The Arizona STEM Acceleration Project

Anatomy of Homeostasis

Anatomy

of

Homeostasis

A 10-12 grade STEM lesson

Jess Bushman

5/24

Notes for teachers

• This is multi-day lesson. It can be used in full or in part.
• This is an indepth look at homeostasis that can be used along with Biology, AP Biology, and Anatomy and Physiology.
• This is also a great review off all the major organs and their roles.
• Teachers notes for classroom discussion are in red.
• Student slides have pictures that follow the pictures that are in this slideshow with the teacher notes.
• Articles can be used as discussion or a homework assignment

List of Materials

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• Student Slides
• Cardio
• Lab: Heart rate and exercise
• Stopwatch / time
• Stethoscope (cleaning pads) / heart rate monitor
• Respiratory System
• Lab: Ventilations and exercise
• Stopwatch
• Lab: Investigating Lung Capacity Using a Balloon and Water Displacement
• Balloons
• Large Bowl
• Water
• Large Graduated Cylinder (2000 mL)
• Basin to catch displaced water
• Article: When Athletes Combine Smoking and Exercise with questions
• Integumentary System
• Lab - What is the Best Way to Take a Person's Temperature
• Digital thermometer
• Infrared thermometer
• Disposable thermometer probe covers
• Bag of ice
• Heater
• Article: Time to Redefine Normal Body Temperature?
• Article: Wondering About Goosebumps?
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• Digestive System
• Article: What is Hypochlorhydria with questions
• Lab: Stomach Digestion
• Clear plastic bags
• Sandwich bags - ziplock type
• Food (bread / crackers / fruit etc.)
• Vinegar
• Plastic spoons
• Stopwatch
• pH strips / meter
• Blender (optional)
• Lab: Stomach Acid and Antacids
• HCL solution
• Sodium bicarbonate
• Antacid tablets (Tums / Rolaids)
• Eater
• Clear plastic cups
• Stir rods
• pH stips / meter
• Stop watch

Notes for teacher cont.

List of Materials cont.

• Blood Sugar
• Article: The History of a Wonderful Thing We Call Insulin with questions
• Lab: Blood Sugar Levels
• Glucose meter
• Lancet device
• Test strips
• Stop watch
• Sugary snacks
• Calcium
• Article: What You Can Do Now to Prevent Osteoporosis with questions
• Bones Bending lab
• Chicken leg bones - cleaned
• Large beakers
• Vinegar / Drano
• Nitrile Gloves
• Bone Bendability chart (laminated)
• Brittle Bones Lab
• Chicken leg bones - cleaned
• Cookie Sheet
• Oven
• Lab Goggles
• Fluids and Electrolytes
• Lab: Electrolytes
• Different Electrolyte drinks to test
• Water
• Salt
• Large Petri dish
• Uninsulated copper wire
• 9V battery
• 9V battery snap connector
• 3 alligator clips
• 4 inch piece of Straw
• Multimeter with probes and/o Simple Circuit set up with light bulb
• and/or
• Light bulb with mini bulb holder
• IV calculations
• IV calculations - Answers
• Acid / Base
• Article: Acid Base Balance
• Acid Base Balance Tic-Tac-Toe
• Acid / Base Balance Practice
• Acid / Base Balance Practice - Answers
• Assessment
• Assessment - Answers

Standards

• Essential HS.L1U1.20

Ask questions and/or make predictions based on observations and evidence to demonstrate how cellular organization, structure, and function allow organisms to maintain homeostasis.

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Standards

• HS-LS1-3 From Molecules to Organisms: Structures and Processes

Plan and conduct an investigation to provide evidence that feedback mechanisms maintain homeostasis.

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1.1.2a - Skeletal - Mineral storage

1.1.2b - Muscular - Functions of the Muscular system

1.1.2c - Integumentary - Functions of the Integumentary system

1.1.2d - Cardiovascular - Functions of the Cardiovascular system

1.1.2f - Respiratory - Functions of the Respiratory System

1.1.2g - Nervous - Functions of the Nervous system

1.1.2i - Digestive - Functions of the Digestive system

1.1.2j - Urinary - Functions of the Urinary system

Other ASAP Homeostasis lessons

Exercise and Homeostasis by Bryce Wolcott: https://docs.google.com/presentation/d/1vEt9SmmZLVRLl3BtxmfLVydseVfqzNuL/edit#slide=id.p4

Keeping Warm by Victoria Rackley:

https://docs.google.com/presentation/d/19TO2xUfbREfwv0SdMULsaNj0rrJMc7Pc/edit#slide=id.p1

Homeostasis in cells by Mitzi Noreen Cantillep:

https://docs.google.com/presentation/d/19hzTskHNYi5RrmJLLGSYqAQEPbE5n7y6/edit#slide=id.p1

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Objectives:

An indepth look at all the systems that the human body needs to keep in balance, how the body tries to mediate imbalances, and the health impacts from an imbalance in homeostasis. Also, a look at how other systems try to mediate systems that are out of balance.

Teacher background knowledge

• Homeostasis and the skin
• How does the skin regulate body temperature?
• Homeostasis and the nervous system
• Homeostasis: How your Body Stays in Balance with its Environment
• Respiratory Homeostasis
• Carbon Dioxide Homeostasis
• Homeostasis Blood Pressure Regulation
• Negative Feedback Regulation of Blood Pressure
• Kidney Homeostatic Functions
• Metabolism and Homeostasis (series on cellular metabolism and homeostasis)
• What does the pancreas do?
• Homeostasis in the Digestive System
• Acid Base Balance: Bicarbonate Ion Buffer
• Acid Base Balance
• ABG Interpretation Made Easy: Tic-Tac-Toe Method
• Acid Base Arterial Blood Gases (ABG) Interpretation with Tic-Tac-Toe Method

Agenda

• Each Section (8 sections) is designed to be 1-2 days in length - but could vary based upon students
• This can be taught as a whole Homeostasis lesson (8-10 days), or used as supplements into an already established lesson
• There is a bonus section that is more of a “food for thought” section that would only take ½ day - Robotics in Medicine

Intro/Driving Question/Opening

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What are different ways to body tries to fix itself when there is a problem?

Can the body always fix itself?

What is homeostasis?

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The human body maintaining a state of equilibrium during different stressors.

Image obtained from:https://i.ytimg.com/vi/vyjB56l0RfU/maxresdefault.jpg

Homeostatic Feedback Loop

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Homeostasis and Feedback - Amoeba Sisters (6:30)

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• What is the difference between negative feedback loop and positive feedback loop?
• What does the human body use to maintain balance - negative feedback or positive feedback?
• What is an example of when the body can provide negative feedback and outside interventions have to be used?

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Cardiovascular System

Discussion - Heart Anatomy

• Function of cardiovascular system
• Heart rate
• Normal Heart rate - 60-100
• Blood Pressure
• Normal Pressure for an adult 120/80
• Is the amount of pressure exerted on the aortic arch, carotid body and at the bifurcation of the carotid artery during rest (diastolic) and during ventricular contraction (systolic).
• Blood pressure measured by the body in the aortic arch, carotid body and at the bifurcation of the carotid artery by baroreceptors.
• Levels of carbon dioxide and oxygen measured in aortic arch, carotid body and at the bifurcation of the carotid artery by chemoreceptors.
• Transportation of waste to the lungs, kidneys, and digestive systems.
• Carbon dioxide, creatinine, urea

Image obtained from: https://qph.cf2.quoracdn.net/main-qimg-b455f2ad3d4b6728ce4014fa09dbcf2d

Normal Adult Blood Pressure

Image obtained from: https://pbs.twimg.com/media/ERJ8GTjWkAUYQgE.jpg

How does the body lower heart rate and blood pressure?

• The parasympathetic nervous system (part of the autonomic nervous system) releases acetylcholine to slow down heart rate after the stressor is gone.
• To lower blood pressure, the body senses the increase blood pressure mainly in the aortic arch, the body responds through vasodilation (increases the “tank” that holds the blood, thus lowering pressure)
• Vasodilation and constriction mainly happen in arteries, although vein dilate and constrict, the arteries have more smooth muscle
• The kidneys also excrete water through urination and Na+ to reduce pressure by lowering volume

Image obtained from: https://biologydictionary.net/wp-content/uploads/2017/01/Vasoconstriction-and-Vasodilation.jpg

Hands-on Activity Instructions

• This can be done as a class or in small groups of 4-5.
• Take care of those that have physical limitations, they can still participate in the activity, while not being able to do the physical part - they can help with timing, monitoring heart rate, and listening to others hearts with a stethoscope
• Note if a student is listening to another's heart beat, have the student that is being listened to hold the bell on their chest.
• Be sure to have students clean the stethoscope after they use it with an antiseptic wipe

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Heart Rate and Exercise Lab

Image obtained from: https://images.ctfassets.net/4f3rgqwzdznj/1028zVengQys8fv7fcOBfC/12efd2abbbd68d80d8da3ce9264701bc/woman_check_pulse_exercise-1019967520.jpg

Hands-on Activity Instructions

• Place people in groups of 2-3
• DO NOT SHARE BALLOONS
• Have a easy access to water source
• Make sure that if the floor becomes wet, it does not cause a slip hazard
• If a person has a large lung capacity, the graduated cylinder may have to be filled more than once to measure the displaced water

Lung Capacity by Water Displacement Lab

How does the body regulate?

• Increased heart rate to deliver more oxygen and take more carbon dioxide away from cells
• Vasodilates to allow for a higher blood flow to deliver more oxygen to cells and take more carbon dioxide away from cells
• Responding to changes sense in the chemoreceptors
• Changes blood pressure through sensing changes in baroreceptors
• kidneys regulate Na+ and adjust through urination

Respiratory System

Discussion - Respiratory Anatomy

Image obtained from:https://stock.adobe.com/search?k=lung+anatomy

https://www.firstaidforfree.com/anatomy-and-physiology-ap-of-the-upper-airway/

Upper Airway - Epiglottis is the border

Lower Airway - Epiglottis is the border

Respiratory Terms

Inhalation - the act of bring air into the lungs

Exhalation - the act of air leaving the lungs

Ventilation - the act of bringing air into the lungs and air leaving the lungs - can be natural or with medical intervention

Internal Respiration - the exchange of O2 and CO2 between the bloodstream and cells in the capillaries

External Respiration - the act of bringing air into the lung and air leaving the lungs

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What is in air we breathe in?

Image obtained from: https://www.meritnation.com/ask-answer/question/what-is-the-composition-of-air-describe-it/air/6973392

We breathe in 21% O2, we breathe out 16% O2.

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We breathe in 0.03% CO2, we breathe out 4.4% CO2.

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Normal breathing rate for an adult 12-20 breaths per minute.

Why do we breathe out less O2 and more CO2?

Cellular Respiration needs O2, and produces CO2 as waste.

CO2 leaves the body through exhalation.

Image obtained from: https://www.khanacademy.org/science/high-school-biology/hs-energy-and-transport/hs-cellular-respiration/a/hs-cellular-respiration-review

Breathing and Exercise

With exercise, there is an increased demand for more Cellular Respiration - the cells increase their demand for O2 and increase their need to eliminate CO2.

Article: When athletes combine smoking and exercise

More CO2?

With the rise of CO2 in the bloodstream leaving cells, the chemoreceptors in the carotid body senses in the increased levels of CO2 and then signals the lungs to increase ventilations.

Image obtained from: https://cadenceheart.sg/wp-content/uploads/2022/01/shutterstock_426398653-1024x683.jpg

https://www.researchgate.net/publication/339887650/figure/fig1/AS:868430005669906@1584061256989/Carotid-sinus-and-carotid-body-Afferent-nerve-fibers-travel-from-the-baroreceptors.png

Hands-on Activity Instructions

• This can be done as a class or in small even groups (4, 6, 8).
• Take care of those that have physical limitations, they can still participate in the activity, while not being able to do the physical part - they can help with timing, monitoring heart rate, and listening to others hearts with a stethoscope
• It may be a good idea to place students in gender groups since they will be counting each others breaths

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Ventilations and Exercise Lab

Image obtained from: https://i0.wp.com/pulmonary-performance.com/wp-content/uploads/2020/08/sad-runner.jpg?ssl=1

How does the body regulate?

• Need for more O2 due to exercise
• Body increase ventilations
• Body increases heart rate to deliver more O2 to cells
• Body vasodilates vascular system to allow for more movement of blood
• Increase of blood pressure to quickly move blood
• Too much CO2 in bloodstream from exercise
• Body increases ventilations to release CO2 transport from cells
• Body increases heart rate to also quickly release CO2
• Body vasodilates vascular system to allow for more movement of blood
• Increase of blood pressure to quickly move blood

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Integumentary System

Discussion - Integumentary Anatomy

The Integumentary System consists of Hair, Skin, and Nails

Image obtained from:https://microbenotes.com/wp-content/uploads/2020/06/Integumentary-System.jpg

The skin has 3 main layers:

• Epidermis
• Stratum Corneum (dead layer)
• Stratum Lucidum
• Stratum Granulosum
• Stratum Spinosum
• Stratum Basale
• Dermis
• Papillary dermis
• Reticular dermis
• Subcutaneous layer (adipose tissue)

Image obtained from: https://dr282zn36sxxg.cloudfront.net/datastreams/f-d%3A9ce8906e9614e677277be4248eadeb8f777498207cff1a7422c6f9d6%2BIMAGE_TINY%2BIMAGE_TINY.1

• The Integumentary system protects the body from the outside world and is the first barrier against bacteria / viruses / fungus as well as protection from UV radiation.
• The Integumentary system is the main component for thermoregulation
• The body’s core temperature should be 98.6 degrees F or 37 degrees C
• In 1968, a German physician determined the 98.6 F (37 C) temperature.
• According the a Stanford study and Harvard school of Medicine, it is believed that a “normal temperature is around 97 degrees F or 36.11 degrees C
• The hypothalamus, in the brain registers temperature and then causes the body to compensate

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Article: Time to redefine normal body temperature?

Images obtained from: https://cdn.flintrehab.com/uploads/2020/03/hypothalamus-damage-1.pnghttps://render.fineartamerica.com/images/rendered/default/greeting-card/images/artworkimages/medium/2/doctor-looking-at-thermometer-and-smiling-science-photo-library.jpg?&targetx=-25&targety=0&imagewidth=750&imageheight=500&modelwidth=700&modelheight=500&backgroundcolor=CDAAA2&orientation=0

Thermoregulation - keep you warm

• To try to keep the body warm, the body will reduce blood flow to outer extremities and skin to keep vital organs functioning (shunting)
• During extreme cases, this can cause frostbite
• Hypothermia is when core temperature drops to 95 degrees F or lower
• The body generates heat using the muscular system to shiver
• Goosebumps
• May conserve heat or make you look scary
• Adipose tissue serves as an insulator to keep your muscles and vital

organs warm

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Images obtained from:https://i0.wp.com/braveskimom.com/wp-content/uploads/2016/01/frostbite-clipart-cold.jpg?fit=400%2C450&ssl=1

https://ars.els-cdn.com/content/image/1-s2.0-S0020138322005186-gr1.jpg

https://cdn.mos.cms.futurecdn.net/HNGhDCn8mGXiqqvUpqmpbG.jpg

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Article: Wondering About Goosebumps

Thermoregulation - keep you cool

• To try to keep the body cool, the body vasodilates blood vessels and increases heart rate to allow more heat to be lost through the skin
• During extreme cases, this can cause heat exhaustion and even heat stroke
• Hyperthermia is when core temperature increases 104 degrees F or higher
• Fever caused by illness is above 100 degrees F
• The body generates sweat too cool down the body through convection
• Can lose 10 -15% of heat
• Causing a need to hydrate often
• Exercise can leave salt after sweat has dried
• Cause need for electrolyte replacement

Images obtained from: https://i0.wp.com/post.medicalnewstoday.com/wp-content/uploads/sites/3/2020/01/iStock-1162624130_hero-1024x575.jpg?w=1155&h=1528

Heat Exhaustion vs Heat Stroke

• When a persons has a change in mental status, a core temperature above 104, and is no longer sweating they have Heat Stroke.
• Very dangerous - call 911

Hands-on Activity Instructions

• Have students in groups of 3-4 people or this can be done as a class with a few student volunteers

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What is the best way to take a person's temperature lab

Images obtained from: https://www.health.com/thmb/JpHWOpif1BePwNhzu7kBptHfR_s=/fit-in/1500x2900/filters:no_upscale():max_bytes(150000):strip_icc()/hlt-thermometers-test-berrcom-non-contact-infrared-forehead-jjuliao-0933-361a3ad1d3eb4a02b82261d3e87715b1.jpg

https://opentextbc.ca/vitalsignmeasurement/wp-content/uploads/sites/326/2021/01/Oral-Temperature-Wide.jpg

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How does the body regulate?

• When body it too cold
• Shiver - muscles produce heat
• Rise of surface hairs
• Adipose tissue
• Shunting of blood to vital organs
• When body is too hot
• Release of sweat for cooling through convection
• Feel thirst

Digestive

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Discussion - Digestive Anatomy

• Mouth and pharynx are shared between Digestive and Respiratory system
• Digestive system can be activated by smell - begins salivation
• Small intestine consists of:
• Duodenum
• Jejunum
• Illium
• Large intestine consists of:
• Ascending colon
• Transverse colon
• descending colon
• Sigmoid colon
• Rectum
• Anus
• Intestines made of smooth muscle

Image obtained from: https://cdn.britannica.com/39/8039-050-B124FC20/human-digestive-system-front.jpg

The Stomach

• Stomach acid pH can be 1.5 - 3.5
• Esophageal sphincter prevents stomach contents from traveling back up the esophagus (acid reflux)
• Remedies for Acid Reflux
• Sleeping more upright
• Antacids
• Prescription from doctor
• Pyloric sphincter regulates when stomach contents empty into the small intestine
• The top of the stomach is the fundus and allows for stomach expansion for large meals
• The stomach is made up of smooth muscle

Image obtained from:https://www.pharmacy180.com/media/article/article-Stomach-6yI.jpg

Homeostasis in the digestive system

• Regulation of pH in stomach
• pH too low (Hyperchlorhydria)
• Stomach produces bicarbonate (HCO3-) to act as a buffer
• This buffer comes in mucus form to prevent stomach damage
• Damage can include ulcers
• Ulcers can perforate the stomach wall allowing stomach contents to spill out into the abdominal cavity - this requires immediate medical attention, antibiotics, and surgical intervention - this is life threatening
• pH too high (Hypochlorhydria)
• the body can not natural fix this
• causes indigestion, malnutrition, can can cause bacterial overgrowth

Hands-on Activity Instructions

• Group size 2-3
• Best done in an area with a running water supply
• Can use pH strips, a meter, or a drop indicator
• There should never be any eating done in a lab area or during a lab

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Stomach Digestion Lab

Hands-on Activity Instructions

• Group size 2-3
• Best done in an area with a running water supply
• This can be combined with the Stomach Digestion Lab and you can use the “stomach acid” and food solution that was made

Stomach Acid and Antacids Lab

How does the body regulate?

• When stomach acid is too low (pH is a low number)
• Body releases a buffer
• prevents ulcers
• When stomach acid is too high (pH is a high number)
• Body can not mediate

Blood Sugar

Discussion - Blood Sugar Anatomy

• Funny video - Diabetes Intervention

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• The Pancreas sits posterior (beind) the stomach and liver
• It attaches into the small intestine and the gallbladder
• Produces pancreatic enzymes that break down foods
• Attached to the duodenum
• (small intestine = duodenum, jejunum, illium)
• Pancreas produces insulin (beta cells) in response to glucose levels

Image obtained from: https://medlineplus.gov/ency/images/ency/fullsize/17194.jpg

• The body senses glucose levels in the pancreas in the Islets of Langerhans
• The Islets of Langerhans then release beta cells (insulin) to accompany the glucose in the blood into cells
• The brain detects low blood sugar levels (hypoglycemia) in the hypothalamus
• Body feels hunger
• When the body is in hypoglycemia, the Islets of Langerhans releases glucagon
• Glucagon causes the liver to convert stored glucose (glycogen) into a usable form and releases it into the bloodstream to be taken to cells
• The Islets of Langerhans detects high blood sugar (hyperglycemia)

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Images obtained from:https://medlineplus.gov/ency/images/ency/fullsize/17151.jpg

https://neuroscientificallychallenged.com/files/images/hypothalamus-1-24.jpg

• When blood sugar levels are too high and the body is not able to produce insulin, the body tries to eliminate the sugar in the bloodstream through increasing thirst to flush out the sugar
• This causes increased urination
• Since the body is unable to take the sugar into cells, cells don’t have energy
• The body will burn fat and muscle for energy causing weight loss
• This is called ketosis
• If ketosis continues for too long, the body goes into ketoacidosis (DKA - Diabetic Ketoacidosis)
• The body’s pH changes more acidic
• Person can smell sweet (like Juicy Fruit gum)

Image obtained from: https://www.verywellhealth.com/thmb/n7LFbP1dqAI9elgJt6ei8NVOsKY=/1500x0/filters:no_upscale():max_bytes(150000):strip_icc()/hyperglycemia-symptoms-5ada088fba617700366b24fc.png

When you eat too much sugar, what does your body want?

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WATER

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Hands-on Activity Instructions

• BE SURE TO GET PARENTAL / GUARDIAN PERMISSION BEFORE PROCEEDING WITH THIS LAB.
• BE SURE TO SENSITIVE RELIGIOUS AND CULTURE PREFERENCES OF STUDENTS
• If there is a student in the class that has diabetes, they should be given the option of participating. If they have well managed they can participate and compare their baseline blood sugar to their blood sugar after a sugary snack and monitor how their blood sugar rises compared to those that are not diabetic.
• They will probably have a higher baseline
• This is a great opportunity for the diabetic student to share with other students.

Blood Sugar Levels Lab

Images obtained from: https://www.eatthis.com/wp-content/uploads/sites/4/2020/09/various-candy.jpg?quality=82&strip=all&w=640

https://www.umassmed.edu/globalassets/diabetes-center-of-excellence-dcoe/images/thumbnails/glucose-testing-blood-sugar-diabetes.jpg

How does the body regulate?

• When body has too much sugar →
• Increase thirst to flush out sugar
• Pancreas releases Beta cells (insulin)
• Body uses stored fat and muscle for energy
• When body does not have enough sugar
• Sense of hunger
• Release of glucagon → Liver converts glycogen into usable sugar

Calcium

Discussion - Calcium Anatomy

• The parathyroid glands sit on the back (posterior aspect) of the thyroid gland
• The parathyroid glands sense the blood levels of calcium
• Calcium:
• builds and maintains strong bones
• helps with heart and muscle function
• helps with nerve function
• calcium can also help with cancer, diabetes, and high blood pressure

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Image obtained from: https://www.niddk.nih.gov/-/media/Images/Health-Information/Endocrine-Diseases/Thyroid-illustration.jpg?imbypass=true

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• If calcium is low → the parathyroid gland releases the parathyroid hormone to increase vitamin D3 and decrease calcitonin levels
• Vitamin D3 helps the body to absorb calcium
• The body can take calcium from the bones to compensate
• Symptoms of low calcium
• muscle cramps . twitching
• numbness and tingling in hands and feet
• Long term deficiencies can result in osteoporosis
• Weak and brittle bones - more common in women
• Typically seen in older people with kyphosis

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Image obtained from: https://images.ctfassets.net/yixw23k2v6vo/spu_wysiwyg_fid30502_asset/8c85df38f828a75add2d80a1405bf275/osteoporosisages18003390_m.jpg

• If Calcium is too high → parathyroid gland increases calcitonin to inhibit osteoblast activity
• Osteoblasts are cells that build and form new bone
• Body can eliminate calcium through urination
• Too much calcium in the body can leave to kidney stones
• Symptoms of high calcium levels
• digestive issues
• increased thirst → urination
• muscle weakness / twitching
• tired / confusion

Image obtained from: https://ssl.adam.com/graphics/images/en/17091.jpg

https://medlineplus.gov/images/KidneyStones_share.jpg

Hands-on Activity Instructions

• Groups should be 2-3 in a group
• Make sure that eyewear and gloves are used
• Do this experiment where you have access to a sink
• Make sure that this lab is kept in an area that has less airflow (such as a chemistry hood) and where it can not be knocked due to the smell that can come from this experiment since it occurs over several weeks.

Bones Bending Lab

Hands-on Activity Instructions

• Groups should be 2-3 in a group
• Make sure the eyewear is used
• It might be best to have the bones put in the oven at the end of class and then the teacher remove then later and then test the bones the next say

Brittle Bones Lab

Images obtained from: https://i.etsystatic.com/5561099/r/il/026cd4/3940634716/il_fullxfull.3940634716_e5mv.jpg

https://www.shutterstock.com/image-photo/broken-chicken-bone-260nw-512535205.jpg

How does the body regulate?

• If calcium is too low →
• the parathyroid will cause the body to release D3
• the body takes calcium from bones
• If calcium is too high →
• the parathyroid causes an increase in calcitonin to decrease osteoblast activity

Fluids and Electrolytes

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What are the kidneys and what do they do?

Basic background

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Excretory System and the Nephron - Amoeba Sisters

Discussion - Fluids and Electrolytes Anatomy

• Electrolytes include
• Sodium
• Potassium
• Calcium
• Magnesium

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• Sodium (Na+) levels are sensed in the brain in the Subfornical Organ (SFO)
• Potassium levels are sensed in the gut
• Calcium levels are sensed in the parathyroid glands
• Magnesium levels are sensed in kidney and intestine

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Image obtained from:https://pbs.twimg.com/media/EpYepteXIAIHYXa.jpg

https://ars.els-cdn.com/content/image/1-s2.0-S2157171616000071-gr2.jpg

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• Electrolytes
• Conduct electricity through heart muscle
• Regulate nervous system
• Muscle function
• Hydration
• Balance blood acidity
• Balance blood pressure
• Rebuild damage tissue

• When Na+ levels are too low (Hyponatremia)
• The kidneys slow down urinary function
• When Na+ levels are too high (Hypernatremia)
• The body increases thirst to flush Na+ out of the body
• The tubule of the Nephron (located in the renal cortex)
• Sodium levels do not affect an EKG of the heart

Images obtained from: https://upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Blausen_0592_KidneyAnatomy_01.png/640px-Blausen_0592_KidneyAnatomy_01.png

https://www.niddk.nih.gov/-/media/Images/Health-Information/Kidney/Nephron_Extraction_330x380.png

• When potassium levels are low (Hyperkalemia)
• the body does not correct
• Symptoms include constipation, irregular heart beat
• When potassium levels are high (Hypokalemia)
• too much potassium is filtered out through the kidneys
• Symptoms include nausea, chest pain, shortness of breath, muscle weakness, weak pulse
• Changes in Potassium levels can be seen on an EKG

Images obtained from: https://i.ytimg.com/vi/RjsdwdJ7pQk/maxresdefault.jpg

https://manualofmedicine.com/wp-content/uploads/2021/04/Hyperkalemia-and-Hypokalemia-ECG-Changes-2.jpg

• If Calcium is low (Hypocalcaemia) → the parathyroid gland releases the parathyroid hormone to increase vitamin D3 and decrease calcitonin levels
• Vitamin D3 helps the body to absorb calcium
• The body can take calcium from the bones to compensate
• Symptoms of low calcium
• muscle cramps . twitching
• numbness and tingling in hands and feet
• Long term deficiencies can result in osteoporosis
• Weak and brittle bones - more common in women
• Typically seen in older people with kyphosis
• If Calcium is too high (Hypercalcaemia)→ parathyroid gland increases calcitonin to inhibit osteoblast activity
• Osteoblasts are cells that build and form new bone
• Body can eliminate calcium through urination
• Too much calcium in the body can leave to kidney stones
• Symptoms of high calcium levels
• digestive issues
• increased thirst → urination
• muscle weakness / twitching
• tired / confusion

Image obtained from: https://images.ctfassets.net/yixw23k2v6vo/spu_wysiwyg_fid30502_asset/8c85df38f828a75add2d80a1405bf275/osteoporosisages18003390_m.jpg

• Calcium levels can be seen on an EKG in the distance between the end of the S wave and T wave (ST Segment)

Images obtained from: https://upload.wikimedia.org/wikipedia/commons/thumb/0/09/ECG-PQRST%2Bpopis.svg/1200px-ECG-PQRST%2Bpopis.svg.png

https://litfl.com/wp-content/uploads/2018/08/ECG-QT-changes-Hypocalcaemia-Hypercalcaemia-2.png

• If Magnesium is low (Hypomagnesemia) →
• regulatory mechanisms for magnesium by the kidneys in still unknown
• balance is obtained through the kidneys
• symptoms of hypomagnesemia - fatigue, irregular heart beat, muscle spasms
• If Magnesium is too high (Hypermagnesemia)→
• regulatory mechanisms for magnesium by the kidneys in still unknown
• balance is obtained through the kidneys
• symptoms of hypermagnesemia - muscle paralysis, decreased ventilations
• Magnesium levels can be detected on an EKG

Images obtained from: https://healthandwillness.org/wp-content/uploads/2023/03/PQRST-Hypomagnesemia-and-low-magnesium-levels.jpg

https://labpedia.net/wp-content/uploads/2020/01/ECG-hpermagnesemia-1.jpg

Fluid administration due to dehydration electrolyte imbalance

Basic fluid administration in children

4 - 2 - 1 rule

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1st hour:

4 mL / Kg

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2nd Hour:

2 mL / Kg

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Maintenance:

1 mL / Kg

No more than 100 mL per hour

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IV Calculation Scenarios

IV Calculation Scenarios - Answers

Scenario

A 6 year old child has been vomiting for the past 3 days and is unable to keep any fluids down. He has not urinated in the past 24 hours. His mother brings him to the ED of the local hospital. He weighs 52 pounds. How much normal saline solution would he receive in the first hour? Second hour? Maintenance until the doctor deems him well enough to go home?

Solution

52 pound child

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52 / 2.2 = 23.636 kg

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23.636 x 4 = 94.544 mL for the first hour

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23.636 x 2 = 47.272 mL for the 2nd hour

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23.636 x 1 = 23.636 mL for maintenance each hour

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To convert pounds to kilograms, divide the pounds by 2.2

Hands-on Activity Instructions

• 2-3 students per group
• Have students bring in the beverages they want to test

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Electrolytes Lab

How does the body regulate?

• Through urine output (increase & decrease)
• Thirst
• Release of hormones

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Acid / Base Balance

Respiratory and Metabolic

Terms

Hypercapnia - having too much or too high levels of carbon dioxide

Hypocapnia - having too little or too low levels of carbon dioxide

Acidosis - the human body being in a acidotic state - having too many H+ ions

Alkalosis - the human body being in a alkalotic state - having too many OH- ions

Respiratory Acidosis - when the lungs can not remove the needed amount of carbon dioxide

Respiratory Alkalosis - when the lungs removes too much carbon dioxide

Metabolic Acidosis - when the body’s pH is lower than 7.35 due to a metabolic disorder

Metabolic Alkalosis - when the body’s pH is greater than 7.45 due to a metabolic disorder

Normal neutral pH is 7.0

Normal pH of the human body

The normal pH of the human body is 7.35-7.45 - slightly alkalotic.

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Image obtained from:https://www.registerednursern.com/wp-content/uploads/2017/08/abgs-full-compensation-nursing.png

Acid Base Balance Flow Chart

Link

Respiratory Acidosis

• Things that cause the Respiratory Acidosis (trapping of CO2):
• Unconscious and not breathing
• Lung infections
• Over use of sedatives (depressed respirations)
• Obesity - difficulty breathing

What happens of CO2 becomes trapped in the body?

• CO2 is naturally acidic. If CO2 is trapped in the body, the bodies acidity will rise.

Image obtained from: https://medictests.com/units/acid-base-balance

https://www.jems.com/patient-care/acid-base-balance-understanding-is-critical-to-treat-patients/

How does the body compensate for Respiratory Acidosis to maintain homeostasis.

• The kidneys will excrete more hydrogen ions in the urine (urine will be more acidic) and retain bicarbonate (alkaline)
• Bicarbonate is produced in the pancreas and kidneys.

Respiratory Alkalosis

• Things that cause the Respiratory Alkalosis (blowing off CO2):
• Hyperventilation
• High fever - can also increase respirations
• Extreme pain - increased respirations

How does the body compensate for Respiratory Alkalosis to maintain homeostasis.

• The kidneys decrease bicarbonate reabsorption and production.
• When anxiety is the cause of hyperventilation, the body will stop breathing (remember the amount of CO2 in the body is the driving force to breathe - when there is low CO2 present, the body will not have a desire to breathe) this often results in a person passing out and “resetting” and when the person has higher levels of CO2, they will start to breathe again and regain consciousness.*

Where is the homeostasis in Respiration?

• As exercise increases and the demand of increased cellular respiration increases; there is an increased need for more O2 as well as an increase need to expel CO2, thus the body increases External Respirations / Ventilations.

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• The body will do all that is can to return the body to homeostasis through compensatory actions. That involve the metabolic system.
• Metabolism is the conversion of food into energy, conversion of food into lipids, proteins, nucleic acids and some carbohydrates, and eliminating metabolic wastes.

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Metabolic Acidosis

• Things that cause the Metabolic Acidosis:
• High levels of blood sugar (Diabetic ketoacidosis - DKA)
• Severe Diarrhea
• Severe dehydration in children

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How does the body compensate for Metabolic Acidosis to maintain homeostasis.

• The respiratory system will compensate by increasing ventilations to blow of CO2 and adjust bicarbonate levels.

Diabetic Ketoacidosis (DKA)

• When the body is in DKA, the body will respond with Kussmaul Respirations

Image obtained from: https://www.verywellhealth.com/thmb/7KgSpJ0eeHQbj0IrQnf32dKO40M=/1500x0/filters:no_upscale():max_bytes(150000):strip_icc()/VWH-JulieBang-KussmaulBreathing-4000x2700-db89e63d5ba84372837fc40003cfe65c.png

Metabolic Alkalosis

• Things that cause the Metabolic Alkalosis:
• Stomach acid loss
• Severe vomiting
• Aspirin overdose

How does the body compensate for Metabolic Alkalosis to maintain homeostasis.

• The respiratory system will compensate by decreasing ventilations to increase CO2.

How is pH measured in the body

• Nurses will obtain Arterial Blood Gases (ABG’s) to determine the bodies pH and levels of CO2.
• obtained through the radial artery
• obtained through artery since chemoreceptors are located in the carotid body and that is what the body responds to

image obtained from: https://img.medscapestatic.com/pi/meds/ckb/02/12202tn.jpg

Hands-on Activity Instructions

• Can be done individually or as a pair
• Using the article, “Acid Base Balance”, list Respiratory Acidosis, Respiratory Alkalosis, Metabolic Acidosis, and Metabolic Alkalosis; then list causes of each.
• It could be helpful to watch these videos:
• ABG Interpretation Made Easy: Tic-Tac-Toe Method
• Acid Base Arterial Blood Gases (ABG) Interpretation with Tic-Tac-Toe Method
• (The practice is only done with compensated and uncompensated - not partial)

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Acid / Base Balance Practice

Acid / Base Balance Practice - Answers

How does the body regulate?

• By increasing H+ when HCO3- is high
• By decreasing H+ when HCO3 is low
• Done through respiratory systems and metabolic system

Spotlight - Robotics in Medicine

Robotics in surgery

Robotic nurse

Medical Robots

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Ethical question: Would healing time change if the human element was lessened or taken away?

Assessment

Quiz

Quiz - Answers

Differentiation

• Use of a student aide
• Pair with an advanced student for practice problems
• Use of videos (from Teacher Background Knowledge)

Remediation

Extension/Enrichment

• Pair with a student that needs help
• Have student explain Acid / Base Balance to the class
• Have student explain IV calculation to the class
• Have student summarize articles to class