The marathon runners collapsed due to multiple body system failures caused by dehydration. The respiratory system was unable to efficiently exchange gases due to lack of water, the muscular system fatigued because cellular respiration broke down without water to create ATP, and the thermoregulatory system could not properly cool the runners through sweating. The lack of water intake over several hours also stressed the excretory system's ability to filter waste and regulate water content in the blood and tissues. Overall, the runners' dehydration overwhelmed multiple homeostatic mechanisms, leading to a systemic shutdown.
2. Case Study
What is happening to these runners?
1. In your notes, jot down what you
think is happening in their bodies -
what systems are affected, how
can you explain what you see?
2. What questions do you have?
Write those questions on Post it
Notes.
3. Compare and discuss with your
table partner.
4. As a class: categorize questions
and group questions on wall.
2
3. Not enough OXYGEN
- Gas Exchange
▹ Why do we have a
respiratory system?
▹ What makes up the
human respiratory
system?
▹ How does it work?
3
4. 1. Model
1. Sketch a model of what makes up our respiratory system. How does it work?
Include labels, arrows, anything that will help you describe your model.
2. Compare and discuss with your table partner. How/where do you agree?
Disagree? Continue to add to your model as needed.
3. With your lab group: compare models and discuss. Modify your model as needed.
How could we test this?
4. Sketch/write on the whiteboards a way you could do this in a lab.
4
6. Human Respiratory System
1. Label the diagram of the
respiratory system in your notes.
2. What questions do you have
about this system? (functions of
particular parts, how to say
names, etc) Jot down at least two
questions in your notes
3. What makes the lung cavity larger
and smaller?
4. Why should we breathe through
our nose?
7. What is the function of the respiratory system?
● Gas exchange → picks up and delivers (diffusion) oxygen
from the air to our blood and releases carbon dioxide from
our blood (diffusion) back to the air
1. What is the respiratory
surface of the lung?
2. What is the function of:
a. The capillary?
b. The venule?
c. The arteriole?
8. STRUCTURES & FUNCTIONS:
8
Structure Function
Capillary Only one cell
thick with very
flexible walls.
Thin walls = easy
diffusion!
Connect arteries
and veins in order
to allow for gas,
nutrient, and
waste exchange
10. STRUCTURES & FUNCTIONS:
10
Structure Function
Venule Small vessels that
form when
capillaries come
together -
connect to veins.
Allows
deoxygenated
blood to return to
the heart to get
more oxygen and
rid itself of waste
(CO2).
11. STRUCTURES & FUNCTIONS:
11
Structure Function
Arteriole Tiny branches of
arteries that lead
to capillaries.
They are able to
constrict and
dilate to regulate
blood flow.
Transport blood
from arteries to
capillaries.
Regulate the
blood flow and
blood pressure.
13. Okay... but what is diffusion?
● Diffusion is net movement of anything from a region of
higher concentration to a region of lower
concentration.
○ If you took earth science you’d remember, “winds always blow from high
to low.”
● In this case oxygen and carbon dioxide are diffusing into
and out of our blood to help us maintain homeostasis
within the body.
13
15. Where does gas exchange take place?
● Alveoli = single cell thick air sacs (thin, moist, in
contact with circulatory system) that hold air
and diffuse gases to and from capillaries
16. What’s the circulatory system?
● Composed of the heart, arteries, capillaries, and veins
● Works together with the lungs to transport oxygen and
nutrients (from what you’ve eaten) throughout the body via
arteries.
○ ARTERIES go AWAY from the heart
● Carbon dioxide and other waste products are carried back
to the heart/lungs to be recharged with nutrients and
oxygen.
○ VEINS go back TOWARDS the heart 16
17. In every aspect of life...
STRUCTURE
DETERMINES
FUNCTION!
17
REMEMBER
THIS!
18. What does the epiglottis do?
● Flap of cartilage that folds over trachea when
we swallow so food goes down esophagus
Looks gross,
saves you
from choking
= trade-off
19. What can go wrong?
● Pneumonia
● Bronchitis
● Asthma
● Choking
● Emphysema
● Lung cancer
23. ERYTHROCYTES)
▹ Hemoglobin is a protein found in
red blood cells that binds to oxygen
to help carry it to the body.
▹ RBC also carry CO2 waste to lungs
to be exhaled.
23
24. STRUCTURES & FUNCTIONS:
24
Structure Function
RED
BLOOD
CELLS
Small and
round with a
flattish,
indented
center (like a
doughnut) that
lacks a
nucleus.
Carries oxygen
from lungs to
body cells and
removes CO2
waste to be
exhaled.
25. Stomata/Guard Cells
● Found on the leaves of plants
● When open, allows for CO2 to enter
the plant for photosynthesis
○ H2O and O2 are released
● TRADE-OFF: Photosynthesis can
occur but water is lost
USE YOUR BRAINS: When would
this be harmful to the plant?
25
26. STRUCTURES & FUNCTIONS:
26
Structure Function
Stomata
& Guard
Cells
Stomata: pores in
leaf
Guard Cells: open
or close stomata
Open stomata allows
for gas exchange =
photosynthesis can
occur.
Closed stomata does
not allow for gas
exchange in order to
conserve H2O..
27. ”
What role might the respiratory
system have had in our marathon
runners collapse?
27
28. Muscles got tired -Not
enough ENERGY -
▹ Why do we have a
muscular system?
▹ When do you notice your
muscles getting tired?
▹ How does it work?
28
29. 1. Model
1. Sketch a model of what makes up our muscular system. How does it work? Why do
muscles get tired? What happens when muscles are tired? Include labels, arrows,
anything that will help you describe your model.
2. Compare and discuss with your table partner. How/where do you agree? Disagree?
Continue to add to your model as needed.
3. With your lab group: compare models and discuss. Modify your model as needed.
How could we test this?
4. Sketch/write on the whiteboards a way you could do this in a lab.
29
31. What are the three types of muscles and where are
they found?
1. Smooth → involuntary movements (stomach,
blood vessels, intestines, pupils)
a. From Nervous System - they are connected
and transmit electrical impulses
2. Skeletal → voluntary movement
a. Large (1 mm - 30 cm) with lots of nuclei and
mitochondria
3. Cardiac → found only in the heart (combo of
smooth and skeletal); involuntary movement
a. Contracts on its own without direct
stimulation from nervous system
32. How do muscles and bones
interact to produce movement?
● Bones = levers
● Muscles = pull bones
● Tendons = connect muscles to bones
● Ligaments = connect bones to bones
33. ”
What is the source of ENERGY for all
our muscles?
33
34. Carbs (Bread, veggies)
Made up of sugars
(glucose) and starches.
Used for quick energy
and structure.
FOOD!
Protein (meat,
veggies)
Made up of amino
acids. Used for lots of
things such as energy,
movement, structure,
speeding up reactions,
and protection.
34
Lipids/Fats (meat,
butter)
Made up of fatty acids
and glycerol. Used for
energy storage and
structure (cell
membranes).
35. ”
How does the stored energy in FOOD
move our MUSCLES?
35
36. CELLULAR RESPIRATION! -breaking the bonds of food and releasing
that stored energy to build ATP (charged batteries that supply energy
for work).36
No oxygen used
Happens in
cytoplasm
2 ATP made
Lactic acid produced
AKA fermentation
Oxygen used
Happens in
cytoplasm and
MITOCHONDRIA
36-38 ATP made
CO2 and H2O
produced
Occurs in both
plants and animals
Both
create
energy
from
glucose.
ANAEROBIC AEROBIC
37. What is ATP (Adenosine Triphosphate)?
Energy to BUILD ATP
comes from FOOD.
Energy to BREAK ATP
comes from WATER
(hydrolysis).
Net RESULT - more
energy comes from
BREAKING than needed
to build.
37
Charged
battery
Uncharged
battery
38. A PICTURE IS WORTH A
THOUSAND WORDS
▹What goes in?
▹What comes out?
▹Where would we
find LOTS of
mitochondria?
38
39. What can go wrong?
● HEART ATTACK
● Muscular dystrophy (MD)
● Tetanus
● Spasms/cramps
● Tears
40. ”
What role might the muscular system
and cellular respiration have had in
our marathon runners collapse?
40
41. Runner got too HOT -
Thermoregulation
▹ What is thermoregulation?
▹ Why does our body need to
regulate itself?
▹ How does it work?
41
42. What circumstances can you think of where your
body needs to regulate temperature? What else does
it regulate?
42
44. 1. Model
1. Sketch a model of how your body cools itself down when it’s too hot and how your
body warms up when it’s too cold. How does it work? Include labels, arrows, anything
that will help you describe your model.
2. Compare and discuss with your table partner. How/where do you agree? Disagree?
Continue to add to your model as needed.
3. With your lab group: compare models and discuss. Modify your model as needed.
How could we test this?
4. Sketch/write on the whiteboards a way you could do this in a lab.
THESE ARE FEEDBACK LOOPS!!!
44
46. 46
Glucagon
Glycogen
Insulin
Storage molecule
of excess glucose
in the muscle.
Hormone secreted to release
glucose into bloodstream
from the muscle.
Hormone secreted to pull
glucose into muscle from the
bloodstream.
SET POINT
47. What happens if we don’t thermoregulate?
Hypothermia -
getting too cold
47
Hyperthermia (heat
stroke) - getting too hot
48. ”
What role might thermoregulation
have had in our marathon runners
collapse?
48
49. Runner was dehydrated...
▹ What does it mean to be
dehydrated?
▹ What should you do if
you’re dehydrated?
▹ How does water aid in
thermoregulation?
49
50. ”
We know that water is necessary for
life, but can also kill you...what makes
water so special?
50
51. Water is necessary for a
runner to run (and any
organism to live) - WHY?
▹ What are three things
that make water
unique? Jot them
down in your notes!
▹ What is one thing that
you think is special
about water?
51
52. Back to the runner being
dehydrated...
▹ What does this mean at
the cellular level?
▹ What happens to your cells
when you’re dehydrated?
▹ What do dehydrated cells
look like?
52
53. 1. Model
1. Sketch a model of what our cells look like when they’re dehydrated. How does it
work? Include labels and arrows to show the movement of water and include
anything that will help you describe your model.
2. Compare and discuss with your table partner. How/where do you agree?
Disagree? Continue to add to your model as needed.
3. With your lab group: compare models and discuss. Modify your model as needed.
How could we test this?
4. Sketch/write on the whiteboards a way you could do this in a lab.
53
55. Runner hasn’t had a
drink in hours - too
little water.
▹ Why do we have a
excretory system?
▹ What makes up the
human excretory
system?
▹ How does it work?
55
56. 1. Model
1. Sketch a model of what makes up our excretory system. How does it work?
Include labels, arrows, anything that will help you describe your model.
2. Compare and discuss with your table partner. How/where do you agree?
Disagree? Continue to add to your model as needed.
3. With your lab group: compare models and discuss. Modify your model as needed.
How could we test this?
4. Sketch/write on the whiteboards a way you could do this in a lab.
56
57. What organs make up the excretory system and what
do they excrete?
● Skin = sweat
● Lungs = CO2
● Liver = turns toxic waste
into urea
● Kidney = filters blood
58. How do the kidneys help maintain homeostasis?
1. Remove waste → urine
2. Maintain blood pH
3. Regulate H2O content in
the blood
60. How does water regulation differ in freshwater vs.
saltwater organisms?
60
61. What can go wrong?
● Kidney stones
● Kidney damage
● Kidney failure
● Lung cancer
● Liver cancer
● Liver cirrhosis
62. 1. Model
1. Sketch a model of a freshwater fish and a saltwater fish. How does water
regulation work? Include labels, arrows, anything that will help you describe your
model.
2. Compare and discuss with your table partner. How/where do you agree?
Disagree? Continue to add to your model as needed.
3. With your lab group: compare models and discuss. Modify your model as needed.
How could we test this?
4. Sketch/write on the whiteboards a way you could do this in a lab.
62
