Exocrine glands Flashcards
What are the two categories of galnds?
Endocrine and expocrine
What type of tissue are glands derived from?
Epithelial tissue
What are endocrine glands?
Glands that synthesize and release hormones into the blood
What are exocrine glands?
Glands whose secretions are conveyed in epithelial-lined excretory ducts
What significance do glands have in disease?
CA (adenoma/carinoma)
How are exocrine glands classified (3)?
by the
- type of secretion
- mode of secretion
- cell numbers
What are the four different types of secretions that glands can have?
mucous
Serous
Mixed
Sebaceous
What do mucus glands secrete?
Secrete mucinogens, large glycosylated proteins (PAS positive), that when hydrated form a thick (viscous), protective fluid called mucin. Mucin is a component of mucus.
What are serous secretions?
Watery enzyme laden secretions (parotid and exocrine)
What are mixed gland secretions?
serous and mucous
What are sebaceous secretions?
waxy oily substances (skin)
Sebum
What are the three classifications that glands can have based on their mode of secretion?
Merocrine
Apocrine
Holocrine
What is merocrine secretion?
Exocytosis w/o loss of membrane
What is the most common mode of secretion?
Merocrine
What is apocrine secretion?
Secretory product is released along with apical cytoplasm and apical plasmalemma
(lipids in breast milk)
What is holocrine secretion?
When entire cell and its secretory product released
What are the two types of classification of glands based on their cellular number?
unicellular
multicellular (organized glands)
What stain would be used to identify goblet cells?
PAS (there are glycosylated proteins in mucus)
Acinar cells are formed by the formation of what?
Acinus
What are two key characteristics of mucus secreting cells?
Pale area where mucus is, and a nucleus pushed/flattened to the periphery
What are the two key characteristics of serous cells?
Acidophilic cytoplasm, round nucleus
What are the two key characteristics of sebeaceous cells?
Clear cytoplasm
Central, round nucleus