- sebaceous gland
any of the cutaneous glands that secrete oily matter for lubricating hair and skin.[1720-30]
* * *Small oil-producing gland in the skin, usually connected to a hair follicle by a duct into which it releases sebum, a component of the slightly greasy film on the skin that helps keep it flexible and prevents too much water loss or absorption.The glands are distributed over the entire body except the palms and soles, most abundantly on the scalp and face. Large and well developed at birth, they shrink during childhood but enlarge again and increase their sebum output at puberty (apparently in response to male hormones), often leading to acne.
* * *▪ anatomysmall oil-producing gland present in the skin of mammals. Sebaceous glands are usually attached to hair follicles and release a fatty substance, sebum, into the follicular duct and thence to the surface of the skin. The glands are distributed over the entire body with the exception of the palms of the hands and the soles of the feet; they are most abundant on the scalp and face.The sebaceous gland secretes a mixture of fats (triglycerides, wax esters, squalene, and cholesterol) and cellular debris, which is discharged as sebum through the sebaceous duct connecting the gland to the hair follicle. Sebum helps to form the slightly greasy surface film of the skin; it thus helps keep the skin flexible and prevents the skin's loss of absorption of excessive amounts of water.Sebaceous glands begin to form from embryonic hair follicles during the fourth month of gestation and are large and well-developed at birth. They shrink during childhood but enlarge again with the onset of puberty; the maturation of the glands seems to be dependent on circulating levels of male hormones, in particular testosterone.The sebaceous glands are involved in the development of the common adolescent skin disorder known as acne vulgaris. Acne occurs when the outlet from the gland to the surface of the skin is plugged, allowing sebum to accumulate in the follicle and sebaceous duct. The chemical breakdown of triglycerides in the sebum, possibly by bacterial action, releases free fatty acids, which in turn trigger an inflammatory reaction producing the typical lesions (pimples) of acne.
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Sebaceous gland — Infobox Anatomy Name = Sebaceous gland Latin = glandula sebacea GraySubject = 234 GrayPage = 1069 Caption = Schematic view of a hair follicle with sebaceous gland. Caption2 = Cross section of all skin layers. A hair follicle with associated… … Wikipedia
sebaceous gland — UK / US noun [countable] Word forms sebaceous gland : singular sebaceous gland plural sebaceous glands medical an organ in your body that allows a type of oil called sebum to flow onto your skin and hair to keep them soft … English dictionary
Sebaceous gland — A normal gland of the skin which empties an oily secretion into the hair follicle near the surface of the skin. * * * sebaceous gland n any of the small sacculated glands lodged in the substance of the derma, usu. opening into the hair follicles … Medical dictionary
sebaceous gland — noun a cutaneous gland that secretes sebum (usually into a hair follicle) for lubricating hair and skin • Syn: ↑sebaceous follicle, ↑glandulae sebaceae • Hypernyms: ↑oil gland • Hyponyms: ↑Meibomian gland, ↑tarsal gland, ↑ … Useful english dictionary
sebaceous gland — noun A gland of the skin which secretes an oily substance, sebum, usually into a hair follicle near the surface of the skin. Syn: sebaceous follicle, glandulae sebaceae … Wiktionary
sebaceous gland — any of the simple or branched glands in the skin that secrete an oily substance, sebum. They open into hair follicles and their secretion is produced by the disintegration of their cells. Some parts of the skin have many sebaceous glands, others… … The new mediacal dictionary
sebaceous gland — noun a small gland in the skin which secretes a lubricating oily matter (sebum) into the hair follicles to lubricate the skin and hair … English new terms dictionary
sebaceous gland — seba′ceous gland n. anat. any of the cutaneous glands that secrete oily matter for lubricating hair and skin • Etymology: 1720–30 … From formal English to slang
sebaceous gland — /səbeɪʃəs ˈglænd/ (say suhbayshuhs gland) noun any of the cutaneous glands which secrete oily matter for lubricating hair and skin … Australian English dictionary
sebaceous gland — Oil secreting glands, mostly clustered around hair follicles. The oil, sebum, is released into the oil glands from the disintegrated cytoplasm of shedding holocrine cells that line the alveolar surfaces. The nature of the secretion is often a… … Herbal-medical glossary