Autonomic Nervous System Review Flashcards
2 main neurotransmitters of autonomic nervous system
Ach, NE
type of autonomic innervation: adrenal medulla
sympathetic only
type of autonomic innervation: most sweat glands
sympathetic only
type of autonomic innervation: blood vessels
although they do have cholinergic receptors on endothelium of BV, but only innervated by SNS
dominant basal tone: cardiac
parasympathetic
dominant basal tone: bronchial smooth muscle
parasympathetic
dominant basal tone: GI tract
parasympathetic
dominant basal tone: urinary tract
parasympathetic
dominant basal tone: salivary glands
parasympathetic
dominant basal tone: most sweat glands
sympathetic
dominant basal tone: arterioles/veins
sympathetic
how many ganglion in somatic nervous system
1
postganglionic receptor and neurotransmitter in PSNS
Ach, mAchR (cholinergic)
postganglionic receptor and neurotransmitter in SNS
NE, adrenergic receptors (alpha, beta)
postganglionic receptor and neurotransmitter in sweat glands
Ach, mAchR (cholinergic) (even though its a part of the SNS)
postsynaptic neurotransmitters in adrenal medulla
80% epi, 20% NE
adrenal medulla innervation, number of neurons, type of postsynaptic cells, neurotransmitters
sympathetic innervation, only 1 neuron, postsynaptic neuroendocrine cells, secrete epi/norepi into blood, mimics sympathetic stimulation
anatomical origin of SNS
T1-T12, L1-L5
anatomical origin of PSNS
CN 3, 7, 9, 10 (90% vagus nerve), S2-S4
location of sympathetic ganglia
sympathetic chain of paravertebral column
location of PSNS ganglia
target organ
receptor on postganglionic neuron of SNS and PSNS
nAchR
receptor on target tissue of SNS and exceptions
adrenergic, sweat glands, adrenal medulla
receptor on target tissue of PSNS
mAchR
steps of neurotransmission
- synthesis
- storage in vesicles
- release r/t AP (vesicles fuse with nerve terminal)
- action at receiving tissue
- termination (reuptake via transporter, enzyme degradation, diffusion)
steps of cholinergic neurotransmission
- synthesis from choline, acetyl-CoA
- storage in vesicles
- action potential triggers Ca++ entry, Ca++ interacts with SNARE protein on vescicle –>fusion of vesicle and opening –> release of Ach
- binding to receptor
- termination of action. primary mechanism: enzyme degradation via AchE
- recycle choline via reuptake
ligand gated ion channel
fast response, binds and channels open so ions can pass through ex) nAchR and GABA
GPCR
connected to g protein, most common receptor that drugs act on
transmembrane with linked enzymatic domain
when drug binds, enzyme activates ex) oncology medications
intracellular receptor
receptor either in cytosol or nucleus, drug has to be lipophilic. effects transcription and increases or decreases amount of protein synthesis ex)cortisol, sex hormones
muscarinic cholinergic receptor specs
- it is a GPCR
- there are 5 subtypes with 2 subgroups
- diverse cellular responses, not very selective
- autonomic effector tissues: heart, endothelium, smooth muscle, glands, CNS
nicotinic cholinergic receptor specs
- ligand gated ion channel (Na/K)
- 2 major subtypes: NicN, NicM
- location: autonomic ganglia, skeletal muscle innervated by somatic nerves, CNS
- Ach binds, conformational change, channel opens and positively charged ions pull through channel
- depol of postsynaptic cells
where are M1 receptors
CNS
where are M2 receptors
heart
where are M3 receptors
smooth muscle, glands, endothelium, eye (circular, ciliary muscle)
where are M4 receptors
CNS