module 5 (3) Flashcards
(17 cards)
what are steroids
lipid soluble (pass through membrane)
hormone-receptor complex acts as TF (oestrogen)
what are non-steroid hormones
hydrophilic
so can’t pass membrane
triggers cascade reactions
what is the endocrine tissue of the pancreas
islets of langerhan
what is the proportion of cells in the islets
more alpha cells
how does insulin work
when binded, changes the tert structure of glucose transport channels (opens)
insulin activates enzymes which catalyse glycogenesis
what happens in beta cells (pancreas) with normal glucose levels
K+ channels are open and go out the cell
inside the cell = -70mV
describe the mechanism for insulin secretion
glucose enters by transporter and used to produce ATP
ATP binds to K channels to close them
pot. diff. reduces to -30mV + depolarisation occurs
causes Ca VGIC open
Ca ions enter and cause secretory vesicles to release insulin by exocytosis
what are the issues with insulin injections
too much insulin = hypoglycaemia –> unconsciousness
little insulin = hyperglycaemia –> unconsciousness, death
so important to monitor glucose levels
what are the advantages of stem cell therapy for diabetes
donor availability isn’t an issue
reduced rejection chance
no longer have to inject insulin
what happens to the hypothalamus under the fear response
andreno-cortico and sympathetic system communicated and stimulated
what is cAMP
cyclic adenosine mono-phosphate
define the cascade effect
at each stage the number of molecules involved increases
where are baroreceptors
in aorta, vena cava and carotid arteries
where are chemoreceptors
aorta, carotid artery and medulla
how does the body respond to low pH
increase heart rate
carbon dioxide is exhaled out
how does the body respond to increasing pH
detected in wall of carotid artery + aorta
results in reduction in frequency of AP sent to medulla
reduces the frequency of AP sent to SAN
so HR decreases
how to calculate the tidal volume
ventilation rate / breathing rate
