Lecture 15 - Circulation Flashcards Preview

FHB Exam 1 - Cardiovascular Physiology > Lecture 15 - Circulation > Flashcards

Flashcards in Lecture 15 - Circulation Deck (46)
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1
Q

As you move further from the heart, the pulse pressure changes how? Why? What is a good example of this?

A
  1. WIDENS (increased difference between systole & diastole)
    - COMPLIANCE DECREASES as you move further from heart
  2. Left $ right arm – right arm has lower diastolic and higher systolic pressure because it is further from the heart
2
Q

How is the diastolic pressure of the Aorta as compared to the Left Ventricle?

A

HIGHER in Aorta (more compliant)

  • thus velocity is converted to pressure - recoil of the aorta
3
Q

Mean arterial pressure is determined ore by systolic than diastolic pressure. True or False?

A

FALSE

  • diastolic pressure determines MEAN arterial pressure
4
Q

Why is systolic pressure higher & diastolic pressure lower in the arteries as compared to aorta?

A

Arteries are less compliant

  • compliance decreases as you go further from the heart
5
Q

Where is there NO PULSE PRESSURE?

A

Capillaries & veins

6
Q

As vessels get less compliant (stiffer), how is the pulse pressure affected?

A

INCREASES (widens)

7
Q

What drives blood forward if systolic pressure is higher downstream?

A

MEAN ARTERIAL pressure declines (energy declining)

  • so the pressure gradient is created again
8
Q

What type of hypertension is common in younger people? Older people?

A

Younger - DIASTOLIC hypertension

Older - Systolic

9
Q

Which ventricle generates 5 times higher pressure?

A

LEFT VENTRICLE

Due to the elasticity of the Aorta & after load of the arterial BP

  • more energy
  • ventricle hypertrophies slightly due to the pressure
10
Q

The incisura/ or high frequency component, is dampened where?

A

FURTHER from heart

11
Q

How are the following affected as you move further from the heart:

  1. Incisura
  2. Systolic Peak
  3. Diastolic Hump
A
  1. Dampens peak
  2. Systolic peak INCREASED
  3. LATE DIastolic hump
12
Q

What are 3 causes for alterations in pressure profiles? What is the main reason?

A
  1. Reflection at branch points - flow hits branch pt. & they summate
    = wave hits wall & peak is HIGHER
  2. Vascular Tapering - forces fluid into a narrow opening, increasing pressure
  3. DECREASE IN ARTERIAL COMPLIANCE

= MAIN REASON!!

13
Q

What is atherosclerosis?

A

ATHEROSCLOROSIS: hardening of the arteries, compliance of the vessels is decreasing

14
Q

Which vessel has the highest amount of elasticity?

A

AORTA

15
Q

Which vessels: arteries or veins, have strong connective tissue?

A

VEINS

16
Q

What cells provide protective lining & release local transmitters like NO?

A

ENDOTHELIAL CELLS

  • if damaged = inflammation to rest of arterial wall
  • stents: put in to prevent further endothelial damage
17
Q

What are all blood vessels & lymphatic vessels lined with?

A

ENDOTHELIAL CELLS

18
Q

What are the 3 layers of both arteries and veins?

A
  1. Tunica Intima
  2. Tunica Media
  3. Tunica Adventitia
19
Q

Which vessel, veins or arteries has the following:

  1. IEL
  2. EEL
  3. innervation
  4. vasa Vasorum
A

ARTERIES

20
Q

Which vessels have well developed connective tissue in the tunica adventitia?

A

VEINS

  • no IEL
  • no EEL
21
Q

What does vasa vasorum provide?

A

NUTRIENTS to the vessels (both veins & arteries)

22
Q

Why can veins withstand high pressures? What can veins be used for?

A
  1. well-developed ADVENTITIA
  2. BYPASS graft (saphenous vein)
    - due to large connective tissue
23
Q

Which vessels have the following:

  1. Elastic Lamina
  2. MORE SMOOTH muscle
  3. LESS CONNECTIVE TISSUE
A

ARTERIES

24
Q

Which layer has the highest compliance (elastic lamina, smooth muscle, collagen)?

A

ELASTIC LAMINA

25
Q

How do the compliance characteristics of arteries tissues affect arterial pressure?

A

Compliance of arteries (low) so this causes an increase in arterial pressure

26
Q

What is the change in compliance in low & high volume situations for arteries?

A

LOW volume = HIGH compliance

  • high volume = stretching the collagen so compliance is LOW
27
Q

What type of capillaries are found in the following:

  1. Muscle, connective tissue
  2. Liver, bone marrow, spleen
  3. Kidney, Intestine

Which have tight junctions? Diaphragm? Discontinuous endothelial cells w/ discontinuous basal laminae

A
  1. Continuous Capillary
  2. Discontinuous Capillary (allows large substances to pass)
  3. Fenestrated Capillary
    - filters fluid, absorbs nutrients
28
Q

Which have tight junctions? Diaphragm? Discontinuous endothelial cells w/ discontinuous basal laminae

  1. Continous Capillaries
  2. Fenestrated
  3. Discontinuous
A
  1. tight jcts = COntinuous
  2. Fenestrated = Diaphragm
  3. Discontinuous endothelial & basal laminae
29
Q

What allows for greater control of vessel diameter & blood flow?

A

HIGHER

Wall thickness/lumen diameter ratio!

30
Q

What vessels have highest wall thickness/lumen diameter ratio & GREATEST control? Least?

A

Pre- capillary sphincters (2nd is arterioles)

  • VEINS
    thin wall, large diameter (small ratio)

= regulate VOLUME not flow or pressure

31
Q

Higher wall thickness/lumen diameter ratio directly corresponds with what?

A

LOW WALL TENSIOn

  • allows vascular smooth muscle to easily constrict the vessel

(arteriole - 1.3 & capillaries - 2)

32
Q

Why is an increase in pulse pressure bad? This is a result of what specific value that relies on change in volume & pressure?

A

increases the AFTERLOAD
which increases the oxygen consumption of the heart

  • COMPLIANCE (low compliance = increased after load & widens the pulse pressure)
  • increase systolic
  • decrease diastolic
33
Q

What occurs when blood is ejected into the arterial system under HIGH COMPLIANCE?

A

moves the wall(during systole),

-by moving the wall you reduce the pressure because the movement is KINETIC energy

  • so Potential energy is reduced so systole is LOW
  • then after the aortic valve closes: the aorta recoils & the kinetic component (velocity) is put back into PRESSURE (potential component) & moves the diastolic pressure a little higher**
34
Q

When is the diastolic pressure higher: under high compliance or low compliance? When is it low?

A

HIGH compliance

  • low compliance = stiff –> PE not converted to KE during systole (wall doesn’t move; stiff)

and when diastole occurs there is no recoil so pressure DROPS OUT

  • lower since KE not converted back to PE
35
Q

What is an independent risk factor for heart failure? Why?

A

LOW COMPLIANCE

  • due to increased oxygen consumption
36
Q

As radius or volume increase, how does pressure change? What is a clinical application of this?

A

INCREASES
-at low volume, low pressure change

  • at higher volumes, LARGE pressure change because the LOAD is no longer on elastin & smooth muscle, it is on collagen

Clinical: blood volume expansion causes HYPERTENSION - given diuretics/ace inhibitors to decrease blood volume & after load

37
Q

What are the Windkessel/Hydraulic Filter properties of the aorta?

A

blood ejected into the aorta - when it is initially ejected it DISTENDS as a result of the compliance characteristics

–it recoils after valve closes & acts as a secondary PUMP

(no recoilL no increase in diastolic pressure & thus higher pulse pressure)
ex: loss of dicrotic notch due to no recoil = RIGID ARTERY

38
Q

How does aortic compliance change with age?WHY?

A

LESS compliance
- more collagen, less elastin

  • given increase in volume elicits a LARGER increase in pressure
    = wider pulse pressure MORE CARDIAC WORK
39
Q
The following is due to what?:
1. CHF
Contributes to:
2. Systolic Hypertension
3.Cardiac Hypertrophy
4. Aortic DIlation
5. Low exercise tolerance
A

INCREASED pulse pressure

40
Q

Arteries are ____ vessels & Veins are ______ vessels.

A
  1. Resistance vessels (due to low compliance)
  2. Capacitance Vessels
    - high compliance in physiologic pressure range
41
Q

Why do veins exhibit a high compliance in physiological pressure rage?

A

Due to their geometry

- ability to dilate & collapse
ex: when sitting, they are collapsed

42
Q

What is the PRESSURE PULSE (not pulse pressure)? The larger this is, means the more what changes?

A

Pulse felt in the wrist (radial) due to an energy wave distending the artery

  • movement of the artery is transferred into wall

LARGER PRESSURE PULSE = more the wall distends

43
Q

Propagation of pressure pulse wave depends on what characteristic of the vessel wall? What kind of vessels have greater propagation?

A

COMPLIANCE

  • stiffer = greater propagation since the wall distends less
44
Q

The arterial pressure pulse is directly related to changes in what?

A

ARTERIAL PRESSURE PROFILE

  • ex: close to aorta –> the pressure pulse is small because it is very COMPLIANT & elastic
45
Q

Which pulse would be stronger: pedal or radial pressure pulse?

A

PEDIAL

46
Q

How is pressure pulse related to atrial fibrillation? How would this be noticeable when taking someones pulse with AFib?

A
  • since amount of blood ejected with every contraction is IRREGULAR (and not constant) & amount of energy with each beat is different

PRESSURE PULSE IS NOT CONSTANT!

  • so if you feel a radial pulse it would be faster, slower, and changing