Select the correct statement regarding epithelia. a. pseudostratified epithelia consist of at least two layers of cells stacked on top of one another. b. simple epithelia form impermeable barriers. c. stratified epithelia are present where protection from abrasion is important. d. stratified epithelia are tall, narrow cells.

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.