CCMA Anatomy and Physiology Basics 4

Question 1

Which layer of the skin contains the keratinocytes that produce the protein keratin?

Accepted Answer

Epidermis

Answer

Keratinocytes are the predominant cells of the epidermis and synthesize keratin to form a protective barrier.

Question 2

The sinoatrial (SA) node is located in which chamber of the heart?

Accepted Answer

Right atrium

Answer

The SA node, the heart's natural pacemaker, is located in the upper wall of the right atrium.

Question 3

Which hormone is responsible for stimulating the reabsorption of sodium in the renal tubules?

Accepted Answer

Aldosterone

Answer

Aldosterone, secreted by the adrenal cortex, promotes sodium reabsorption in the distal tubule and collecting duct.

Question 4

The brachial plexus originates from which spinal cord segments?

Accepted Answer

C5–T1

Answer

The brachial plexus arises from ventral rami of C5 through T1 and innervates the upper extremity.

Question 5

Which digestive enzyme, secreted by the pancreas, specifically cleaves peptide bonds adjacent to aromatic amino acids?

Accepted Answer

Chymotrypsin

Answer

Chymotrypsin cleaves peptide bonds on the carboxyl side of aromatic (phenylalanine, tyrosine, tryptophan) and large hydrophobic amino acids.

CCMA - Certified Clinical Medical Assistant Practice Test