control of blood flow test 2

Question 1

explain the vasodilator theory of acute control

Answer 1

increase metabolism leads to decreased oxygen availability which leads to the formation of vasodilators

Question 2

explain the oxygen (nutrient) lack theory of acute control

Answer 2

decreased oxygen concentration leads to blood vessel relaxation which leads to vasodilation

Question 3

what leads to the long-term control of local blood flow

Answer 3

increase in sizes/numbers of vessels

Question 4

define vasomotion

Answer 4

cyclical opening and closing of pre capillary sphincters

Question 5

what is the active reaction to hyperemia

Answer 5

when tissue becomes active, rate of blood flow increases

Question 6

what does rapid increase in arterial pressure do to blood flow

Answer 6

increases blood flow

Question 7

explain the metabolic theory of blood flow autoregulation

Answer 7

increase in blood flow leads to too much oxygen or nutrients which washes out vasodilators

Question 8

explain the myogenic theory of blood flow autoregulation

Answer 8

stretching of vessels lead to reactive vasculature constriction

Question 9

what neurotransmitters are involved in vasoconstriction

Answer 9

norepinephrine, epinephrine, angiotensin II, vasopressin

Question 10

what is the major function of vasopressin/ADH

Answer 10

to control body fluid volume

Question 11

what is the function of angiotensin II

Answer 11

normally acts to increase total peripheral resistance

Question 12

what neurotransmitters are involved in vasodilation

Answer 12

bradykinins and histamines

Question 13

what does bradykinins do

Answer 13

causes both vasodilation and increased capillary permeability

Question 14

what is histamine derived from

Answer 14

mast cells and basophils

Question 15

what vessels does the sympathetic system not innervate

Answer 15

capillaries

Question 16

what is the primary result of sympathetic regulation in blood flow

Answer 16

vasoconstriction

Question 17

what is the vasoconstrictor area of the brain

Answer 17

anterolateral portions of upper medulla

Question 18

what is the definition of vasomotor tone

Answer 18

partial state of contraction of blood vessels in the vasoconstrictor area of the brain

Question 19

what is the vasodilator area of the brain

Answer 19

bilateral in the anterolateral portions of lower medulla

Question 20

what is the sensory area of the vasomotor center

Answer 20

bilateral in tractus solitarius in posterolateral portion of medulla

Question 21

what does the sensory area of the vasomotor center in the brian receive signals from

Answer 21

vagus and glossopharyngeal nerves

Question 22

what are the higher nervous centers of the vasomotor center in the brain

Answer 22

reticular substance (RAS)
hypothalamus
cerebral cortex

Question 23

what does the adrenal medulla secrete

Answer 23

epinephrine and norepinephrine

Question 24

where are baroreceptors located

Answer 24

carotid sinuses and aortic sinus

Question 25

what pressure are carotid sinuses stimulated at

Answer 25

greater than 60 mm Hg

Question 26

what pressure are aortic sinuses stimulated at

Answer 26

greater than 30 mm Hg

Question 27

what signals come from baroreceptors

Answer 27

inhibit vasoconstrictor center excite vasodilator center signals cause either increase or decrease in arterial pressure primary function is to reduce the minute-by-minute variation in arterial pressure

Question 28

where are chemoreceptors located

Answer 28

in carotid bodies in bifurcation of the common carotids and in aortic bodies

Question 29

what are chemosensitive cells sensitive to

Answer 29

lack of oxygen, carbon dioxide excess, and hydrogen ion excess

Question 30

what doe the signals from chemoreceptors pass through

Answer 30

Herring's nerves and vagus nerves

Question 31

what do chemoreceptors play an important role in

Answer 31

respiratory control

Question 32

what does an increase in atrial stretch result in

Answer 32

``` reflex dilation of kidney afferent arterioles increase in heart rate signals to hypothalamus ANP decrease sodium reabsorption ```

Question 33

define arterial pressure

Answer 33

cardiac output X total peripheral resistance

Question 34

what are common characteristics of primary hypertension

Answer 34

increased cardiac output, sympathetic nerve activity, angiotensin II and aldosterone levels impairment of renal-pressure natriuresis mechanism inadequate secretion of salt and water

Question 35

what are major factors of primary hypertension

Answer 35

weight gain and sedentary life style

Question 36

what are renal causes of hypertension

Answer 36

``` chronic renal disease renal artery stenosis renin-producing tumors acute glomerulonephritis polycystic disease renal vasculitis ```

Question 37

what are the endocrine causes of hypertension

Answer 37

``` cushing syndrome exogenous hormones pheochromocytoma acromegaly hypothyroidism hyperthyroidism pregnancy induced ```

Question 38

what are the cardiovascular causes of hypertension

Answer 38

``` coarctation of the aorta polyarteritis nodosa increased intravascular volume rigidity of the aorta increased cardiac output ```

Question 39

what are the neurologic causes of hypertension

Answer 39

psychogenic increased intracranial pressure sleep apnea acute stress

Question 40

what factors result in decreased peripheral resistance (vessel dilation) leading to decreased blood pressure

Answer 40

increased production of nitric oxide increased release of prostacyclin and kinins increase in ANP decreased neural factors

Question 41

what factors result in decreased cardiac output leading to decreased blood pressure

Answer 41

decreased blood volume, heart rate, contractility

Question 42

what factors result in increased cardiac output leading to increased blood pressure

Answer 42

increased heart rate, contraction, and blood volume (aldosterone)

Question 43

what factors result in increased peripheral resistance leading to increased blood pressure

Answer 43

increased angiotensin II, catecholamines, thromboxane, neural factors

Question 44

what are the humoral vasoconstrictors

Answer 44

angiotensin II, catecholamines, endothelin

Question 45

what are humoral vasodilators

Answer 45

kinins, prostaglandins, nitric oxide

Question 46

what are the lethal effects of chronic hypertension

Answer 46

early heart failure and coronary artery disease cerebral infarct kidney failure

Question 47

what is the major characteristic of artherosclerosis

Answer 47

presence of lesions within the intima of the vessel wall that protrude into the vessel lumen

Question 48

what is C-reactive protein

Answer 48

CRP: major marker for inflammation (synthesized by liver, plays important role in opsonizing bacteria and activating complement)

Question 49

what are characteristics of metabolic syndrome

Answer 49

obesity, insulin resistance, fasting hyperglycemia, increased lipid triglycerides, decreased HDL levels, hypertension

Question 50

where do lipoproteins accumulate

Answer 50

intima

Question 51

how are lipoproteins oxidized

Answer 51

by oxygen free radicals generated by macrophages or endothelial cells

Question 52

what ingests oxidized LDL

Answer 52

macrophages which become foam cells

Question 53

what does oxidized LDL stimulate the release of

Answer 53

growth factors, cytokines, and chemokines

Question 54

what is oxidized LDL toxic to

Answer 54

endothelial cells and smooth muscle cells

Question 55

what controls the short term control of arterial pressure

Answer 55

via sympathetic nervous system effects on total peripheral vascular resistance and capacitance; cardiac pumping ability)

Question 56

what controls the long term control of arterial pressure

Answer 56

via multiple nervous and hormonal controls | via local controls in kidney that regulate: salt and water excretion

Question 57

what are the primary determinants of the long-term arterial pressure level

Answer 57

degree of pressure shift of the renal output curve for water/salt level of water/salt intake

Question 58

define chronic hypertension

Answer 58

one;s mean arterial pressure is greater than the upper range of the accepted normal measure

Question 59

what are the lethal effects of chronic hypertension

Answer 59

``` early heart failure coronary heart disease heart attack cerebral infarct destruction of areas of kidneys, leading to kidney failure, leading to uremia and eventually death ```

Question 60

when does one kidney goldblatt hypertension occur

Answer 60

when one kidney is removed and remaining renal artery is constricted