Blood Vessels and Blood Pressure

Question 1

What are blood vessels?

Answer 1

conduits to move blood to peripheral tissue to bring nutrients and remove waste

Question 2

what is the general path of a portal system in the circulatory system? What are two portal systems found in the body?

Answer 2

blood flows from arteriole to the capillary bed, to the venule then to a second capillary bed then back to the venous system
hepatic, hypophyseal

Question 3

What are 3 components of microcirculation?

Answer 3

arterioles
capillaries
venules

Question 4

What is the equation for blood flow rate?

Answer 4

F = deltaP/R
F = flow
deltaP = pressure gradient
R = resistance

Question 5

why is a pressure gradient important in flow rate? how is the cardiac pump involved?

Answer 5

it is the main driving force for flow

cardiac pump = energy source

Question 6

Is mean arterial pressure (MAP) usually higher or lower than the pressure in arterioles right before it reaches capillaries? Why?

Answer 6

higher

absolute pressure downstream from the point of high resistance usually decreases

Question 7

what is flow?

Answer 7

measure of volume per unit of time

Question 8

what is velocity?

Answer 8

measure of linear distance per unit of time

Question 9

what slows blood flow rate?

Answer 9

friction - greater surface area in contact with blood will have greater resistance

Question 10

what is the fourth power of vessel radius rule?

Answer 10

increase the radius 2x leads to a 16-fold increase in flow rate and a 16-fold decrease in resistance

Question 11

what is poiseuille’s law?

Answer 11

describes the factors that affect flow rate
flow rate = (pi)(deltaP)(r^2)/8nL
n = viscosity
L = vessel length
r = vessel radius (important)

Question 12

how does atherosclerosis affect vessel radius and flow rate?

Answer 12

decrease radius due to plaque, leading to decreased flow rate

Question 13

how does hypertension affect vessel radius and flow rate?

Answer 13

decrease radius do to impaired vascular function, leading to decreased flow rate

Question 14

what is systolic pressure?

Answer 14

arterial pressure during contraction (120mmHg)

Question 15

what is diastolic pressure?

Answer 15

arterial pressure during relaxation (80mmHg)

Question 16

what is a blood pressure reading?

Answer 16

systolic/diastolic

120/80 (pressure difference = 40mmHg)

Question 17

what is pulse pressure?

Answer 17

what you can feel on the skin due to shallow arteries

Question 18

what is mean arterial pressure?

Answer 18

average pressure driving the blood forward into tissues

Question 19

how do you calculate MAP? what is the typical MAP when BP is 120/80

Answer 19

MAP = ((S-D)/3) + D or pp/3 + D
pp = pulse pressure
MAP = 93mmHg

Question 20

What are components of sphygmomanometry?

Answer 20

arm cuff
stethoscope
pressure-recording device

Question 21

what occurs when cuff pressure is greater than 120mmHg?

Answer 21

no blood flow

no sound heard

Question 22

what occurs when cuff pressure is between 120mmHg and 80mmHg?

Answer 22

blood flow is turbulent whenever pressure exceeds cuff pressure
intermittent sounds heard as BP fluctuates throughout cardiac cycle

Question 23

what occurs when cuff pressure is below 80mmHg?

Answer 23

smooth blood flow

no sound heard

Question 24

what are korotkoff sounds?

Answer 24

sounds heard in stethoscope from blood flowing

Question 25

what is considered high normal blood pressure?

Answer 25

sys: 130-139
dia: 85-90

Question 26

what is considered hypertension?

Answer 26

sys > 140

dia > 90

Question 27

what is considered stage 1 hypertension?

Answer 27

sys: 140-159
dia: 90-99

Question 28

what is considered stage 2 hypertension?

Answer 28

sys > 160

dia > 100

Question 29

what is considered hypertension in diabetic/kidney disease patients?

Answer 29

sys >130

dia >80

Question 30

what are 3 drugs that are often prescribed for hypertension?

Answer 30

lisinopril
amlodipine besylate
hydrochlorothiazide