Cardio I

Question 1

Name 9 functions of the cardiovascular system.

Answer 1

1. Bringing nutrients into the body (from intestine to liver)
2. Bringing fuel to cells (glucose from liver to brain)
3. Bringing O2 to cells from lungs
4. Removal of waste products
5. Circulation of hormones
6. Circulation of immune cells and antibodies
7. Regulation of pH
8. H2O balance
9. Thermoregulation

Question 2

Which organ makes the most use of the cardiovascular system for fuel transport? Explain why.

Answer 2

The brain, because it does not have its own stores of glucose, which it uses for energy. This also means that it’s the first organ affected in the case of cardiac arrest.

Question 3

Explain why the cardiovascular system is needed for thermoregulation during exercise and during extreme heat/cold events.

Answer 3

When you exercise, your body produces heat. Muscle is not very efficient - only 15% of the energy expended produces work. The other 80% becomes heat (hyperthermia) that the cardiovascular system allows for the loss of. The body must ensure that it loses heat fast enough to avoid the body’s temperature rising too high. On the flipside, if it’s too cold, if the body temperature falls too low, you will die.

Question 4

Give an example of an organism that doesn’t require a cardiovascular system and explain why.

Answer 4

Amoeba. They are about 0.3 mm in length, and do not need a vascular system or a heart. The oxygen in the water can just diffuse directly into their bodies, and they take in bacteria with pseudopodia.

Question 5

A single cardiac muscle cell is called a […]

Answer 5

cardiomyocyte

Question 6

[…]% of the cells in the heart are contractile cardiomyocytes

Answer 6

99%

Question 7

On average, what is the ratio of capillaries to cardiac myocytes?

Answer 7

1:1

Question 8

Is the ratio of capillaries to cardiomyocytes relatively high or low? Explain the function of this.

Answer 8

It is the highest of any other organ. Because it works all the time, so the oxygen consumption is very high. A dense network of capillaries is therefore needed to produce big concentration gradients.

Question 9

What is diffusion?

Answer 9

The spontaneous movement of particles caused by random thermal motion.

Question 10

Diffusion is dictated by […] law.

Answer 10

Fick’s

Question 11

What is the formula for fick’s law?

Answer 11

Flow = D x concentration gradient x A
Where D is diffusion coefficient and A is cross-sectional area of membrane

Question 12

State Fick’s law with the formula for concentration gradient integrated. State each variable.

Answer 12

Flow = D x ((Cout - Cin)/d) x A
Where D is diffusion coefficient
A is cross-sectional area
Cout is concentration outside of membrane (ISF)
Cin is concentration inside cell
d is thickness of membrane (distance travelled)

Question 13

What is flux? State the formula.

Answer 13

Flux = flow/area = D x ((Cout - Cin)/d)

Question 14

How does the diffusion rate of O2 compare to CO2?

Answer 14

CO2 diffuses 20 times more easily than oxygen in water.

Question 15

Transportation of glucose from the liver to the brain is an example of what cardiovascular system function?

Answer 15

Bringing fuel to cells

Question 16

Bringing CO2 to lungs is an example of what cadiovascular system function?

Answer 16

Removal of waste products

Question 17

Bringing ammonia in the liver to the urea and to the kidneys is an example of what cardiovascular system function?

Answer 17

Removal of waste products

Question 18

The transportation of adrenaline from adrenal glands to heart muscles is an example of what cardiovascular system function?

Answer 18

Circulation of hormones

Question 19

[…] can be described as a brick wall.

Answer 19

Cardiomyocytes