Glands and histology Flashcards
What is a gland?
An organ or tissue which secretes substances in the body
What type of cells are glands made from?
Epithelial cells
What can products of glands be?
Proteins - enzymes, hormones (steroids), mucous
Lipids
What is mucous made from?
Glycoproteins
What is the difference between glycoproteins and proteoglycans?
Proteoglycans contain more protein than glycoproteins
What are the two main classifications of glands? Where do they act?
Exocrine-locally from gland
Endocrine -away from gland
Exocrine glands secrete products from which surface of individually secretory cells?
Apical
Endocrine glands release products from which surface of individual secretory cells? Where do the products go to?
Basal surface
Into capillary to target organ
Why are exocrine glands (ducts) better than individual secretory cells in the mouth?
There is the fewest number of openings to the epithelial surface
Describe how exocrine glands release products
Secretory cells in duct release product from apical surface into the lumen
Product flows from lumen onto the epithelium
Endocrine glands are made up from what group of cells?
Aggregates of secretory cells (with capillaries in between)
Why aren’t endocrine glands further classified into different groups? Give examples of endocrine glands
They are highly individual
Adrenal, thyroid glands
How are exocrine glands classified?
By shape: simple or compound
By secretion cell: tubular or alveolar
What is the definition of a simple secretory unit?
An exocrine gland which secretes via one or no ducts
What is the definition of a compound secretory unit?
An exocrine gland which secretes via a branched duct system
Secretion cells can be tubular or alveolar. What products do these cells secrete, hence the other name for these cells?
Tubular - mucous cells
Alveolar -serous cells
What type of cells make up the thyroid gland? What is different about the thyroid gland structure?
Aggregated secretory cells
It contains follicles
What is within the follicles of the thyroid?
Precursor of thyroid hormones - thyroglobulin
When required, thyroglobulin is broken down into the thyroid hormones so they can be released into the bloodstream. What are the thyroid hormones called?
T3 and T4
The adrenal gland is made up of what 3 layers?
Capsule
Cortex
Medulla
Describe the shape of cells in tubular glands. How do they stain? What shape are the nuclei?
Appear round but are columnar - due to artefact
Pale due to mucous
Flat nucleus
Describe the shape of alveolar gland nuclei, how do they stain?
Round
Dark
