The quadriceps group the thigh and the hamstring group the thigh.

Correct Answer: C

Rationale: Quadriceps extend the knee, straightening the leg, while hamstrings flex it, bending it, acting as antagonists at the knee joint. Abduction-adduction involves lateral-medial thigh motion, not their primary knee focus. Extension-flexion defines their opposing actions, distinct from side movements, crucial for leg dynamics.

Correct Answer: C

Rationale: The external occipital protuberance, a midline bump on the occipital bone, is termed the inion, a landmark for neck muscle attachment (e.g., trapezius). The nasion is the forehead-nose junction, a facial point. The acromion, on the scapula, is a shoulder feature, not cranial. The mental protuberance is the chin's prominence on the mandible. Inion's specific occipital location and role in muscle anchorage distinguish it, aligning with skull anatomy, unlike facial, shoulder, or mandibular misnomers.

Correct Answer: D

Rationale: Elite athletes in prolonged high-intensity exercise (>2.5 hours), like marathons, should consume 90 g of glucose plus fructose per hour. This mix leverages multiple transporters (SGLT1 for glucose, GLUT5 for fructose), maximizing absorption beyond glucose's 60 g/h limit, delivering ~1.5 g/min of energy. Solo 60 g glucose caps at 1 g/min, insufficient for sustained high intensity. Adding fructose to 60 g boosts uptake slightly, but 90 g optimizes fuel, reducing fatigue. Excess glucose alone (90 g) overloads SGLT1, risking GI distress. The dual-carb approach distinguishes it, critical for elite endurance performance.

Correct Answer: C

Rationale: The temporalis muscle spans the side of the head, originating from the temporal bone's fossa and inserting on the mandible, elevating it for chewing. The forehead hosts frontalis for brow movement. The neck has muscles like sternocleidomastoid for head turning. The chin area features mentalis for lip motion. Temporalis' lateral cranial position and masticatory role distinguish it, essential for jaw closure, unlike forehead, neck, or chin functions.

Correct Answer: B

Rationale: Triceps brachii extends the forearm, straightening the elbow, with its three heads inserting on the ulna. Biceps brachii flexes it. Brachialis flexes beneath biceps. Deltoid abducts the arm, not elbow-focused. Triceps' extension role distinguishes it, essential for pushing, unlike flexors or shoulder movers.