Flashcards in Hemodynamics Ballam Deck (72)

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1

## the rate at which blood is pumped from the ventricles is called the

### cardiac output

2

## cardiac output =

### SV X HR

3

## CO%: Cerebral

### 15%

4

## CO%: Coronary

### 5%

5

## CO%: Renal

### 25%

6

## CO%: Gastrointestinal

### 25%

7

## CO%: Skeletal muscle

### 25%

8

## CO%: skin

### 5%

9

## Three main mechanisms of distributing blood to the major organ systems: 1

### CO is constant, but blood flow is redistributed among the organ systems by the selective alteration of arteriolar resistance

10

## Three main mechanisms of distributing blood to the major organ systems: 2

### CO increases or decreases, but %'s remain the same

11

## Three main mechanisms of distributing blood to the major organ systems: 3

### CO is altered AND %s are altered

12

## Stressed Volume

### the volume of blood in the arteries (under high pressure)

13

## where is the site of highest resistance to blood flow

### arterioles

14

## arterioles have what kinds of receptors that do what

###
alpha 1 adrenergic receptors that cause vasoconstriction. vasoconstriction increases resistance

beta adrenergic receptors

15

## at any given moment the greatest amount of blood is contained in the

### veins

16

## unstressed volume

### % of blood in the veins (!00%)

17

## veins have ____ receptors

### adrenergic receptors, causing contraction and reducing their capacitance, therefore, reducing unstressed volume

18

## velocity of blood flow =

###
v = Q/ A

Q = flow ml/s

A = cross sectional area (cm squared)

A = pi(r^squared), r= radius

19

## the units of velocity are

### cm/s

20

## as vessel diameter increases, velocity

### decreases, because radius in the calculation for Area is squared, so it continually gets bigger

21

## the relationship between pressure, resistance, and flow: formula

###
Flow (Q) / Delta Pressure/ R

Q = P/R

22

## the magnitude of blood flow is directly proportional to

###
size of pressure difference

Q = P/R

23

## Blood flow is _____ proportional to resistance

###
inversely proportional

Q = P/R

24

## TPR

###
total peripheral resistance

can be measured by substitution Q (flow) with CO, and the pressure difference between vena cava and aorta

25

## SVR

### systemic vascular resistance (SVR) = TPR

26

## Poiseuille equation tells us what

###
the relationship between resistance, blood vessel diameter and blood viscosity

the Poiseuille equation allows us to determine the resistance of the a blood vessel to blood flow.

27

## Poiseuille equation: formula

### R = (8 * viscosity of blood * length of blood vessel)/ (radius of blood vessel raised to fourth power * pi)

28

## What big picture relationshops of the Poiseuille equation can we talk about without seeing numbers?

###
direct and indirect relations, and that with each increase in the radius of the blood vessel, the numerator is reduced by fourth power of the radius

when radius increases, resistance decreases

29

## Total resistance of the system arranged in series is

###
equal to the sum of the individual resistances

R+R+R

30