Human Anatomy & Physiology

Elaine N. Marieb, Katja Hoehn

Bell Work 

• In what way does physiology depend on anatomy?
• Using the root definitions in the back of the book, define each of the following terms:
• Gastritis 
• Leukocyte
• Nephropathy 
• There are 206 bones in the adult human body, many of which greatly differ in shape and structure. The femur makes up your thigh bone.
• What do you notice about its structure?
• What is its function?
• How does structure follow function in this example?

​

​

The Human Body: An Orientation  

Unit 1: Organization of the Body

Chapter 1:

Overview of A&P

Levels of Structural Organization 

Maintaining Life 

Homeostasis 

The Language of Anatomy 

Overview of Anatomy and Physiology 

• How do Anatomy and Physiology differ? How are they similar?
• Anatomy - studies the structure of body parts and their relationships to one another.
• Concrete study as anatomy can be seen, felt, and examined.
• Broad field with subdivisions
• Gross / Macroscopic anatomy, Regional anatomy, Systemic anatomy, Microscopic anatomy, Developmental anatomy, ect 
• Physiology – studies the function of the body. 
• physiology is explainable only in terms of the underlying anatomy.
• Broad field with subdivisions
• Renal physiology, Neurophysiology, Cardiovascular physiology

​

​

Overview of Anatomy and Physiology 

• function follows form
• What do you notice about the form/structure?
• What is the function of RBCs?
• What is the relationship? 

Levels of Organization 

• Chemical level
• Atoms, tiny building blocks of matter, combine to form molecules. 
• Molecules associate to form organelles in cells. 
• Cellular level
• Cells have common functions but can vary widely in size and shape.
• Tissue level
• Groups of similar cells that have a common function. 
• Epithelium, muscle, connective, and nervous
• Organ level
• An organ is a structure composed of at least two tissue types that performs a specific function.
• Extremely complex functions become possible.
• Organ System level
• Group of organs that work together to accomplish a common purpose.
• Organism level
• Sum total of all structural levels working together to keep us alive.�

Levels�of Organization 

Chemicals 

Cells 

Tissue

Organs 

Organ Systems 

Organism

Maintaining Life 

• Vital body functions are parceled out among different organ systems
• There are 11 total organ systems

How many can you name?

Bell Work 

• There are 206 bones in the adult human body, many of which greatly differ in shape and structure. The femur makes up your thigh bone.
• What do you notice about its structure?
• What is its function?
• How does structure follow function in this example?

​

Maintaining Life ​

Maintaining Boundaries

• Internal environment must remain distinct from external environment 
• How? 
• Selectively permeable membrane of the cell 
• Integumentary system (skin)
• Why? 

​

​

Maintaining Life ​​

Movement

• Ability to propel ourselves from one place to another
• Ability to move food, blood, and waste throughout the body
• How?
• Skeletal and muscular systems 
• Why?
• Need to be able to manipulate our environment 

​

​

Maintaining Life ​​​

Responsiveness

• Ability to sense changes in the environment and then respond to them. 
• How?
• Nervous System 
• Via electrical impulses 
• Why? 
• Need to be able to react to an ever-changing environment 

​

Bell Work 

• Why do we have wisdom teeth? 
• What is one broad category needed for maintaining life.
• One major factor for determining basal metabolic rate is thyroid hormone production. What organ system must play a prominent role in metabolism?  

​

​

Maintaining Life ​​​

Digestion

• Breaking down of ingested foodstuffs to simple molecules that can be absorbed into the blood. 

How?

• Digestive and Circulatory System 

Metabolism

• Broad term for all chemical reactions that occur within body cells.
• How?
• Digestive and Respiratory System 
• Regulated by endocrine system 

​

​

​

Maintaining Life ​​​​

Excretion 

• Process of removing waste from the body.
• How?
• Digestive, Urinary, and Respiratory Systems 
• Why? 
• Must get rid of non-useful substances produced during digestion and metabolism.

Maintaining Life 

Reproduction 

• Occurs at the cellular and organismal level
• How?
• Reproductive and endocrine system 

Growth 

• Increase in size of a body part or the organism. 
• Constructive activities must occur at a faster rate than destructive ones.
• How?
• Endocrine system 

Homeostasis 

• "The ability to maintain relatively stable internal conditions even though external conditions changes continuously."
• Literal translation - "unchanging"
• Indicates a dynamic state of equilibrium in which internal conditions vary, but within relatively narrow limits. 
• Nearly every organ system has a role in maintaining homeostasis 
• All variables in the body are regulated by homeostatic processes involving three components

Homeostasis 

Homeostatic Control

• The receptor responds to changes in the environment by sending information (input) to the control center along the afferent pathway.
• The control center determines the set point, analyzes the input, and determines the response.
• Information (output) then flows from the control center to the effector along the efferent pathway.
• The effector provides the response to the stimulus. 
• Response influences the effect of the stimulus
• Reducing it (in negative feedback) so that the whole control process is shut off.
• Enhancing it (in positive feedback) so that the whole process continues at an even faster rate.

​

Bell Work

• What is homeostasis?
• What are the three main components in a homeostatic control mechanism?
• What is the difference between afferent and efferent pathways?

​

Homeostasis ​

Figure 1.4 Interactions among the elements of a homeostatic control system.

Bell Work

1. Review the regulation of blood sugar (glucose) levels in the body and identify the feedback mechanism involved. 
1. Stimulus 
2. Receptor 
3. Control Center
4. Effector
5. Type of response

​

​

​

Blood Glucose Mechanism 

• Here's an example of how this mechanism works:
• After a meal, blood sugar levels rise due to the digestion and absorption of carbohydrates. In response, beta cells release insulin into the bloodstream.
• Insulin promotes the uptake of glucose by cells, reducing blood sugar levels.
• As blood sugar levels return to the normal range, insulin secretion decreases.
• Between meals, when blood sugar levels start to drop, alpha cells release glucagon.
• Glucagon signals the liver to release stored glucose into the bloodstream, raising blood sugar levels.
• As blood sugar levels return to the normal range, glucagon secretion decreases.

​

Homeostasis 

Positive Feedback Mechanisms

• Enhances the original stimulus so that the response is accelerated.
• Variable changes in the same direction as the initial change.
• Amplifying effect
• Ex: Blood Clotting 
• Controls infrequent events that do not require continuous adjustments.

​

​

Homeostasis 

Negative Feedback Mechanisms 

• Reduces intensity of initial stimulus is slowed. 
• Variable changes in a direction opposite to the initial change.
• Ex: Home heating system 
• Stimulus? Receptor? Control Center? Effector? Type of response? 
• Ex: Regulation of body temperature
• Stimulus? Receptor? Control Center? Effector? Type of response? 

​

​

The Language of Anatomy 

Anatomical Position and Directional Terms

• Why might is be important to have an agreed upon anatomical position? 
• Need an initial reference point for an ability to indicate direction 
• Anatomical position = body standing upright, facing forward, legs parallel and shoulder width apart, upper limbs hang at either side, palms facing forward
• Directional terms = allow us to explain where one body structure is in relation to another.
• Why is it important to have official directional terms for understanding anatomy? 
• More efficient and less ambiguous 

​

The Language of Anatomy �Directional Terms ​

The Language of Anatomy �Directional Terms ​

Bell Work

• Why might pH be an extremely important variable to maintain within narrow limits? 
• What process allows us to adjust to either extreme heat or extreme cold?
• When we begin to get dehydrated, we usually get thirsty, which causes us to drink fluids. Is thirst part of a negative or a positive feedback control system? Defend your choice.

​

​

​

​

​

​

The Language of Anatomy ​

Regional Terms 

• Used to designate specific body areas.
• Fundamental divisions are axial and appendicular. 
• Axial makes up the main axis of our body including the head, neck, and trunk. 
• Appendicular consists of the appendages, or limbs, which are attached to the body’s axis. 

Bell Work 

• Using the anatomical directional terms label each of the following (A through F)
• Using anatomical directional terms describe where the abrasions are for our patient. 

The Language of Anatomy�Regional Terms 

The Language of Anatomy ​​

Body Planes and Sections 

• Body is sectioned along a flat surface called a plane
• Most frequent are sagittal, frontal, and transverse
• Sagittal – vertical plane dividing body into right and left parts 
• Midsagittal and parasagittal 
• Frontal – vertical plane dividing the body into anterior and posterior parts 
• Transverse – horizontal plane dividing body into superior and inferior parts 

The Language of Anatomy   

• Can you guess the body planes in the following CT Scans? 

Medical Imaging

The Language of Anatomy 

• Determine the plane each of these MRI scans are taken in.
• What might the shade of grey tell you about the tissue you are looking at?

Bell Work 

1. What body plane was this MRI taken in?
1. What symptoms do you think the patient may be experiencing based on their MRI scan? 

​

​

​

• What body planes was this MRI taken in?

The Language of Anatomy   ​

Body Cavities and Membranes 

• Two sets include the dorsal and ventral body cavities 
• Differ in their location, lining/protection, and organs found within 

Dorsal Body Cavity - Houses the nervous system and has 2 subdivisions.

• Cranial Cavity – within the skull, encases the brain 
• Spinal Cavity – within the vertebral column, encases the spinal cord

​

The Language of Anatomy    

Ventral Body Cavity – Houses the visceral organs and has 2 major subdivisions.

• Thoracic cavity - superior subdivision surrounded by ribs and muscles of the chest.
• Pleural cavities - lateral cavities enveloping the lungs.
• Pericardial cavity – medial cavity that encloses the heart.
• Mediastinum - contains the pericardial cavity and surrounds the remaining thoracic organs.

The Language of Anatomy    

• Abdominopelvic cavity – inferior subdivision separated by the diaphragm.
• Abdominal cavity - superior portion that contains the digestive organs.
• Pelvic cavity – inferior portion that lies in the bony pelvis and contains the urinary bladder, some reproductive organs, and the rectum. 

​

Homeostatic Imbalance

• When the body is subjected to physical trauma (as in an automobile accident), the organs of which cavity are most vulnerable? 

The Language of Anatomy 

Membranes in the Ventral Body Cavity 

• Serosa (serous membrane) = Thin double-layered membrane covering the walls of the ventral body cavity and the outer surfaces of the organs.
• Parietal Serosa = Lines the cavity walls
• Visceral Serosa = Lines the organs
• Serous fluid = thin layer of lubricating fluid that separates both membranes. 
• What might be the purpose of this fluid? 

The Language of Anatomy 

• Serous membranes are named for the specific cavity and organs with which they are associated. 
• Parietal pericardium = membrane lining the walls of the pericardial cavity
• Visceral pericardium =
• Parietal pleurae = membrane lining the lines the walls of the thoracic cavity
• Visceral pleurae =

​

The Language of Anatomy 

Other Body Cavities

• Most are in the head and open to the body exterior   
• What are some you can think of?
• Oral and digestive cavities - (mouth), containing the teeth and tongue, continuous with the cavity of the digestive organs, which opens to the body exterior at the anus. 
• Nasal cavity - Located within and posterior to the nose, part of the respiratory system passageways.
• Orbital cavities - houses the eyes in the skull at the anterior position.
• Middle ear cavities - medial to the eardrums containing tiny bones that transmit sound vibrations to the hearing receptors in the inner ears.
• Synovial cavities - joint cavities enclosed within fibrous capsules that surround freely movable joints of the body.

Check Your Understanding 

•  Of the uterus, small intestine, spinal cord, and heart, which is/are in the dorsal body cavity?
• When you rub your cold hands together, the friction between them results in heat that warms your hands. Why doesn’t warming friction result during movements of the heart, lungs, and digestive organs?

The Language of Anatomy 

Bell Work 

Homeostatic Imbalance

1. When serous membranes are inflamed, their normally smooth surfaces become roughened. What might be the side effects of this imbalance?
2. Which of the following organs are found in the dorsal body cavity? (Kidneys, small intestine, spinal cord, heart)
3. When you rub your cold hands together, the friction between them results in heat that warms your hands. Why doesn’t warming friction result during movements of the heart, lungs, and digestive organs?

​

​

​

The Language of Anatomy 

Abdominopelvic Quadrants

• Why might having quadrants for the abdominopelvic cavity be helpful?

​

• Medical personnel use this scheme to locate the abdominopelvic cavity organs.

​

• Two planes divide the abdominopelvic cavity into four quadrants.

​

The Language of Anatomy ​

Abdominopelvic Regions 

• Method of division used primarily by anatomists
• Two transverse and two parasagittal planes divide the cavity into nine regions
• Umbilical region - centermost region deep to and surrounding the umbilicus (navel)
• Epigastric region - superior to the umbilical region
• Hypogastric (pubic) region - inferior to the umbilical region 
• R/L iliac (inguinal) regions - lateral to the hypogastric region
• R/L lumbar regions - lateral to the umbilical region 
• R/L hypochondriac regions - lateral to the epigastric region and deep to the ribs

​

The Language of Anatomy  

Concept Check

• Joe went to the emergency room where he complained of severe pain and tenderness in the right iliac region of his abdomen. He has also been experiencing nausea, loss of appetite, and a chronic low grade fever. What might be his problem?
• What type of cut would separate the brain into anterior and posterior parts?
• The part of a serous membrane that lines the cavity wall is called _______? 
• One specific serous membrane is called visceral pericardium. What major body cavity do you think it might be found in and what might it be attached to?  
• Draw the sagittal, transverse, and frontal planes of a banana 

​

​

​

​

​

1. The correct sequence of levels forming the structural hierarchy is  (a) organ, organ system, cellular, chemical, tissue, organismal; (b) chemical, cellular, tissue, organismal, organ, organ system; (c) chemical, cellular, tissue, organ, organ system, organismal; (d) organismal, organ system, organ, tissue, cellular, chemical.
2. Which of the following is a major functional characteristic of all organisms? (a) movement, (b) growth, (c) metabolism, (d) responsiveness, (e) all of these.
3. Relate each of the following conditions or statements to either the dorsal body cavity or the ventral body cavity.   (a)surrounded by the bony skull and the vertebral column   (b) includes the thoracic and abdominopelvic cavities   (c) contains the brain and spinal cord   (d) contains the heart, lungs, and digestive organs
4. Terms that apply to the backside of the body in the anatomical position include:   (a) ventral; anterior   (b) back; rear   (c) posterior; dorsal   (d) medial; lateral

​

Concept Check