One of the following is not a function of the skeletal system

Correct Answer: C

Rationale: The skeletal system has several key functions: producing blood cells (hematopoiesis) in the bone marrow, storing minerals like calcium and phosphorus, and protecting vital organs (e.g., skull protects the brain, rib cage protects the heart and lungs). However, storing carbohydrates is not a function of the skeletal system; carbohydrate storage primarily occurs in the liver and muscles as glycogen.

Correct Answer: C

Rationale: Paranasal sinuses are air-filled cavities in the frontal, ethmoid, sphenoid, and maxilla bones, reducing skull weight and resonating sound. The vomer, a thin midline bone in the nasal septum, lacks a sinus.

Correct Answer: D

Rationale: The os coxa (hip bone) comprises the ilium, ischium, pubis, acetabulum (socket), and obturator foramen. The capitulum is a feature of the humerus, not the os coxa.

Correct Answer: A

Rationale: The sphenoid bone lacks a styloid process. The temporal bone has a styloid process (near the ear), and the ulna and radius have styloid processes at their distal ends in the wrist.

Correct Answer: B

Rationale: The periosteum is a dense connective tissue membrane covering the outer surface of bones, aiding in growth, repair, and attachment. The pericardium surrounds the heart, perichondrium covers cartilage, and endosteum lines the medullary cavity—only periosteum fits the description.