Chapter 11: Efferent Division

*last new info for exam 2

smooth and cardiac muscle, glands, adipose tissue

what are the autonomic efferent targets?

sympathetic, parasympathetic, enteric

divisions of efferent autonomic motor control

skeletal muscle

what are the somatic efferent targets?

efferent division

response going out of the nervous system

homeostasis

ANS, Endocrine, and Behavioral State Systems maintain _____________

hypothalamus, pons, medulla

control centers of autonomic reflexes and homeostasis

on postganglionic neurons

where do preganglionic neurons synapse?

target tissues

where do postganglionic neurons synapse?

preganglionic neurons

cell bodies located in cns and extend out

postganglionic neurons

cell bodies originate in ganglion and extend toward target tissue

sympathetic preganglionic neurons

originate in thoracic and lumbar spinal regions; short axons

parasympathetic preganglionic neurons

originate in brainstem, sacral spinal regions; long axons

-Vagus (Cranial Nerve X) nerve is major pathway

parasympathetic postganglionic neurons

located at tissue level; short axons

sympathetic postganglionic neurons

form 2 chain ganglia, along aorta; long axons

acetylcholine

neurotransmitter used for communication in preganglionic neurons

muscularic acetycholine

what does ACh bind to in postganglionic neurons of the autonomic nervous system?

Norepinephrine , adenergic receptors

what neurotransmitter is used for communication in sympathetic postganglionic neurons and what is its target receptor?

ACh, mAChRs

what neurotransmitter is used for communication in parasympathetic postganglionic neurons and what is its target receptor?

adrenal medulla

exception to typical communication rules

neural crest

what is the adrenal medulla derive dform?

chromaffin cells

found in adrenal medulla, lack axons but secrete Epinephrine > Norepinephrine into systemic circulation

varicosities

enlarged regions on axon that contain mechanism for the release of neurotransmitters

action potential arrives, opens voltage-gated channels, NE exocytosis, NE diffuses and binds to target cell receptors, removed by diffusion

steps for signaling in autonomic pathways using norepinephrine as example

adrenergic receptors

-GPCRs expressed in target tissues,
-activated by sympathetic signaling

autonomic muscarinic receptors

-GPCRs expressed in target tissues
-activated by parasympathetic signaling,
-most tissues express M2 or M3 subtypes

somatic

is the somatic or autonomic motor system simpler?

always

the somatic motor system is ________ excitatory

single, single

the somatic motor system contains ________ neuron and __________ target cell

neuromuscular junction

how is a connection made between somatic motor neuron and its target

motor nerve terminal

Presynaptic cell in NMJ

cleft

space between NMJ contains fibrous ECM with the enzyme Acetylcholinesterase

postsynaptic cell

motor end plate of the skeletal muscle fiber in NMJ

cations, depolarization

what ions can flow through in synaptic transmission at the NMJ, what does this cause

wave of depolarization

what releases neurotransmitters at neuroeffector junctions?