ANS anatomy and physiology 4 Flashcards
Which structure is the origin of preganglionic parasympathetic fibers in the oculomotor nerve?
a. nucleus ambiguus
b. superior salivatory nucleus
c. nucleus of tractus solitarius
d. Edinger-Westphal nucleus
d. Edinger-Westphal nucleus
All preganglionic autonomic neurons originate in the
CNS
The IML lies in
Rexed’s lamina 7
The cell bodies (soma) of preganglionic sympathetic fibers are located within the
lateral horn of the spinal cord grey matter- specifically within the IML
The cell bodies of cranial nerve 3 lies within
the Edinger-Westphal
The cell bodies of cranial nerve 7 lies within the
superior salivatory
The cell bodies of cranial nerve 9 lies within the
inferior salivatory
Cell bodies of cranial nerve 10 are located in the
dorsal motor nucleus of 10, the nucleus ambiguus, and the nucleus tractus solitarius
The somatomotor division arises in the
ventral horn of the spinal cord
The anatomic characteristic of the parasympathetic 2-neuron efferent pathways is ____________ preganglionic, and ________ postganglionic
long, short
The four parasympathetic cranial nerve ganglia (3, 7, 9 & 10) transmit postganglionic sympathetic fibers and sensory fibers without
relay interruption
Both preganglionic and postganglionic parasympathetic fibers of CN 7 and 9 piggyback on branches of the
trigeminal nerve to reach their ultimate effector targets
Parasympathetic preganglionic nerves to the inferior hypogastric plexus originate from
the IML horn of S2-S4
Parasympathetic outflow arises from spinal cord levels:
S2-S4
List 5 nerve plexuses that distribute parasympathetic fibers to the viscera.
Cardiac
pulmonary
celiac
pharyngeal
& esophageal
The inferior hypogastric plexus is also known as the
pelvic plexus
Discomfort in the left arm and left side of the chest due to nociceptive input from the left ventricle is called:
a. referred pain
b. phantom limb pain
c. pure visceral pain
d. viscerosomatic pain
a. referred pain
All internal organs are densely innervated by
visceral afferents
Sensory afferents from the viscera trek in the
autonomic plexuses
Sensory afferents from the body wall (somatic) travel in the
spinal nerves
Visceral afferents from the heart, lungs, & GI tract are conveyed in the _________ nerve to the ______________
vagus; nucleus of the tractus solitarius
_________ is the phenomenon whereby noxious stimuli that originate in a visceral structure, such as the heart or stomach, are perceived as pain arising from a somatic portion of the body wall such as skin, bones or skeletal muscles
Referred pain
Sensory afferent fibers are called
pseudounipolar neurons
______________ have a cell body (soma) with a short, single process that branches into a peripheral process and central process
Pseudounipolar neurons
Visceral afferent fibers travel from the periphery to the CNS by two routes:
from the viscera in the autonomic plexuses
from the body wall (somatic) in the spinal nerves
The cell bodies of visceral (autonomic) afferents are located in one of two places:
the sensory ganglia of cranial nerves containing ANS fibers
the dorsal root ganglia of spinal nerves
The sympathetic efferent pathways START in the ____ and END at the ___________
CNS; effector (target) organs
The visceral afferent sensory pathways START at the _____________ and END at the
Organs; CNS
Preganglionic and postganglionic apply only to __________ autonomic pathways
efferent
_________ is felt in the region of the affected organ
Pure visceral pain
Pure visceral pain is characteristically
vague and deep-seated, often accompanied by nausea or sweating
Another name for viscerosomatic pain is
parietal pain
A good example of parietal pain is
appendicitis- reported in the area of the umbilicus or just below (referred pain) but also pain directly over the appendix with palpation
What type of nerve fibers are visceral afferents?
C fibers and A Gamma
Which cranial nerve with parasympathetic components does NOT transmit sensory information?
CN 3
Noxious visceral sensations generally travel in which division of the ANS?
sympathetic division
Which neurotransmitter is released from postganglionic parasympathetic varicosities?
a. norepinephrine
b. glutamate
c. acetylcholine
d. serotonin
c. acetylcholine
What are the kinds of messages transmitted in the autonomic (visceral) nervous system?
electrical
chemical
______________ are action potentials traveling along neurons and ______________ are the neurotransmitters released from neurons.
Electrical messages; chemical messages
All preganglionic neurons in the ANS use __________ as their neurotransmitter
ACh
______________________ mediate the majority of PNS physiologic effects
Muscarinic acetylcholine receptors (mAChRs)
Postganglionic parasympathetic neurons release ________ onto the target tissue
ACh
ACh released from all preganglionic nerve terminals acts on _____________ receptors in the autonomic ganglia
Nicotinic (Nn)
The synapse between a postganglionic neuron and the effector (target) is a special type of synapse called the
neuroeffector junction
Whether a neurotransmitter causes excitation or inhibition at an effector is usually determined by the nature of the
receptor protein in the cell membrane and the subsequent signal transduction initiated by the receptor
Nicotinic ACh receptors are ________ receptors
ionotropic
_______________- mediate the majority of the PNS physiologic effects
Muscarinic acetylcholine receptors
M1 receptors exist in the
autonomic ganglia and in some glands
M2 receptors are often called ___________ receptors because they are primarily found in the
cardiac; heart
M3 receptors are prominent in
exocrine glands and smooth muscles
How many subtypes of muscarinic receptors exist?
M1-M5 (5)
What is stored in postganglionic terminal varicosities?
neurotransmitters
