The vastus intermedius muscle is deep to which of the following muscles?

Correct Answer: B

Rationale: The vastus intermedius, part of the quadriceps, lies deep to the rectus femoris, which overlays it, both inserting into the patella via the quadriceps tendon for knee extension. Biceps femoris , a hamstring, is posterior, not overlying. Vastus medialis and lateralis , also quadriceps, are lateral and medial to intermedius, not superficial. Rectus femoris's anterior position over intermedius, per thigh anatomy, makes 'b' the correct answer.

Correct Answer: A

Rationale: Pronation turns the palm downward or posterior, with the radius rotating over the ulna, crossing at the radioulnar joints, as in typing. Supination turns it upward. Rotation is a general term, not specific here. Elevation raises, unrelated to forearm twist. Pronation's distinct radius-ulna crossover, per forearm mechanics, makes 'a' the correct answer.

Correct Answer: C

Rationale: Tight junctions form impermeable seals between adjacent cells, preventing substances from leaking between them, as in the gut lining to block bacteria. Gap junctions allow communication via channels for ions/small molecules, not sealing. Desmosomes anchor cells mechanically, resisting stress, not blocking passage. Hemidesmosomes tether cells to the basement membrane, not each other. Tight junctions' role in creating barriers, like in the blood-brain barrier, distinguishes them, making 'c' the correct junction type.

Correct Answer: C

Rationale: Stratified squamous epithelium forms the epidermis, multi-layered and keratinized, protecting against abrasion, UV, and pathogens, as skin's outer barrier. Simple cuboidal is for secretion (e.g., glands), simple columnar for absorption (e.g., gut), and transitional for stretching (e.g., bladder) none match skin's needs. Stratified squamous's tough, renewable structure, per integumentary system, makes 'c' correct.

Correct Answer: C

Rationale: Long bones, like the femur or humerus, are longer than wide, designed for support and movement via levers. Short bones are cuboidal (e.g., carpals), flat bones are thin (e.g., skull), and irregular bones are complex (e.g., vertebrae). Long bones' length-to-width ratio, per bone classification, makes 'c' correct.