11

Question 1

cardiac reserve

Answer 1

•cAMP-dependent protein kinase activates a number of targets (phosphorylates) that increases
contractile strength (and velocity)
•high Ca2+ release when excited (more cross bridging)
•faster Ca2+ re-uptake (needed for faster heart rate)
•troponin is phosphorylated, making it more responsive

Question 2

beta blockers

Answer 2

used to treat hypertension
(high blood pressure).

propranolol = antagonist of β adrenoreceptors

Question 3

heart cells rely on what for ATP

Answer 3

oxidative phosphorylation

Question 4

coronary arteries provide blood to heart:

Answer 4

•left coronary artery supplies most of blood to
left ventricle
•right coronary artery supplies mostly the right ventricle
and portions of the left ventricle

Question 5

cardiac muscle contraction (systole)

Answer 5

compresses arteries and reduces blood
flow
Highest when theheart is relaxed (diastole)

Question 6

Ischemic Heart Disease

Answer 6

insufficient blood flow to the heart

atherosclerosis (narrowing/hardening of arteries) - due to cholesterol

Question 7

cholesterol = essential lipid molecule

Answer 7

steroid hormone
bile salts (aids digestion
regulation of membrane fluidity

Question 8

cholesterol is transported in blood associated with

Answer 8

lipoproteins
• very low density lipoproteins
• low density lipoproteins
• high density lipoproteins

Question 9

what is the source of lipoproteins

Answer 9

liver

Question 10

high concentrations of LDL in the

blood can

Answer 10

cause cholesterol to deposit on artery walls

•LDLs must bind to cell surface receptor to enter cells (LDL receptor).

Some people have genetic deficiency
of LDL receptors, make them more
prone to atherosclerosis

Question 11

other factors influencing LDL/cholesterol

Answer 11

-high cholesterol diet
- dietary fiber interferes with cholesterol absorption in intestine
- saturated fatty acids stimulate
cholesterol synthesis and
inhibit bile salt synthesis

Question 12

role of cholesterol in atherosclerosis

Answer 12

-small irregularities on
endothelium 
-atherosclerotic plaque
-cholesterol deposit with other fats
-Ca2+ may contribute to insoluble complex

•reduced blood flow to heart
•angina (chest pains)
•can lead to local blood clot (thrombus)
 causes even more occlusion of the
 coronary artery

Question 13

myocardial infarction

Answer 13

cells deprived of oxygen will die

Question 14

collateral circulation

Answer 14

coronary blood supply
can develop alternative blood source
when occlusion develops slowly

Question 15

• decreased cardiac output (heart failure)
• fibrillation of the heart
• rupture of the heart (weakened vessel walls)

Answer 15

body compensates by increasing blood

volume (water and salt retention) = Leads to congestive heart failure

Question 16

arteries

Answer 16

Transport blood at high pressure
to the tissues, arteriolesrapid blood flow.
Have thick, strong vascular walls
Serve as pressure reservoirs

Question 17

arterioles

Answer 17

control blood flow into capillaries

capable of narrowing/widening to direct blood where needed

Question 18

capillaries

Answer 18

site of exchange of fluid, nutrients,

salts, hormones, O2

Question 19

venules

Answer 19

collect blood from capillaries

Question 20

veins

Answer 20

take blood back to heart
reservoirs of blood
low pressure - thin walls 
contract = force more blood back into circulation
contain greatest amount of blood

Question 21

entire vascular system is lined by

Answer 21

endothelial cells - contact the blood

Question 22

arteries

Answer 22

1/3 of blood in arteries is injected into the arterioles with each ventricular contraction

rest of the blood is held in the elastic artery as it swells (distends)

ventricular relaxation the artery walls recoil and propel the rest of the blood into the arterioles = keeps arterioles continuously pressurized

Question 23

the heart is relaxed (diastolic) more than

it is contracting (systolic)

Answer 23

Mean Arterial Pressure = diastolic pressure + 1/3 (systolic-diastolic)

Question 24

pulse pressure

Answer 24

systolic - diastolic pressure

Question 25

pressure throughout the circulatory system

Answer 25

falls as you move away from the heart, and differences in pressure due to cardiac systole and diastole get muffled

Question 26

major pressure drop

Answer 26

arterioles = smaller than arteries + lots of sm + readily adjust diameter

Question 27

arterioles regulate blood flow to tissues

Answer 27

by changing diameter

Question 28

Arterioles serve two functions

Answer 28

•determine blood flow to each tissue/organ to match its need - at any blood pressure major source of resistance in the circulatory system = important for determining the overall arterial pressure

Question 29

pressure reservoir

Answer 29

arteries

Question 30

Flow =

Answer 30

change in Pressure / Resistance arterioles receive blood at same pressure/diameter of arteriole determines blood flow to organs

Question 31

resistance depends on

Answer 31

r = the radius of the vessel L = length of the vessel η= viscosity of blood

Question 32

decreased radius/increased radius

Answer 32

decreased radius (vasoconstriction) increased resistance and decreases flow increased radius (vasodilatation) decreases resistance and increases flow

Question 33

extrinsic/intrinsic control

Answer 33

extrinsic - hormones/nerves (regulate bp) intrinsic - locally within tissues

Question 34

active hyperaemia

Answer 34

increase in organ blood flow as a result of increased metabolism

Question 35

vasodilators increased in ECF as a result of metabolism

Answer 35

``` CO2 H+ adenosine K+ eicosanoids osmolarity bradykinin NO ```

Question 36

other factors besides increased metabolism can cause these same local vasodilators to increase in the ECF:

Answer 36

lower blood pressure (less blood delivered, so things like CO2 build up) = causes vasodilation - termed flow autoregulation • local occlusion of blood flow - results in reactive hyperemia

Question 37

active hyperemia

Answer 37

- increase metabolic activity of organ - decrease o2, increase metabolites in ECF - arteriolar dilation in organ - increase blood flow

Question 38

flow autoregultion

Answer 38

- decrease pressure in organ - decrease blood flow to organ - - decrease o2, increase metabolites, decrease vessel-wall stretch in organ - arteriolar dilation in organ - restoration of blood flow to normal again

Question 39

Sympathetic Control

Answer 39

extrinsic regulator most arteriolar smooth muscle have α adrenergic receptors NE released = vasoconstriction (not involved in local flow in response to metabolic changes) -maintenance of arterial BP -reduce blood flow to particular organs in response to stress

Question 40

skeletal muscle has high concentrations of β2 adrenergic receptor

Answer 40

= vasodilatation in muscles, but | vasoconstriction elsewhere in body

Question 41

MAP

Answer 41

= cardiac output X total peripheral resistance

Question 42

Capillaries

Answer 42

capillary walls have single layer of endothelial cells (no smooth muscle, connective tissue) The thin wall and decreased velocity of blood in capillaries favors exchange Since the same amount of blood flows through the arteries and capillaries over time, the velocity of blood flow in the capillaries decreases