Which secretion mode is characterized by release at the apical surface with surrounding cytoplasm?

• A. Merocrine
• B. Apocrine
• C. Holocrine
• D. Endocrine

Answer: (B)

Apocrine secretion involves releasing the product together with a portion of the cell’s apical cytoplasm as the apical part of the cell buds off. This means the secreted material is enveloped by cytoplasm and membrane fragments, coming out at the apical (luminal) surface. After shedding, the cell remains intact and can regenerate the lost apical portion to continue secreting. This differs from merocrine secretion, where only vesicles fuse with the membrane to release product without losing cytoplasm; holocrine secretion, where the entire cell disintegrates to release its contents; and endocrine secretion, which releases hormones into the bloodstream rather than into a duct or lumen.