ANS Neurotransmitters Flashcards
Which autonomic neuron releases acetycholine and which releases noradrenalin (norepinephrine)?
cholinergic produces ACh and adrenergic produces noradrenalin
Where is ACh stored and how is it released?
It is stored in synaptic vesicles and released by exocytosis.
How does ACh reach the cholinergic receptors to cause excitation or inhibition of the postsynaptic cell?
diffuses across the synaptic cleft
Where is the location of the only sympathetic postganglionic neurons found among cholinergic neurons?
sweat glands
What type of neurons make up the adrenergic neurons?
most sympathetic postganglionic neurons
They are integral membrane proteins located in the plasma membrane of the postsynaptic neuron or effector cell. What are they?
neurotransmitter receptors
What are the 2 types of cholinergic receptors and what distinguishes them?
Nicotinic (nicotine mimics ACh when it binds to it) and muscarinic (muscarine mimics ACh when it binds to it)
Nicotine can activate muscarinic receptors. T or F?
F
What inactivates ACh?
acetylcholinestrerase
Which receptors causes the depolarization (excitation) of the postsynaptic cell?
nicotinic receptor and muscarinic receptor
Which receptor causes the hyperpolarization(inhibition) of the postsynaptic cell?
muscarinic receptor
What effect does the binding of ACh to the muscarinic receptors of smooth muscle sphincters in the gastrointestinal tract have?
Causes relaxation
What effect does ACh have on the sphincter muscles of the eye?
contraction (miosis)
What is the acronym for the result of activating muscarinic receptors and what do they mean?
DUMBELS
Defecation, Urination, Miosis, Bronchoconstriction, Emesis (vomiting), Lacrimation, Salivation
Adrenergic receptors are activated by?
norepinephrine from sympathetic postganglionic neurons; epinephrine and norepinephrine released as hormones from adrenal medulla
What are the 2 types of adrenergic receptors?
alpha and beta receptors
Activation of which adrenergic receptors results in excitation?
alpha 1 and beta 1
Activation of which adrenergic receptors results in inhibition?
alpha 2 and beta 2
The activation of beta 3 adrenergic cells in brown adipose tissue causes?
thermogenesis
Why does effects triggered by adrenergic neurons usually last longer than effects due to choligernic?
because norepinephrine lingers in the synaptic cleft longer than ACh