An example of a gliding joint is the

Correct Answer: A

Rationale: Gliding joints allow sliding movements, as seen in the intercarpal joints (between wrist bones). The radiocarpal joint is a condyloid joint, intervertebral joints are cartilaginous (amphiarthroses), and phalangeal joints are hinges—not gliding.

Correct Answer: C

Rationale: The talus, in the ankle, articulates distally with the calcaneus (heel bone) below it, forming the subtalar joint. The navicular and cuneiforms are more distal, and the first metatarsal is further forward.

Correct Answer: B

Rationale: Bone marrow consists of adipose tissue (yellow marrow, fat storage), areolar tissue (loose connective tissue supporting structure), and blood (red marrow, site of hematopoiesis producing blood cells). Fibroblasts are present but not a major component, making B the most complete and accurate description.

Correct Answer: A

Rationale: Haversian canals are channels in compact bone containing blood vessels and nerves, characteristic of long bones like the humerus. Scapula (flat), pubis (irregular), and clavicle (long but less typical) have compact bone, but the humerus is a classic example of Haversian system structure.

Correct Answer: B

Rationale: The human spine (vertebral column) consists of 33 bones: 7 cervical, 12 thoracic, 5 lumbar, 5 sacral (fused into the sacrum), and 4 coccygeal (fused into the coccyx). In adults, the sacral and coccygeal bones fuse, but the total count remains 33 individual vertebrae.