Unit 1 Lecture 7

Question 1

Define hemodynamics

Answer 1

The study of fluid flow in the circulatory system

Question 2

What way do fluids ALWAYS flow in the circulatory system?

Answer 2

High pressure -> low pressure

Question 3

What causes resistance to fluid flow?

Answer 3

Friction between molecules in fluid and the walls of the tube

Question 4

What is the relationship between flow and resistance?

Answer 4

frictional resistance REDUCES flow

Question 5

List the increasing order of system’s total cross sectional area

Answer 5

Aorta - 3 cm^2

Vena Cavae - 14 cm^2

Capillaries - 5000 cm^2

Question 6

What does cross sectional area mean?

Answer 6

Probably the area that the system covers in the body????

Question 7

What system has the strongest flow velocity?

Answer 7

aorta @ 40 cm/sec

Question 8

What system has the weakest flow velocity?

Answer 8

capillaries

Question 9

What is the capillary flow velocity?

Answer 9

0.1 cm/sec

Question 10

What is unique about capillaries cross sectional area and flow velocity?

Answer 10

They have a very high cross sectional area and very low flow velocity

Question 11

True or false:

Blood pressure is not equal throughout the cardiovascular system

Answer 11

True, blood requires a pressure difference in order to flow

Question 12

Define driving pressure

Answer 12

blood’s pressure difference that allows it to flow

Question 13

What does blood pressure due in relation to the heart beat?

Answer 13

It flows with the heatbeat

Question 14

What word describes how blood pressure is in phase with the heartbeat

Answer 14

pulsatile

Question 15

When is blood pressure the highest?

Answer 15

during systole

Question 16

define systole

Answer 16

heart contraction

Question 17

When is blood pressure the lowest?

Answer 17

during diastole

Question 18

define diastole

Answer 18

heart relaxation

Question 19

Where is there the highest pressure in the body?

Answer 19

Aorta -> arteriest -> arterioles -> capillaries -> venules -> veins -> vena cava

Question 20

What is the mean arterial blood pressure?

Answer 20

Blood pressure in between systolic and diastolic blood pressure

Question 21

What is the formula for mean arterial blood pressure?

Answer 21

MAP = DAP + 1/3 (SBP-DBP)

Question 22

2 factors of arterial blood pressure

Answer 22

1. elasticity (distensibility)

2. amount of blood forced into them

Question 23

Characteristic of arterial blood pressure

Answer 23

BP is pulsatile

Question 24

Define distensibilty

Answer 24

the capacity to swell as a result from the pressure inside

Question 25

What is atrial compliance?

Answer 25

the ability of arterial walls to expand and contract passively w/ changes in pressure

Question 26

Why is high atrial compliance good?

Answer 26

allows the flow to go throughout the body -> expansion and recoil of arteries after contraction

Question 27

What does the expansion and recoil of arteries generate?

Answer 27

a pulse

Question 28

What is the formula for pulse pressure?

Answer 28

PP = SBP - DBP

Question 29

What does the pulse pressure reflect?

Answer 29

stroke volume

Question 30

What is the formula for articular compliance?

Answer 30

C = dV / dP

Question 31

Does the pulmonary or systemic circuit have higher blood pressure?

Answer 31

systemic

Question 32

What is true about pulmonary circulation?

Answer 32

is it very compliant *it is easier for things to travel through pulmonary arteries vs. systemic arteries bc pul. has bigger arteries, less pressure and less resistance to slow them down

Question 33

What is the formula for vascular resistance?

Answer 33

R= (viscosity)(vessel length) / radius^4

Question 34

What are the 2 ways to calculate cardiac output?

Answer 34

CO = SV x HR CO = pressure gradient / R

Question 35

What is systemic vascular resistance (SVR)?

Answer 35

Sum of all resistance offered by the vessels of systemic circulation

Question 36

What is the formula for SVR?

Answer 36

SVR = (mean arterial pressure - mean right arterial pressure (4) ) / CO

Question 37

What does mean right arterial pressure =?

Answer 37

4 mmHg

Question 38

What is pulmonary vascular resistance (PVR)?

Answer 38

Sum of all resistance offered by the vessels of pulmonary circulation

Question 39

What is the formula for PVR?

Answer 39

PVR = (MAP - LMAP(5)) / CO

Question 40

What does mean left arterial pressure =?

Answer 40

5 mmHg

Question 41

What is the formula for mean arterial pressure?

Answer 41

MAP = DBP + 1/3 (SBP - DBP)