Haemodynamics 1

Question 1

Blood flow through the circulatory system may be either series or

Answer 1

parallel

Question 2

where does blood flow from the left ventricle to

Answer 2

the aorta

Question 3

the aorta supplies which circuit

Answer 3

systemic

Question 4

the vena cava pumps blood into which part of the heart

Answer 4

the right atrium

Question 5

blood goes from the right ventricle to which blood vessel

Answer 5

the pulmonary artery

Question 6

the pulmonary artery supplies which circuit

Answer 6

the pulmonary circuit

Question 7

the pulmonary veins supply which part of the heart

Answer 7

the left atrium

Question 8

which side of the heart supplies the systemic circuit

Answer 8

left

Question 9

which side of the heart supplies the pulmonary circuit

Answer 9

right

Question 10

blood flow within circuits is parallel, what does this mean?

Answer 10

that blood goes from the aorta, arteries, arterioles, capillaries, venules, veins, vena cava

Question 11

what is the functional significant of blood flow within the series circuit being parallel? - 2 points

Answer 11

1. ensures each capillary bed receives oxygenated blood

2. allows independent regulation of blood flow to organs

Question 12

what percentage of the cardiac output is delivered to the kidneys at rest?

Answer 12

20%

Question 13

volume of fluid that moves past a given point per unit time is dependant upon…

Answer 13

the change in pressure over resistance

Question 14

blood moves from a

Answer 14

high pressure to a low pressure

Question 15

flow is ____ proportional to resistance

Answer 15

inversely

Question 16

The greater the pressure gradient the ____ the flow

Answer 16

faster

Question 17

is the pressure gradient or the absolute pressure more important in relation to flow

Answer 17

the pressure gradient

Question 18

list four factors that affect the resistance to flow

Answer 18

length of tube, viscosity of fluid and the radius

Question 19

which of these four is the most significant in terms of resistance to flow: length of vessel, radius of vessel, viscosity of fluid, pressure gradient

Answer 19

radius of vessel

Question 20

describe vasoconstriction in terms of radius and resistance

Answer 20

decrease in radius

increase in resistance

Question 21

describe vasodilation in terms of radius and resistance

Answer 21

increase in radius

decrease in resistance

Question 22

the greater the length of a vessel the ____ the resistance

Answer 22

greater

Question 23

an increased viscosity increases the resistance. what does blood viscosity depend on

Answer 23

the amount of red blood cells and proteins

Question 24

according to poiseuille’s equation flow is directly proportional to which two factors

Answer 24

pressure gradient and radius

Question 25

according to poiseuille's equation flow is inversely proportional to which two factors

Answer 25

the length of the vessel and viscosity of fluid

Question 26

why must pressure exist throughout the circulatory system

Answer 26

to maintain blood flow

Question 27

what is the pressure in the aorta

Answer 27

90mmHg

Question 28

what is the pressure in the vena cava

Answer 28

0mmHg

Question 29

what is the pressure gradient in the pulmonary arteries

Answer 29

15mmHg

Question 30

what is the pressure gradient in the pulmonary veins

Answer 30

0mmHg

Question 31

which circuit has less resistance, the pulmonary circuit or the systemic circuit

Answer 31

the pulmonary circuit

Question 32

the pulmonary vascular resistance is ____ than the total peripheral resistance

Answer 32

less

Question 33

describe the pulmonary circuit in terms of pressure gradient and resistance

Answer 33

low pressure gradient and low resistance

Question 34

describe the systemic circuit in terms of pressure gradient and resistance

Answer 34

high pressure gradient and high resistance

Question 35

what makes up the microcirculation

Answer 35

the arterioles, capillaries and venules

Question 36

what is the innermost layer of blood vessels called

Answer 36

the tunica intima

Question 37

what is the tunica intima made of

Answer 37

endothelial lining - simple squamous epithelium

Question 38

what is the tunica media made of

Answer 38

smooth muscle encircles the vessel

Question 39

what is the outermost layer of the blood vessels made of

Answer 39

tunica adventitia

Question 40

what is the tunica adventitia made of

Answer 40

primarily connective tissue fibres and nerves+nutrient capillaries

Question 41

where is the internal elastic lamina found

Answer 41

between the tunica intima and the tunica media

Question 42

where is the external elastic lamina found

Answer 42

between the tunica media and the tunica adventitia

Question 43

all blood vessels do not have three walls, which ones lack one or more layer

Answer 43

arterioles, capillaries and venules

Question 44

describe arteries with three points

Answer 44

rapid transport pathway, large diameter, elastic recoil and thick walls

Question 45

what happens to arteries during systole

Answer 45

the arteries expand as blood enters

Question 46

what happens to the arteries during diastole

Answer 46

they recoil

Question 47

what is the point of arteries recoiling during diastole

Answer 47

maintain driving force for blood flow whilst the heart is relaxing

Question 48

what is compliance

Answer 48

how easy / hard it is to stretch something - measure of how pressure of a vessel will change with change in volume

Question 49

do arteries have a low or high compliance

Answer 49

low

Question 50

because arteries have a low compliance, a small increase in blood volume creates a ____ in pressure

Answer 50

large increase

Question 51

because veins have a high compliance meaning they are easy to stretch a _____ in blood volume is required to produce an increase in prssure

Answer 51

large increase

Question 52

describe venous and arterial compliance at low pressures

Answer 52

at low pressures venous compliance is 10-20times greater than arterial compliance

Question 53

describe venous and arterial compliance at high pressures

Answer 53

arterial and venous compliance are similar

Question 54

what is systolic pressure

Answer 54

the max pressure when the heart is contracting de to ejection of blood into the aorta

Question 55

what is diastolic pressure

Answer 55

min pressure when the heart is relaxing, not zero due to elastic recoil property of arteries

Question 56

what is the pulse pressure

Answer 56

the force that the heart generates every time it contracts

Question 57

what is the formula for pulse pressure

Answer 57

the systolic blood pressure - diastolic blood pressure

Question 58

what is the mean arterial pressure

Answer 58

the average driving pressure throughout the cardiac cycle

Question 59

what is the equation for the mean arterial pressure

Answer 59

mean arterial pressure = diastolic arterial pressure + 1/3 pulse pressure