Talirauhasten

Talirauhasten, or sebaceous glands, are small exocrine glands in the skin that produce sebum, an oily lipid-rich secretion. They are typically associated with hair follicles as part of the pilosebaceous unit and are distributed across most skin surfaces, with the highest density on the scalp, face, and upper trunk. They are relatively sparse on the palms and soles.

Anatomically, each gland is lobulated and made up of secretory cells called sebocytes. The glands drain through ducts that usually open into the hair follicle pore, though some may release sebum directly onto the skin surface. Sebaceous glands are holocrine, meaning mature sebocytes fill with lipids and rupture to release their contents into the duct.

Secretion and function: Sebum lubricates and waterproofs the skin and hair and contains antimicrobial lipids that contribute to the skin’s barrier function. The composition typically includes triglycerides, wax esters, cholesterol esters, squalene, cholesterol, and free fatty acids. Sebum production varies by body site and is influenced by hormonal status, age, and circadian factors.

Regulation and clinical relevance: Sebaceous gland activity is strongly influenced by hormones, particularly androgens, with activity increasing during puberty. Abnormal sebum production or ductal blockage can contribute to skin conditions such as acne vulgaris and seborrheic dermatitis. Sebaceous hyperplasia presents as small, yellowish papules, often on the face. Diagnosis is usually clinical; histology shows clustered lobules of sebocytes connected to ducts that open into hair follicles or the skin surface.