Which of the following abdominal muscles is not a part of the anterior abdominal wall?

Correct Answer: A

Rationale: The anterior abdominal wall includes rectus abdominis , internal oblique (c, likely 'interior' typo), and external oblique , forming the front's muscular sheath for flexion and compression. Quadratus lumborum , in the posterior abdominal wall, attaches to the lumbar vertebrae and iliac crest, aiding lateral flexion and posture, not anteriorly. Its deep, posterior location excludes it from the anterior group, making 'a' the correct non-member.

Correct Answer: C

Rationale: The vertebral foramina of cervical vertebrae (C1-C7) are triangular, larger than in other regions, accommodating the cervical spinal cord and its mobility. Round fits thoracic/lumbar foramina more closely. Oval describes cervical bodies, not foramina. Heart-shaped is unrelated to vertebral anatomy. The triangular shape, widest at the base, reflects the cervical spine's need for space (e.g., C1's ring, C7's transition), making 'c' the correct answer per spinal anatomy.

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.