Correct Answer: A

Rationale: The left atrium receives oxygenated blood from the lungs via the pulmonary veins. This oxygen-rich blood is then pumped into the left ventricle before being circulated throughout the body. The right atrium, on the other hand, receives deoxygenated blood from the body via the vena cava.

Correct Answer: C

Rationale: Insulin is the hormone secreted by the Islets of Langerhans in the pancreas. These specialized cells are responsible for regulating blood sugar levels by releasing insulin in response to high blood glucose levels. Insulin helps cells absorb glucose from the bloodstream, thereby lowering blood sugar levels.

Correct Answer: B

Rationale: 1 cc (cubic centimeter) is equal to 1 ml. Therefore, 20 cc is equal to 20 ml. To convert between cubic centimeters (cc) and milliliters (ml), the values are equivalent, as they both measure volume in the metric system.

Correct Answer: C

Rationale: The appropriate route of administration for insulin is subcutaneous. Subcutaneous injections are commonly used for insulin administration due to the slower absorption rate compared to intramuscular or intravenous routes, allowing for better control of blood glucose levels.

Correct Answer: B

Rationale: The knee-chest position is correctly identified as the genu-pectoral position. In this position, a person rests on their knees and chest with the abdomen raised and the head turned to one side. This position is commonly used in medical examinations and procedures involving the rectal or pelvic areas, allowing for better visualization and access.