CV intro

Question 1

what are the main “resistance vessels”?

Answer 1

arterioles- they determine BP, regulate what reaches capillaries/blood distribution

Question 2

where is most of the blood volume in the body located?

Answer 2

in veins

Question 3

equation for Q

Answer 3

Q = dP/R

Q=CO

Question 4

what is dP?

Answer 4

Parterial - Pvenous

Question 5

what is necessary for blood to flow in the proper direction in the body?

Answer 5

Pa > Pv

Question 6

why are the aorta and pulmonary artery “elastic arteries”?

Answer 6

these vessels have elastic fibers that allow for recoil during diastole, this serves to maintain pressure inside of the vessel even though the heart is at rest

Question 7

what is vascular compliance?

Answer 7

property of distensible tissue

dVolume / dPressure

Question 8

what is true of vessels with high compliance?

Answer 8

vessels with high compliance are able to accommodate more changes in volume while resisting changes in pressure

Question 9

equation for compliance in the aorta

Answer 9

compliance = SV x pulse pressure

Question 10

equation for pulse pressure

Answer 10

PP = SBP - DBP

Question 11

what is the consequence of low pulse pressure?

Answer 11

low pulse pressure indicates that there is only a small difference between SBP and DBP, this means that there will be low aortic compliance (aorta is rigid)

Question 12

what is low aortic compliance a rf for?

Answer 12

CV disease

Question 13

which vessels are typically more compliant?

Answer 13

veins > arteries

Question 14

equation for MAP

Answer 14

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

Question 15

when is BP the highest?

Answer 15

highest right as it leaves the heart and is maintained until it reaches the arterioles when is falls drastically

Question 16

what are the typical Bps for the systemic vs pulmonary systems?

Answer 16

systemic 120/80

pulmonary 30/10

Question 17

what 2 values can be used to determine the pressure drop over the entire systemic circulation?

Answer 17

MAP
RAP (right atrial pressure)
change in pressure = MAP - RAP

Question 18

equation for SVR

Answer 18

SVR = (MAP-RAP)/CO

Question 19

what is the “arrangement” of blood vessels? consequence of this?

Answer 19

bv are arranged in parallel, this means that a change in resistance for an organ system will change flow to that organ system as well as others

Question 20

resistance equation

Answer 20

R = 8nl/pi x r^4

Question 21

resistance variables

Answer 21

viscosity- increase viscosity, increase R
length- increase length, increase R
radius^4- increase radius, decrease R

Question 22

which resistance variable has the biggest effect?

Answer 22

radius

Question 23

what are some situations that will increase blood viscosity?

Answer 23

increased hct, increased proteins in blood, sphereocytosis

Question 24

what is Pouiselle’s law?

Answer 24

Q = dP x pi x r^4 / 8nl

increased r, increase pressure, increase flow

Question 25

what is the limitation of Pouiselle’s law in biologic systems?

Answer 25

law applies to a rigid tube- properties of distensibility and compliance result in a non-linear relationship in blood vessels

Question 26

velocity equation

Answer 26

v = Q/A

smaller tube = increased velocity

Question 27

what is a consequence of increased velocity?

Answer 27

turbulence and turbulent flow will increase resistance

Question 28

what is used to predict turbulence?

Answer 28

reynold’s number (Re)= vdp/n

Question 29

signs of turbulence on PE

Answer 29

murmurs and bruits