Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physiology > Test 1, Deck 4 > Flashcards

Test 1, Deck 4 Flashcards

1
Q

what determines coronary blood flow? what regulates it?

A
  • determines: aortic pressure

- regulates: metabolic activity/changes in arteriolar resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

when do you see a reversal in the blood flow of the left- but not right- coronary artery?

A

during max systolic pressure (isovolumetric contraction- rapid ejection) aka early systole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

60-65% of coronary blood perfusion to LV muscle occurs during ______

A

diastole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Vessels in the endocardium or epicardium are more compressible?
Which vessels are more dilated?
Which is more at risk for ischemia?

A
  • endo to ALL
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What compress endo/epicardium vessles?

A

Diastolic pressure and contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the relationship between blood flow and metabolic activity?

A

linear

* increased metabolism, decreased resistance, increased blood flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are the metabolic substrates for the heart, and what is the largest consumer of O2?

A

fatty acids (LARGEST O2), carbs, ketones/lactate/proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how does the heart get more oxygen?

A

it is flow limited- must vasodilate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the equation for cardiac work, and which factor matters more?

A

cardiac work= MAP x systolic stroke volume
(W=F*D)
- pressure is more important

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

which factors affect myocardial oxygen supply?

A
  • diastolic perfusion pressure
  • coronary vascular resistance (external vs intrinsic (metabolites))
  • O2 carrying capacity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

which factors create largest O2 demand?

A
  • afterload
  • heart rate
  • contractility
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is ischemia, considering O2?

A

imbalance in the ratio of oxygen supply to oxygen demand; creates a relative lack in blood flow
- excessive O2 demand is NEVER the primary cause (always too little supply)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is coronary steal?

A

an increase in blood flow to one region can cause a decrease in flow to another-
* problematic with vasodilation if there is a stenosis *

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

when would coronary steal present clinically?

A
  • exercise-induced ischemia
  • stress testing
  • peripheral arterial disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What happens to skeletal muscle circulation during exercise?

A
  • the flow oscillates

- overall, there is a significant reduction in resistance to blood flow to vasodilation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Skeletal flow can increase ___ time during exercise, which is called _____. It constitutes the ____ vascular bed in the body. Which type of muscle has more vascular supply- tonic or phasic?

A

20
active hyperemia
largest
tonic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the main vasodilator- working against sympathetics- in skeletal muscle?

A

adenosine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Skeletal muscle vasculature is primarily innervated by _____ fibers

A

sympathetic adrenergic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Ach causes ___ by acting on ___ coupled to ___

A

vasodilation
muscarinic (on endothelials)
NO production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Epinephrine from ____ causes ____ at low concentrations through activating _____, but _____ at high concentrations through activating ____

A
  • adrenal medulla
  • vasodilation
  • beta-2 adrenergic receptors
  • vasoconstriction
  • alpha adrenergic receptors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

The brain primarily uses _____ metabolism of _____. How metabolically active is it?

A

aerobic metabolism of glucose

most metabolically active tissue in the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the BBB due to? What can cross?

A
  • endothelial tight junctions
  • basement membrane
  • neuroglial processes
  • metabolic enzymes
  • lipid soluble substances- O2, CO2, ethanol, steroids, glucose
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is CPP? If CPP falls, what happens? What reduces CPP?

A
  • cerebral perfusion pressure
  • CPP= MAP- intracranial venous pressure
  • vasodilation
  • reduced by decrease in MAP or increase in intracranial pressure
24
Q

what is the monroe-kellie doctrine?

A

brain volume + cerebral vascular volume + CSF volume= constant

25
Q

What happens as CSF pressure rises?

A
  • increase CSF pressure
  • cerebral blood flow decreases (veins compressed)
  • metabolic autoregulation dilates the arteries
  • this only works up until a certain pressure, where the arteries become compressed
26
Q

Cerebral blood flow is very sensitive to which metabolite?

A

PCO2

27
Q

An increase in pH (hyperventilation) causes what? This helps with what clinical scenario?

A
  • vasoconstriction & decreased blood flow

- cerebral edema (high intracranial pressures)

28
Q

mechanism for nitric oxide

A
  • causes vasodilation of smooth muscle
  • increases cGMP and PKG
  • increases phosphorylation of MLCK
  • decreases phosphorylation of myosin light chain
29
Q

what is the cushing response?

A

with elevated intracranial pressure, you see

  • high blood pressure (medulla sympathetics)
  • low heart rate (parasympathetics)
30
Q

when does the cushing response occur?

A

when CSP (cerebral spinal pressure) is greater than the mean arterial pressure

31
Q

Pulmonary circulation is a ____ pressure, ____ volume system, ___ resistance; mean pressure gradient= ____

A

low pressure, high volume, low resistance

mean pressure gradient 6 mm Hg

32
Q

Pulmonary arteries are ___ compliant than regular arteries because____

A

7x more; they lack smooth muscle

33
Q

Pulmonary capillaries represent ___ of the vascular resistance

A

40%

34
Q

T/F Pulmonary vessels autoregulate

A

F

35
Q

During inspiration, negative pressure ______’s extra-alveolar vessels and _____ resistance in alveolar vessels - net effect on resistance = ?

A

distends; increases

net effect- no change!

36
Q

intravascular (hydrostatic) pressure is greatest at which part of the lung? what does this cause?

A

bottom

waterfall effect

37
Q

what happens in zone 1?

A

alveolar pressure exceeds arterial and veous pressures, causing capillaries to collapse
- exists w/ hypotension or positive pressure mechanical ventilation

38
Q

what happens in zone 2?

A

alveolar pressure exceeds venous pressure but does not exceed arterial pressure; capillaries are partially collapsed, is the upper 1/3rd of lung

39
Q

what happens in zone 3?

A

arterial and venous pressures exceed alveolar pressure; flow depends on AV pressure gradient

40
Q

primary function of cutaneous circulation

A

maintain a constant body temperature

- provides transport of heat to the body surface for exchange with the environment

41
Q

what is apical skin?

A
  • high surface-volume ratio that favors heat loss

- has lots of AV anastomoses called glomus bodies

42
Q

what is nonapical skin?

A
  • lacks AV anastomoses

- innervated by sympathetic fibers- postganglionics release Ach; vasodilation

43
Q

neural control of apical skin

A

sympathetic adrenergic nerves that produce vasoconstriction of cutaneous vessels (withdrawal produce passive vasodilation)

44
Q

neural control of nonapical skin

A
  • sympathetic vasoconstriction (NE)

- active vasodilation via cholinergic fibers via bradykinin

45
Q

temperature regulation (what kind?) is primarily controlled by major sensory sites in the ______ and less by receptors in the spinal cord

A

core body temperature; hypothalamus

46
Q

fetal circulation pathway

A

fetal branch villi- umbilical vein- ductus venosus- IVC- RA- foramen ovale- LA-LV- aorta

some blood goes RA- RV-pulm artery- ductus arteriosis- systemic circulation

47
Q

valves close, pressure changes, pipes shut

A

valves close- foramen ovale
pressure changes- atria
pipes shut- ductus venosus & ductus arteriosus

48
Q

difference between HbF and HbA and why?

A

HbF has greater affinity for O2 due to DpG shifting O2 dissociation curve left- more saturation at lower pressures

49
Q

umbilical artery
umbilical vein
ductus venosus
ductus arteriosus

A

umbilical artery- medial umbilical ligament
umbilical vein- ligamentum teres
ductus venosus- legamentum venosus
ductus arteriosus- ligamentum arteriosum

50
Q

what happens with skin circulation and exercise?

A

sympathetics want to vasoconstrict

internal metabolic heat stimulates cutaneous vasodilation

51
Q

what does the arrangement of vessels within the intestinal villus form?

A

contercurrent flow system; arteries and venules run parallel to each other- solutes such as sodium dissolve from the arteries back to the venules to increase osmolarity/blood flow

52
Q

What ist he portal system?

A

1- portal vein- blood from intestine/stomach/pancreas (only a few mmHg higher than IVC)
2- liver capillaries- blood from portal vein
3- hepatic vein- liver capillaries
4- IVC

53
Q

metabolic control of splanchnic circulation

A 
increase metabolism
O2 decreases
metabolites (CO2, H+, adenosine) increase
vasodilation 
(moderate autoregulation)
54
Q

hormonal control of splanchnic circulation

A

cholecystokinin & neurotensin increase vasodilation

55
Q

neural control of splanchnic circulation

A
  • sympathetic vasoconstriction via NE acting on alpha adrenergic receptors on vascular smooth muscle (also have beta receptors)
  • parasympathetics act indirectly by contacting sympathetics in intestinal wall & stimulates motility
56
Q

what is postprandial hyperemia?

A

after eating, get increase in intestinal blood flow due to metabolic/hormonal/neural/mechanical influences

Physiology (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions