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Flashcards in control of blood flow test 2 Deck (60):
1

explain the vasodilator theory of acute control

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

2

explain the oxygen (nutrient) lack theory of acute control

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

3

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

increase in sizes/numbers of vessels

4

define vasomotion

cyclical opening and closing of pre capillary sphincters

5

what is the active reaction to hyperemia

when tissue becomes active, rate of blood flow increases

6

what does rapid increase in arterial pressure do to blood flow

increases blood flow

7

explain the metabolic theory of blood flow autoregulation

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

8

explain the myogenic theory of blood flow autoregulation

stretching of vessels lead to reactive vasculature constriction

9

what neurotransmitters are involved in vasoconstriction

norepinephrine, epinephrine, angiotensin II, vasopressin

10

what is the major function of vasopressin/ADH

to control body fluid volume

11

what is the function of angiotensin II

normally acts to increase total peripheral resistance

12

what neurotransmitters are involved in vasodilation

bradykinins and histamines

13

what does bradykinins do

causes both vasodilation and increased capillary permeability

14

what is histamine derived from

mast cells and basophils

15

what vessels does the sympathetic system not innervate

capillaries

16

what is the primary result of sympathetic regulation in blood flow

vasoconstriction

17

what is the vasoconstrictor area of the brain

anterolateral portions of upper medulla

18

what is the definition of vasomotor tone

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

19

what is the vasodilator area of the brain

bilateral in the anterolateral portions of lower medulla

20

what is the sensory area of the vasomotor center

bilateral in tractus solitarius in posterolateral portion of medulla

21

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

vagus and glossopharyngeal nerves

22

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

reticular substance (RAS)
hypothalamus
cerebral cortex

23

what does the adrenal medulla secrete

epinephrine and norepinephrine

24

where are baroreceptors located

carotid sinuses and aortic sinus

25

what pressure are carotid sinuses stimulated at

greater than 60 mm Hg

26

what pressure are aortic sinuses stimulated at

greater than 30 mm Hg

27

what signals come from baroreceptors

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

28

where are chemoreceptors located

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

29

what are chemosensitive cells sensitive to

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

30

what doe the signals from chemoreceptors pass through

Herring's nerves and vagus nerves

31

what do chemoreceptors play an important role in

respiratory control

32

what does an increase in atrial stretch result in

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

33

define arterial pressure

cardiac output X total peripheral resistance

34

what are common characteristics of primary hypertension

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

35

what are major factors of primary hypertension

weight gain and sedentary life style

36

what are renal causes of hypertension

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

37

what are the endocrine causes of hypertension

cushing syndrome
exogenous hormones
pheochromocytoma
acromegaly
hypothyroidism
hyperthyroidism
pregnancy induced

38

what are the cardiovascular causes of hypertension

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

39

what are the neurologic causes of hypertension

psychogenic
increased intracranial pressure
sleep apnea
acute stress

40

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

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

41

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

decreased blood volume, heart rate, contractility

42

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

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

43

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

increased angiotensin II, catecholamines, thromboxane, neural factors

44

what are the humoral vasoconstrictors

angiotensin II, catecholamines, endothelin

45

what are humoral vasodilators

kinins, prostaglandins, nitric oxide

46

what are the lethal effects of chronic hypertension

early heart failure and coronary artery disease
cerebral infarct
kidney failure

47

what is the major characteristic of artherosclerosis

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

48

what is C-reactive protein

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

49

what are characteristics of metabolic syndrome

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

50

where do lipoproteins accumulate

intima

51

how are lipoproteins oxidized

by oxygen free radicals generated by macrophages or endothelial cells

52

what ingests oxidized LDL

macrophages which become foam cells

53

what does oxidized LDL stimulate the release of

growth factors, cytokines, and chemokines

54

what is oxidized LDL toxic to

endothelial cells and smooth muscle cells

55

what controls the short term control of arterial pressure

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

56

what controls the long term control of arterial pressure

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

57

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

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

58

define chronic hypertension

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

59

what are the lethal effects of chronic hypertension

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

60

when does one kidney goldblatt hypertension occur

when one kidney is removed and remaining renal artery is constricted