Which type of sweat gland is characterized by secretion that involves loss of part of the gland cell?

Apocrine sweat glands are indeed characterized by a mode of secretion in which part of the gland cell is lost along with the secretion. This process, known as apocrine secretion, involves the vesicles forming in the cytoplasm of the cells and a portion of the cell membrane protruding outward, forming a pocket that eventually pinches off, releasing the secretion along with some cytoplasmic material. This type of secretion typically results in a product that is richer in proteins and lipids, contributing to the distinct odor associated with apocrine sweat.

In contrast, eccrine glands, which are involved in thermoregulation, secrete a watery, hypotonic fluid directly onto the skin surface without any loss of cell material. Merocrine glands also do not lose any part of their cells; instead, they release their secretions via exocytosis, maintaining the integrity of the glandular cells. Endocrine glands, while involved in secretion, release hormones directly into the bloodstream and are not primarily focused on sweat production. This understanding differentiates the role and structure of apocrine glands from other gland types, highlighting why this answer is appropriate.