circulation

Question 1

What are 2 main functions of circulatory systems?

Answer 1

1. transport/ exchange respiratory gases
2. transport nutrients, hormones, and immune cells to critical sites

Question 2

Do all animals have circulatory systems? If not, what do they have and how does it
work?

Answer 2

no, they have gastrovascular cavities
where gases and nutrients diffuse through

Question 3

What are the three main features of circulatory systems?

Answer 3

circulatory fluid, pump, vessels

Question 4

List and define the vessels in the order in which blood flows away from the heart

Answer 4

arteries: carry blood away from heart
capillaries: blood slows down here, microscopic vessels with porous walls for gas exchange
veins: carry blood back towards heart

Question 5

What is single circulation? How does blood flow and what happens to oxygen? Which
animals have this system?

Answer 5

blood travels through body in a single loop
1) heart pumps once to take blood to respiratory surface and to body
2) contraction of muscles speeds up circulation
fish have this system

Question 6

What is the atrium? What is the ventricle?
name right and left functions

Answer 6

they are 2 chambers of the heart

the atrium receives blood from body
- right: deO2
- left: O2

the ventricle pumps blood away from body
- right: deO2
-left: O2

Question 7

Describe both examples of double circulation presented in class. How does blood flow
and what happens to oxygen? How does the heart differ in each example? What circuits
are involved in each example? Which animals use which type of double circulation?

Answer 7

involves 2 circuits of blood flow
right side pumps O2 poor blood into beds in lungs
left side pumps O2 rich blood to rest of body
mammals: 4 chambered hearts
amphibians: 3 chambered hearts; icomplete division of ventricle allows frogs to shut off blood flow to hearts and shift it to skin

Question 8

What is an intermittent breather?

Answer 8

incomplete division of ventricle allows frogs to shut off blood flow to hearts and shift it to skin

Question 9

What are the 4 major components of blood?

Answer 9

plasma
RBCs
Platelets
White cells

Question 10

What is a red blood cell? What does it do? What important protein does it contain?
Know that it is also called an erythrocyte.

Answer 10

transport oxygen, hemoglobin

Question 11

Why are red blood cells red?

Answer 11

from iron concentration

Question 12

What is affinity and how does oxygen binding to hemoglobin change affinity? Know that
this is called cooperativity

Answer 12

affinity is the strength of hemoglobin to bind to O2 molecules in blood

hemoglobin changes shape to bind or unload O2
bind –> high affinity
unload –> low affinity

Question 13

Where (in lungs or tissue) is partial pressure for oxygen high? Where is it low? How does
that impact the affinity of hemoglobin for oxygen?

Answer 13

in lungs: high O2
in tissue: low O2

Question 14

Explain the oxygen hemoglobin dissociation curve. Start in the top right corner of the figure from class and explain what is happening to hemoglobin affinity for oxygen as you move to the left

Answer 14

top right: hemoglobin has high affinity for O2 bc of high PO2

bottom left: low affinity for oxygen because of low PO2 tissues

Question 15

How does exercise shift this curve?

Answer 15

more exercise leads to CO2 increase, which decreases the pH in blood, thus changing hemoglobin shape

this reduces the binding of O2 and allows for more O2 to unload

Question 16

Where are animals naturally exposed to low oxygen conditions?

Answer 16

the deep sea

Question 17

What are 3 respiratory adaptations found in deep sea diving mammals (the seal example)?

Answer 17

1. more blood (more oxygen storage)
2. more myoglobin (oxygen storing protein in muscle)
3. blood not routed to muscles (they use myoglobin instead)

Question 18

What is myoglobin?

Answer 18

oxygen storing protein

Question 19

What is an example in humans of adaptation to deep sea diving?

Answer 19

larger spleen with more RBCs

Question 20

What pathway is activated by hypoxia that leads to red blood cell increases?

Answer 20

HIF pathway, increases Epo to produce more red blood cells

Question 21

What was a surprising finding related to high-altitude genes identified in Tibetans who
have lived for 1000s of years at high altitudes (i.e., lived under conditions of extreme
hypoxia)?

Answer 21

they don’t have more RBCs than the average human. instead they actually have less to reduce blood thickness, and increase efficient use of oxygen