lecture 2 - intro to CVS physiology

Question 1

What is the difference between diffusion and bulk flow in the CVS?

Answer 1

Diffusion occurs across short distances in the lungs or tissues across a plasma membrane, while bulk flow transports around the body across long distances.

Question 2

What are the 5 types of vessels in the vasculature?

Answer 2

Arteries, arterioles, capillaries, venules, veins

Question 3

How many litres of blood are found in the body?

Answer 3

4-6, usually 5L

Question 4

What is the purpose of the pulmonary circulation?

Answer 4

Carry blood from the heart to the lungs, load O2, offload CO2, and return blood to the heart.

Question 5

Do the pulmonary arteries contain oxygenated or deoxygenated blood?

Answer 5

Deoxygenated

Question 6

Do the pulmonary veins contain oxygenated or deoxygenated blood?

Answer 6

oxygenated

Question 7

Why does the pulmonary vasculature have little resistance to flow?

Answer 7

The lungs are very close to heart, there is not much distance between them

Question 8

Why is the pulmonary circulation separate to the systemic circulation?

Answer 8

So that all of the blood passes through the lungs for gas exchange, and the lungs do not have to compete with other organs for blood flow.

Question 9

Is the systemic circulation mostly in series or parallel?

Answer 9

parallel

Question 10

Which 2 regions of the systemic circulation are in series?

Answer 10

The splanchnic circulation (between gut and liver), the renal system

Question 11

Why is the splanchnic circulation in series not parallel?

Answer 11

Blood from the GI tract must go through the liver for metabolism before returning to the heart

Question 12

What are the 2 main reasons why the systemic circulation is arranged in parallel?

Answer 12

Reduces total resistance, blood flow to individual organs can be independently controlled

Question 13

How does the relative cardiac output to the brain change during exercise?

Answer 13

remains constant

Question 14

How does the relative cardiac output to the heart change during exercise?

Answer 14

increases

Question 15

How does the relative cardiac output to the gut change during exercise?

Answer 15

decreases

Question 16

How does the relative cardiac output to the kidneys change during exercise?

Answer 16

decreases

Question 17

How does the relative cardiac output to the skeletal muscle change during exercise?

Answer 17

increases

Question 18

How does the relative cardiac output to the skin change during exercise?

Answer 18

increases

Question 19

Which part of the vasculature contains the highest volume of blood?

Answer 19

Veins and venules

Question 20

Which vessels are known as capacitance vessels, and why?

Answer 20

Veins and venules, because they hold the majority of the blood volume, and some can serve as a reserve supply if necessary.

Question 21

At which type of vessel is pulsatility lost?

Answer 21

Arterioles

Question 22

On which side of the capillaries is there a greater number of vessels?

Answer 22

More on the venous side than the arterial side

Question 23

What are the 2 biggest veins in the body?

Answer 23

Inferior and superior vena cava

Question 24

How does blood flow change across the CVS?

Answer 24

It doesn’t, flow is constant everywhere

Question 25

Where is blood flow velocity the greatest in the CVS?

Answer 25

The aorta

Question 26

Where is blood flow velocity the slowest in the CVS, and why?

Answer 26

Capillaries - flow is constant across the system, but cross sectional area is greatest at the capillaries, reducing velocity

Question 27

Which type of vessels in the CVS have the greatest total cross sectional area?

Answer 27

Capillaries