Pilosebaceous unit

Pilosebaceous Unit

The Pilosebaceous unit is a unique anatomical structure found in the skin, primarily responsible for hair growth and sebum production. It is composed of a hair follicle, sebaceous gland, and arrector pili muscle.

Structure

The pilosebaceous unit is located in the dermis, the second layer of the skin. It consists of a hair follicle, which is a small tubular cavity where the hair grows; a sebaceous gland, which produces sebum, an oily substance that lubricates the hair and skin; and an arrector pili muscle, a tiny muscle connected to the hair follicle that causes hair to stand up when it contracts.

Function

The primary function of the pilosebaceous unit is to produce and secrete sebum. This oily substance helps to waterproof and lubricate the skin and hair, preventing them from drying out. The unit also plays a role in hair growth, with the hair follicle facilitating the growth of hair from its root.

Clinical significance

Disorders of the pilosebaceous unit can lead to a variety of skin conditions. Overactive sebaceous glands can result in excessive sebum production, leading to conditions such as acne and seborrheic dermatitis. Conversely, underactive glands can result in dry skin and hair. Inflammation of the hair follicle can lead to conditions such as folliculitis and hidradenitis suppurativa.

See also

• Sebaceous gland
• Hair follicle
• Arrector pili muscle
• Dermis
• Skin