Exam 3 Week 13 ppt 2 ANS components Flashcards
______ division is sympathetic
thoracolumbar
where is the thoracolumbar division located
its CNS effector “pre-ganglionic” neurons located in lateral horn (intermediolateral cell column) of thoracic and upper lumbar spinal cord
the sympathetic paravertebral ganglia is (close/far) from the vertebra
~ganglia are located either immediately lateral to the spinal cord and vertebral column paravertebral ganglia or some distance from the spinal cord prevertebral ganglia
~very short pre-ganglionic axons and very long post-ganglionic axons.
what is the sympathetic paravertebral ganglia
sympathetic trunk and include the 3 cervical ganglia
what is the sympathetic prevertebral ganglia
celiac, superior and inferior mesenteric ganglia
Are there many convergence and/or divergence btw the preganglionic and postganglionic neurons in the sympathetic division?
~Great deal of convergence and divergence between pre-ganglionic and postganglionic neurons
~Divergence dominates with ratio of preganglionic to postganglionic fibers 1:10–1:196 so with between 10 and 200 ganglion cells innervated by a single pre-ganglionic neuron
Sympathetic preganglionic releases
preganglionic neurons have ACh released at their terminals
Sympathetic postganglionic releases
NE released at postganglionic terminal on the target tissue
Sympathetic adrenal medulla releases
~specialized sympathetic ganglion that instead of releasing NE as a transmitter it releases Epinephrine and NE as hormones into the blood (instead of to another nerve)
______ division is parasympathetic
craniosacral division
the parasympathetic ganglia is (close/far) from the vertebra
ganglia are located close to the target organ they innervate so there are very long pre-ganglionic fibers and short post-ganglionic fivers
what is the craniosacral division of the parasympathetic division located?
~cranial nerve nuclei (remember Edinger-Westphal nucleus, superior and Inferior salivatory nuclei, Dorsal Motor Nucleus of X)
~sacral spinal cord segments (S2-S4) intermediate cell column
Are there many convergence and/or divergence btw the preganglionic and postganglionic neurons in parasympathetic division?
~very little divergence and convergence
~Ratio of preganglionic to postganglionic fibers 1:3 – very little divergence
Parasympathetic division- where do preganglionic axons end? (more specific)
~Terminal ganglia within the walls of the gastrointestinal tract, urinary bladder and erectile tissues ~Ciliary ganglion ~Otic ganglion ~Ptergopalatine ganglion ~Submandibular ganglion
what NT is released in the parasympathetic system?
ACh released at preganglionic and post-ganglionic terminals in the parasympathetic division
Autonomic afferents Originate mostly from ____ receptors (and where)
Also, how do these afferents reach the spinal cord and brainstem?
~Autonomic afferents originate mostly from unencapsulated and encapsulated receptors in the viscera and walls of blood vessels
~afferents from the thoracic and abdominal viscera reach spinal cord via the sympathetic trunks and reach the brainstem via the glossopharyngeal (CN IX) and vagus (CN X) nerves
autonomic afferents from the thoracic travel..
From the thoracic viscera afferents travel to the sympathetic trunk in the cardiac and pulmonary nerves
autonomic afferents from the abdominal travel..
From the abdominal viscera afferents travel to the sympathetic trunk in the splanchnic nerves
autonomic afferents from the pelvic travel..
From the pelvic viscera afferents travel to the sympathetic trunk in the lower thoracic and upper lumbar spinal nerves
visceral sensation (how does it feel)
Vague, poorly localized, and affective visceral sensations
examples of visceral sensation
Hunger, heartburn, nausea
visceral sensation- describe how there is feeling
~Visceral organs insensitive to ordinary mechanical and thermal stimuli
~mechanoreceptors-sensitive to distensions
~chemoreceptors- sensitive to a variety of chemical substances
~Both can trigger visceral local or long-loop reflexes
~Sudden or large magnitude distensions and spasms of muscular walls of viscera or decreased blood supply to the viscera may cause severe pain
what type of fibers for visceral
“C” fiber afferents
~burning and pressure sensations are the most common symptoms
Higher level control of the autonomic nervous system comes from the ______
hypothalamus
What three regions do Hypothalamic descending supra-spinal projections go to?
Preganglionic sympathetic neurons in the following regions:
- to T1-L2 via hypo-thalamospinal tract
- to S2-S4
- brainstem nuclei: (Edinger-Westphal nucleus, Dorsal motor nucleus of X, and Salivatory nuclei)
Hypothalamic descending supra-spinal projections to: Preganglionic parasympathetic neurons to T1-L2 travel in what tract?
hypo-thalamospinal tract
Hypothalamic descending supra-spinal projections to Preganglionic parasympathetic neurons in the brainstem. Name three brainstem nuclei:
Edinger-Westphal nucleus
Dorsal motor nucleus of X
Salivatory nuclei
General functions of the autonomic nervous system
regulate and control visceral activities that maintain a stable internal environment in response to changing internal conditions and external stresses
Sympathetic system’s functions of the autonomic nervous system
generally catabolic, prepares for “fight or flight”
Parasympathetic functions of the autonomic nervous system
~anabolic, conserves energy, and promotes the maintenance, and restoration of bodily reserves
~nicknamed either “feed and breed” or “rest and digest
ANS: Heart and BP sympathetic function
~increase heart rate
~increase contractility
~increase blood pressure
ANS: Heart and BP parasympathetic function
~decrease heart rate
~decrease blood pressure
ANS: vascular sympathetic function
~vasodilation (cholinergic) muscle
~vasoconstriction (adrenergic) muscle
~vasoconstriction most other beds
ANS: vascular parasympathetic function
no effect
ANS: lung sympathetic function
bronchiolar dilation
ANS: lung parasympathetic function
bronchiolar constriction
ANS: metabolic/ blood sympathetic function
~increase serum glucose ~increase glycogenolysis ~increase serum lipids ~increase lipolysis ~increase coagulation
ANS: metabolic/blood parasympathetic function
no effects except slight glycogen synthesis
ANS: GI sympathetic function
~decrease salivation
~decrease peristalsis
~increase sphincter tone
ANS: GI parasympathetic function
~increase salivation
~increase peristalsis
~decrease sphincter tone
ANS: urinary system sympathetic function
~detrusor relaxation (slight)
~trigone (internal sphincter) contraction
ANS: urinary system parasympathetic function
~detrusor contraction
~trigone (internal sphincter) relaxation
ANS: sexual response sympathetic function
male- ejaculation
ANS: sexual response parasympathetic function
~male- erection
~female- clitoral engorgement, vaginal lubrication
What are four parasympathetic division cranial nerve ganglia that preganglionic axons end in?
Ciliary ganglion (behind eye orbit)
Otic ganglion
Ptergopalatine ganglion
Submandibular ganglion
