Circulation

Question 1

What are the 3 functions of Circulation?

Answer 1

1. Transportation of nutrients to tissues
2. Transporting waste products away from tissues
3. Transporting hormones from one part of the body to another

Question 2

Blood flow rate is controlled by

Answer 2

needs of the tissues

Question 3

The kidneys need ____ blood flow than the ____

Answer 3

more; brain

Question 4

All diffusion occurs here; most essential for determining what is needed

Answer 4

Capillaries

Question 5

Arteries transport blood under ____ pressure to the tissues

Answer 5

high

Question 6

_____ act as control conduits through which blood is released into the capillaries

Answer 6

arterioles

Question 7

_____ exchange fluid, nutrients, electrolytes, hormones and other substances b/w the blood and interstitial fluid

Answer 7

capillaries

Question 8

_____ collect blood from the capillaries and gradually coalesce into progressively larger veins

Answer 8

venules

Question 9

What functions as conduits for transport of blood from venules back to the heart and is where 64% of blood is stored?

Answer 9

veins

Question 10

Velocity is equal to

Answer 10

Flow / Area

Question 11

The ___ volume of blood (F) much pass through each segment of the circulation each ___.

Answer 11

same; minute

Question 12

Velocity (v) of blood flow is ______ proportional to the vascular cross-sectional area (A)

Answer 12

inversely

Question 13

All blood vessels are

Answer 13

distensible

Question 14

____ allows for the pulsatile output of the heart; smooth continuous blood flow through very small blood vessels of tissues

Answer 14

distensibility

Question 15

Which vessel has the highest distensibilty?

Answer 15

Veins, because they hold 64% of blood

Question 16

Mean Arterial Pressure (MAP)

Answer 16

(1/3 [SBP-DBP] + DBP)

Question 17

Pulse Pressure

Answer 17

SBP-DBP

Question 18

This type of pressure system extends from the left ventricle in contracted state all the way to systemic arterioles (CONTRACTED)

Answer 18

high pressure system

Question 19

This type of pressure system extends from the systemic capillaries thru rest of systemic circuit, into right heart, then thru pulmonary circuit, into left heart, in relaxed state (RELAXED)

Answer 19

low pressure system

Question 20

Blood flow to most tissues is controlled according to what?

Answer 20

the tissue need

Question 21

What is the sum of all local tissue flows?

[Hint: it’s amount of blood pumped into the aorta each minute (STROKE VOLUME x HR)]

Answer 21

cardiac output

Question 22

Arterial Pressure Regulation is generally independent of what 2 things?

Answer 22

local blood flow control OR cardiac output

Question 23

Ohm’s Law states that F is equal to

Answer 23

Change in pressure / vascular resistance

Question 24

As the blood increases in thickness (viscosity), disruption or turbulence

Answer 24

decreases

Question 25

Systemic Vascular Resistance (SVR) is equal to

Answer 25

MAP / CO

Question 26

The flow will dramatically increase if the _____ increases, since it is to the fourth power in the Blood Pressure Blood Flow equation

Answer 26

radius

Question 27

Blood Pressure Blood Flow

Answer 27

Flow =Л r4 ΔP/8nℓ

Question 28

Laminar Flow

Answer 28

Steady state flow through a long, smooth blood vessel; streamline flow (each layer of blood remains same distance from vessel wall); central most portion of blood stays in center of vessel

Question 29

Turbulent Flow

Answer 29

Blood flowing in all directions in the vessel and continually mixing within vessel

Question 30

According to parabolic velocity, flow on the outside moves _____ than flow on the inside

Answer 30

slower

Question 31

Turbulent or disorderly flow can be created by (4)

Answer 31

1. Rate of blood flow becoming too great 2. Passing by an obstruction in vessel (plaque) 3. Making a sharp turn 4. Passing over roughened surface

Question 32

Turbulent flow creates eddy currents, where the blood flows with much greater resistance due to added

Answer 32

friction

Question 33

Reynold's number

Answer 33

is the tendency for turbulence to occur Re = (v x d x p)/n

Question 34

Reynold's number is ______ proportional to the velocity of blood flow, the diameter of the vessel and the density of the blood

Answer 34

directly

Question 35

Reynold's number is _____ proportional to the viscosity of the blood

Answer 35

inversely

Question 36

Poiseuille's Law states that the VOLUME of a liquid flowing through a vessel is _____ proportional to the pressure of the liquid, _____ proportional to the 4th power of the radius of the vessel, and ______ proportional to the viscosity of the liquid and length of vessel.

Answer 36

directly; directly; inversely

Question 37

About ____ of the total SVR to blood flow is arteriole resistance in the small arterioles

Answer 37

2/3

Question 38

SVR is MAP/CO however, it cannot

Answer 38

be measured

Question 39

SVR is the _____ to blood flow in a vessel

Answer 39

impediment

Question 40

Conductance is the reciprocal of ______

Answer 40

resistance

Question 41

Conductance is the measure of the blood flow through a vessel for a given ______ difference

Answer 41

pressure

Question 42

Hematocrit

Answer 42

proportion of blood that is red blood cells (rbc)

Question 43

Who has more hematocrit?

Answer 43

Men (42%) vs. Women (38%)

Question 44

What are 3 examples of hematocrit alterations?

Answer 44

1. Anemia (lowered n = increased C) 2. Activity Levels (elite athletes) - (increased O2 demand) 3. Altitude (significant increase in hematocrit during 1st 72 hours of change in elevation)

Question 45

If you _____ hematocrit, you will markedly ____ blood viscosity.

Answer 45

increase; increase

Question 46

Hematocrit equation (pouiseuille)

Answer 46

F = n x change in P x r^4 / 8 x n x l

Question 47

Blood Flow Autoregulation say that: - if n increases, the c will ____ - during sympathetic inhibition, there is 2x flow and vaso_____ - During sympathetic stimulation, the blood flow is tightened up and vaso_____ - A decrease in pressure = ____ in resistance

Answer 47

- if n increases, then c will decrease - during sympathetic inhibition, 2x flow and vasodilation - during sympathetic stimulation, tightened up and vasoconstriction - decrease in pressure = decrease in resistance

Question 48

Take homes of Circulation (4) 1. The majority of blood is distributed among ____ circulation with majority within _____ system 2. Rate of blood flow in controlled by __________ 3. ____ of the vessel is the most important factor in determining the flow of blood 4. About 2/3 of the total SVR to blood flow is arteriole resistance in the _______

Answer 48

1. systemic; venous 2. needs of the tissues 3. Radius 4. small arterioles