Eksokrine

Eksokrine, or exocrine, refers to glands that secrete their products onto an epithelial surface through ducts, rather than into the bloodstream. This distinguishes them from endocrine glands, which release hormones directly into the circulatory system. Examples of eksokrine glands include the salivary glands, lacrimal glands, sweat glands, and the pancreatic acini that deliver digestive enzymes to the duodenum.

Structure and secretion mechanisms vary among eksokrine glands. Most have secretory units called acini or tubules that produce a primary secretion, which is then conducted through ducts to a surface or body cavity. Secretions can be serous (watery with enzymes), mucous (thick and glycoprotein-rich), or mixed. The predominant mode of secretion is merocrine (exocytosis of vesicles), but some glands use apocrine or holocrine mechanisms, depending on cell type and species.

Functions of eksokrine secretions are diverse. Digestive enzymes from the pancreas and saliva begin chemical breakdown of nutrients. Mucus from various glands protects and lubricates surfaces such as the oral cavity and respiratory tract. Sweat and other secretions help regulate temperature and maintain skin integrity. Regulation involves neural input and hormones; for example, secretin and cholecystokinin stimulate pancreatic exocrine output, while autonomic innervation modulates salivary and sweat glands.

Clinical relevance includes exocrine pancreatic insufficiency, which impairs digestion; cystic fibrosis, which affects pancreatic and other exocrine secretions; and autoimmune or obstructive disorders that reduce glandular secretion, causing symptoms such as dry mouth or dry eyes. Understanding eksokrine function aids in the diagnosis and management of these conditions.