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    Related Topics

    From Integumentary System

    Adipose Tissue
    Fat tissue in the hypodermis that insulates and stores energy.
    Nails
    Hard, keratinized extensions at the tips of fingers and toes.
    Ceruminous Glands
    Specialized sweat glands in the ear canal that produce earwax.
    Nail Bed
    Skin under the nail plate, supplying nutrients.
    Sensory Nerve Endings
    Nerve endings in the skin that detect sensory information.
    Reticular Layer
    Deeper dermal layer, housing collagen and elastin fibers.
    Hair Root
    Part of hair within the follicle, undergoing growth.
    Apocrine Sweat Glands
    Sweat glands found in the armpits and genital areas.
    Nail Plate
    Hard, visible part of the nail.
    Carotene
    Pigment contributing to the yellow-orange coloration of the skin.
    Ruffini Endings
    Receptors that detect skin stretch and finger position.
    Hair Follicle
    Root of the hair embedded in the skin.
    Pheomelanin
    Type of melanin that produces yellow and red pigmentation.
    Eccrine Sweat Glands
    Most common sweat glands, found all over the body.
    Hemoglobin
    Oxygen-carrying protein in blood responsible for the red coloration of skin.
    Dermis
    Layer below the epidermis providing structure and flexibility.
    Stratum Lucidum
    Layer found only in thick skin, providing extra protection.
    Dermal Papillae
    Extensions of the dermis into the epidermis that provide nutrients and sensory functions.
    Eumelanin
    Type of melanin that produces brown and black pigmentation.
    Hair Shaft
    Visible part of hair extending from the follicle.
    Melanin
    Pigment responsible for skin color.
    Connective Tissue
    Fibrous tissue supporting the skin and other organs.
    Hair Papilla
    Cluster of cells at the base of the hair follicle containing capillaries.
    Lamellated (Pacinian) Corpuscles
    Receptors that detect deep pressure and vibration.
    Stratum Basale
    Deepest layer of epidermis responsible for cellular regeneration.

    Sweat Glands

    Reviewed by our medical team

    Glands that produce sweat to regulate body temperature.

    1. Overview

    Sweat glands, also known as sudoriferous glands, are specialized exocrine glands of the integumentary system that produce and secrete sweat. Their primary function is thermoregulation through evaporative cooling, but they also play roles in excretion, skin hydration, and antimicrobial defense. There are two main types of sweat glands in humans: eccrine (merocrine) glands and apocrine glands. These glands are crucial for maintaining homeostasis, especially during heat exposure, physical exertion, and emotional stress.

    2. Location

    Sweat glands are distributed throughout the skin but vary in type and density based on body region:

    • Eccrine sweat glands:

      • Found all over the body, especially abundant on the palms, soles, forehead, and axillae.

    • Apocrine sweat glands:

      • Restricted to specific areas: axillae (armpits), areola of the breasts, perianal region, external genitalia, and eyelids (as modified glands).

    Eccrine glands open directly onto the skin surface, whereas apocrine glands usually open into hair follicles.

    3. Structure

    Sweat glands are coiled tubular structures composed of two main parts:

    • Secretory portion:

      • Located deep in the dermis or hypodermis; consists of a coiled glandular epithelium surrounded by myoepithelial cells.

    • Duct portion:

      • Leads from the secretory coil to the skin surface or hair follicle; lined by stratified cuboidal epithelium.

    Eccrine Glands

    • Simple coiled tubular glands.

    • Innervated by cholinergic fibers of the sympathetic nervous system.

    Apocrine Glands

    • Larger, less numerous glands.

    • Begin functioning at puberty and are influenced by adrenergic stimuli.

    • Produce a thicker secretion rich in proteins and lipids.

    4. Function

    Sweat glands serve a variety of essential functions:

    • Thermoregulation: Sweat evaporation cools the body, especially during physical activity or heat exposure.

    • Excretion: Helps eliminate small amounts of metabolic waste (e.g., urea, ammonia, electrolytes).

    • Skin hydration: Maintains moisture balance of the stratum corneum, particularly by eccrine glands.

    • Body odor generation: Apocrine secretions are metabolized by skin flora, producing characteristic scent.

    5. Physiological role(s)

    Beyond their immediate functions, sweat glands contribute to broader physiological processes:

    • Homeostasis: Regulation of body temperature and water balance via evaporative cooling and electrolyte excretion.

    • Immune defense: Sweat contains antimicrobial peptides such as dermcidin, which help protect against pathogens.

    • Emotional signaling: Apocrine sweating increases during emotional stress, potentially playing a role in nonverbal communication.

    • pH maintenance: Sweat contributes to the skin's acid mantle, inhibiting microbial overgrowth.

    6. Clinical Significance

    Sweat glands are involved in several dermatological and systemic conditions:

    • Hyperhidrosis:

      • Excessive sweating, often localized to palms, soles, or axillae; can be idiopathic or secondary to systemic disease.

    • Anhidrosis or hypohidrosis:

      • Reduced or absent sweating due to nerve damage, skin conditions, or genetic disorders, increasing risk of overheating.

    • Miliaria (heat rash):

      • Blockage of sweat ducts leads to retention of sweat and inflammation, commonly seen in hot, humid environments.

    • Bromhidrosis:

      • Foul-smelling body odor caused by bacterial decomposition of apocrine sweat; common in axillary and genital regions.

    • Apocrine gland disorders:

      • Hidradenitis suppurativa: chronic inflammatory condition of apocrine gland-bearing areas, causing painful nodules and abscesses.

    • Target for treatment:

      • Botulinum toxin (Botox) injections are used to block acetylcholine release and reduce excessive eccrine gland activity in hyperhidrosis.

    Did you know? Your skin produces sweat to cool your body down, which is why you sweat when you get too hot or during exercise.