Hormones Flashcards
what does GH do
increase lipolysis, anabolism, bone and cartilage growth
what does thyroid hormone do
increases sodium and potassium pump
increases b adrenorecptors
increases glucose uptake, utilisation, gluconeogenesis, ffa oxidation, anabolism, Co and HR
what are the actions of insulin
increases protein synthesis
iincreases glycogenesis, lipogenesis, glut 4 on membrane
what are the functions of cortisol
proteolysis, lipolysis, gluconeogenesis,
decreases T cell growth factors, mononuclear cells, cytokines, IgG
negative feedback on CFR and ACTH
reduced vasodilation and fluid exudation
decreases osteoblasts and increases osteoclasts
where is corticotropin releasing hormone released from
The paraventricular nucleus (PVN) of the hypothalamus
what are the features of an adrenal crisis
hypotension, vomiting, loss of consciousness
what drug do you use for benzo overdose
flumazenil
where is the taste area in the cortex
most inferior portion of the post central gyrus to the insula
also has a limbic component via the thalamus (vomiting, salivation)
describe activation of the odorant receptor
amplifies the initial stimulus
molecule binds to the receptor of the primary olfactory neurone
the receptor activates a G protein which stimulates adenyl cyclase to convert ATP to AMP
camp activates a cation channel making it permeable to Na and Ca
action potential frequency is proportional to log concentration of odorant
what is the medial olfactory pathway
ancient
limbic system- emotion and memory
what is the lateral olfactory pathway
less ancient- pyriform and prepyriform cortex in the temporal lobe
likes and dislikes and brainstem reactions
does not go to thalamus
what is the recent olfactory pathway
passes through the thalamus and orbitofrontal cortex
involved in conscious discernment of odour
what is the function of the piriform cortex
lateral olfactory pathway (less ancient)
likes and dislikes
where is endolymph found
scala media, semicircular canals, vestibule
where is perilymph found
scala vestibuli, scala tympani
describe signal detection in the organ of corti
upward deflection of the basilar membrane moves the inner and outer hair cells laterally
most cochlear nerve endings end on the inner hair cells
describe cochlear tuning
outer hair cells are stimulated to depolarise, this causes them to contract
this enhances the auditory signal at the centre of the standing wave and inhibits on either side
under olivocochlear control
where are the dorsal and ventral cochlear nuclei found
upper medulla
where do first order vestibulocochlear neurones synapse
upper medulla dorsal and ventral cohclear nucleus
what is the pathway of signals from the ear
dorsal and ventral cochlear nucleus in the upper medulla where first order synapses
some signals travel ipsilaterally but most are contralateral to the inferior colliculus where most fibres synapse
the pathways then project to the medial geniculate nucleus of the thalamus where the fibres synapse
they then join the auditory radiation to the auditory cortex
also goes to reticulum and vermis
what is lesioned in Kluver bucy
bilateral temporal lobe
what is the reward system
mesolimbic dopamine system
ventral tegmental area of the midbrain, medial prefrontal cortex
what is fluoxeting
ssri
prozac
what are the functions of the limbic system
emotions and drives via amygdala
homeostasis and motivation via hypothalamus
olfaction via olfactory cortex
memory via hippocampus
what is the moa of glucocorticoids
bind to intracellular receptors, migrate to the nucleus and regulate gene transcription
also signalling systems in the cytosol
mediated by camp dependant protein kinase
what are the side effects of systemic use of glucocorticoids
opportunistic infecions oral fungal/ yeast wound healing impaired osteoporosis Cns effects
what enzyme is missing in CAH
C-21
describe the intersection of autoimmunity and diabetes
1st stage- insulitis- T lymphocyte invasion of pancreatic islets
2nd stage- overt diabetes. massive death of islet B Cells
B reactive t cells meet antigen in pancreatic lymph node
PLN is where tolerance to pancreas is first broken down
