Exocrine Glands and Cystic Fibrosis Flashcards
What is an exocrine gland?
A gland with a duct.
What is an endocrine gland?
A ‘ductless’ gland which secretes into the bloodstream.
What is a unicellular gland?
A gland where the cells are interposed in and between the epithelium.
NO DUCTS
they produce mucin which becomes mucus when mixed wth water e.g. Goblet cells.
What is a multicellular gland?
A gland composed of two elements - an epithelium derived duct and a secretory unit.
What is the difference between a acinar and tubular gland?
Acinar glands are ‘grape like’ and often come in bundles - have a large head.
Tubular gland and tube shaped - like a column.
What is a gland?
An epithelial cell or collection of cells specialised for secretion.
Describe the merocrine method of secretion. Example.
Majority of glands secrete using this method.
Essentially exocytosis - vesicles in the cell move through the cytoplasm, attach to the plasma membrane and come out the other side.
However, no cell components are gained/lost.
Example being salivary, pancreas and normal sweat glands.
What is apocrine secretion? Example.
An apocrine secretion, parts of the cytoplasm or fat droplets move to the end of the cell and ‘pitches’ a piece of the plasma membrane to create its own membrane when outside the cell. This the method of secretion happens in lactation and sweat concerning body odour.
What is holocrine secretion?
This is when the entire cell degrades and pieces of the cytoplasm are released as secretions. An example is semen.
What are the three major type of salivary glands? Locations.
Sublingual (small one at the front), submandibular (slightly larger one in the jaw), paratoid (large one in the back of the face, this is a serous gland which secretes no mucus).
What ion channel is missing cystic fibrosis sufferers?
Cystic Fibrosis Transmembrane Regulator (CFTR) - not present in epithelial suffered of CF sufferers.
How does the lack of CFTR in cystic fibrosis sufferers cause sticky mucus in their body?
The lack of CFTR affects the chloride ion transport across membranes. A high chloride content in the cells, by rules of osmosis, means water stays in the cells too. This means the mucus in CF sufferers cannot by hydrate by water, making it viscous and difficult to move.
What often happens in newborn babies with cystic fibrosis
they cannot pass their first faeces - difficult to move unhydrated faeces down colon.
What often happens to older CF sufferers?
They become constipation and invagination of internal membranes which open to the exterior.
How is the pancreas affected in CF sufferers?
The pancreas is both an endocrine and exocrine gland.
The exocrine secretions in patients contain too little water, which blocks the ducts.
This often causes pancreatitis and fibrosis (thickening and scarring).
This causes insufficient lipase production, and they often have undigested fat in their faeces as it cannot be broken down by the lipase.
