Answer to Question 1
B
Cardiac output is decreased as a result of the slowed heart rate and weaker cardiac contractions. This is not usually a noticeable problem unless older persons are exposed to stressors that exceed their reserves. Responses A, C, and D are incorrect. The aging heart is slower and weaker, the valves become thickened and more rigid, and blood vessels thicken and become less elastic.
Answer to Question 2
D
One physiological theory of aging focuses on genetics, stating that people are born with a genetic program that predetermines life span. Another focuses on a person's nutrition during his or her life span, and yet another focuses on the fact that all fine-tuned machineryand that includes body partswear out or become less effective as they are repeatedly used. Response Dpersonalityis incorrect because it does not relate directly to a physiological factor.
An example of a homeostatic control system.
Summation of Heart Sounds, S3
Endocrine System - male
Relationship of the electrocardiogram to electrical conduction in the heart.
Layers of the heart
Organs of the Digestive System