AEMCA PREP

Question 1

What are the three layers to the heart?

Answer 1

Endocardium (lining)
Myocardium (muscle)
Epicardium (outer layer)

Question 2

What are the atrioventricular valves? What are the other components and how does it work?

Answer 2

The mitral (bicuspid) and tricuspid valve.
The valves have guide wires called chordae tendinae attached to the edges of the valve leaflets and anchored to the papillary muscles which attach to the ventricular walls. They prevent the valves from being forced back into the atria during ventricular contraction.

Question 3

Whats happens if a papillary muscle infarcts and ruptures in an acute myocardial infarction?

Answer 3

Leads to inability of an AV valve to close properly during ventricular contraction. Blood leaks back into atria if this happens to the mitral valve, blood may leak back into lungs.

Question 4

What is starlings law?

Answer 4

Within physiological limits, the greater the hearts muscle is stretched, the greater its force of contractility.

Question 5

Explain pericardial tamponade

Answer 5

In inflammation or trauma, the normally thin layer of serous fluid in the pericardial space may increase. Stretching of the pericardium to accomodate for fluid buildup is limited, which may begin to interfere with the hearts ability to pump.