Which one of the following is the primary function of long bones?

Correct Answer: C

Rationale: Long bones (e.g., femur) primarily act as levers for muscle movement (e.g., walking) and provide support (e.g., weight-bearing). A is broad, B is more flat bones, and D is cartilage/joints, making 'Act as levers for muscles and to provide support' correct.

Correct Answer: B

Rationale: The occipital bone, at the skull’s base, is the most superior in anatomical position (topmost). The manubrium (sternum top) is chest-level, cervical vertebra #3 is mid-neck, and patella is knee-level. Answer is B, per the document.

Correct Answer: B

Rationale: Osteocytes reside in lacunae, small pits in bone matrix (compact or spongy). Haversian canals hold vessels, trabeculae are spongy structures, and endosteum lines cavities—not homes for osteocytes. Answer is B, per the document.

Correct Answer: A

Rationale: A tuberosity is a projection for muscle attachment, not a depression. Facet (flat surface), meatus (tube), and sinus (cavity) are depressions/cavities. Answer is A, per the document.

Correct Answer: A

Rationale: Osteoblasts (bone-forming) and osteoclasts (bone-resorbing) are in the periosteum, the membrane around bones. Lacunae hold osteocytes, not these cells. Answer is A, per the document.