Heart Physiology 2

Question 1

What are the functions of the circulatory system?
1)
2)
3)
4)
5)

Answer 1

1) Distribution of dissolved gasses
2) Waste removal
3) Chemical signalling
4) Mediate inflammatory, immune responses
5) Conserve or release heat from skin surface

Question 2

What is a portal system?

Answer 2

Two capillary beds in series

EG: In kidneys, stomach, liver

Question 3

Which blood vessels have elastic tissue?

Answer 3

Arteries, veins

Question 4

Which blood vessels have smooth muscle?

Answer 4

Arteries, arterioles, veins

Question 5

Where is the highest and lowest mean systemic blood pressure?

Answer 5

Aorta (highest)
Vena cavae (lowest)

Question 6

Where is blood flow slowest?

Answer 6

Capillaries

Question 7

What is the Windkessel effect?

Answer 7

Reduction in arterial pressure changes during systole and diastole (heartbeat)

Caused by elastin in walls of arteries, walls distend in systole, recoil in diastole

Question 8

Where is the Windkessel effect relevant?

Answer 8

In arteries

Question 9

How to proteins move across the membranes of capillaries?

Answer 9

Transcytosis

Question 10

Which tissues make up the walls of arteries?

Answer 10

Endothelium
Elastic tissue
Smooth muscle
Fibrous tissue

Question 11

Which tissues make up the walls of veins?

Answer 11

Endothelium
Elastic tissue
Smooth muscle
Fibrous tissue

Question 12

Which tissues make up the walls of arterioles?

Answer 12

Endothelium

Smooth muscle

Question 13

Which tissues make up the walls of capillaries?

Answer 13

Endothelium

Question 14

Which tissues make up the walls of venules?

Answer 14

Endothelium

Fibrous tissue

Question 15

Mean arterial diameter

Answer 15

4mm

Question 16

Mean venous diameter

Answer 16

5mm

Question 17

Mean arterial wall thickness

Answer 17

1mm

Question 18

Mean venous wall thickness

Answer 18

0.5mm

Question 19

Proportion of blood stored in systemic veins

Answer 19

64%

Question 20

Proportion of blood stored in arteries

Answer 20

13%

Question 21

How far are most cells from a capillary?

Answer 21

0.1mm

Question 22

What is bulk flow?

Answer 22

Overall movement of fluid between blood and tissues

Difference between hydrostatic pressure and colloid osmotic pressure

Question 23

What is absorption?

Answer 23

Movement of fluid from interstitium into capillaries

Question 24

What is filtration?

Answer 24

Fluid movement out of capillaries into interstitium

Question 25

What is oedema?

Answer 25

Interstitial fluid accumulation

Question 26

Difference in solute concentrations between blood and interstitial fluid

Answer 26

Electrolyte balance the same Proteins in blood, too large to get into interstitial fluid

Question 27

What are the pressures influencing bulk flow?

Answer 27

Osmotic pressure (pi) - Movement into capillary Hydrostatic pressure (P) - Movement out of capillary

Question 28

What is colloid (or oncotic) osmotic pressure?

Answer 28

Osmotic pressure caused by proteins in the blood that can't penetrate the endothelium of capillaries

Question 29

What is the plasma oncotic pressure vs the interstitial fluid oncotic pressure?

Answer 29

25mmHg (plasma) | 0mmHg (interstitial)

Question 30

What is hydrostatic pressure?

Answer 30

The pressure exerted by the blood on the blood vessel walls. Decreases with length

Question 31

What is hydrostatic pressure in capillaries at the arteriolar end?

Answer 31

32mmHg

Question 32

What is the hydrostatic pressure in capillaries at the venous end?

Answer 32

15mmHg

Question 33

What is the hydrostatic pressure in the interstitial fluid?

Answer 33

0mmHg

Question 34

What is the bulk flow at the arterial end of a capillary?

Answer 34

~7mmHg

Question 35

What is the bulk flow at the venous end of a capillary?

Answer 35

~-10mmHg

Question 36

Which pressure favours filtration?

Answer 36

Hydrostatic pressure

Question 37

Which pressure favours absorption?

Answer 37

Colloid osmotic pressure

Question 38

Is colloid osmotic pressure constant, or does it change with capillary length?

Answer 38

Constant

Question 39

Is hydrostatic pressure constant, or does it change with capillary length?

Answer 39

Decreases with capillary length

Question 40

What is the net fluid movement of fluid per day?

Answer 40

3L out of capillaries per day

Question 41

Where does the excess fluid filtrated into the interstitial fluid go?

Answer 41

Into the lymphatic system

Question 42

Where do the largest lymph vessels empty?

Answer 42

Into the venous system Where the left/right subclavian veins join internal jugular veins

Question 43

What plays a large role in pumping lymph?

Answer 43

Skeletal muscle pump

Question 44

Roles of lymphatic system 1) 2) 3)

Answer 44

1) Return fluid and proteins filtered back into circulation 2) Pick up fat absorbed in small intestine, transfer to circulatory system 3) Immune system

Question 45

What factors pump lymph? 1) 2) 3)

Answer 45

1) Smooth muscle contractions in larger lymph nodes 2) Skeletal muscle contraction 3) One-way valves