Which of the following is not required by animals to control body temperature?
a. animals must find a source of heat.
b. animals must switch between ectotherm and endotherm methods.
c. animals must be able to conserve heat when temperatures drop.
d. animals must be able to get rid of excess heat when temperatures increase.

Define the apical impulse and describe its normal location, size, and duration. which abnormal conditions may affect the location of the apical impulse? explain the mechanism producing normal first and second heart sounds. describe the effect of respiration on the heart sounds. describe the characteristics of the first heart sound and its intensity at the apex of the heart and at the base. describe the characteristics of the second heart sound and its intensity at the apex of the heart and at the base.