Block 3 Quiz: Cardiovascular

Which of the following changes would you expect to increase an individual's hematocrit? 

increased release of EPO

Increased Influx of calcium through voltage gated L-type calcium channels occurs during the_______ phase of the cardiac muscle cell.

Plateau

Which of the following is the correct sequence of the spread of action potentials to the ventricular muscle?

septum → apex → base

Action potentials of cardiac muscle, nodal cells and neurons all involve:

repolarization due to opening of voltage gated potassium channels

Which of the following clotting factors is responsible for converting fibrinogen to fibrin?

thrombin

Blood flow is inversely proportional to _______ and directly proportional to _______.

resistance; pressure gradient

If the radius of an artery were doubled, the resistance in that artery would be _____ (increased; decreased) by a factor of _______ (four, sixteen).

Decreased; sixteen.

Which of the following has a role in preventing the formation of blood clots?

nitric oxide

The hyperpolarization cyclic nucleotide gated non-selective cation (HCN) channel is found in _____ and is open during the ______.

nodal cells; pacemaker potential

During the pacemaker potential of the sino-atrial (SA) nodal cells the membrane becomes depolarized due to which one of the following events?

sodium entry through the voltage-gated, non-selective cation channel: HCN channels

Which of the following components of the conduction system have the fastest conduction velocity?

purkinje fibers

Red blood cells have a life span of approximately ____ days and are then broken down with the _____.

120 days ; liver and spleen

Which of the following would be a compensatory response to return blood pressure to normal after a sudden increase in blood pressure?

Increased PNS activity

The first heart sound is heard when the ___ valves closed and is heard at the onset of ____.

AV; systole

An individual experiences a sudden decrease in blood pressure which activates the baroreceptor reflex. This compensatory reflex operates to restore blood pressure and involves multiple cardiovascular changes to return blood pressure back to normal. Which of the following is one of these compensatory changes to return blood pressure back to normal?

increased systemic vascular resistance (SVR)

Capillaries usually tend to absorb fluid:

at the venular end

A patient undergoes echocardiography which reveals an EDV of 120 mL and an ESV of 80 mL. At the time of the echocardiography her HR was 100 beats per minute. Given these numbers, calculate the stroke volume and ejection fraction.

SV 40 mL; EF 33%

The site of greatest resistance in the vasculature and the site that determines the systemic vascular resistance is within the:

arterioles

Norepinephrine binds to ___ receptors on cardiac myocytes to ___ stroke volume.

β-1; increase

Which of the following would result most likely decrease venous pressure and decrease venous return?

Decreased amount of blood in veins

Which of the following changes in Starling Forces would favor increased filtration of fluid put of the capillaries and into the interstitium?

Increased capillary hydrostatic pressure

Which of the following is the correct sequence of events that occurs during ventricular diastole?

isovolumetric relaxation → opening of AV valve → passive ventricular filling → atrial systole

An INCREASE in heart rate results in increased activity of cardiac muscle and a build up of metabolites surrounding nearby coronary blood vessels which causes vasodilation of these blood vessels. This is an example of:

active hyperemia

Which of the following statements is most accurate about the regulation of the SA node by the sympathetic nervous system?

Norepinephrine binds to β-1 receptors to increase heart rate

According to the Frank-Starling law of the heart, stroke volume increases with increases in:

end diastolic volume

Which of the following blood vessel types is characterized as having high elastance and low compliance?

aorta and large arteries

During which phase of the cardiac cycle are the AV valves open and the semilunar valves closed?

Atrial systole