Mechanisms Of Disease Exam 3

Front 1

Poiseuille's Law

Back 1

Q (flow) = P x π x r^4/8nL

(P=pressure, n=viscosity, L=length)

Front 2

In Poiseuille's Law: as radius decreases, what happens to the flow?

Back 2

-flow exponentially decreases

Front 3

In Poiseuille's Law: as length increases, what happens to flow?

Back 3

-flow decreases

Front 4

In Poiseuille's Law: as viscosity increases, what happens to flow?

Back 4

-flow decreases

Front 5

What can change the viscosity of the blood?

Back 5

-Polycytemia vera (too many RBCs) with hematocrit up in 60s
-severe dehydration

Front 6

"Resistance" Vessels

Back 6

Arterioles: because most of the resistance to flow is in the arterioles

Front 7

Which vessels:
-are very elastic and muscular

Back 7

arteries

Front 8

Which vessels:
-are relatively compliant and will increase their volume if bp is increased

Back 8

-arteries

Front 9

Which vessels:
-have α1 adrenergic receptors on them

Back 9

-arterioles
-veins

Front 10

"Capacitance" Vessels

Back 10

Veins: capacitance of the veins serves a very similar purpose to electric capacitors (storage of charge)

Front 11

Which vessels:
-contain about 2/3 of all our blood at any moment

Back 11

-veins

Front 12

Which vessels:
-are very compliant but not very elastic (expand in volume with very small changes in bp but do not spring back well once expanded)

Back 12

-veins

Front 13

Phenomenon of blood pressure increase as we age is due to:

Back 13

-the natural change in composition of the blood vessel walls
-ie. less elastic and collagen leads to decreased compliance

Front 14

The changes in elastic and collagen in arteriolar walls causes what is most strictly called:

Back 14

-arteriosclerosis (different from atherosclerosis)

Front 15

The build up of gunk or "gruel in vessel walls is called:

Back 15

-atherosclerosis

Front 16

Which is worse: arteriosclerosis or atherosclerosis?

Back 16

-atherosclerosis

Front 17

Physiologic determinants of arterial blood pressure

Back 17

1. Heart Rate
2. Stroke Volume
3. Cardiac Output
4. Total Peripheral Resistance

Front 18

Physical Determinants of Arterial Blood Pressure

Back 18

1. Viscosity
2. Circulatory Fluid Volume
3. Arterial Compliance

Front 19

How to remember which is a physiologic and which is a physical determinant of arterial blood pressure.

Back 19

-physiologic ones can receive sympathetic tone which can alter them (ie. they can change with changes in neuronal activity)
-physical determinants don't really respond to anything in the short term (they are much more long term)

Front 20

____ and ____ determine the mean arterial pressure.

Back 20

-CO and TPR

Front 21

____ and ____ determine the pulse pressure.

Back 21

-SV and Arterial Compliance

Front 22

What is pulse pressure?

Back 22

-the difference between diastolic and systolic

Front 23

Mean arterial pressure (Pa) equation

Back 23

Pa = Pd + (Ps-Pd)/3
= 80 + (120-80)/3 = 99mmHg

Front 24

Flow (Q) = CO = _____

Back 24

5-6 L/min

Front 25

Pressure = _____

Back 25

120/80

Front 26

Ohm's Law

Back 26

-V=IR comparable to P=Q x TPR
-solve for resistance: R=V/I

Front 27

TPR = _____

Back 27

TPR = (Pa - Pra)/CO
= Pa/CO
= 93mmHg/83ml/sec
= 1.12 mmHg*sec*mL-1
(1 peripheral resistance unit)

Front 28

What happens to TPR during:
a)hypertension
b)vasoconstriction
c)exercise

Back 28

a) goes up
b) goes up as high as 4 PRU
c) goes down because arterioles open up due to CO2 production - CO increases which increases BP

Front 29

Pulmonary vascular resistance is much _____ than TPR.

Back 29

-lower

Front 30

Any increase in pulmonary vascular resistance will cause:

Back 30

-RV failure (Cor pulmonale)

Front 31

Carotid Sinus Reflex (CSR)

Back 31

-momentary increase in BP
-detected by stretch receptors of carotid sinus (and aortic arch)
-CSR causes decreased HR and arteriolar dilation
-causes decreased BP
-and vice versa

Front 32

Area known as the vasomotor center

Back 32

-the nucleus of the tractus solitarius of the medulla

Front 33

The carotid sinus nerve becomes ______.

Back 33

-cranial nerve 9

Front 34

What kind of receptors are in the vasomotor center?

Back 34

-alpha 2

Front 35

NL HR

Back 35

60-80

Front 36

NL SV

Back 36

83 mL/stroke

Front 37

NL CO

Back 37

5 L/min

Front 38

EDV (end diastolic volume)
a)definition
b)normal level
c)during exercise

Back 38

a)when either ventricle has received all the blood it will receive before it pumps
b)120 mL
c)200-250mL

Front 39

ESV
a)normal level
b)during exercise

Back 39

a)37 mL
b)10-20 mL

Front 40

EJ (ejection fraction)

Back 40

-ESV = SV/EDV
= 83/120
= 80%
-during exercise: 180/200 = 90%

Front 41

CI (cardiac index)

Back 41

= 3

Front 42

Preload

Back 42

EDV

Front 43

Afterload

Back 43

-aortic blood pressure
-the highest BP in the body