How does the heart's ability to contract differ from that of other muscles of the body?

Identify the structures in the following diagram of a sectional view of the heart.

a. ___

b. ___

c. ___

d. ___

e. ___

f. ___

g. ___

h. ___

i. ___

j. ___

k. ___

l. ___

m. ___

The serous membrane covering the outer surface of the heart is the:

(a) Parietal layer of the serous pericardium

(b) Endocardium

(c) Myocardium

(d) Visceral layer of the serous pericardium

The simple squamous epithelium covering the heart valves is the:

(a) Epicardium

(b) Endocardium

(c) Myocardium

(d) Endothelium

Cardiac muscle cells are joined by structures called:

a. T-tubules.

b. tight junctions.

c. sarcoplasmic reticulum.

d. intercalated discs.

The portion of the intrinsic conduction system located in the superior interventricular septum is the:

a. AV node

b. SA node

c. AV bundle

d. Subendocardial conducting network

More than one choice may apply.

Using the figure, identify the most external part of the pericardium.

Draw a diagram of the heart showing the three layers composing its wall and its four chambers. Label each. Show where the AV and semilunar valves are, and name them. Show and label all blood vessels entering and leaving the heart chambers.