AskDefine | Define exocrine

Dictionary Definition

exocrine adj : of or relating to exocrine glands or their secretions [ant: endocrine]

User Contributed Dictionary

English

Adjective

  1. Producing external secretions that are released through a duct.
  2. Pertaining to the exocrine glands or their secretions.

See also

Extensive Definition

Exocrine glands are glands that secrete their products (enzymes) into ducts (duct glands). They are the counterparts to endocrine glands, which secrete their products (hormones) directly into the bloodstream (ductless glands) or release hormones (paracrines) affect only target cell near the release site by.

Examples

Typical exocrine glands include sweat glands, salivary glands, mammary glands, stomach, liver and the pancreas. (Example of an endocrine gland is the adrenal gland, which is found on top of the kidneys and secretes the hormone adrenaline).

Types

There are multiple ways of classifying exocrine glands:

Structure

Exocrine glands contain a glandular portion and a duct portion, the structures of which can be used to classify the gland.
  • The duct portion may be branched (called compound) or unbranched (called simple).
  • The glandular portion may be tubular, acinar, or may be a mix of the two (called tubuloacinar). If the glandular portion branches, then the gland is called a branched gland.

Method of secretion

Exocrine glands are named apocrine gland, holocrine gland, or merocrine gland based on how their product is secreted.
  • Apocrine glands - a portion of the plasma membrane buds off the cell, containing the secretion. Apocrine gland is often used to refer to the apocrine sweat glands which use merocrine secretion.
  • Holocrine glands - the entire cell disintegrates to secrete its substance.
  • Merocrine glands - cells secrete their substances by exocytosis. Also called "eccrine."

Product secreted

List of exocrine glands

Glands typically may be referred to by two or more means, though some terms are rarely seen. The names of the anatomists who first described them are often employed, as:
Prostate gland is an exocrine gland of the male mammalian reproductive system. It secretes a clear and basic fluid that constitutes 1/3 of the volume of semen.

Additional images

References

External links

exocrine in Arabic: غدة قنوية
exocrine in German: Exokrine Drüse
exocrine in Spanish: Glándula exocrina
exocrine in French: Glande exocrine
exocrine in Icelandic: Útkirtietethhethetll
exocrine in Hebrew: בלוטה אקסוקרינית
exocrine in Japanese: 外分泌腺
exocrine in Portuguese: Glândula exócrina
exocrine in Russian: Железа внешней секреции
exocrine in Slovenian: Žleza z zunanjim izločanjem
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