Background Information Flashcards
Get acquainted with relevant foundations of my master's thesis topic, MRI assessment of pulmonary arterial hypertension.
Which source says “The instantaneous change in vessel circumference closely resembles the form of the arterial pressure pulse?”
Olson, RM and DK Shelton, Jr. A nondestructive technique to measure wall displacement in the thoracic aorta. J Appl Physiol 32: 147-157, 1972.
What do Olson & Shelton (1972) say about the arterial pressure pulse?
The instantaneous change in vessel circumference closely resembles the form of the arterial pressure pulse.
The human aorta shows invasive diameter oscillations of _____ throughout the cardiac cycle.
9-12%
The human carotid artery shows invasive diameter oscillations of _____ throughout the cardiac cycle.
1-2%
The human femoral artery shows invasive diameter oscillations of _____ throughout the cardiac cycle.
2-15%
The human main pulmonary artery shows invasive diameter oscillations of _____ throughout the cardiac cycle.
6-10%
Which varies more throughout the cardiac cycle, inner or outer vessel diameter?
inner, assuming incompressible wall material.
When excised, arteries retract to what proportion of their in situ length?
2/3
Shortly after birth, the _____ closes, causing PA pressure to fall.
ductus arteriosus
In healthy humans, when does the ductus arteriosus close?
shortly after birth (minutes? hours?)
Describe two ways in which characteristic impedance may be estimated.
- correlation of pressure and flow in early systole.
2. averaging input impedance magnitude above a sufficiently high harmonic (in my case, f = 15 Hz)
The average of high harmonics of input impedance magnitude is known as…
characteristic impedance
What effect would oblique slice prescription have on pulse pressure?
An angled slice prescription through the PA would overestimate pulse pressure while leaving flow relatively unchanged.
PVR is minimized at what degree of lung inflation?
intermediate; the PVR versus lung inflation curve is U-shaped.
At what lung inflation levels would PVR be relatively high?
At either very low or very high lung volume. Source: Levitzky, Pulmonary Physiology (2003)
What does the Valsalva maneuver do to aortic CSA?
Decreases by ~17%
What does the Valsalva maneuver do to aortic blood flow rate?
Decreases it.
The AV valves are between…
the atria and ventricles
What valves regulate blood flow between the atria and ventricles?
The AV valves, i.e., mitral and tricuspid
The mitral valve is between the…
left atrium and left ventricle
The mitral valve is also known as the…
bicuspid valve
The bicuspid valve is also known as the…
mitral valve
The tricuspid valve separates the ___ and ____.
RA, RV
The RA and RV are separated by the ____ valve.
tricuspid
How many leaflets does the mitral valve have?
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.
Where are the semilunar valves?
Between the ventricles and great arteries
Blood from the ventricles flows into the great arteries through the ____ valves.
semilunar; aortic and pulmonary
