05a: Circulation and P Flashcards

1
Q

The pressure in all distensible vessels is determined by its:

A
  1. Compliance

2. Volume (contained within it at any moment)

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

Compliance of veins is determined by product of their (X) and (Y).

A
X = distensibility (specific compliance)
Y = volume
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Since veins have (X) times the distensibility as arteries and carry (Y) times the volume. Hence, their compliance is (Z) times that of arteries.

A
X = 5-6
Y = 3-4
Z = 15-24
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define distensibility (with an equation).

A

Percent change in V as a function of P;

(delta V/V)/delta P

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

At relaxed volume, the cross-section of vein looks (X) shape. With volume and small P increases, shape changes to (Y). The cross-sectional area and circumference of vessel (increase/decrease).

A
X = biconcave
Y = elliptical then circular;

CS Area increases BUT no change in circumference of vessel

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

When higher V and P changes (increase/decrease) (X) of vein, its distensibility finally begins to decrease.

A

Increase;

X = circumference

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

Change in volume in artery during given time period is determined by:

A

Flow in - Flow out

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

During the period of the entire cardiac cycle, SV is (greater/smaller) than runoff volume.

A

Equal!

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

In steady state, the time averaged volume in artery (increases/decreases).

A

Doesn’t change

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

In steady state, the time averaged pressure in artery (increases/decreases).

A

Doesn’t change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

During systole, flow into artery is (greater/smaller) than flow out, causing (increase/decrease) in P and V.

A

Greater;

Increase

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

During diastole, flow into artery is (greater/smaller) than flow out, causing (increase/decrease) in P and V.

A

Flow into artery is ZERO!

Decrease (“diastolic run off” to pump out rest of blood from systole)

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

During diastole, it’s the (X) property of the arteries that provides driving force to propel blood out.

A

X = elastic recoil

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

T/F: Since pressure in aorta is relatively constant, it’s possible to approximate MAP.

A

False - despite constantly changing P of aorta, MAP can still be approximated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

MAP equation…

A

Pd + (1/3)(PP)

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

Pulse pressure equation…

A

Ps-Pd

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

In an aortic pressure curve, the peak pressure is (X).

A

X = aortic systolic P

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

List the key physiological factors that affect arterial blood volume.

A
  1. CO (HR and SV)

2. Peripheral resistance

19
Q

The pulse pressure is predominantly determined by (X) and (Y) characteristic of (Z) vessel.

A
X = SV
Y = compliance
Z = aorta
20
Q

The actual systolic P that will be attained is actually dictated by which other P?

A

Diastolic P (prior to ejection)

21
Q

List the factors that influence aortic systolic P.

A
  1. SV
  2. Ejection velocity
  3. Aortic distensibility
22
Q

List the factors that influence aortic diastolic P.

A
  1. Aortic distensibility
  2. HR
  3. Peripheral resistance
23
Q

List the changes in factors that, at given (X) P, will increase pulse pressure by (increasing/decreasing) systolic P.

A

X = diastolic;
Increasing;

  1. Increase SV
  2. Increase ejection velocity
  3. Decrease in aortic distensibility
24
Q

An increase in peripheral resistance will (increase/decrease) pulse pressure by (increasing/decreasing) (diastolic/systolic) P. What’s being directly affected in this case?

A

Decrease;
Increasing;
Diastolic P;

Rate of “run-off” (decline of arterial V and P) is decreased

25
An increase in HR will (increase/decrease) pulse pressure by (increasing/decreasing) (diastolic/systolic) P. What's being directly affected in this case?
Decrease; Increasing; Diastolic P; Time for run-off (decline of arterial V and P) is decreased
26
Vessels downstream of aorta experience (increase/decrease) in systolic P and (increase/decrease) in diastolic P, causing (increase/decrease) in Pulse P.
Increase; Decrease; Increase
27
Vessels downstream of aorta experience (increase/decrease) in mean P.
Always decrease (loss of E due to friction)
28
(X) is the primary factor propelling blood through venous system. Explain what it is.
X = vis a tergo Pressure difference between peripheral venous pressure (Pv) and RA pressure (Pra)
29
Standing perfectly still for prolonged time may cause fainting, because it compromises which secondary factor influencing (X).
X = venous return (decreased) Skeletal muscle pumps
30
Describe how (inspiration/expiration) helps in venous return.
Inspiration; | Descent of diaphragm increases intra-abdominal P, increasing pressure gradient that drives venous return
31
Venomotor tone is factor in venous return because (increase/decrease) in venous wall tension, resulting in increase (P/compliance) helps increase venous return.
Increase; | P
32
Ventricular ejection aids in venous return by which mechanism?
Reaction force pulls heart downward, decreasing RA pressure
33
When considering flow of fluid between two points at different levels above the ground, it's crucial to consider difference in (X) between the two points. Which components make up (X)?
X = TOTAL fluid E 1. Lateral P 2. KE 3. Gravitational PE
34
T/F: Fluid flowing between two points at different levels above ground will always flow from high to low lateral pressures.
False
35
Upon standing, (arterial/venous) pressure in foot is (increased/decreased) by larger value.
Both increase by same amount!
36
Upon standing, (arterial/venous) (X) pressure in head is (increased/decreased) by larger value.
X = lateral; Both decreased by same amount!
37
T/F: SV decreased with decrease in respiratory rate.
True
38
T/F: SV decreased with hypotension.
False
39
An individual in which HR, TPR and compliance are kept constant, and increase in stroke volume results in (increase/decrease) pulse pressure and (increase/decrease) in MAP.
Increase in both
40
Because (veins/arteries) are compliant, standing leads to (X) and (rise/fall) in VR. In the absence of (Y), this would lead to fall in (Z) and fainting.
``` Veins; X = venous distension/pooling Fall; Y = reflex response for BP Z = MAP ```
41
What causes (veins/arteries) in head and neck to collapse?
Veins; If they have pressure below atmospheric pressure
42
T/F: A patient with aortic stenosis is likely to have a lower than normal fluid velocity through the aortic valve.
False
43
T/F: A patient with aortic stenosis is likely to have a higher than normal pulmonary venous pressure.
True