Cholinergic and Adrenergic Part II Flashcards
what are visceral afferents
monitors either nociceptive (painful) input or sensitive to mechanical and chemical stimuli (stretch of the heart, blood vessels, and hollow viscera, and changes in PCO2, PO2, pH, blood glucose, temperature of skin and internal organs)
what are the internal organs densely innervated by?
visceral afferents.
what do the visceral nociceptive fibers travel with? what about the axons from the physiological receptors?
sympathetic nerves; parasympathetic fibers
where are the visceral afferents mainly concentrated, in what nerve? what does this nerve carry?
in the vagus nerve; carries non-nociceptive afferent input from the viscera of thorax and abdomen to the CNS.
where are the cell bodies of the vagal afferents located?
in the nodose ganglion of medulla.
In the CNS, how is the visceral input mapped? why?
viscerotopically at the level of the spinal cord because most visceral nociceptive fibers travel with the sympathetic fibers and enter the spinal cord along with a spinal nerve.
Where is the CNS mapping also present?
in the brain stem but not the at the level of the cerebral cortex
what does the cerebral cortex do once awareness of pain is detected?
it is not localized to a specific organ but is instead referred to the dermatome that is innervated by the same spinal nerve.
how does referred pain work in terms of function for the visceral afferents?
Afferent fibers traveling in autonomic nerves may converge upon sensory neurons in the spinal cord that also synapse with somatic afferents.
The convergence “confuses” the brain, which “feels” pain in the region supplied by the somatic nerve, even though it is the autonomic fiber that has been activated by pain.
afferent fibers travel through both sympathetic and parasympathetic nerves, T/F?
True
what is the sensory cell body of the visceral afferents contained in?
ganglion, and its also one neuron that connects the visceral organ with the CNS
*what is the function of the myenteric plexus or Auerbach’s plexus?
it is involved in the control of motility
where does the myenteric plexus or Auerbach’s plexus lie?
between the external longitudinal and the deeper circular smooth-muscle layers.
deeper than the myenteric plexus lies another plexus, what is this plexus called?
Submucosal (Meissner’s) plexus
where does the meissner’s plexus lie?
lies between the circular muscle and the most internal layer of smooth muscle, the muscularis mucosae. (closer to the lumen)
*what is the function of the Submucosal (Meissner’s) plexus?
it is involved in the control of ion and fluid transport
T/F, the myenteric plexus overlies the deeper meissner plexus and have separate functions?
T
what is unique about the enteric nervous system?
its intrinsic to the wall of the gut and though it can function independently, it is governed closely by sympathetic and parasympathetic systems.
Which of the following is correct for the myenteric (Auerbach’s ) plexus?
lies between the circular muscle and the most internal layer of smooth muscle
lies between the external longitudinal and the deeper circular smooth-muscle layers.
is involved in the control of ion and fluid transport
receives preganglionic sympathetic innervation from the glossopharyngeal nerve
lies between the external longitudinal and the deeper circular smooth-muscle layers.
what causes the release of epinephrine?
acetylcholine, it stimulates the chromaffin cell in the adrenal medulla and then it is going to release the epinephrine so that the cell can go through the process of making dopa, dopamine, norepinephrine then epinephrine. Ach is what releases the epinephrine because it is the primary nt between the pre and post ganglion in the sympathetic nervous system
Cells of the adrenal medulla receive synaptic input from which of the following type of neurons?
preganglionic parasympathetic neurons
postganglionic sympathetic neurons
preganglionic sympathetic neurons.
postsynaptic parasympathetic neurons
preganglionic sympathetic neurons.
