About Vermilion zone, all true except:

Correct Answer: C

Rationale: The vermilion zone's epithelium is thinner than the outer labial skin, not thicker, allowing the underlying vascularity to show through, giving it a red appearance.

Correct Answer: C

Rationale: The muscularis externa of the esophagus transitions from skeletal muscle (upper third) to smooth muscle (lower third), not entirely smooth muscle.

Correct Answer: C

Rationale: Intracellular canaliculi are not continuous with rER; they are specialized for ion transport and expand with microvilli during secretion.

Correct Answer: B

Rationale: Pyloric glands have deeper pits (about half the mucosal thickness) compared to the shorter pits of fundic glands.

Correct Answer: A

Rationale: Parotid acini produce saliva, which begins carbohydrate digestion, not lipid digestion; hepatocytes and pancreatic acini produce bile and lipase for lipids.