ANS - Karius Flashcards
where do PS pre-ganglionic axons leave the CNS?
cranial
sacral
where are ganglia located in the PS system?
on or near target organs
describe pre and post-ganglionic fibers
Long Pre
short post
where do Sympathetic pre-ganglionic axons leave CNS?
thoracic
lumbar
where are ganglia located in Sympathetic?
sympathetic chain
describe length of pre/post sympathetic fibers
short pre
LONG post
what nt is released by the pre-ganglionic PS system?
what is the receptor?
Ach
nAchR
what nt does the PS post-ganglionic cell release?
Ach
what is special about PS nt release?
varicosities are not protected, therefore leakage of NT into systemic circulation
what kind of receptor is located on effector organ?
what type of receptor is it?
muscarinic receptor
GPCR
what does a M2 receptor do?
what is it coupled to and what happens?
cardiac
Gi coupled, DEC cAMP and INC K+
what does M3 receptor do?
what is it coupled to?
what is its effect?
glandular tissue
Gq
INC IP3 and DAG, INC intracellular Ca
what do M4 receptors do?
what is it coupled to?
what is the effect?
autoreceptors on neurons
Gi (inhibit adenylate cyclase)
Dec cAMP –> DEC Ach release
what is the Sympathetic pre-ganglionic nt?
what is its receptor on the post-ganglionic?
Ach
nAchR (alpha or beta-adrenergic)
what nt is released in the Sympathetic post-ganglionic fiber?
NE
do alpha-adrenergic receptors have a higher affinity for Epi or NE?
NE
what are the types of alpha-adrenergic receptors and what do they do?
a,b,d
INC IP3 and DAG, DEC K+
Gq coupled
what do the Beta-adrenergic receptors do?
what nt do they have a higher affinity for?
INC cAMP (Gs coupled)
Epinephrine
What produces epinephrine?
chromaffin cells in the adrenal medulla
how is epinephrine formed in the adrenal medulla?
dopamine –> norepi –> Epi
the radial m. of the eye is what kind of receptor?
contraction of the m. leads to what?
alpha-adrenergic
dilation of pupil
the ciliary m. of the lens is what kind of receptor?
upon symp. activation what happens?
what does this allow?
beta2-adrenergic
relaxation of m. –> flattening of lens
far vision
what receptors are located in the heart?
upon symp. activation what happens?
Beta1 and 2-adrenergic
INC HR and strength of contraction
generally speaking, what causes relaxation of vascular smooth m. and what causes contraction?
Beta receptors
alpha receptors
