Neuroscience Autonomic Nervous System I and II Mary Lou Vallano Flashcards
The sympathetic nervous system is also known as the:
thorocolumbar system
The PNS is aka:
Craniosacral system
Is survival without ANS activity possible?
Yes, but physiological function is severely imparied.
Stimulation of heart rate at the SA node:
- -What ANS branch?
- -What kind of effect?
Sympathetic
Positive chronotropic effect
Stimulation of AV nodal conduction:
- -What ANS branch?
- -What kind of effect?
Sympathetic
Positive dromotropic effect
Stimulation of myocardial contractility:
- -What ANS branch?
- -What kind of effect?
Sympathetic
Positive inotropic effect
Inhibition of heart rate at SA node:
- -What ANS branch?
- -What kind of effect?
Parasympathetic
Negative chronotropic effect
Inhibition of AV nodal conduction:
- -What ANS branch?
- -What kind of effect?
PS
Negative dromotropic effect
Inhibition of atrial contractility:
- -What ANS branch?
- -What kind of effect?
PS
Negative inotropic effect (mild)
What kind of receptor antagonists are used to treat hypertension and tachycardias?
B1
Propranolol
What is divergence?
The avg preganglionic axon in the SNS contacts an estimated 100 postganglionic neurons by collateral branching, enables widespread responses. Not a thing in the PNS (1:15-20)
En passant synapses are aka
varicosities, show divergence
Are ANS preganglionic axons myelinated?
No
smaller diameter than skeletal axons
slower-conducting
B-fibers
Are ANS postganglionis axons myelinated?
No
smaller diameter than skeletal axons
slower-conducting
C-fibers
What is the main player NT in the PNS?
Acetylcholine, in both ganglion and target tissue
What kind of receptor is the main PNS receptoron target tissue?
Muscarinic
What is the main player NT in the somatic nervous system?
Acetylcholine, N1 receptors (nicotinic cholinergic)
Where are N2 receptors found?
- PNS at the 1st synapse (peripheral ganglion)
2. Peripheral ganglia of SNS
What kind of receptor is a muscarinic cholinergic receptor?
GPCR:
- PLC –> generation of IP3 and DAG, OR
- Inhibition of adenylate cyclase –> cAMP down
In most postganglionic SNS synapses, the NT is:
norepinephrine
When is the postganglionic SNS NT epinephrine?
Adrenal medulla, synapse on chromaffin cell instead of ganglion
T or F: The adrenal medulla secretes enough epi (and norepi) to maintain a near normal blood pressure if sympathetic innervation to the heart is interrupted.
True
What are the common ANS co-transmitters, being released with norepi and ACh?
ATP
Neuropeptide Y
(others)
What kind of innervation do sweat glands received?
Sympathetic cholinergic innervation (MUSCARINIC receptor, ACh NT)
What are the common themes of the MOA’s of a1, b1 and b2 adrenoreceptors?
Norepi binds to receptor
GDP –> GTP and subunit comes off
Subunit (a-q or a-s) activated other pathways leading to either Ca2+ influx, or physiological changes in the cell
What is the major adrenergic receptor in the heart
B1