signal transdruction and hypothalamus/pituitary Flashcards
3 types of cellular signalling pathways
physical/chemical signals, signal transduction, signal amplification/response
what is extracellular domain
binding site for hormones/other molecules
what is transmembrane domain
anchors receptor in cell membrane
what is ion channel linked receptors
membrane is impermeable to ions, channels open and ions flood in, rapid response, specific for sodium, potassium, calcium, chlorine ions
what is intracellular domain
effectors domains, transduce the signal
what do GPCRs do
G protein coupled receptors, can regulate ion channels, channels opened or closed by g protein, slow acting
how do enzyme linked receptors works
mostly tyrosine kinase, hormone binds to enzyme linked receptors, conformational changes induced, enzyme activity activated
signal amplification steps
1 messenger binds to 1 receptor, multiple G proteins activated, each G protein activates an adenylate cyclase, and each adenylate cyclase generates hundreds of cAMP molecules which activates a protein kinase A, each protein kinase A phosphorylates hundreds of proteins
messenger–>receptor–>G proteins–>adenylate cyclase–>cAMP–>protein kinase A–>phosphorylates hundreds of proteins
5 major second messenger molecules
cAMP, cGMP, DAG, IP3, calcium
other types of signalling molecules
neurotransmitters, cytokines, neurohormones, eicosanoids
what is endocrine axis
independent glands working together to control body functions
master regulators (hypothalamic pituitary axis)
thyroid, adrenal cortex, gonads
features of hypothalamic pituitary axis
pineal gland, hypothalamus, pituitary gland, spinal chord
what is autocrine signalling
bind receptors on the same cell
what is paracrine signalling
targets neighbouring cell
what is endocrine signalling
targets distant cells via bloodstream
what is neuroendocrine signalling
neurons target distant cells via bloodstream
what is the hypothalamus
small brain region, grey matter, contains multiple neural centres and neural fibres, connects to other brain regions
what does the hypothalamus control
hunger, thirst, body temp, blood pressure, childbirth, emotion, sex drive, social bonding, circadian rhythms
what is the pituitary
neural and vascular connections