Where do I find preganglionic neuron cell bodies of the ANS?
Brain & Spinal Cord
Where do I find efferent (motor) neuron cell bodies of the somatic division of peripheral nervous system?
Ventral (Anterior) horn of spinal cord.
Where do I find postganglionic neuron cell bodies of the ANS?
Ventral (Anterior) horn of spinal cord.
What is the primary function of the ANS?
Maintain Homeostasis, Increase or decrease activity of visceral organs & skin in response to changes in internal & external environment.
What are 3 types of autonomic ganglia & which division of the ANS are they associated with?
1. Paravertebral – Ganglion of the sympathetic ANS located lateral to vertebral column from C1-S3. 2. Prevertebral Ganglion (Sympathetic) located anterior to the vertebral column. 3. Terminal Ganglion (Parasympathetic) located close to or in wall of organ
Where are the various autonomic ganglia located and what are the names of the major autonomic ganglia?
1. Paravertebral – Ganglion of the sympathetic ANS located lateral to vertebral column from C1-S3 2. Prevertebral Ganglion (Sympathetic) located anterior to the vertebral column. 3. Terminal Ganglia next to tissue / organ they innervate.
What is the autonomic plexus?
The autonomic plexus is a network of interlaced nerves that arise from the ANS.
What are the locations of the major autonomic plexuses?
Tympanic, Pharyngeal, Cardiac, Pulmonary, Celiac, Superior & Inferior Hypogastric
What are Splanchnic Nerves?
Neurons that pass through the sympathetic trunk of ganglia without synapsing
What are the specific locations of sympathetic GVE neuron cell bodies in CNS?
(Thoracolumbar) Lateral Horn of T1-L2 Spinal Segments.
Sympathetic GVE neurons emerge from the spinal cord in the _________ roots of the spinal nerves from spinal segments _____________?
1. Ventral (Anterior) 2. T1-L2
Sympathetic preganglionic neuron fibers exit the spinal nerve via the _________ to enter the ____________ ganglia?
1. White Rami 2. Paravertebral Chain (AKA Sympathetic Chain Ganglia)
Once the sympathetic GVE neuron exits the spinal nerve & enters the paravertebral ganglia, one of four things can happen. What arc they?
1. Synapse in Paravertebral chain at level of entrance. 2. Ascend or descend Paravertebral chain and synapse w/ postganglionic neuron cell bodv. 3. Pass thru Paravertebral chain w/out synapsing and form the splanchnic nerves 4. Synapse Adrenal Medulla
Sympathetic neurons which exit the paravertebral ganglia to rejoin the spinal nerve do so via what structure?
Gray Rami
Which spinal nerves are associated with the white rami & gray rami?
a. White Rami – spinal nerves (T1-L2)
What neurotransmitters are released from preganglionic sympathetic neurons?
ACH(Acetylcholine)& Acetyl CoA
What enzyme inactivates the neurotransmitter released from preganglionic sympathetic neurons?
Acetylcholinesterase
What neurotransmitter is released from the majority of postganglionic neurons?
Catecholiamines -norepinephrine
What are the names & locations of the enzymes which inactivate the neurotransmitters released from the majority of the sympathetic postganglionic neurons?
1.MAO (MonoamineOxidase)-inactivates catecholamines by oxidation. Occurs in the preneuron axon boot 80% is brought back into the neuron. 2.COMT(Catechol-O-Methyl Transferase) - catecholamines inactivated by methylation. Occurs in the synaptic space/cleft
What are the types & locations of the adrenergic receptors?
Postganglionic neurons of the facial nerve innervate what structures & have what effect upon these tissues?
Lacrimal, Submandibular, & Sublingual glands - secretion of fluids
Preganglionic fibers from cell bodies located in the __________ are conveyed by the vagus nerve and synapse in the ___________?
1. Inferior Salivatory Nucleus 2. Otic Ganglion
Postganglionic neurons of the glossopharyngeal nerve innervate what structures & have what effect upon these tissues?
Parotid glands increase secretion of fluids & salivation
Preganglionic fibers from cell bodies located in the ___________ are conveyed by
1. Doral Motor Nucleus of the Vagus nerve 2. Terminal Ganglia
Postganglionic neurons of the vagus nerve innervate what structures & have what effect upon these tissues?
Visceral organs of thorax & abdomen 1. Heart - decrease heart rate and conduction rate 2. Lungs – causes constriction of bronchioles 3. GI Tract –increases the GIT secretions 4. Pancreas stimulates exocrine secretions
What neurotransmitter is released from preganglionic parasyrnpathetic neurons & what enzyme inactivates that neurotransmitter?
1. ACH(Acetvlcholine) 2. Acetylcholinesterase
What is the definition of cholinergic?
Choline activated or transmitted by choline (ACH) or Nerve cells that release or have receptors that respond to ACH
What is the definition of adrenergic?
Catecholamine activated or transmitted by catecholamines (primarily norepinephrine) or Neurons which release or have receptors which resoond to norepinephrine or epinephrine
Where is the location of nicotinic receptors?
Located on postganglionic located neurons in Autonomic Ganglia & on skeletal muscle motor endplate (Myoneural Junction).
Where is the location of muscarinic receptors?
Located on neuroeffector tissues innervated by Autonomic Postganglionic Cholinergic Fibers (smooth muscle, cardiac muscle, & glands)
What effect does stimulation of nicotinic receptors have?
Release ACH and Norepinephrine
What effect does stimulation of muscarinic receptors have?
Parasympathetic Effects
What effect does stimulation of muscarinic receptors have?
Parasympathetic Effects
The ___________ is considered to be the highest and main subcortical regulatory center for the ANS?
Hypothalmus
The centers which monitor heart rate & blood pressure are located where?
Medulla Oblongota
What is the definition of anticholinergic?
a. Anticholinerqic-antagonistic to the action of cholinergic receptors (e.s.atropine). b. Parasympatholytic-prevents parasympathetic = increased sympathetic. c. Sympathomimetic - mimics that of the sympathetic.
What effect would a muscarinic blocker, like atropine have upon heart rate, pupil diameter, gut motility, GIT secretions, bronchial secretions, etc.?
Definition – denoting mimicking of action of the sympathetic system; Heart Rate – increases; pupils dilate; gut motility decreases; GIT Secretion decreases; Bronchial Tree - dilates
Why are you unable to focus on objects up close after your eyes have been dilated at the opthalmologist's office with an anticholinergic drug such as tropicamide (mydriacyl)?
Causes paralysis of the ciliary muscles of the eye (muscles of accomodation) = can't focus.
What is the difference in the ratio of pre to postganglionic fibers in the sympathetic vs. parasympathetic nervous system?
a. Sympathetic – 1 to Many. b. Parasympathetic - 1 to 1.
What effect does ANS input have upon skeletal m. fibers? Does it cause them to contract, relax, or have no effect?
No direct effect
What effect would bilaterally cutting the vagus n. have upon heart rate, gut motiliry & GI Tract secretions?
No Parasympathetic = increased HR,; decreased gut motility; decreased GIT secretions.
Why is epinephrine given to a patient in status asthmaticus or during anaphylatic shock?
a, Anaphylaxis –contracts smooth muscle; constriction of bronchi; & dilates capillaries. b. Epinephrine - most effective stimulant of adrenergic (alpha & beta) receptors, resulting in increased HR & force of contraction, bronchodilation, etc.
What is meant by dual autonomic innervation of a tissue & how is this used to control various bodily functions?
a. innervated by both Sympathetic & Parasympathetic NS b. One acts to slow while other acts to speed up
A male with a herniated disc in the region of Ll-L2 which is compressing the spinal cord would have which sexual dysfunction: failure to ejaculate or failure to attain an erection? Why?
Failure to ejaculate because (L1-L2) is part of Sympathetic Nervous System which controls ejaculation & orgasm
Cardio Block2anatomy
