Which hormone-bone cell combination may result in osteoporosis?

Correct Answer: A

Rationale: Osteoporosis involves excessive bone resorption. Cortisol (from the adrenal glands) stimulates osteoclast activity, which breaks down bone tissue, potentially leading to porosity if unbalanced. Estrogen supports osteoblasts (bone formation), thyroid hormone can increase both formation and resorption but isn’t primarily linked to osteoporosis, and thyrocalcitonin (calcitonin) inhibits osteoclasts, reducing bone loss.

Correct Answer: D

Rationale: The mastoid process, a bony projection behind the ear, is part of the temporal bone. The sphenoid, parietal, and occipital bones lack this feature.

Correct Answer: C

Rationale: The false pelvis (greater pelvis) lies above the pelvic brim and is wider in females for childbirth, thus narrower in males. It’s part of the skeletal system, not inferior to the true pelvis or male-only.

Correct Answer: D

Rationale: Tendons (connecting muscle to bone) and ligaments (connecting bone to bone) are both dense, fibrous connective tissues composed primarily of collagen fibers. While ‘connective tissue’ (B) is broadly correct, ‘fibrous connective tissue’ (D) is more specific and accurate, distinguishing them from other connective tissue types like adipose or loose areolar tissue.

Correct Answer: D

Rationale: Hyaline cartilage is avascular (lacks blood capillaries), contains cells (chondrocytes) in lacunae (spaces), but does not have prominent fibers like elastic or fibrous cartilage. Its matrix is smooth and glassy, making ‘fibres’ the correct feature it lacks.