hormone structure and action Flashcards
different types of chemical communication?
- autocrine
- neurocrine (synaptic)
- paracrine
- endocrine (hormone)
- pheromone
- allomone
effects more distant around the body as going from 1-6
what is autocrine communication?
chemical releaed from cell feeds back on cell and affects its own activity
what is paracrine communication?
chemical release into extracellular enviro around cell and affects traget cells near by
what is pheromone communication?
chemical released into external enviro outside body and affects conspecifics (members of same species)
what is neurocrine communication?
chemical released by neuron diffuses across synaptic cleft and affects post synaptic membrane
what is endocrine communication?
chemical released into bloodstream and selectively affects distant organs (hormone)
what is allomone communication?
chemical released into external enviro outside body and affects heterospecifics (members of ther species)
describe hormones?
what are they?
what do they do?
bioregulators of the endocrine system
molecules secreted by specialised endocrine cells directly into the blood
where they’re transported to selectively act on target cells
describe the transmission of endocrine signals?
- signal stimulates endocrine cell to release hormone which it has produced
- hormones travel into bloodstream circulating around whole body
- affect any target cells possessing correct receptor for the hormone
what are the 3 main types of hormones?
- protein (incl peptides which are short chain proteins)
- amine
- steroid
describe protein hormones?
structure?
examples of different functions?
chain of amino acids
e.g insulin (metabolism),
FSH (female oestrous cycle), oxytocin (social bonding and care) and releasing hormones (cause other endocrine cells to release hormones)
predominantly release from hypothalamus
describe amine hormones?
modified single amino acid (monoamine)
e.g adrenaline and melatonin (metabolism and body function)
describe the action of protein and amine hormones?
bind to receptor on outside of cell membrane
changes the shape of receptor in cell membrane
receptor releaes another chemical into cell (secondary messenger) which alter function of cell
- act rapidly
- prolonged effects
how is sensitivity to amine and protein hormones changed?
by upregulating (increasing) or downregulating (decreasing) number of receptor for hormone on cell
describe steroid hormones?
structure and examples?
- derived from cholesterol
- soluble in lipids (dissolve in fats) so able to cross cell membrane
- e.g oestrogen and stress hormones