endocrine system Flashcards
what can activate ligand gated ion channels
hormones and neurotransmitters (agonists)
how do hormones reach target hormones and what is not involved
released to blood stream, no ducts involved
what makes a neurotransmitter a neurotransmitter
if released through synaptic transmitter
what is the neuroreceptor to adrenoreceptors and is it para/sympathetic
NA, sympathetic
what subunits do adrenoreceptors have
G protein subunits: alpha and beta-gamma dimer subunit
once adrenoreceptor is binded, how is it activated
alpha subunit GDP is replaced with GTP
how are adrenoreceptors deactivated
alpha subunit GTP –> GDP
what alpha subunit is activated in B1
alphaS subunit
what happens when alpha S subunits are activated
adenylyl cyclase converts ATP –> cAMP which activated PKA
what happens when alpha Q subunits are activated
phospholipase C converts PIP2 –> PIP3
what happens when alpha I subunits are activated
inhibits adenylyl cyclase converting ATP –> cAMP, beta-gamma subunit opens K channels to stop depolarisation
what happens to the body when adrenaline binds to B1 adrenoreceptors
increased HR and contractility
what type of subunits to B1 adrenoreceptors have
alpha S
what happens to the body when adrenaline binds to B2 adrenoreceptors
bronchodilation
what type of subunits to B2 adrenoreceptors have
alpha S
what happens to the body when adrenaline binds to A1 adrenoreceptors
vasocontriction
what type of subunits to A1 adrenoreceptors have
alpha Q
what happens to the body when adrenaline binds to A2 adrenoreceptors
GI relaxation
what type of subunits to A2 adrenoreceptors have
alpha i
what happens to tyrosine kinase receptors when insulin binds
dimerization, tyrosine phosphorylated by ATP, tyrosine molecules then illicit different responses within the cell
what is autocrine signalling
signal molecules released from cell and bind to receptors on the cell itself
what is paracrine signalling
signal molecules released from cells and bind to receptors on surrounding cells
what is endocrine signalling
chemical hormone released to blood and travels to target cells
what is the purpose of endocrine regulation
homeostasis
what does negative feedback do
opposes a change
what does positive feedback do
increases response eg blood clots
what is intrinsic regulation
resolved within cell/ small clump - autocrine and paracrine signalling
what is extrinsic regulation
nervous and endocrine system
what is the hypothalmic negative feedback loop
physiological stress causes hypothalamus to secrete hormones which stimulate pituitary to release hormones which have an action that reduces the stress, the hypothalamus detects this and then stops secreting
what are the major endocrine glands (10)
pineal, hypothalamus, pituitary, thyroid, parathyroid, thymus, adrenals, pancreas, ovary + testes
what is the highest level of endocrine control
hypothalamus
what is diurnal hormone control
light (day) and dark (night) influence hormone secretion
what hormones are secreted from the anterior pituitary
GH, LH/ FSH, ACTH, TSH, prolactin
what inhibits prolactin
dopamine
what does the posterior pituitary secrete
ADH, oxytocin
what does the hormone concentration depend on
rate of secretion
what effect do adrenaline and cortisol have on glucose levels
increase them
what types of hormone receptors are there
GPCR, receptor kinases, nuclear receptors
what types of hormone structures are there
steroids (oestrogen, testosterone, cortisol), amine/ tyrosine derived (adrenaline, epinephrine, thyroid hormone), peptides + glycoproteins (oxytocin, ADH, GH, insulin)
what are steroids made of
lipids and cholesterol
where are steroids stored
haha trick question they are secreted on demand xx
what is the RLS in steroid production
cholesterol –> pregnenolone
how do steroids bind to their receptors and what are they
pass through membrane and bind with nuclear kinase receptor in cytoplasms, then enters nucleus and binds to DNA
which types hormones are carried in blood by cotransporters
steroids
which type of hormones are stored and where
amines - cytoplasm
which type of hormones are hydropholic
amines and peptide/protein hormones
which type of hormones are hydrophobic
steroids
what amine hormone required a transporter
thyroid hormone
what are 3 important hormone carriers
cortisol-binding globulin (CBG), thyroxin binding globulin (TBG), o Sex steroid binding globulin (SSBG)
what organs eliminate hormones
liver and kidney
where are steroids secreted from
adrenal cortex (cortisol), gonads and placenta
where are amines secreted from
(thyroid) and adrenal medulla
where are peptide/ protein hormones secreted from
brain, heart, stomach, liver, kidneys
