1. Carbon dioxide is carried in the plasma in the blood.
2. Our blood vessels have special receptors which detect chemical changes in the blood.
3. These are called chemoreceptors.
4. They send a message to the medulla oblongata in the brain.

Challenge: what are baroreceptors and proprioceptors?

Cheat Sheet

1. Oxygen Carbon Dioxide Helium
2. Fingers Heart Blood Vessels
3. Receptors Stimulus Detectors
4. Baroreceptors Proprioceptors Chemoreceptors
5. Liver Lungs Brain

Individuals and Their Physiology

I understand cardiac function, which includes an understanding of the role of extrinsic factors and how they work with the intrinsic mechanisms controlling heart rate

How is our body specialised to detect changes?

1. Carbon dioxide is carried in the plasma in the blood.
2. Our blood vessels have special receptors which detect chemical changes in the blood.
3. These are called chemoreceptors.
4. They send a message to the medulla oblongata in the brain.

Challenge: what are baroreceptors and proprioceptors?

Cheat Sheet

1. Oxygen Carbon Dioxide Helium
2. Fingers Heart Blood Vessels
3. Receptors Stimulus Detectors
4. Baroreceptors Proprioceptors Chemoreceptors
5. Liver Lungs Brain

Individuals and Their Physiology

I understand cardiac function, which includes an understanding of the role of extrinsic factors and how they work with the intrinsic mechanisms controlling heart rate

How is our body specialised to detect changes?

• A change in …… is detected by…. in the ….
• This sends a message to the …. in the …

​

I understand cardiac function, which includes an understanding of the role of extrinsic factors and how they work with the intrinsic mechanisms controlling heart rate

Describe how these two systems work together

Individuals and Their Physiology

20 minutes = 20 marks

Individuals and Their Physiology

What are the 3 types of specialised receptors?

Proprioceptors, baroreceptors and chemoreceptors are specialized cells that respond to stimuli to initiate responses by the nervous system.

Changes to blood pressure levels or CO₂ concentrations will trigger changes in heart rate

​

Vagus Nerve (slows down)

Sympathetic Nerve (speeds up)

I understand cardiac function, which includes an understanding of the role of extrinsic factors and how they work with the intrinsic mechanisms controlling heart rate

The medulla obongata sends a nervous impulse down the….

I understand cardiac function, which includes an understanding of the role of extrinsic factors and how they work with the intrinsic mechanisms controlling heart rate

Individuals and Their Physiology

Sympathetic Nerve

Vagus Nerve

State how the nervous system and circulatory system are linked.

I understand cardiac function, which includes an understanding of the role of extrinsic factors and how they work with the intrinsic mechanisms controlling heart rate

Individuals and Their Physiology

Extrinsic factors include:

Neural control (parasympathetic and sympathetic)

Hormonal Control (epinephrine and noradrenaline)

Other factors (temperature, ions and fitness)

• State how the Nervous system and Circulatory system are linked
• Describe how these two systems work together
• Describe how the nervous system is organised
• Explain how is our body specialised to detect changes

​

​

​

Checkpoint

I understand cardiac function, which includes an understanding of the role of extrinsic factors and how they work with the intrinsic mechanisms controlling heart rate

Individuals and Their Physiology

Challenge: How are hormones involved in this process?

a. sinoatrial node/SAN is a specialized group of muscle cells�OR

sinoatrial node/SAN is located in the right atrium ✔

b. acts as a pacemaker/controls the heart rate�OR

initiates/generates the heart beat/starts the cardiac cycle ✔

c. sends out electrical signal/impulses/depolarisations ✔

d. electrical signal stimulates contraction «of heart muscle» ✔

e. signal passes through walls of atria/passes to AV node ✔

f. then through walls of the ventricles ✔

g. medulla «oblongata of brain» can change/increase/decrease the rate ✔

h. through nerves/named example of nerve/autonomic/sympathetic/ parasympathetic nervous system ✔ In mph, only accept vagus nerve for slowing heart rate and sympathetic nerve for accelerating it.

1. one nerve increases the rate and the other decreases it ✔

j. epinephrine/adrenaline increases heart rate/force of contraction ✔

k. epinephrine/adrenaline prepares the body for vigorous activity/is part of fight or flight response ✔

​

6.2 The Blood System

Explain the control mechanism of the heart rate. (7 Marks)

Checkpoint

v

• AV valve opens
• Blood moves into the ventricle
• AV Valve Closes
• Aortic Valve is closed
• Ventricle Pressure Increases

​

​

6.2 The Blood System

6.2 A2 Pressure changes in the left atrium, left ventricle and aorta during the cardiac cycle.

• @70% capacity AV Valve Closes to prevent backflow
• Aortic Valve is closed
• Ventricle Contracts
• Pressure Increases

• Aortic Valve opens
• Ventricle Contracts
• Pressure Increases as blood leaves the aorta
• Ventricle pressure drops

6.2 The Blood System

6.2 A2 Pressure changes in the left atrium, left ventricle and aorta during the cardiac cycle.

• Medulla oblongata: Contains the respiratory center, which sends signals to the respiratory muscles (diaphragm and intercostal muscles) to contract, regulating inhalation and exhalation.
• Chemoreceptors detect changes in CO₂ levels.
• When CO₂ levels increase, pH drops (indicating more acidity), triggering an increase in the rate and depth of breathing to expel more CO₂.

Individuals and Their Physiology

Explain how is the nervous and hormonal system involved in breathing and ventilation

A.1.2.1—Homeostasis is any self-regulating biological process aiming to produce a relatively stable, constant internal environment for optimal functioning of the body

Homeostasis is any self-regulating biological process aiming to produce a relatively stable, constant internal environment for optimal functioning of the body.

Individuals and Their Physiology

What is homeostasis?

Homeostasis generally occurs via negative feedback mechanisms that reverse a change back to a controlled condition.

Challenge: List some biological processes which need constant maintenance

Challenge: State how it is achieved

Individuals and Their Physiology

I can Use diagrams to explain how the nervous and endocrine systems work together to regulate internal conditions like body temperature, pH levels, and glucose concentration.

A.1.2.1—Homeostasis is any self-regulating biological process aiming to produce a relatively stable, constant internal environment for optimal functioning of the body

Vasoconstriction - The narrowing of blood vessels caused by contraction

Vasodilation -

The widening of blood vessels caused by relaxation

Individuals and Their Physiology

True or False?

Factors that affect thermoregulation are training status, body composition, environment and sex differences (including hormonal phases).

Everyone sweats the same amount

Challenge: Suggest and justify factors that would influence the rate at which people sweat

• hypothalamus, located in the brain, acts as the body’s thermostat
• It constantly monitors body temperature by receiving information from thermoreceptors in the skin
• In cold conditions, the sympathetic nervous system triggers vasoconstriction, narrowing blood vessels to reduce blood flow to the skin, thus conserving heat.
• In hot conditions, the sympathetic system induces vasodilation, expanding blood vessels to increase heat loss through the skin.

Individuals and Their Physiology

Explain how is the nervous and hormonal system involved in temperature control

Regulation of temperature (thermoregulation) relies on the cardiovascular, muscular, nervous and integumentary systems working together to maintain a core body temperature of 37 ± 1°C.

Individuals and Their Physiology

What is non-shivering thermogenesis?

Thermoregulation occurs via the sweat response, vasodilation, vasoconstriction, shivering and non-shivering thermogenesis.

Thermo =heat

Genesis = creation

Non = not/without

Shivering = small involuntary muscle contractions

Individuals and Their Physiology

What is non-shivering thermogenesis?

Thermoregulation occurs via the sweat response, vasodilation, vasoconstriction, shivering and non-shivering thermogenesis.

A hormone is a chemical messenger that is transported via the bloodstream to act on distant target cells

​

Individuals and Their Physiology

What is a hormone?

Hormones are mediator molecules that are released in one part of the body but regulate the activity of cells in other parts of the body.

Individuals and Their Physiology

What is homeostasis?

A.1.2.1—Homeostasis is any self-regulating biological process aiming to produce a relatively stable, constant internal environment for optimal functioning of the body. In response to changing internal and external conditions, various mechanisms work constantly towards homeostasis

Individuals and Their Physiology

How is blood glucose regulated?

Regulation of blood glucose relies on insulin and glucagon.

Challenge: Explain how exercise limits the release of insulin and facilitates the uptake of glucose to regulate blood sugar levels.

6

• Epinephrine (also called adrenaline) released into the bloodstream as a hormone released from the adrenal gland

​

• Norepinephrine (noradrenaline) released by sympathetic neurons acts more as a neurotransmitter. released from the adrenal gland and sympathetic nerves
• It’s role is blood pressure regulation

​

• Both play a crucial role in the body’s "fight or flight" response.

​

• They are released primarily by the adrenal gland in response to stress, danger, or excitement

Individuals and Their Physiology

What is the role of epinephrine and norepinephrine?

Epinephrine and norepinephrine cause changes in blood pressure, heart rate and blood sugar levels.

• Increased heart rate: Epinephrine and norepinephrine stimulate the heart rate to increase (increading CO)

​

• Blood sugar: Rises to supply energy for muscular activity and brain function during stress.

Individuals and Their Physiology

What is the role of epinephrine and norepinephrine?

Epinephrine and norepinephrine cause changes in blood pressure, heart rate and blood sugar levels.

• Vasoconstriction:
• Norepinephrine causes vasoconstriction (narrowing of blood vessels), particularly in the skin and digestive system. This increases blood pressure because the blood vessels become narrower, requiring more pressure to push blood through them.

Individuals and Their Physiology

What is the role of epinephrine and norepinephrine?

Epinephrine and norepinephrine cause changes in blood pressure, heart rate and blood sugar levels.

• Vasodilation in muscles:
• Epinephrine can cause vasodilation (widening of blood vessels) in skeletal muscles and the heart, ensuring these tissues get more oxygen and nutrients during times of stress or exercise.
• The combined action of these hormones results in an overall increase in blood pressure, allowing more blood to flow to critical areas like the heart, brain, and muscles.

Individuals and Their Physiology

What is the role of epinephrine and norepinephrine?

Epinephrine and norepinephrine cause changes in blood pressure, heart rate and blood sugar levels.

• pH within a narrow range (typically 7.35 to 7.45).
• CO₂ Dissolves in Blood
• it reacts with water (H₂O) to form carbonic acid (H₂CO₃)
• Carbonic acid is unstable and quickly dissociates into hydrogen ions (H⁺) and bicarbonate ions (HCO₃⁻):
• The hydrogen ions (H⁺) increase the acidity of the blood, thereby lowering blood pH.

Individuals and Their Physiology

Explain how does carbon dioxide concentration affect blood pH

Blood pH (hydrogen ion concentration) is influenced by carbon dioxide concentration.

• The lungs and kidneys are crucial in maintaining the balance:
• Lungs: Control CO₂ levels by adjusting breathing. If CO₂ levels are too high, breathing rate increases to expel more CO₂, helping to raise the pH.
• Kidneys: Help regulate bicarbonate (HCO₃⁻) and H⁺ levels over the long term to balance blood pH.

Individuals and Their Physiology

Explain how does carbon dioxide concentration affect blood pH

Blood pH (hydrogen ion concentration) is influenced by carbon dioxide concentration.

• During exercise, CO₂ production increases, which increases H⁺ ions in the blood, lowering pH.
• Chemoreceptors throughout the body detect the change
• Medulla increases diaphragm muscle contractions
• To compensate, the body increases respiration and breathing rate to expel more CO₂, helping maintain pH within the normal range.

Individuals and Their Physiology

Explain the immediate responses to increasing exercise intensity

pH is monitored through the respiratory control centre of the brain and chemoreceptors throughout the body.

• This process is a negative feedback loop:
• High CO₂ (low pH) → Medulla increases breathing → CO₂ is expelled → pH returns to normal.
• Low CO₂ (high pH) → Medulla decreases breathing → CO₂ is retained → pH returns to normal.

Individuals and Their Physiology

Explain the immediate responses to increasing exercise intensity

pH is monitored through the respiratory control centre of the brain and chemoreceptors throughout the body.

D5 Hormones and Metabolism

Steroid Hormone

Hormone Receptor

Hormone Receptor Complex

Cellular Response

Challenge: What examples can you think of?

Steroid hormones include those produced by the gonads (i.e. estrogen, progesterone and testosterone)

D5 Hormones and Metabolism

Peptide Hormone

Receptor

Signal Transduction

Initiated indirectly by messengers

Challenge: What examples can you think of?

Peptide hormones include insulin, glucagon, leptin, ADH and oxytocin

cGMP is a common secondary messenger

• The hypothalamus gives the commands (control center).
• The pituitary gland follows these commands and regulates other glands and processes in the body (second in charge).

Individuals and Their Physiology

How is blood glucose regulated?

A.1.2.1—Homeostasis is any self-regulating biological process aiming to produce a relatively stable, constant internal environment for optimal functioning of the body

1. Hypothalamus Signals the Pituitary:The hypothalamus acts as the control center. When the body needs more growth hormone, the hypothalamus sends a message to the pituitary gland by releasing a chemical called Growth Hormone-Releasing Hormone (GHRH).
2. Pituitary Gland Releases Growth Hormone: In response to GHRH, the pituitary gland (sometimes called the "master gland") releases growth hormone (GH) into the bloodstream.
3. Growth Hormone Acts on the Body: Growth hormone travels through the blood and acts on bones, muscles, and tissues to stimulate growth, repair cells, and build muscle mass. It also helps regulate the body’s metabolism.
4. Feedback Loop:When there is enough growth hormone in the body, the hypothalamus sends another signal (called somatostatin) to the pituitary gland to stop releasing growth hormone, ensuring the right balance is maintained.

1. Neural – signals from the nervous system – eg medulla oblongata to sympathetic nerve to increase heart rate
2. Humoral – changes to the chemistry of the blood eg pancreas will secrete more insulin after eating food
3. Hormonal – hypothalamus detects changes in hormone levels and initiates changes accordingly eg when the stomach is empty, receptors tell the hypothalamus to secret Ghrelin (the hunger hormone) which increases appetite.

Individuals and Their Physiology

How is homeostasis maintained?

A.1.2.1—Homeostasis is any self-regulating biological process aiming to produce a relatively stable, constant internal environment for optimal functioning of the body

Individuals and Their Physiology

How is homeostasis maintained?

Antidiuretic hormone regulates water retention in the kidney.

Exercise = increased sweat rate

Causes an increase in electrolytes in the blood

Hypothalamus detects changes in electrolytes in the blood

Pituitary gland secretes ADH into the blood

ADH acts on Kidneys

Kidneys reabsorb more water and produce less urine

Homeostasis

Individuals and Their Physiology

What is homeostasis?

A.1.2.1—Homeostasis is any self-regulating biological process aiming to produce a relatively stable, constant internal environment for optimal functioning of the body. In response to changing internal and external conditions, various mechanisms work constantly towards homeostasis

Homeostasis as the process by which the body maintains a stable internal environment despite changes in external conditions.

Challenge: suggest how homeostasis is important in sports performance

once a person reaches their peak intensity, stroke volume plateau

What examples can you think of?

Individuals and Their Physiology

What are the key components of homeostasis?

A.1.2.1—Homeostasis is any self-regulating biological process aiming to produce a relatively stable, constant internal environment for optimal functioning of the body

Stimulus → Receptor → Control Center → Effector → Response

Challenge: suggest what happens when homeostasis is your example is not maintained

Individuals and Their Physiology

I can Use diagrams to explain how the nervous and endocrine systems work together to regulate internal conditions like body temperature, pH levels, and glucose concentration.

A.1.2.1—Homeostasis is any self-regulating biological process aiming to produce a relatively stable, constant internal environment for optimal functioning of the body

Draw a diagram to show how temperature, pH and glucose are maintained.

Individuals and Their Physiology

I can Use diagrams to explain how the nervous and endocrine systems work together to regulate internal conditions like body temperature, pH levels, and glucose concentration.

A.1.2.1—Homeostasis is any self-regulating biological process aiming to produce a relatively stable, constant internal environment for optimal functioning of the body

Explain how exercise limits the release of insulin and

facilitates the uptake of glucose to regulate blood sugar levels.

Individuals and Their Physiology

I can explain how systems work together to regulate internal conditions like body temperature

A.1.2.1—Homeostasis is any self-regulating biological process aiming to produce a relatively stable, constant internal environment for optimal functioning of the body

1. Explain how the body regulates temperature during exercise.
2. Discuss vasodilation and vasoconstriction, the role of sweating and shivering, and how these mechanisms help cool or warm the body.
3. Reflect on how you think the body responds.

Group 1

Individuals and Their Physiology

I can explain how systems work together to regulate internal conditions like body temperature

A.1.2.1—Homeostasis is any self-regulating biological process aiming to produce a relatively stable, constant internal environment for optimal functioning of the body

1. Explain how the body regulates blood sugar levels during exercise using insulin and glucagon.
2. Discuss how glycogen stores are used during exercise and the role of glucose in providing energy
3. Research the glycemic index (GI) of different foods and discuss how athletes can use high-GI and low-GI foods to regulate glucose levels before and after competition.

Group 2

Individuals and Their Physiology

I can explain how systems work together to regulate internal conditions like body temperature

A.1.2.1—Homeostasis is any self-regulating biological process aiming to produce a relatively stable, constant internal environment for optimal functioning of the body

1. Discuss how the body controls pH levels in the blood during intense exercise, particularly how the accumulation of lactic acid can lead to muscle fatigue.
2. Explain buffer systems like bicarbonates in maintaining pH balance.
3. Talk about strategies athletes use to counteract lactic acid build-up, such as active recovery.

Group 3

Individuals and Their Physiology

I can explain how systems work together to regulate internal conditions like body temperature

A.1.2.1—Homeostasis is any self-regulating biological process aiming to produce a relatively stable, constant internal environment for optimal functioning of the body

1. What is non-shivering thermogenesis
2. Imagine you are the director of a “Fat Loss’” company, how could you apply principles of science to fat loss.
3. Suggest how training status, body composition, environment and sex differences (including hormonal phases) influence homeostasis

Challenge

Individuals and Their Physiology

Practise Questions

Challenge:

1. Describe the structure and function of the nervous system and its divisions
2. Outline how sensory and motor systems communicate to coordinate responses to internal and external conditions
3. Explain the role of proprioceptors, baroreceptors and chemoreceptors
4. Label the location of the major endocrine organs in the human body
5. Outline the key functions of hormones
6. Explain how circulating hormone levels are regulated
7. Explain the relationship between the hypothalamus and pituitary gland.

Individuals and Their Physiology

How does gender influence sports performance?

Reproductive hormones impact health and athletic performance in the following ways: progesterone—a thermogenic effect on thermoregulation and sleep quality, and an effect on fuel availability

Challenge: Suggest how hormones could influence a male and female gender athlete

• Progesterone is a reproductive hormone produced mainly by the ovaries after ovulation and during pregnancy.
• It plays a vital role in regulating the menstrual cycle and maintaining pregnancy.

Individuals and Their Physiology

progesterone—a thermogenic effect on thermoregulation and sleep quality, and an effect on fuel availability

• Progesterone can raise body temperature.
• Impact on Performance:
• Increases core body temperature during physical activity.
• Which can lead to increased sweating and faster dehydration.
• May affect endurance performance, especially in hot conditions.

Individuals and Their Physiology

What does thermogenic effect mean?

progesterone—a thermogenic effect on thermoregulation and sleep quality, and an effect on fuel availability

Challenge: Suggest how an increase in body temperature might influence sports performance

• Sleep Quality: Progesterone has a sedative effect, promoting relaxation and better sleep quality.
• Benefits for Athletes:
• Enhances recovery and muscle repair during sleep.
• Improves overall performance by supporting hormonal balance and reducing stress.

Individuals and Their Physiology

How does progesterone affect sleep quality?

progesterone—a thermogenic effect on thermoregulation and sleep quality, and an effect on fuel availability

Challenge: Suggest how an increase in sleep quality might influence sports performance

• Fuel Availability & Metabolic Role: Progesterone affects how the body uses energy sources (carbohydrates, fats, proteins).
• Performance Effects:
• Promotes fat utilisation during exercise, helping to spare glycogen stores.
• Important for endurance sports but may limit energy availability for high-intensity activities.

Individuals and Their Physiology

How does progesterone change the source of energy substrate?

progesterone—a thermogenic effect on thermoregulation and sleep quality, and an effect on fuel availability

Challenge: Suggest how an increase in fat utilization might influence sports performance

• Oestrogen is a primary female reproductive hormone produced mainly by the ovaries. It plays a critical role in the menstrual cycle, reproductive health, and various physiological processes in both females and males.

Individuals and Their Physiology

oestrogen—effects on sparing glycogen and joint stiffness

Challenge:

• Oestrogen can influence how the body uses glycogen (stored carbohydrates) during exercise.
• Impact on Performance:
• Promotes the utilization of fat as a primary energy source, which helps to conserve glycogen stores.
• This glycogen-sparing effect is beneficial for endurance athletes, allowing for sustained energy levels during prolonged activities.
• It may enhance performance by delaying fatigue during long-duration exercises.

Individuals and Their Physiology

oestrogen—effects on sparing glycogen and joint stiffness

• Oestrogen affects joint flexibility and stiffness due to its impact on connective tissues and ligaments.
• Impact on Performance:
• Fluctuating oestrogen levels can lead to changes in joint stiffness, potentially affecting athletic performance and increasing the risk of injury.
• Lower oestrogen levels (e.g., during the luteal phase of the menstrual cycle) may result in increased joint stiffness, which can hinder performance, especially in activities requiring agility and flexibility.

Individuals and Their Physiology

oestrogen—effects on sparing glycogen and joint stiffness

• Testosterone is essential for bone health and plays a significant role in bone density and strength.
• Stimulates the production of bone tissue, helping to increase bone density and reduce the risk of fractures.
• Higher testosterone levels are associated with stronger bones, which is crucial for athletes who participate in high-impact sports.

Individuals and Their Physiology

testosterone—effects on bone formation, protein synthesis and erythropoietin

• Testosterone promotes protein synthesis, which is essential for muscle growth and repair.
• Impact on Performance:
• Enhances muscle mass and strength by increasing the rate of muscle protein synthesis.
• Facilitates recovery after workouts by repairing muscle tissues damaged during exercise.

Individuals and Their Physiology

testosterone—effects on bone formation, protein synthesis and erythropoietin

• Testosterone stimulates the production of erythropoietin (EPO), a hormone produced by the kidneys that promotes the formation of red blood cells.
• Increased red blood cell production enhances oxygen delivery to muscles, improving endurance and performance.
• Higher oxygen-carrying capacity can lead to improved stamina and reduced fatigue during prolonged exercise.

Individuals and Their Physiology

testosterone—effects on bone formation, protein synthesis and erythropoietin

Individuals and Their Physiology

A.1.3.2—The respiratory system enables the exchange of gases between the external environment and the body, to facilitate cellular respiration.

Challenge: how does genetics influence lung capacity?

• Explain what hormones effect sports performance

​

Individuals and Their Physiology

• Minute ventilation is the total amount of air that you breathe in and out in one minute.
• It is calculated by multiplying the tidal volume (the amount of air inhaled or exhaled in a single breath) by the respiratory rate (the number of breaths taken per minute).

Individuals and Their Physiology

Define minute ventilation, tidal volume, and respiration rate, and explain their significance in respiratory physiology.

Challenge: Suggest what tidal volume is measured in?

• Tidal volume is the volume of air that is inhaled or exhaled during a normal breath.
• For an average adult at rest, tidal volume is typically around 500 milliliters (mL).

Individuals and Their Physiology

Define minute ventilation, tidal volume, and respiration rate, and explain their significance in respiratory physiology.

• Normal Respiration Rate:
• For adults, the normal resting respiration rate is typically between 12 to 20 breaths per minute.
• During Exercise: The respiration rate increases to meet the body’s higher oxygen demand and to expel more carbon dioxide.

Individuals and Their Physiology

Define minute ventilation, tidal volume, and respiration rate, and explain their significance in respiratory physiology.

Challenge: Suggest what increased breathing rate does to the tidal volume

Individuals and Their Physiology

Students will be able to calculate minute ventilation using tidal volume and respiration rate.

Individuals and Their Physiology

Students will analyze how tidal volume and respiration rate change during different physical activities and their implications for health and fitness.

Individuals and Their Physiology

Compare the tidal volume of 4 different people

Minute ventilation, Tidal volume, Change in respiration rate can vary, and depend on factors such as age, sex differences, body size, level of fitness, type of activity and intensity of activity.

Challenge:

Movement of air into and out of the lungs in 2 stages: inspiration and expiration. Controlled by the diaphragm and ribcage

The exchange (diffusion) of oxygen and carbon dioxide to and from the blood at the alveoli and the respiring tissues

This is the production of ATP at the cellular level (mitochondria). Aerobic respiration uses oxygen.

Individuals and Their Physiology

What is the difference between ventilation, gas exchange and respiration?

A.1.3.2—The respiratory system enables the exchange of gases between the external environment and the body, to facilitate cellular respiration.

Trachea

Bronchus

Bronchiole

Alveolus

Diaphragm

Lung

Rib

Individuals and Their Physiology

A.1.3.2—The respiratory system enables the exchange of gases between the external environment and the body, to facilitate cellular respiration.

Alveolus

Capillary

Ventilation (Air Flow)

CO₂

O₂

Individuals and Their Physiology

A.1.3.2—The respiratory system enables the exchange of gases between the external environment and the body, to facilitate cellular respiration.

Individuals and Their Physiology

A.1.3.2—The respiratory system enables the exchange of gases between the external environment and the body, to facilitate cellular respiration.

Individuals and Their Physiology

Individuals and Their Physiology

Individuals and Their Physiology

Individuals and Their Physiology

• Explain how hormones work and the effect of hormones on sport (8 marks)
• Outline the process of a heart beat (6 marks)
• Explain how CO2 is removed from the body (5 marks)
• Describe how levers work using examples (7 marks)
• Explain how blood is oxygenated in breathing (6 marks)
• Outline the role of valves in the heart (3 marks)
• Define adduction , abduction, inversion and eversion and state how they are used in specific sports (6 marks)

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Individuals and Their Physiology

causes

causes

Individuals and Their Physiology

A.1.3.2—The respiratory system enables the exchange of gases between the external environment and the body, to facilitate cellular respiration.

Large numbers of alveoli gives large surface area for gas exchange

Single layer of flattened cells in wall of alveoli

Surrounded by dense network of capillaries

Short distance for diffusion of gases

Oxygen dissolves in thin film of moisture on inside of alveoli - this aids diffusion

Individuals and Their Physiology

A.1.3.2—The respiratory system enables the exchange of gases between the external environment and the body, to facilitate cellular respiration.

11.3 The Kidney and Osmoregulation

11.3.S1 Drawing and labelling a diagram of the human kidney.

11.3 The Kidney and Osmoregulation

11.3.U4 The ultrastructure of the glomerulus and Bowman’s capsule facilitate ultrafiltration.

11.3.S2 Skill: Annotation of diagrams of the nephron.

11.3 The Kidney and Osmoregulation

The Nephron is the functional unit of the kidney

11.3.S2 Skill: Annotation of diagrams of the nephron.

Bowman’s Capsule

Ultrafiltration

Glomerulus

Delivers blood

Proximal Convoluted Tubule (PCT)

Distal Convoluted Tubule (DCT)

Loop of Henle

Osmoregulation

Collecting Duct

Urine to pelvis

Selective Reabsorption

Reabsorption

11.3 The Kidney and Osmoregulation

What is the structure of the Glomerulus?

11.3.U4 The ultrastructure of the glomerulus and Bowman’s capsule facilitate ultrafiltration.

Podocytes*

Capillary (Endothelium)

Fenestrations (gaps in the capillary)

Glomerular Space

These cells form a porous membrane surrounding the endothelial cells of the glomerulus.

Negatively charged glycoproteins form a mesh to avoid plasma proteins being filtered out

11.3 The Kidney and Osmoregulation

This shows the relationship between the Glomerus and the Bowman’s Capsule

11.3.U4 The ultrastructure of the glomerulus and Bowman’s capsule facilitate ultrafiltration.

Efferent = Exit

Afferent Arteriole

Efferent Arteriole

Check out the diameters

Lumen of the Bowman’s Capsule

Proximal Convoluted Tubule (PCT)

Glomerular Filtrate goes for further filtration and absorption in the nephron

Renal (Bowman’s) Capsule

Efferent Arteriole

11.3 The Kidney and Osmoregulation

Selective reabsorption of useful substances from the proximal convoluted tubule (PCT)

11.3.U5 The proximal convoluted tubule selectively reabsorbs useful substances by active transport.

11.3 The Kidney and Osmoregulation

Selective reabsorption of useful substances from the proximal convoluted tubule (PCT)

11.3.U5 The proximal convoluted tubule selectively reabsorbs useful substances by active transport.

microvilli cell lining to increase the surface area for the absorption

a large number of mitochondria provide ATP for active transport

PCT cell

lumen of the nephron

The PCT extends from the Bowman’s capsule to the loop of Henle

plasma

filtrate

11.3 The Kidney and Osmoregulation

There is around 1 million of these nephrons in each Kidney

11.3.S2 Skill: Annotation of diagrams of the nephron.

11.3 The Kidney and Osmoregulation

11.3 The Kidney and Osmoregulation

Osmoregulation is the control of water and solute concentrations in the body fluids (e.g. the blood plasma).

11.3.U6 The loop of Henle maintains hypertonic conditions in the medulla. AND 11.3.U7 ADH controls reabsorption of water in the collecting duct.

The job of the loop of Henlé is to generate a high concentration of solutes (low concentration of water) in the tissue fluid of the medulla compared to the filtrate in the nephron. This aids the reabsorption of water in the collecting duct..

The hormone ADH balances the water concentration of the blood by changing the permeability of the collecting duct by opening aquaporins.

11.3 The Kidney and Osmoregulation

11.3.U7 ADH controls reabsorption of water in the collecting duct.

If a person is dehydrated, ADH(a hormone) acts on the walls of the collecting duct, producing aquaporins (channels), making it more permeable to water

Filtrate enters the collecting duct from the DCT

Water moves into the capillaries via osmosis

They flow in opposite directions, maintaining a concentration gradient – a counter-current system

11.2 Movement

11.2.U2 Synovial joints allow certain movements but not others.

11.2 Movement

11.2.U4 Skeletal muscle fibres are multinucleate and contain specialised endoplasmic reticulum. AND 11.2.U5 Muscle fibres contain many myofibrils.

Muscle fibre cells are held together by the plasma membrane referred to as the sarcolemma.

11.2 Movement

11.2.U8 ATP hydrolysis and cross bridge formation are necessary for the filaments to slide.

Sarcolemma

Myofibril

Mitochondria

Nucleus

Sarcoplasmic Reticulum

T Tubules

11.2 Movement

11.2.U4 Skeletal muscle fibres are multinucleate and contain specialised endoplasmic reticulum. AND 11.2.U5 Muscle fibres contain many myofibrils.

Muscle cells contain sarcoplasmic reticulum, a specialised type of endoplasmic reticulum, that stores calcium ions and pumps them out into the sarcoplasm when the muscle fibre is stimulated.

11.2 Movement

11.2.U7 The contraction of the skeletal muscle is achieved by the sliding of actin and myosin filaments.

• An action potential propagated along a motor neuron arrives at the neuromuscular junction.
• This causes the release of the neurotransmitter acetylcholine into the synapse between the terminal axon of the motor neuron and the sarcolemma of the skeletal muscle.
• The acetylcholine binds to receptors on the sarcolemma, causing voltage-gated channels to open and Na⁺ ions to flow into the muscle cells.
• This creates an action potential in the striated muscle.
• The action potential is further propagated along the sarcolemma of the skeletal muscle.

11.2 Movement

11.2.U9 Calcium ions and the proteins tropomyosin and troponin control muscle contractions.

Actin

Tropomyosin

Troponin

Ca+ released by the sarcoplasmic reticulum attaches to the troponin

The tropomyosin moves off the actin binding sites

Myosin attaches to the actin binding sites

11.2 Movement

11.2.U7 The contraction of the skeletal muscle is achieved by the sliding of actin and myosin filaments.

• The action potential moves into the interior of the muscle cell through folds called t tubules.
• The depolarization of the t tubules causes voltage-gated Ca⁺ channels on the sarcoplasmic reticulum to open, causing an influx of Ca⁺ ions into the sarcoplasm.
• Ca⁺ ions bind to troponin which causes tropomyosin to move exposing the myosin binding sites (troponin and tropomyosin are regulatory proteins blocking the myosin binding sites).

11.2 Movement

11.2.U9 Calcium ions and the proteins tropomyosin and troponin control muscle contractions.

11.2 Movement

A sarcomere is a repeating unit of a striated muscle cell.

11.2.U9 Calcium ions and the proteins tropomyosin and troponin control muscle contractions.

http://www.sumanasinc.com/webcontent/animations/content/muscle.html

11.2 Movement

11.2.U4

Skeletal muscle fibres are multinucleate and contain specialized endoplasmic reticulum.

Sarcolemma

Capillary

Sarcoplasmic Reticulum

Mitochondria

Nucleus

Myofibrils

Myofibril

Light Bands

Dark Bands

Striations

Many mitochondria are present due to the high demand for ATP

A single skeletal muscle cell is multinucleated, with nuclei positioned along the edges

11.2 Movement

Muscle Contraction Summary

11.2.S2 Drawing labelled diagrams of the structure of a sarcomere.

Myosin + Myosin Heads

Actin

Light (Thin)

Dark (Thick)

Light (Thin)

Dark (Thick)

11.2 Movement

Sarcomere

11.2.U7 The contraction of the skeletal muscle is achieved by the sliding of actin and myosin filaments.

• Lies between two Z lines which are dense protein discs.
• Contains the thick filament (myosin) and thin filament (actin).
• Myosin contains a head which binds to the binding site on the actin; interaction between myosin and actin (cross-bridge) is responsible for muscle contraction.
• Myosin is seen as dark bands while actin is seen as light bands.
• A bands contain a full length of myosin and some of the actin filaments.
• I bands contain only actin filaments.

11.2 Movement

11.2 Movement

11.2.U8 ATP hydrolysis and cross bridge formation are necessary for the filaments to slide.

ATP attaches to myosin head

The energy is used in the power stroke as the sarcomere shortens

ADP detaches from the myosin and myosin attaches to actin and forms a new crossbridge

ATP hydrolysis causes the myosin head to swivel

11.2 Movement

11.2.U8 ATP hydrolysis and cross bridge formation are necessary for the filaments to slide.

11.2 Movement

Muscle Contraction Summary

11.2.U7 The contraction of the skeletal muscle is achieved by the sliding of actin and myosin filaments.

• During a muscle contraction, myosin filaments pull actin filaments towards the centre of the sarcomere
• This shortens the sarcomere and the overall length of the muscle fibre
• When this occurs, the myosin heads bind to sites on the actin filaments, creating cross-bridges, pulling (sliding) the actin filaments along the myosin filaments with energy from ATP 
• This is called sliding filament theory and is explained further below.

11.2 Movement

11.2.U7 The contraction of the skeletal muscle is achieved by the sliding of actin and myosin filaments.

• ATP attaches to the myosin heads breaking the cross-bridges between the myosin heads and actin binding sites
• The ATP undergoes a hydrolysis reaction forming ADP + P_i. This causes a positional change in the myosin head (cocked back).
• The myosin heads bind to actin filaments forming cross-bridges at a site one position further from the centre of the sarcomere
• When the ADP + P_i are released the myosin heads change conformational position, sliding the actin filaments towards the center of the Sarcomere. This is called the “power stroke”.
• After the power stroke ATP again binds to the myosin head, causing it to detach from the actin filament ready for another cycle.

11.2 Movement

a spontaneous or natural liking for someone or something.

D6 Transport of Respiratory Gases

Affinity

• Protein in red blood cells (RBC)
• Composed of four subunits (4 polypeptide chains)
• Each subunit has a “heme group” (contains iron, Fe)

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D6 Transport of Respiratory Gases

Sea Level = 760mm Hg

Mt Everest = 250mm Hg

• FUNCTION:
• O2 binds to Fe in the heme
• Carries 98% of O2 in the blood
• Grabs O2 when pO2 is high
• Lets go of O2 when pO2 is low

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D6 Transport of Respiratory Gases

SATURATION:

The percentage of hemoglobin binding sites in the bloodstream occupied by oxygen.

D6 Transport of Respiratory Gases

What causes hemoglobin's

affinity for O2 to change?

Body Tissues

Lungs

Higher affinity

Lower affinity

Complete the table by adding high or low to the blanks:

Complete the table by adding high or low to the blanks:

D6 Transport of Respiratory Gases

�

Where in the body will hemoglobin saturation be the highest?

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�

Where in the body will hemoglobin saturation be lower?

�

When Partial Pressure of Oxygen is High, Haemoglobin Saturation is High

D6 Transport of Respiratory Gases

�

Where in the body will hemoglobin saturation be the highest?

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�

Where in the body will hemoglobin saturation be lower?

�

When Partial Pressure of Oxygen is High, Haemoglobin Saturation is High

This occurs in the lungs

When Partial Pressure of Oxygen is Low, Haemoglobin Saturation is Low (Hb lets go of O2)

This occurs in the tissues

Oxygen Dissociation Curve

Hemoglobin affinity for O₂ is high when there is a high pO₂.

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Lots of O₂ around HB →

HB grabs and holds O₂

Oxygen Dissociation Curve

Hemoglobin affinity for O₂ is low when there is a low pO₂.

Not a lot of O₂ around HB →

HB lets go of any O₂ it is holding

D6 Transport of Respiratory Gases

AFFINITY:

A measure of how tightly hemoglobin attaches to oxygen.  

High affinity=  tight hold on O2

Low affinity = gives O2 away

D6 Transport of Respiratory Gases

D6 Transport of Respiratory Gases

Which of these pO2 values will change when exercising?

Atmospheric pO2

pO2 of blood arriving at alveoli

pO2 of blood leaving alveoli

pO2 in blood arriving at tissue capillary

pO2 in body tissues

pO2 in blood leaving tissue capillary

Which of these pO2 values will change when exercising?

Atmospheric pO2

pO2 of blood arriving at alveoli

pO2 of blood leaving alveoli

pO2 in blood arriving at tissue capillary

pO2 in body tissues

pO2 in blood leaving tissue capillary

NO CHANGE

NO CHANGE

NO CHANGE

LOWER. Why?

LOWER.

LOWER. Impact?

D6 Transport of Respiratory Gases

FETAL HEMOGLOBIN

• oxygen binding molecule
• in fetus 
• HIGHER O₂ affinity 

HEMOGLOBIN

• oxygen binding molecule
• after birth
• LOWER O₂ affinity

D6 Transport of Respiratory Gases

A small change in pO2 causes a larger change in saturation; Hb will give away O2 rapidly when pO2 drops.

Myoglobin will hold on to O2 even when pO2 drops. It “stores” oxygen until the pO2 is very low (like in exercising tissues).

D6 Transport of Respiratory Gases

Outline the role of myoglobin in muscle fibres [2]

1. binds oxygen when level is high;
2. releases oxygen when level is low;
3. acts as an oxygen store;
4. allows muscles to continue with aerobic respiration for longer;

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D6 Transport of Respiratory Gases

Explain the oxygen dissociation of myoglobin [6]

1. myoglobin is specialized for oxygen storage;
2. myoglobin has a single heme/globin unit/polypeptide chain;
3. found in muscle;
4. myoglobin has a higher affinity for oxygen than haemoglobin; (allow this point if haemoglobin dissociation curve correctly drawn to right of myoglobin curve and labelled)
5. in normal conditions/at rest myoglobin is saturated with oxygen;
6. used during intense muscle contraction when the oxygen supply is insufficient/when muscle is very active its oxygen concentration may fall (below 0.5 kPa);
7. when this happens myoglobin releases oxygen;

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D6 Transport of Respiratory Gases

Exercise

↑ pCO₂

↓ pH

↓ hemoglobin’s affinity for O₂

↓O2 saturation (more O2 for the cells)

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How will the oxygen dissociation curve change?

On the same graph, add a line for your predicted curve.

and/or ↓ pH

“Bohr Shift”: an increase in blood CO₂ concentration leads to a decrease in blood pH which will result in hemoglobin proteins lowering their affinity for oxygen.

• This mechanism allows for the body to adapt the problem of supplying more oxygen to muscles undergoing strenuous activity.

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• The muscles generate CO₂ and lactic acid which lowers the pH making hemoglobin let go of oxygen.

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Carbonic Anhydrase

CO₂ + H₂O ↔ H₂CO₃ ↔ H+ + HCO₃–

D6 Transport of Respiratory Gases

Effect of Altitude

“As altitude _increases__,

the pO2 _decreases__ and the O2 saturation _decreases_.”

So, less oxygen is being carried by hemoglobin.

Difference in pO2 between air in the lung lung and cell tissues

There is a smaller pO2 difference between the air in the lungs and respiring tissues at altitude. So, diffusion of O2 into the tissues decreases (remember, diffusion depends on pressure gradients). As a result, the tissues get less O2.

air in lungs at sea level

air in lungs at altitude

tissues

Effects of less O2 due to altitude depends on how fast you ascend and let your body acclimate (get used to) the altitude.

Short-term (days):

• Increased respiratory rate leading to increased oxygen in the alveoli of the lungs
• Increased heart rate helping to increase delivery of oxygen to tissues

D6 Transport of Respiratory Gases

How does the body respond to altitude?

Short-term responses and long-term adaptations in the body can vary in response to the external environment (temperature, humidity, altitude).

Medium-term (weeks):

• Increased urine output leading to reduced plasma volume and concentration of the hemoglobin in the blood (more CO2 = more acidic = more bicarbonate from kidneys = more urine)
• Increased production of hemoglobin so there is more ways to “catch” the O2 that is present in the air

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D6 Transport of Respiratory Gases

How does the body respond to altitude?

This is why athletes will train at altitude

Long-term (months):

• Increased density of capillaries in the tissues so there is more surface area for gas exchange

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D6 Transport of Respiratory Gases

How does the body respond to altitude?

Another reason why athletes will train at altitude

D6 Transport of Respiratory Gases

Outline the changes in the partial pressures of carbon dioxide and oxygen as altitude increases. [2]

1. both pO2 and pCO2 fall with increasing altitude;
2. above certain altitude there is little change in alveolar pO2 / pO2 remains close to 37 mm Hg over a wide range of altitudes;
3. Pco2 changes over the entire range of altitudes;
4. the pO2 is always higher than pCO2;

benefits:

a. improved performance/endurance at lower oxygen levels

b. due to higher concentration erythrocytes/red blood cells/hemoglobin

c. more oxygen transported/ circulating

d. improved metabolic/lung efficiency/gas exchange

e. increase in myoglobin/number of capillaries/mitochondria

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risks:

f. altitude sickness/stroke/lower immunity

g. increased muscle tissue breakdown

h. effects are not immediate/not permanent/extended training at high altitude required

i. may be unfair to competitors who cannot train at high altitude

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D6 Transport of Respiratory Gases

Discuss high altitude training for athletes. [6]

Hypoxia-induced hyperventilation: At high altitudes, the lower oxygen levels (hypoxia) cause the body to increase breathing rate (hyperventilation). This leads to a reduction in carbon dioxide levels in the blood, causing respiratory alkalosis (a more alkaline blood pH). The kidneys respond by excreting more bicarbonate and water through urine to restore the acid-base balance, resulting in increased urine output.

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Reduced plasma volume: As part of acclimatization to altitude, the body reduces plasma volume to concentrate red blood cells, increasing hemoglobin concentration and improving oxygen transport. This reduction in plasma volume is partially achieved by increased urine production.

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Fluid shifts: At altitude, there is a shift in fluid from the intravascular space (inside blood vessels) to the interstitial space (outside blood vessels), which can cause the kidneys to respond by eliminating excess fluid.

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Erythropoietin (EPO) is a hormone primarily produced by the kidneys (and to a smaller extent, the liver) that plays a crucial role in the production of red blood cells. Its primary functions include:

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Regulation of red blood cell production: EPO stimulates the bone marrow to produce more red blood cells (erythropoiesis) in response to low oxygen levels in the blood (hypoxia). This increases the oxygen-carrying capacity of the blood.

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Response to hypoxia: When oxygen levels decrease—such as at high altitudes, during intense exercise, or in cases of anemia—the kidneys sense this and secrete more erythropoietin. The increased EPO levels signal the bone marrow to produce more red blood cells, helping to deliver more oxygen to tissues.

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Acclimatization to altitude: At high altitudes, the body experiences lower oxygen availability (hypobaric hypoxia). In response, the kidneys produce more EPO, which stimulates an increase in red blood cells to improve oxygen transport. This process is a key part of acclimatization to altitude, enabling better performance and endurance in low-oxygen environments.

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Medical uses: Synthetic erythropoietin is used in medical treatments for conditions like chronic kidney disease, anemia in cancer patients, and others where natural EPO production is impaired.

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EPO is also infamously known for its misuse in sports as a performance-enhancing drug to increase endurance by artificially boosting red blood cell count, improving oxygen delivery to muscles.

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