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 refractory period of cardiac muscle is much longer than that of skeletal muscle. Why is this a desirable functional property?

After Randy was diagnosed with stomach cancer, nearly all of his stomach had to be removed. Postoperative treatment included regular injections of vitamin B12. Why was this vitamin prescribed, and why were injections specified?

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 simple squamous epithelium covering the heart valves is the (a) epicardium, (b) endocardium, (c) myocardium, (d) endothelium.

Describe the three distinct layers that make up the heart wall.

The portion of the intrinsic conduction system located in the superior interventricular septum is thea. AV node,b. SA node,c. AV bundle,d. subendocardial conducting network.