Many adults living in the US become curious about doctor prescribed growth hormone replacement therapy when they begin to experience chronic symptoms, such as low energy, fatigue and low sex drive, that are frequently associated with your bodyâs declining growth hormone levels.
External, or exocrine, secretion is distinguished from internal, or endocrine, secretion. In external secretion the products elaborated by a gland are released into the external environment; the secretion first enters the glandular duct, from which it is discharged onto the surface of the body or into hollow organs.
Exocrine glands are glands that secrete chemical substances into ducts to be released. Most exocrine glands release their substances to the outside of the body while others release their substances to the outside of the gland onto a surface still within the body. Three categories of exocrine glands are apocrine, holocrine and merocrine.