What does SI mean? Definitions for SI Here are all the possible meanings and translations of the word SI.
The sebaceous glands are microscopic exocrine glands in the skin that secrete an oily or waxy matter, called sebum, to lubricate and waterproof the skin and hair of mammals.ebaceous glands secrete the oily, waxy substance called sebum (Latin: fat, tallow) that is made of triglycerides, wax esters, squalene, and metabolites of fat-producing cells. Sebum waterproofs and lubricates the skin and hair of mammals.
Oil glands are also called sebaceous glands, and they secrete lubricating sebum via the holocrine secretion method. Sweat glands are also called sudoriferous glands. There are apocrine sweat glands which secrete a viscous, protein-rich sweat via the apocrine method in the armpits, nipple, anus and genital region. There are also eccrine sweat glands which secrete a thin, watery sweat via the merocrine method all over the body.