Background Information

Question 1

Which source says “The instantaneous change in vessel circumference closely resembles the form of the arterial pressure pulse?”

Answer 1

Olson, RM and DK Shelton, Jr. A nondestructive technique to measure wall displacement in the thoracic aorta. J Appl Physiol 32: 147-157, 1972.

Question 2

What do Olson & Shelton (1972) say about the arterial pressure pulse?

Answer 2

The instantaneous change in vessel circumference closely resembles the form of the arterial pressure pulse.

Question 3

The human aorta shows invasive diameter oscillations of _____ throughout the cardiac cycle.

Answer 3

9-12%

Question 4

The human carotid artery shows invasive diameter oscillations of _____ throughout the cardiac cycle.

Answer 4

1-2%

Question 5

The human femoral artery shows invasive diameter oscillations of _____ throughout the cardiac cycle.

Answer 5

2-15%

Question 6

The human main pulmonary artery shows invasive diameter oscillations of _____ throughout the cardiac cycle.

Answer 6

6-10%

Question 7

Which varies more throughout the cardiac cycle, inner or outer vessel diameter?

Answer 7

inner, assuming incompressible wall material.

Question 8

When excised, arteries retract to what proportion of their in situ length?

Answer 8

2/3

Question 9

Shortly after birth, the _____ closes, causing PA pressure to fall.

Answer 9

ductus arteriosus

Question 10

In healthy humans, when does the ductus arteriosus close?

Answer 10

shortly after birth (minutes? hours?)

Question 11

Describe two ways in which characteristic impedance may be estimated.

Answer 11

1. correlation of pressure and flow in early systole.

2. averaging input impedance magnitude above a sufficiently high harmonic (in my case, f = 15 Hz)

Question 12

The average of high harmonics of input impedance magnitude is known as…

Answer 12

characteristic impedance

Question 13

What effect would oblique slice prescription have on pulse pressure?

Answer 13

An angled slice prescription through the PA would overestimate pulse pressure while leaving flow relatively unchanged.

Question 14

PVR is minimized at what degree of lung inflation?

Answer 14

intermediate; the PVR versus lung inflation curve is U-shaped.

Question 15

At what lung inflation levels would PVR be relatively high?

Answer 15

At either very low or very high lung volume. Source: Levitzky, Pulmonary Physiology (2003)

Question 16

What does the Valsalva maneuver do to aortic CSA?

Answer 16

Decreases by ~17%

Question 17

What does the Valsalva maneuver do to aortic blood flow rate?

Answer 17

Decreases it.

Question 18

The AV valves are between…

Answer 18

the atria and ventricles

Question 19

What valves regulate blood flow between the atria and ventricles?

Answer 19

The AV valves, i.e., mitral and tricuspid

Question 20

The mitral valve is between the…

Answer 20

left atrium and left ventricle

Question 21

The mitral valve is also known as the…

Answer 21

bicuspid valve

Question 22

The bicuspid valve is also known as the…

Answer 22

mitral valve

Question 23

The tricuspid valve separates the ___ and ____.

Answer 23

RA, RV

Question 24

The RA and RV are separated by the ____ valve.

Answer 24

tricuspid

Question 25

How many leaflets does the mitral valve have?

Answer 25

Two. The mitral = bicuspid valve is “left out” in that it’s on the left, and is the only cardiac valve with only two cusps.

Question 26

Where are the semilunar valves?

Answer 26

Between the ventricles and great arteries

Question 27

Blood from the ventricles flows into the great arteries through the ____ valves.

Answer 27

semilunar; aortic and pulmonary