Eccrine glands

Eccrine Glands

Eccrine glands are a type of sweat gland that are found throughout the human body. They play a crucial role in thermoregulation and excretion. Unlike apocrine glands, which are concentrated in specific areas such as the armpits and groin, eccrine glands are distributed widely across the skin.

Structure

Eccrine glands are simple, coiled, tubular glands. They are composed of a secretory unit located in the dermis and a duct that opens directly onto the surface of the skin. The secretory portion is responsible for the production of sweat, while the duct transports the sweat to the skin surface.

Secretory Unit

The secretory unit of eccrine glands is made up of two types of cells:

• Clear cells: These cells are responsible for the production of the watery component of sweat. They transport water and electrolytes from the interstitial fluid into the gland lumen.
• Dark cells: These cells secrete glycoproteins and other components that contribute to the composition of sweat.

Duct

The duct of the eccrine gland is lined with two layers of cuboidal epithelial cells. It reabsorbs some of the sodium and chloride ions from the sweat, which helps to conserve electrolytes.

Function

Eccrine glands are primarily involved in thermoregulation. They secrete a watery fluid that evaporates from the skin surface, dissipating heat and cooling the body. This process is essential for maintaining a stable internal body temperature, especially in hot environments or during physical exertion.

Thermoregulation

The autonomic nervous system controls eccrine sweat secretion. When the body temperature rises, the hypothalamus signals the eccrine glands to increase sweat production. This evaporative cooling mechanism is vital for preventing hyperthermia.

Excretion

In addition to thermoregulation, eccrine glands also play a minor role in excretion. They help eliminate small amounts of metabolic waste products, such as urea and lactate, from the body.

Clinical Significance

Eccrine glands can be involved in various medical conditions:

• Hyperhidrosis: A condition characterized by excessive sweating, often due to overactive eccrine glands.
• Anhidrosis: A condition where there is a lack of sweating, which can lead to overheating and heat-related illnesses.
• Eccrine poroma: A benign tumor that arises from the ductal portion of the eccrine gland.

See Also

• Apocrine gland
• Sweat gland
• Thermoregulation