glands introduction

Question 1

definition of a gland

Answer 1

an aggregate of epithelial cells that are specialised for the secretion of a substance. thy regulate human physiology but receiving stimulus from CNS and circulating chemicals from neighbouring cells.

Question 2

features of an endocrine gland

Answer 2

they are ductless. secrete directly into the blood and substances travel to a distant part of the body

Question 3

features of an exocrine gland

Answer 3

they are ducted and secrete into a location through a duct. usually secrete enzymes or lubricants.

Question 4

examples of endocrine glands

Answer 4

pituitary gland, thyroid gland and parathyroid gland

Question 5

examples of exocrine glands

Answer 5

salivary, pancreas, mammary, sweat, sebaceous and lachrymal gland

Question 6

pituitary gland

Answer 6

inferior to hypothalamus. Anterior produces ACTH, LH ,FSH and TSH. regulates most glands of the body. Posterior produces ADH to prevent water loss from kidneys and oxytocin

Question 7

thyroid gland

Answer 7

produces T3 and T4 controlling metabolism and involved in calcium homeostasis

Question 8

parathyroid gland

Answer 8

controls calcium homeostasis

Question 9

salivary gland

Answer 9

secrete salvia which has role in digestion and lubrication

Question 10

pancreas

Answer 10

secretes enzymes amylase, trypsin and lipase.

Question 11

mammary

Answer 11

produces colostrum in milk in response to oxytocin and prolactin

Question 12

sweat glands

Answer 12

secrete sweat which help to regulate body temp

Question 13

sebaceous

Answer 13

secrete sebum onto skin/ in ear to protect skin from pathogens

Question 14

lachrymal glands

Answer 14

secrete water into eye to lubricate it also produce lysozymes

Question 15

how are exocrine glands generated in uetero development

Answer 15

growth signal received, proliferation of cells and epithelial cells invade the space created by digestion by enzymes. central cells die off producing a duct

Question 16

how endocrine glands are generated in utero development

Answer 16

growth signal received, proliferation of cells and epithelial cells invade the space created by digestion by enzymes. angelic factors are produced and this stimulates blood vessel growth and then the link to starting cells is broken by apoptosis

Question 17

how does branching of ducts occur

Answer 17

a growth hormone is realised and the epithelial cells will grow towards it

Question 18

name the shapes of ducts and draw them

Answer 18

simple, simple branched ad compound tubular. simple, simple branched and compound alveolar

Question 19

what are myoepithelial cells

Answer 19

act as both epithelial cells and smooth muscle cells. have the ability to squeeze duct to help release product

Question 20

different types of secretion

Answer 20

merocrine, apocrine and holocrine

Question 21

merocrine

Answer 21

fusion of vesicles with apical membrane e.g exo and end crime glands of pancreas. vesicles move along microtubules and when ca2+ present fuse with membrane. pretty much the same as normal exocytosis

Question 22

apocrine

Answer 22

partial loss of cytoplasm e.g lactating mammary glands or sweat glands

Question 23

holocrine

Answer 23

complete loss of cytoplasm e.g sebaceous gland

Question 24

difference between regulated and constitutive secretion

Answer 24

regulated- only related upon stimulation

constitutive- continuously released

Question 25

role of Golgi in secretion

Answer 25

vesicles emerge from trans Golgi face and become glycolated in the Golgi

Question 26

why do cells become glycolated

Answer 26

to aid protein folding, prevent protein digestion and lipid digestion and cell recognition

Question 27

exo,endo,pino and phagocytosis

Answer 27

exo-secretion via vesicle fusing with membrane
end-englufing molecules form outside into vesicle
Pino-liquid droplets ingested by cells
phago-envleoping cells and other particles

Question 28

what is transepithelial transport

Answer 28

movement through cells;

1) move through aqueous channels at both end
2) move through lipid membrane at both ends
3) transported by carrier proteins at both end s
4) be englulfed by membrane, travel through and exit by exocytosis

Question 29

how are glands controlled

Answer 29

hormonal- most prevelant in endocrine glands
humeral- by feedback loops
neural- by stimulus e.g saliva

Question 30

what is neurocrine communication

Answer 30

example= hypothalamus to pituitary. electrical signal causes release of substance into blood which acts on target cell