Brainscape's Knowledge GenomeTM

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


See full index

Cardiology > Systemic circulation > Flashcards

Systemic circulation Flashcards

1
Q

What is pressure?

A

force per unit area

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

What is transmural pressure?

A

pressure tending to distent/collapse a vessel

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

What is pressure gradient?

A

Pressure differential b/w inflow and outflow

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

What is hydrostatic pressure?

A

generally used as blood pressure

pressure caused by the height of a fluid column

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

What is the mean arterial pressure?

A

avg pressure existing in the aorta and proximal arterial system during one cardiac cycle
Diastolic pressure + 1/3 pulse pressure

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

What are the physiological factors that determine arterial blood pressure?

A
  1. cardiac output (SV x HR)
    -primary affect systolic pressure
    regulated by ANS
  2. peripheral resistance
    -primary affects diastolic pressure
    regulated by local metabolic activity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the baroreceptor reflex?

A

acts via ANS to affect Co and peripheral resistance

*maintains arterial BP moment to moment

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

What is the effect of exercise on mean arterial pressure?

A

systolic P increases and diastolic same or decr
pulse pressure widens
-MAP increases

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

What diseases affect blood pressure?

A

CHF (decr SV & contractility), IM, Bradycardia, sepsis -> decrease BP
hypertension: increase BP

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

What are physical factors that affect arterial blood pressure?

A
  1. arterial compliance
    affects systolic + diastolic P
    determined by age, blood volume, symp tone, pregnancy
  2. blood volume: affects SV and arterial compliance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How does changing peripheral resistance affect arterial pressure?

A

if keep compliance constant,

as peripheral resistance increases, both systolic and diastolic P increase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How does changing compliance affect arterial pressure?

A

if keep peripheral resistance constant,
as decrease compliance, the pulse pressure widens
(increase systolic and decrease diastolic)

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

What are the factors that affect total peripheral resistance?

A

“runoff of blood”

blood viscosity and arteriolar radius

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

What are the global (extrinsic) factors that control arteriolar radius?

A
  1. baroreceptors
  2. hormonal effects
  3. sympathetic activity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the local (intrinsic) factors that control arteriolar radius?

A
  1. myogenic response
  2. endothelium-mediated regulation
  3. local metabolic changes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What effect does parasympathetic stimulation have on mean arterial pressure?

A

decr HR so decr CO and lower BP

17
Q

What effect does sympathetic stimulation have on mean arterial pressure?

A
  1. affect the heart: incr HR and contraction strength -> both increase C.O. which increases BP
  2. affect veins: venoconstrict to increase venous returns so increase SV which increases CO and thus BP
  3. affects arterioles: vasoconstrict to increase peripheral resistance and prevent run off! increase BP
18
Q

What is the effect of sympathetic activity on exercise?

A

increase HR
increase contractility
increase CO

19
Q

What is the effect of sympathetic vasoconstriction?

A

increases vascular resistance
diverts blood away from skin, kidneys, splanchnic regions and inactive muscle
doesn’t affect cerebral, pulmonary and cardiac vasculature

20
Q

What is the effect of metabolic vasodilation?

A

lowers vascular resistance and increases blood flow
to skeletal muscle and heart
change in total peripheral resistance dep on level of exercise and mass of active muscle

*overcomes but still limited by sympathetic innervation

21
Q

What other strategies are used to help during exercise?

A

capillary recruitment

ehanced O2 extraction for muscles (not heart)

22
Q

What helps to increase venous return?

A

sympathetic venoconstriction: decr venous compliance and shunts blood back to heart
muscle pump
respiratory pump

23
Q

What happens to arterial pressure during exercise?

A

systolic pressure is increased (cuz SV), vasoconstriction also helps
diastolic pressure is determined by changes in total peripheral resistance
*pulse pressure widens

24
Q

What are the pre capillary resistance vessels?

A

arterioles
metarterioles
precapillary sphincters

25
Q

What are some characteristics of capillary blood flow?

A
  • low velocity
  • intermittent (vasomotion: not cont, chaotic -> some open, others closed
  • direction (pressure gradients)
  • not uniform
  • rouleaux formation
26
Q

How does oncotic pressure affect transcapillary fluid exchange?

A

proteins are more concentrated in the capillaries so it pulls water in to balance (absorption)

27
Q

How does hydrostatic pressure affect fluid exchange?

A

it decreases as you go from arterial to venous side
all pressure is inside the capillary
push fluid outside to balance it

28
Q

Describe pressures on the arterial side

A

hydrostatic pressure higher then oncotic
net: fluid out

e.g. kidneys

29
Q

Describe pressures on the venous side

A

oncotic pressure higher then hydrostatic

net: fluid in

30
Q

What is the function of lymphatic vessels?

A

pick up extra fluid that ended up in the interstitial space and shut it back to the heart

31
Q

What determines oncotic pressure?

A

albumin concentration

32
Q

What is the effect of arterial pressure on capillary hydrostatic pressure?

A

small effect!

cuz too much pre-capillary resistance

33
Q

What is the effect of venous pressure on capillary hydrostatic pressure?

A

larger cuz few resistance

34
Q

What determines capillary hydrostatic pressure?

A

pre/post capillary resistance ratio

35
Q

What are some substances secreted from the endothelium?

A
  • prostaglandins
  • EDRF
  • NO
  • metabolites
  • all vasodilate

-endothelin: vasoconstrict

36
Q

What is the structure of lymphatics?

A
  • unidirection flow back to heart
  • valves
  • non-fenestrated endothelium, lil to no basal lamina, no smooth muscle
  • large collecting vessels return fluid to subclavian veins
37
Q

What factors govern lymph flow?

A
  • amount of capillary filtration
  • skeletal muscle activity
  • lymphatic unidirectional valves
38
Q

What is edema?

A

accumulation of excess fluid within the interstitial space

39
Q

What precipitates peripheral edema?

A
  • reduction in plasma protein concentration (liver or renal disease)
  • increase in capillary hydrostatic pressure (CHF- back up fluid)
  • increased permeability of capillary membrane (burns)
  • lymphatic obstruction (tumor)

Cardiology (12 decks)

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