The rate of ventricular conduction is best determined by

25 Jun The rate of ventricular conduction is best determined by

Question
Atrioventricular (AV) block

1.

A first degree block is caused by ________________.

a. delay of the action potential between the AV node and Purkinje fibers

b. delay of the action potential between the AV and SA nodes
c. delay of the action potential between the SA node and Purkinje fibers

d. delay of the action potential between the SA and AV nodes

2. The rate of ventricular conduction is best determined by the _______________________ on a ECG.

a. the number of P waves present within a specific unit of time

b. the number of T waves present within a specific unit of time

c. the number of QRS complexes present within a specific unit of time

3. An ECG tracing from someone with a third-degree AV block is best described as a tracing with a ______________________.

a. 1:1 ratio of P waves to QRS complexes

b. 1:1 ratio of T waves to QRS complexes

c. 1:2 ratio of P waves to QRS complexes

d. 2:1 ratio of P waves to QRS complexes

Inotropic Agents

1. Positive inotropes allow the heart to pump ____________ blood with fewer heart beats. They do this by _____________________ the end-systolic volume (ESV).

a. less, increasing

b. more, increasing

c. less, decreasing

d. more, decreasing

2. An individual with high blood pressure (hypertension) is expected to benefit from the administration of ____________________ inotropic drugs that _______________ the hearts workload.

a. positive; decrease

b. negative; increase

c. positive; increase

d. negative; decrease

3. The expected effect of the drug Digoxin is to _________________ ventricular contraction and _________________ stroke volume.

a. strengthen; increase

b. strengthen; decrease

c. weaken; decrease

d. weaken; increase

Heart valve structure and function

1. The AV valves close in response to the ________________________.

a. contraction of the ventricles and the resulting drop in ventricular pressure

b. contraction of the atria and the resulting rise in atrial pressure

c. contraction of the atria and the resulting drop in atrial pressure

d. contraction of the ventricles and the resulting rise in ventricular pressure

2. Action potentials received directly from ________________ stimulate the papillary muscles to contract allowing for the proper _______________ of the AV valves.

a. AV node; closing

b. Purkinje fibers; opening

c. AV node; opening

d. Purkinje fibers; closing

3. Mitral valve prolapse severe enough to cause regurgitation may directly cause _________________ pressure in the ____________ atrium.

a. decreased; left

b. decreased; right

c. decreased; right

d. increased; right