Lecture 31-32

Question 1

Structural components of vessels

Answer 1

Elastin, collagen, smooth muscle, endothelial cells

Question 2

Greater wall thickness/lumen ratio

Answer 2

greater control over vessel diameter and blood flow (LaPlace’s Law)

Question 3

Windkessel vessels

Answer 3

contain abundant elastin very compliant; transforms discontinuous flow to continuous

Question 4

Resistance vessels

Answer 4

Arterioles and precapillary sphincters have the highest wall/lumen ratio - greatest ability to control flow

Question 5

Exchange vessels

Answer 5

capillaries single layer of endothelial cells; efficient diffusion

Question 6

Capitance vessles

Answer 6

abundant collagen; small wall/lumen ratio allows then to control volume not flow or vessel diameter

Question 7

Total cross sectional AREA is _______ proportional to velocity

Answer 7

inversely; capillaries have greatest TOTAL cross-sectionand slowest velocity

Question 8

Resistor vessels

Answer 8

terminal arterioles have the greatest wall/lumen ratio and arterial constriction results in a INCREASE in resistance

Question 9

Major site for pressure control

Answer 9

terminal arterioles

Question 10

Arterial pulse pressure

Answer 10

aortic blood pressure is pulsatile (high during systole and low during diastole)
Systolic P - Diastolic P

Question 11

Peripheral runoff

Answer 11

blood transferring from arterioles to capillaries and veins during diastole

Question 12

Systolic Pressure

Answer 12

pear aortic pressure

Question 13

Diastolic pressure

Answer 13

lowest aortic pressure just prior to ejection; determined by compliance and residual volume

Question 14

Mean Arterial Pressure

Answer 14

average Pressure of blood perfusing CAPILLARIES during the cardiac cycle

Question 15

Windkessel Effect

Answer 15

the distensibility of aorta and arteries to store energy from the cardiac contraction in the form of PE, during diastole the recoil converts PE into capillary flow

Question 16

Aortic compliance is responsible to generate

Answer 16

large diastolic pressure, if it were uncompliant diastolic pressure would be 0

Question 17

Aortic compliance stores 50% SV in walls

Answer 17

continuous flow through cycle, reduces the afterload and work of the left ventricle

Question 18

Distortion of the arterial pressure pulse

Answer 18

arterial pressure wave travels 5m/s while blood flow wave travels 1m/s, pulse changes shape as it travels down limb due to elasticity, radius, and thickness

Question 19

Korotkoffs sounds

Answer 19

measure BP due to high velocity blood flow tubulent vibrations

Question 20

Arterial BP Mean Arterial Pressure = MAP =

Answer 20

HR x SV x Total Peripheral Resistance

Question 21

If cardiac output&raquo_space;> peripheral resistance than

Answer 21

arterial pressure will be HIGH (TRANSIENT)

Question 22

If peripheral resistance&raquo_space;> cardiac output than

Answer 22

arterial pressure will be LOW (TRANSIENT)

Question 23

Peripheral resistance = cardiac output

Answer 23

DURING STEADY STATE CONDITIONS

Question 24

Increased TPR and/or decreased compliance leads to

Answer 24

increased PP

Question 25

decreased SV leads to

Answer 25

decreased PP and SP

Question 26

Determinants of systolic pressure

Answer 26

Compliance and Stroke Volume

Question 27

Determinants of diastolic Pressure

Answer 27

HR and TPR; affect the diastolic end reserve

Question 28

Venous Pressure

Answer 28

Highly compliant, low resistance, and low pressure

Question 29

Cross section of veins

Answer 29

increases but perimeter stays the same, it serves as a conduit and reservoir

Question 30

Venous return in a steady state must be equal to

Answer 30

cardiac output

Question 31

Point of 0 reference point in the body

Answer 31

base of tricuspid valve

Question 32

in supine position

Answer 32

the hydrostatic pressure is insignificant

Question 33

Hydrostatic pressure in standing position

Answer 33

varies significantly down the body, but the PERFUSION PRESSURE does not change

Question 34

Venous return

Answer 34

blood pools in interstitium of legs while standing, venous return decreases while standing and CO and MAP decreases

Question 35

Skeletal pump muscle

Answer 35

muscular contractions of lower limbs to augmenting venous return, increasing ventricular filling and SV

Question 36

Respiratory pump

Answer 36

inspiration causes negative intrathoracic pressure, causing increased venous return from periphery

Question 37

Cardiovascular model

Answer 37

cardiac output and venous return are linked; MUst be equal in steady state;

Question 38

Mean Circulatory Pressure

Answer 38

when arterial pressure = venous pressure due to Blood VOLUME and vessel compliance Blood volume mainly in veins

Question 39

Vascular function curve

Answer 39

When TPR is constant, INCREASED CARDIC OUTPUT will decrease central venous pressure because blood is taken from the venous system for arterial circulation

Question 40

HIghest Qh would cause. Hypovolemia?

Answer 40

vein collapse due to a drop of central venous pressure below ambient pressure

Question 41

Hypervolemia effects on MCP

Answer 41

increased MCP due to increases blood volume; decreased MCP

Question 42

Heart failure effects on arterial BP and venous BP

Answer 42

CO declines, decreased arterial BP and increased venous BP

Question 43

Increased motor tone on MCP

Answer 43

increases MCP; increased BP equals increased MCP

Question 44

Decreased TPR effect on MCP

Answer 44

increase Venous pressure but not effect MCP

Question 45

Increased TPR effect

Answer 45

increased arterial pressure and decreased venous pressue but no effect on MCP

Question 46

Contractility will effect cardiac output...?

Answer 46

increase cardiac output

Question 47

Afterload will effect cardiac output..?

Answer 47

decrease cardia output

Question 48

Equilibrium point of a vascular and cardiac function curve

Answer 48

represents the point at which the system operates

Question 49

Contractility will shift the equilibrium

Answer 49

increased contractility increases Cardiac Function | decreased contractility decreased cardiac function and slightly increases central venous pressure

Question 50

Blood volume will shift equilibrium point

Answer 50

increased blood volume will cause an increase in MCP and increase cardiac function

Question 51

Venomotor will shift the equilibrium point

Answer 51

increased venomotor will cause an increase in central venous pressure and cardiac output

Question 52

Peripheral resistance will shift the equilibrium

Answer 52

increased TPR, decreased central venous pressure and decreased cardiac output

Question 53

Heart failure

Answer 53

causes a decreases in cardiac output, and increased central venous pressure (increase in blood accumulation in veins)