Chapter 5 glands of the skin

Overview of the Integumentary System

• The integumentary system consists of the skin, cutaneous membrane, and its appendages, which include hair, sweat glands, and fingernails.

Sweat Glands

• Sweat glands are a significant component of the skin's appendages.

• They are classified into classes:

  • Eccrine Sweat Glands

    • Most abundant type, prevalent throughout most of the body.

    • Primarily involved in thermal regulation by secreting watery sweat which evaporates, cooling the body.

    • High concentration found in palms of hands, soles of feet, and forehead.

    • Composed mainly of water, with trace amounts of sodium and urea, making the secretion slightly acidic. This acidity helps regulate bacterial growth on the skin.

  • Apocrine Sweat Glands

    • Located in specific areas, including the armpits, genital region, and sides of the torso.

    • Typically not functional until puberty; linked to scent glands in other animals and increases in activity with sexual arousal.

    • Secretions are a mixture of watery and fatty substances.

    • Body odor is caused by bacteria breaking down the fatty content of the apocrine secretion.

    • Management of body odor can be achieved using deodorants, perfumes, or antiperspirants:

      • Deodorants: Mask the odor.

      • Antiperspirants: Limit secretion from glands.

• Mammary Glands

  • A specialized type of apocrine gland, found in both males and females but primarily active in females due to hormonal changes during and after pregnancy.

  • Produce colostrum initially, then milk, facilitated by the hormone prolactin.

  • Colostrum is nutrient-rich and provides immune system components to newborns.

• Ceruminous Glands

  • Also a subtype of apocrine glands, responsible for producing earwax.

  • Earwax is a combination of secretions from ceruminous and sebaceous glands and acts as a barrier against insects, with a bitter taste as a deterrent.

Sebaceous Glands

• Oil glands known for producing sebum, an oily substance that:

  • Keeps skin lubricated and watertight.

  • Lubricates hair to prevent matting.

• Sebaceous glands utilize holocrine secretion, where cells accumulate oil, rupture, and release secretion with cell fragments.

• They are influenced by sex steroids (androgens), which can lead to increased gland activity and acne during puberty.

Acne

• A localized inflammatory response typically associated with the sebaceous glands.

• Develops when bacteria multiply within obstructed glands, resulting in inflammation and infection.

• Stages of acne:

  • Normal Sebaceous Gland: Healthy state.

  • Blackhead (Open Comedone): Darkened surface due to oxidized white blood cells.

  • Whitehead (Closed Comedone): Formed when the infection remains sealed from air.

  • Papule: An inflamed area, typically small yet reddish.

  • Pustule: Larger, inflamed area with potential for pus formation.

• Prevention involves keeping the skin clean and managing skin bacteria levels.

Summary

• The slide set covered the functions and significance of sweat and sebaceous glands as skin appendages, emphasizing their physiological roles in thermoregulation, odor management, moisture retention, and implications for skin conditions like acne.