Glandular

Glandular is an adjective used in biology and medicine to describe anything relating to glands, the organs that synthesize and secrete substances for bodily use or signaling. In animals, glands are typically classified as exocrine, which release secretions through ducts to surfaces such as skin or the digestive tract, and endocrine, which release hormones directly into the bloodstream. Glandular tissue is organized around secretory cells that form clusters such as acini or tubules and is often supported by connective tissue and a network of blood vessels.

Exocrine glands include salivary, sweat, and gastric glands, whereas endocrine glands include thyroid, pituitary, and adrenal glands. Some organs contain both secretory types, known as mixed or pancreatic glands. Histologically, glandular epithelium can be simple or compound and can form tubular, acinar (alveolar), or tubuloacinar structures. Secretions are released by merocrine (exocytosis), apocrine (loss of part of the cell membrane with cytoplasm), or holocrine (cell rupture) mechanisms.

Glandular secretions fulfill diverse roles: digestive enzymes and mucus for digestion and protection; saliva, gastric acid, and pancreatic juice; hormones that regulate metabolism, growth, and reproduction; and lubricants in various mucosal surfaces. In many tissues, glandular cells also participate in immune defense and tissue repair.

Glandular disorders include overactivity or underactivity of endocrine glands, benign tumors such as adenomas and malignant tumors such as adenocarcinomas, hyperplasia, cyst formation, and inflammatory processes affecting glands or their ducts. Accurate diagnosis often relies on imaging, histology, and hormone profiling.

In botany, glandular can describe plant structures such as glandular trichomes or secretory glands that produce essential oils, resins, or mucilages, contributing to defense or attraction of pollinators.