Arteries

Question 1

High compliance of aorta allows the ______ during systole

Answer 1

Stretch

Question 2

What helps propels blood forward during diastole

Answer 2

Elastic recoil

Question 3

What allows the aorta and large arteries absorb energy during systole and redeliver a portion of it back to the column of blood

Answer 3

Elastic fibers

Question 4

What has happened when the systolic pressure rises and capillary flow becomes pulsatile?

Answer 4

Loss of arterial compliance

Question 5

Atheroscletosis results in the loss of

Answer 5

Compliance of the arteries

Question 6

Conducted along vessels at a higher velocity than blood flow

Answer 6

Pulse waves

Question 7

Velocity of conduction increases with _________ stiffness of vessel wall

Answer 7

Increasing

Question 8

Amplitude of pulse wave is _________ with stiffer walls

Answer 8

Greater

Question 9

Constriction of small muscular arteries and arterioles to increase TPR and therefore

Answer 9

Blood pressure

Question 10

Changes in capacitance of veins (constriction) to _____ venous return (preload) to _______ strength of contraction

Answer 10

Increase venous return to increase strength of contraction

Question 11

Aortic and carotid sinuses:

1. _____ nerve endings
2. Depolarize in response to
3. Modulation of
4. Afferent from carotid sinus
5. Afferent from aortic sinus
6. Synapse to and innervate

Answer 11

1. Bare nerve endings
2. Depolarize in response to distortion caused by stretch
3. Frequency modulated
4. Afferent from carotid sinus travel to medulla via CN IX
5. Afferent from aortic sinus travel to medullary via CN X
6. Synapse with autonomic nerves that innervate the heart and vessels

Question 12

Baroreceptor signaling between 75 and 125 mmHg what do we see in AP signaling?

Answer 12

AP occur in early systole and then decrease as the receptors adapt

Question 13

< 75mmHg action potential activity

Answer 13

Drops to low values

Question 14

> 150 mmHg action potentials are

Answer 14

Continuous

Question 15

Largest pressure drop is associated with the

Answer 15

Arterioles

Question 16

Who is primarily responsible for regulating TPR by constriction/relaxation

Answer 16

Arterioles

Question 17

Arterioles 3 functions

Answer 17

1. Reduce the blood pressure to about 30 mmHg at entrance to capillaries (they are very muscular )
2. Dampens pressure pulses (constant flow)
3. Involved in distribution of blood flow between and within tissues

Question 18

Allows local control of blood flow w/out involvement of the ANS

Answer 18

Autoregulation

Question 19

Artificial increase of MAP produces an

Answer 19

Increase in initial blood flow that quickly returns to normal

Question 20

True or false:

Tissue blood flow remains constant in spite of changes in arterial pressure

Answer 20

True

Question 21

Myogenic mechanism of autoregulation

Answer 21

Response to increase in arterial pressure is due to the sensing of the stretch of vascular smooth muscles which leads to calcium released and vasoconstriction

Question 22

Metabolic mechanism of autoregulation

Answer 22

Vasodilator will cause increase blood flow and vasoconstrictors will cause decrease in blood flow

Question 23

Distribution of blood flow between tissues aided by (3)

What does characteristics allow?

Answer 23

1. Muscular walls of arterioles
2. Met arterioles
3. Precapillary sphincters

• allows for time sharing of blood between capillary beds

Question 24

Precapillary sphincters can direct blood flow by

Answer 24

Constriction/relaxation

Question 25

Blood flows down the path of ______ resistance

Answer 25

Least

Question 26

Capillaries are adapted for

Answer 26

Exchange of fluid and nutrient of solutes with tissues

Question 27

Pores or fenestrations in capillaries membranes allow passage of but restrict

Answer 27

Allow passage of water and small molecules but normally restrict larger molecules such as proteins

Question 28

Histamine increases or decreases permeability

Answer 28

Increases thus allowing larger molecules and even leukocytes during inflammation into the extra cellular space

Question 29

Hydrostatic pressure

Answer 29

Forces fluid out of capillary

Question 30

Colloid osmotic pressure (oncotic) of proteins within the capillary

Answer 30

Pulls fluid into the capillary

Question 31

Small excesses of fluids left in the extra cellular space are drained by

Answer 31

Lymphatic

Question 32

Small solute molecules are exchanged by

Answer 32

Solvent drag

Question 33

Edema

Answer 33

Excess accumulation of fluid in the tissues

Question 34

Dehydration

Answer 34

Decrease in extra cellular fluid volume

Question 35

Causes of edema (3)

Answer 35

1. Increased venous pressure which leads to increased capillary hydrostatic pressure 2. Decreased blood osmotic pressure—> less osmotic pressure pulling water into the capillaries 3. increased interstitial osmotic pressure—> increased interstitial protein concentration acts to pull water out of the capillaries

Question 36

Veins have a greater or lesser capacity for blood containment than arteries

Answer 36

Greater

Question 37

Veins have ____ walls:

Answer 37

Thinner walls—> flaccid, less muscular and elastic tissue

Question 38

Veins are hard to collapse and expand

Answer 38

False: collapse when empty and expand easily

Question 39

Veins have steady blood flow

Answer 39

True

Question 40

Veins are subjected to low or high blood pressure

Answer 40

Low

Question 41

What drives the venous return to the heart

Answer 41

Small pressure drop between capillaries and the vena cava

Question 42

Are veins complaint?

Answer 42

Yep— highly complaint they are able to store large volumes of blood when CO is low

Question 43

Sympathetic stimulation in veins

Answer 43

Act on alpha-1 receptors to contract helically arranged smooth muscles to force pooled blood towards the heart

Question 44

Veins have one-way valves?

Answer 44

Yep

Question 45

Veins function as variable capacitor that can either store blood or increase venous return the heart and lead to increased _______ and thus resulting in

Answer 45

Increased EDV (preload) and thus increasing CO

Question 46

In an upright individual where is the most of the body’s blood?

Answer 46

Lower extremities in veins

Question 47

Factors that increase O2 demand of the heart: (3)

Answer 47

1. Increased afterload (arterial pressure) 2. Increased stroke volume 3, increased heart rate

Question 48

The only way to increase O2 delivery is to

Answer 48

Increase coronary circulation

Question 49

Coronary artery smc are innervate by

Answer 49

Alpha-1 sympathetic nerves which constrict them

Question 50

Most important autoregulation of coronary artery?

Answer 50

Adenosine—> potent vasodilator that overcomes sympathetic stimulation

Question 51

Coronary blood flow in left ventricle occurs primarily during

Answer 51

Diastole

Question 52

Increased heart rate can decrease blood flow to the heart

Answer 52

Yep—> it decreases the diastolic interval

Question 53

Aortic regurgitation affects

Answer 53

Lowers diastolic pressure thus limits O2 delivery

Question 54

Lack of O2 delivery to a tissue is called ____ an can lead to

Answer 54

Ischemia which can lead to angina