Which of the following cushions and protects the bones where they meet?

Correct Answer: C

Rationale: At joints, cartilage—specifically articular cartilage—covers bone ends, acting as a cushion to absorb shock and reduce friction during movement (e.g., knee cartilage). Ligaments stabilize joints by connecting bones, tendons attach muscles to bones, and muscles move bones, but cartilage directly protects and cushions, making it the correct answer.

Correct Answer: C

Rationale: Osteons (or Haversian systems) are the cylindrical units of compact bone, containing lamellae, a central canal, and osteocytes. Lamellae are layers within osteons, canaliculi are channels, and trabeculae are in spongy bone, making 'osteons' the correct answer.

Correct Answer: C

Rationale: Intramembranous ossification forms bone directly from fibrous connective tissue membranes, as in flat skull bones. Hematopoiesis makes blood cells, endochondral ossification uses cartilage, and remodeling reshapes bone, making 'intramembranous ossification' correct.

Correct Answer: D

Rationale: The appendicular skeleton includes limbs and girdles. The coxal bone (hip) is part of the pelvic girdle, thus appendicular. Cranium, ribs, and sternum are axial skeleton components, making 'coxal bone' correct.

Correct Answer: C

Rationale: The sphenoid bone, butterfly-shaped, forms the cranium’s floor and sides, housing the pituitary. The ethmoid is anterior, occipital posterior, and temporal lateral, making 'sphenoid' correct.