Lecture 23 10/17/23

Question 1

What is the function of the CV system?

Answer 1

circulate blood at rates that meet metabolic demand while maintaining adequate perfusion and low filling pressures

Question 2

What does blood contain?

Answer 2

-nutrients/waste
-gases
-electrolytes

Question 3

How is oxygen bound to hemoglobin conveyed?

Answer 3

from the lungs to the metabolizing tissues

Question 4

How is CO2 conveyed?

Answer 4

from the metabolizing tissues to the lungs

Question 5

How do gases, nutrients, and wastes move?

Answer 5

via diffusion

Question 6

What are the characteristics of blood flow?

Answer 6

-pulsatile
-established by cyclic mechanical activity of heart

Question 7

What are the two “pumps” of the heart?

Answer 7

-pumping blood through the systemic vascular bed
-pumping blood through the pulmonary vascular bed

Question 8

What is the stroke volume?

Answer 8

the volume of blood that the ventricle ejects each systole

Question 9

What is cardiac output?

Answer 9

the volume of blood that leaves one side of the heart in one minute

Question 10

Why is it important that the cardiac output of the left and right heart are equal over time?

Answer 10

don’t want one side of the heart to fall behind

Question 11

What are the different structures in the heart?

Answer 11

atria
-valves
-ventricles

Question 12

What are AV valves?

Answer 12

valves guarding the entrances to the ventricles

Question 13

What are semilunar valves?

Answer 13

valves guarding the entrances to the great arteries

Question 14

When are AV valves open and closed?

Answer 14

open: during filling/diastole
closed: contraction/systole

Question 15

When are the semilunar valves open and closed?

Answer 15

open: during contraction/systole
closed: filling/diastole

Question 16

What is the function of ventricles, in general?

Answer 16

propel the stroke volume into the respective vascular bed

Question 17

What are the characteristics of the right ventricle?

Answer 17

-thin-walled
-pyrimidal
-“volume pump”
-geometrically suited for low resistance/low pressure

Question 18

What are the characteristics of the left ventricle?

Answer 18

-cylindrical
-“pressure pump”
-generates high pressures

Question 19

What is the vasculature?

Answer 19

branching system of vessels that conveys blood and provides a site for metabolite exchange

Question 20

What is the role of veins/venules?

Answer 20

convey blood to the heart

Question 21

What is the role of arteries/arterioles?

Answer 21

convey blood away from heart

Question 22

What is the role of capillaries?

Answer 22

metabolite exchange

Question 23

What is the main role of arteries?

Answer 23

conduits

Question 24

What is the main role of arterioles?

Answer 24

resistance vessels that determine distribution of cardiac output

Question 25

What is the main role of venules?

Answer 25

convey blood from capillaries to veins

Question 26

What are the roles of veins?

Answer 26

-conduits -reservoirs

Question 27

What type of artery is the aorta?

Answer 27

elastic

Question 28

What type of artery are most arteries?

Answer 28

muscular

Question 29

What does the arteriole wall consist of?

Answer 29

smooth muscle

Question 30

What are capillaries?

Answer 30

single layer of endothelial cells

Question 31

What substances are in the walls of veins?

Answer 31

-smooth muscle -small amounts of elastin and collagen

Question 32

How is blood flow to the tissues controlled?

Answer 32

through changes in local resistance

Question 33

How does venous return impact cardiac output?

Answer 33

increased venous return = increased cardiac output

Question 34

Why is arterial pressure regulation independent of local blood flow and cardiac output?

Answer 34

because maintaining normal blood pressure is the "priority" of the CV system

Question 35

How does vasoconstriction function?

Answer 35

-increases resistance -decreases flow

Question 36

How does vasodilation function?

Answer 36

-decreases resistance -increases flow

Question 37

What are the characteristics of pressure?

Answer 37

-force/area -measured in mmHg

Question 38

What are the characteristics of systemic circulation oxygen levels and pressure?

Answer 38

-high O2 -high pressure

Question 39

What are the characteristics of pulmonary circulation oxygen levels and pressure?

Answer 39

-low O2 -low pressure

Question 40

Where is the greatest proportion of blood volume contained?

Answer 40

systemic veins

Question 41

What should venous pressure normally be?

Answer 41

near 0 mmHg

Question 42

What is resistance?

Answer 42

measure of opposition to electrical current/flow

Question 43

How does change in pressure relate to cardiac output and resistance??

Answer 43

/\P = CO x R

Question 44

What two factors are the determinants of resistance?

Answer 44

-radius (most important) -viscosity

Question 45

What is resistance, in terms of forces?

Answer 45

the sum of forces that must be overcome for a pressure difference to establish flow

Question 46

Why is systemic arterial pressure greater than pulmonary arterial pressure?

Answer 46

because systemic vascular resistance is greater than pulmonary vascular resistance

Question 47

What does venous return result from?

Answer 47

-energy imparted by ventricular ejection -muscular pump -ventricular suction

Question 48

What is laminar flow?

Answer 48

smooth flow (river)

Question 49

What is turbulent flow?

Answer 49

-high velocity flow (fast stream)

Question 50

How do velocity and viscosity relate?

Answer 50

-high velocity, low viscosity -high viscosity, low velocity