ch 6 Flashcards
(44 cards)
3 forms of local communication
Gap junctions
contact dependent signals
chemical diffusion(autocrine and paracrine)
2 forms of long distance communication
chemical and electrical signals
neural and endocrine
neurocrine molecules
neurotransmitters
neuromodulators
neurohormones
cytokines
peptides synthesized and secreted by nucleated cells in response to stimuli
how do cytokines function in development and differentiation
autocrine and paracrine
families of cytokines
interferons, interleukins, colony-stimulating factors, growth factors, tumor necrosis factors, chemokines
how are cytokines made
on demand
which cells can produce
any nucleated cell can produce
when can a cell respond to a particular chemical signal
if the target has a receptor
lipophillic binding
diffuse through membrane to bind to cytosolic receptors
lipophobic ligand binding
bind to receptors outside cell membrane
4 groups of surface receptors
chemically gated
GPCR
receptor enzymes
integrin receptors
cascades
series of events from initial signal
external signal->receptor->transducer->amplifier->response
signal amplification
increases the strength of the signal by upregulating signaling molecules from initial signal
rapid signal pathways
rapid flow of an ion in or out of the cell brings about a rapid response from the cell
where are rapid signal pathways found
in nerve and muscle
G protein
three part transducer
GPCR-cAMP pathways
what many lipophobic hormones use
lipid derived second messengers
phospholipase
diacylglycerol
inositol triphosphate
catalytic receptor enzymes
protein kinases, guanylyl cyclase
5 ways calcium is an intracellular messenger
gaseous signal molecules
NO, CO, H2S
advantages of gaseous second messengers
short acting paracrines or autocrines
disadvantages of gaseous second messengers