module 5 reds Flashcards
what is cell signalling
chemicals bind to glycoprotein receptors to cause a direct response or or a cascade of events
describe the structure of a hepatocyte
large nucleus, prominent golgi, lots of mitochondria
what are kupffer cells
macrophages of the liver- ingest foreign pathogens
what are the three functions of the liver
carbohydrate metabolism, deamination of excess amino acids, detoxification
how does the liver control glucose levels
hepatocytes convert glucose to glycogen, and glycogen to glucose
how does the liver deaminate amino acids
remove amino group and turn it into ammonia then urea to go to the kidney (ornithine cycle)
how does the liver detoxify the body
catalase in hepatocytes breaks down hydrogen peroxide into oxygen and water
describe the action of adh
-adh released from pit gland and binds to receptors on membrane
-triggers formation of camp as second messenger
-vesicles in collecting duct fuse with membranes on outside of the cell in contact with medulla
-aquaporins inserted to make membrane permeable to water
-water moves out of cells into tissue fluid of medulla and blood capillaries
how is glomerular filtration rate measured
measure of creatinine (breakdown prod of muscles)
what does high glomerular filtration rate mean
kidneys are not working properly because there is damage to the sieves
structure of a sensory neurone
one dendron, one axon
structure of a relay neurone
many short axons and dendrons
structure of a motor neurone
many short dendrites, one long axon
describe the events leading to the secretion of insulin
-glucose phosphorylated to produce atp
-atp closes k+ channels so k+ builds up
-ca2+ channels open and ca2+ diffuses in
-results in movement of vesicles to membrane
describe how glucagon is involved in the regulation of blood glucose concentration
-glucagon released from alpha cells in islets of langerhans
-promotes conversion of glycogen to glucose (glycogenolysis)
-negative feedback reduces secretion of glucose
-glucagon inhibits insulin secretion
explain the symptoms of adrenal failure
glucocorticoids regulate carb metabolism, lack of mineralocorticoids causes low blood pressure, salt cravings
functions of adrenaline
inc heart rate, inc blood glucose, inc blood flow to muscles, pupils dilate
functions of noradrenaline
increases heart rate, increases blood pressure, widens pupils
functions of androgens
reg of sex characteristics and cell growth
functions of cortisol
reg of metabolism
examples of commercial use of auxin
rooting powders, micropropagation, weed killers, promotes fruit ripening
which hormones are thought to be involved in control of leaf drop
auxin and ethene
roles of gibberellins
increase in internodal length, seed germination, prevents leaf abcission, aids stomatal opening, promotes fruit development
describe the fight or flight response
when a threat is detected by the ans, the hypothalamus communicates with the sns and the adrenal cortical system. adrenocorticotropic hormone released from pit gland which stimulates the adrenal cortex to release adrenaline etc
