Which Change Contributes to an Adolescent's Lessening Susceptibility Toward Respiratory

question 13

Multiple Choice

Which change contributes to an adolescent's lessening susceptibility toward respiratory infections?

• A) greater exposure to germs from increased social activity
• B) the shrinkage of the lymphoid system
• C) the increase in sex hormones
• D) the growth spurt

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Definitions:

Tricuspid Valve

A valve in the heart that lies between the right atrium and the right ventricle, preventing backflow of blood.

Aortic Valve

A valve in the heart between the left ventricle and the aorta that prevents blood from flowing back into the ventricle after it has been pumped out.

Coronary Sinus

A large vein on the posterior side of the heart that collects blood from the heart muscle (myocardium) and returns it to the right atrium.

Coronary Sulcus

A groove on the surface of the heart that marks the division between the atria and the ventricles.