Lecture 12: Endocrine Flashcards
intracellular communication
chemical signaling molecule responding for regulation
hormone: chemical messenger
- secreted in body fluids ( mostly blood)
- travels through body bathing all cells
- target cell = any cell that has a receptor for the hormone
endocrine signaling
- cells secreted into body fluids, usually blood
- bonds to target cells
- all cells exposed, only those with corrector receptor respond
seq endocrine signaling
- signal gets into blood stream
- travels throughout the body
- diffuses out blood stream
- only one with receptors respond
- highly specific
what are receptors
- large proteins or glycoproteins on surface of (or within) target cells
what are the functions of receptors
- recognize and bind to specific horomones ( unable to interact with other receptors)
- responsible from the specificity of endocrine system
hormone increase for a long period
receptor down- regulated ( constant present, too much insulin) -> stop listening ( lower receptor from membrane)
hormone decrease for long period
receptor up - regulated (doesnt apper very frequently) -> increase # of signals little insulin -> listen harder ( raise receptor to membrane)
intercellular communications classified
- type of secreting cell
- route take signal to target
endocrine signaling
- endocrine cells secrete hormones ( steroids , peptide, amine) into extracellular
- diffuse into bloodstream -> travel to target cells ( all cells, only target cells respond)
- long distance, everywhere , all over the body
paracrine
target cells near secreting cell
autocrine
target is self ( positive feedback loop, involved in activated different components of the immune system) blood - clotting
paracrine & autocrine
cells produce and secrete local regulators lipids ( prostagladins) gases (nitric acid) polypeptides
synaptic signaling
- involves neurons - basic unit of nervous system
- forms synapses or junctions with target cells
- neuron -> cell or neuron - neuron
- diffuse across synapsis
synaptic signaling uses neurotransmitters which are
chemical signals that neurons send and receive back and forth