Glands Flashcards
Describe the process of glycosylation
Glycosylation occurs in the golgi. Different compartments are packaged through condensation, adding to proteins/lipids
Where does glycosylation occur?
Cisternae of the golgi apparatus
What are the functions of glycosylation?
Adhesion to substrates, mobility of cells, communication, contact inhibition of movement, gives rise to specificity.
Describe the three main salivary glands
Parotid - serous secretions only, submandibular and sublingual - serous and mucous secretions
What are the three main types of secretion?
Holocrine - lysing of cells
Apocrine - bubbling off from membrane - non membrane boudn structures push up on apical membrane
Merocrine - exocytosis
What types of glands are there?
Tubular/acinar, coiled/branched, simple/compound, endocrine/serous/mucous
How can secretion be controlled?
Chemically, neurally, endocrine system or neuro-endocrine system.
How are glands classified?
Destination of secretion, structure of gland, nature of secretion, method of discharge
What is endocytosis?
Cellular ingestion by which plasma membrane fold inwards to bring substances into the cell - used in transepithelial transport
Define the term exocrine gland
Gland with ducts
Define the term endocrine gland
Ductless gland which secretes substances directly into the blood
Describe merocrine secretion
Vesicle fuses with plasma membrane, contents of vesicle in continuity with extracellular space, membrane made larger, membrane retrieved. (exocytosis)
Describe apocrine secretion
Non-membrane bound structure approaches plasma membrane, pushes up on apical membrane, droplet formed, membrane = smaller, membrane added
Describe holocrine secretion
Disintegration of entire cell, release of contents
How is transepithelial transport achieved?
Material endocytosed, transport vesicle shuttles it across, material/vesicle exocytosed at other end
Describe the structure of the golgi apparatus
Disc-shaped cisternae, one side is convex, one side is concave, discs have swelling at their edges, distal swellings pinch off
What are the functions of the golgi body?
Sorting into different compartments, condensation, glycosylation, transport
Give an example of nervous control
Sympathetic nervous stimulation of adrenal medullary cells leading to release of adrenaline
Give an example of endocrine control
ACTH stimulates cortex of the adrenal gland to secrete hormones (e.g. cortisol)
Give an example of neuro-endocrine control
Nervous cells of the hypothalamus control ACTH secretion from anterior pituitary gland
Give an example of negative-feedback mechanism
Inhibitory effect of high thyroxine levels on TSH synthesis by the anterior pituitary gland
Where might exocrine glands be located?
Goblet cells in jejunum, parotid glands, submandibular glands
Where might endocrine glands be located?
Pancreas, thyroid gland, parathyroid glands, adrenal glands
