Week 3 - Lesson 1 (Part 10)

Question 1

What do peripheral muscles (eg. calfs) act as?

Answer 1

An alternative pump to the heart

Question 2

What does the cardiac pump do?

Answer 2

It brings flow back to the right atrium due to the contraction and relaxation phases of the cardiac cycle

Question 3

What do venous valves establish?

Answer 3

Unidirectional flow

Question 4

Where are valves more abundant?

Answer 4

In the lower legs

- decreases as it goes closer to the heart

Question 5

What does respiration have a profound effect on? (2)

Answer 5

1. Venous pressure

2. Blood flow

Question 6

What happens to the thoracic pressure during inspiration?

Answer 6

It decreases

Question 7

What happens to the abdominal pressure during inspiration?

Answer 7

It increases

Question 8

What happens to the thoracic pressure during expiration?

Answer 8

It increases

Question 9

What happens to the abdominal pressure during expiration?

Answer 9

It decreases

Question 10

What is the result of increased abdominal pressure?

Answer 10

Pressure decreases the pressure gradients between the peripheral veins in the lower extremities
- reducing blood flow to the peripheries

Question 11

What is the result of decreases abdominal pressure?

Answer 11

Pressure gradient from the lower limbs to the abdomen is increased

Question 12

What are changes in blood flow with respiration are opposite with?

Answer 12

The lower limbs

Question 13

What is the respiratory changes of blood flow in the upper limbs is influenced by?

Answer 13

Changes in posture

Question 14

What happens to the upper parts of the body during respiratory?

Answer 14

Venous flow tends to stop at the height of inspiration and resumes with expiration

Question 15

Why does venous flow tend to stop at the height of inspiration and resumes with expiration?

Answer 15

Probably due to compression of the subclavian vein at the level of the first rib during contraction of the accessory muscles of respiration

Question 16

What does the change of thoracic and abdominal pressures do during respiration?

Answer 16

It opens and closes the valves while moving the blood up toward the heart and drawing blood into the right atrium

Question 17

Phasicity

Answer 17

Changes with respiration

- want to have smooth continual changes

Question 18

What can affect the flow?

Answer 18

Valsalva manouever

Question 19

Valsalva manouever

Answer 19

Is performed by moderately forceful attempted exhalation against a closed airway, usually done by closing one’s mouth, pinching one’s nose shut while expelling air out as if blowing up a balloon

Question 20

Where is flow most spontaneous?

Answer 20

When it is closest to the heart

- instant flow pattern obtainable (readily available)

Question 21

When is spontaneous flow not as common?

Answer 21

Further from the heart

- distal femoral vein and below (less pulsatile)

Question 22

Augmentation

Answer 22

Squeezing of the muscle

- wrap around (aliasing)

Question 23

Why is augmentation used?

Answer 23

In venous flow can be augmented to observe a large bolus of blood flowing through a vein in an unobstructed vessel

Question 24

Why are veins compressible?

Answer 24

Due to a thinner muscular wall

- can rule out clot this way

Question 25

Venous flow characteristics (4)

Answer 25

1. Phasicity
2. Spontanaity
3. Augmentation
4. Compressibility

Question 26

What does valsalca menoever do?

Answer 26

It increases intrathoracic and abdominal pressures and decreases, abolishes or even reverses flow in some peripheral veins

Question 27

How does shallow breathing affect phasicity?

Answer 27

May not sufficiently descend the diaphragm to elevate intraabdominal pressure
- venous flow will be more continuous

Question 28

Where do you see augmentation?

Answer 28

In a vein

- not an artery

Question 29

What does augmentation tell you?

Answer 29

If the vein is obstructed or not

Question 30

How does augmentation show if something is blocked?

Answer 30

You will not get a signal of a sharp increase on spectral doppler and have no warp around
- partially blocked will have a slower increases

Question 31

What does valsalva manoever prove?

Answer 31

If the valve is competent

• properly close valves
• show up as no signal on spectral doppler

Question 32

Arterial hemodynamic characteristics (5)

Answer 32

1. Waveform reflects the cardiac cycle
2. Not affected by respirations
3. High pressure system
4. Pulsatility
   - varies according to the vascular bed it supplies
5. Has a pulse

Question 33

Venous hemodynamic characteristics (5)

Answer 33

1. Waveform reflects the respiratory movements
2. Phasicity
3. Low pressure system
4. Pulsatility
   - varies according to proximity to the heart
5. No pulse