Glands Flashcards
What do endocrine glands secrete?
Endocrine glands secrete directly into the blood stream. They secrete hormones.
What type of glands have ducts?
Exocrine glands have ducts and they secrete onto epithelial surfaces. Such as GI enzymes on the endothelium of the GI or sweat onto the surface of the skin.
Give an example of a unicellular gland.
Goblet cells are unicellular glands. They secrete mucus in the upper parts of the respiratory tract.
What are the cells in a gland which are at the ends of ducts and secrete called?
Acinar cells
If a gland has ducts which do not branch then how can it be classified?
It is a simple gland.
What type of glands stain poorly with H&E?
Mucus glands. Secretions are rich in mucus and mucins (highly glycosylated proteins)
What do serous glands secrete?
Mucus free, watery secretions (usually enzymes). These are eosinophilic and stain pink with H and E.
What is merocrine secretion and where does it occur?
Merocrine secretion is the same as exocytosis. The contents to be secreted are held in a lysosomes which fuses with the cell membrane and releases its contents outside the cell.
Where does apocrine secretion occur?
In the mammary glands. The secretions are within the cell and move towards the plasma membrane where they push out a bulge and take some of the membrane with them.
What type of secretion occurs in hair follicles?
Holocrine. The whole cell disintegrates and releases its contents.
Define trans epithelial transport.
This is where molecules are too big to pass through the plasma membrane. They are taken into the cell by endocytosis on one side of the cell, move across the cell and are then released by exocytosis.
Where does glycosylation of lipids and proteins occur? Why is this process important?
In the Golgi apparatus.
Glycosylation allows for specificity as the branching sugars give complex shapes. If these are destroyed by enzymes then it alters properties: adhesion to substrates, motility of cells, communication with neighbouring cells and inhibition of movement and cell division.
What happens to Golgi product?
Most of it is secreted, but some remains in the cell in the form of lysosomes.
What are the two pathways from Golgi to secretion?
Constitutive
Regulated
Name the three salivary glands
Parotid
Submandibular
Sublingual
