Sweat Glands
Sweat Glands are of two types:
- Eccrine glands. They are the ordinary, small-sized (0.3-0.4 mm) sweat glands which are distributed all over the skin except on the beds of nails, margins of lips and the glans penis. Over 3 million sweat units are present at birth.
The glandular portion is a simple tube folded by a number of unequal twists into the shape of a ball. This tube is composed of a thick, connective tissue basement membrane which is lined by a single layer of cubical or columnar cells. These cells secrete sweat. Between the basement membrane and the secretory cells are longitudinally or obliquely placed spindle-shaped cells called the myo-epithelial cells. These cells are contractile arid are supposed to help in the discharge of sweat.
The sweat gland opens into the sweat duct which has an epithelial lining consisting of two or three layers of cells. The passage of this duct through the epidermis has no proper wall, but is merely, a channel in between the epithelial cells.
- Apocrine glands. They occur in the axillae, areola and nipples of breasts, umbilicus, around the anus and the genitalia. Their glandular portion is very large and may measure 3 mm to 5 mm in diameter (the eccrine glands being only 0.3 to 0.4 mm in diameter). The myo-epithelial cells are highly developed and more abundant in these glands. They are specialized sweat glands, and their secretion is odoriferous with a secondary sexual significance (pheromone).
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Structure of Epidermis
Structure of Dermis
Sebaceous Glands
Sweat Glands
Caring for the Skin
Healthy Skin
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