glands 1

Question 1

what is a gland

Answer 1

an epithelial cell or an aggregate of epithelial cells that are specialised for the secretion of a substance

Question 2

what are the differences between endocrine and exocrine glands

Answer 2

endocrine glands are ductless and exocrine are ducted
endocrine secrete directly into blood flowing through them to let the secretion function at distant parts of the body. They secrete hormones.
exocrine glands secrete Into a location of the body through a duct and their secretions are enzymes or lubricants. only cells in the apex of the duct secret the products whereas in endocrine all epithelial cells secrete the hormones.

Question 3

Examples of endocrine glands

Answer 3

pituitary gland
thyroid gland
parathyroid gland

Question 4

examples of exocrine glands

Answer 4

salivary gland 
pancreas-amylase,trypsin,lipase
mammary 
sweat glands 
sebaceous gland 
lachrymal gland- water and lysozyme in eye

Question 5

how are glands generated in utero

Answer 5

1) growth signal received (from mesenchymal stem cells)
2) proliferation of cells occur and extracellular protein degradation enzymes are produced
3) epithelial cells invade space created
4) exocrine gland:central cells die off to produce duct (canalicularisation)
5) endocrine- produce angiogenic factors to stimulate blood vessel growth in and around the epithelial cells

Question 6

what are the different shapes of gland ducts

Answer 6

simple tubular
simple branched tubular 
compound tubular 
simple alveolar 
simple branched alveolar 
compound alveolar 
compound tubuloalveolar

Question 7

what are myoepithelial cells

Answer 7

cells that have features of an epithelial cell and muscle cell

Question 8

what is another word for acinar

Answer 8

alveolar

Question 9

how can glands be classified in terms of mode of secretion

Answer 9

merocrine
apocrine
holocrine

Question 10

how does merocrine secretion work and what are its two pathways

Answer 10

fusion of vesicles with apical membrane (form of exocytosis)

1) regulated secretion -secretory granules accumulate in large vesicles and are released by exostosis upon stimulation (needs ca2+), uses ATP
2) constitutive secretion- secretary. product is not concentrated into granules but packaged into small vesicles

Question 11

what is apocrine secretion

Answer 11

partial loss of cytoplasm

Question 12

what is holocrine secretion

Answer 12

complete loss of cytoplasm or cell

Question 13

what is a cytocrine secretion

Answer 13

when the cell is released as a secretion

e.g spermatid