Sudoriferous glands, commonly known as sweat glands, are small, tubular structures located within the skin. These exocrine glands produce and secrete substances onto an epithelial surface via a duct. Their primary role involves producing sweat, a watery fluid released to the skin’s surface. These glands are distributed across most of the human body.
The Two Main Types of Sweat Glands
The human body contains two primary types of sudoriferous glands: eccrine and apocrine glands. Eccrine sweat glands are widely distributed across nearly the entire body surface, with the highest concentrations on the palms and soles. These glands open directly onto the skin’s surface and produce a thin, watery sweat composed mainly of water, with small amounts of dissolved salts and amino acids. This watery secretion plays a significant role in cooling the body.
Apocrine sweat glands are concentrated in specific areas, including the armpits, groin, and around the nipples. Unlike eccrine glands, apocrine glands open into hair follicles rather than directly onto the skin surface. These glands become active after puberty due to hormonal changes and are often stimulated by emotional stress. Apocrine sweat is thicker and more viscous, containing lipids and proteins. Body odor develops when bacteria on the skin surface break down these organic compounds, producing volatile fatty acids and ammonia.
How Sweat Regulates Body Temperature
Sweating serves as a primary mechanism for the body to regulate its internal temperature, a process known as thermoregulation. When the body’s temperature rises, from physical activity or a warm environment, the hypothalamus in the brain signals the eccrine sweat glands to produce sweat. This fluid is then released onto the skin’s surface.
As sweat rests on the skin, it absorbs excess body heat. The absorbed heat provides the energy needed for the sweat to transition from a liquid to a gaseous state, a process called evaporative cooling. As sweat evaporates, it carries heat away from the body, lowering the skin’s temperature and, consequently, the overall body temperature. This cooling mechanism helps maintain a stable internal temperature.
Conditions Related to Sweat Gland Function
Malfunctions in sweat gland activity can lead to various conditions. Hyperhidrosis is characterized by excessive sweating, often occurring without a clear trigger like heat or exercise. This condition primarily involves the eccrine glands, leading to large volumes of watery sweat that can affect areas such as the palms, soles, and armpits.
Anhidrosis is the opposite condition, defined by the inability to sweat normally. This can be localized to specific body areas or generalized across the entire body. Anhidrosis impairs the body’s capacity for evaporative cooling, which can lead to overheating and rises in core body temperature, especially during physical activity or in hot environments.
Bromhidrosis refers to excessive or foul body odor resulting from the bacterial decomposition of sweat gland secretions and cellular debris on the skin. While apocrine secretions are the primary source of strong body odor due to their lipid-rich content, eccrine sweat can also contribute if bacteria degrade softened keratin on the skin. This condition is largely determined by apocrine gland activity and can affect a person’s quality of life.