Lecture 9 The excitable heart

Question 1

Electrical cells of the heart are: 
A. High in actin and myosin 
B. Pale with a striated appearance 
C. Red striated appearance 
D. Connected by tight junctions

Answer 1

B.

Question 2

In a contractile cell….cytoslic ca2+ levels increase and X=bridge attachment/contraction ______

Answer 2

Increases, increases

Question 3

Intercalated disks contain ___ junctions

Answer 3

Gap

Question 4

What is the order of the conduction pathway?

Answer 4

SA node, internodal bundles, AV node, AV bundle and purkinje bundles

Question 5

Why is the SA node the pacemaker?

Answer 5

These cells have the ability to sponatenous generate an electrical impulse.

Question 6

What is the function of the AV node?

Answer 6

It slows the electrical signal before it enters the ventricles. This delay gives the atria time to contract before the ventricles do

Question 7

If the left atrium of the heart is contracting, which of the following is most likely to be TRUE
A. The left ventricle is also contracting
B. The right ventricle is contracting.
C. The right atrium is contracting
D. The vena cava is relaxing.

Answer 7

C

Question 8

Atrial depolarization is initiated by the ___ node and causes the__ wave

Answer 8

SA, P

Question 9

With atrial depolarization complete, the impulse is delayed at the ___ node

Answer 9

AV

Question 10

Ventricular depolarization begins at the ____ causing the ___ complex. Atrial repolarization occus.

Answer 10

apex, QRS

Question 11

Ventricular depolarization is complete, and ventricular repolarization begins at the ____ causing the ___wave

Answer 11

Apex, T