Autonomic Nervous System Flashcards
(T/F?) Adrenergic Receptors can also bind Dopamine?
True
Define the ANS?
The ANS is the involuntary branch of the PNS that conducts impulses from brainstem or spinal cord to cardiac muscle, smooth muscle and glandular tissue.
Other names for the ANS
1) Visceral Nervous System
2) Involuntary Nervous System
3 Divisions of the ANS?
1) Sympathetic
2) Parasympathetic
3) Enteric (GI) Nervous system
The ANS regulates involuntary activities such as?
1) Visceral functions
2) Metabolic functions to maintain homeostasis
3) BP & HR
4) GI motility and secretion
5) Bladder emptying/filling
6) Sweating and temperature regulation
7) near/far vision and pupil size
8) secretions of certain endocrine glands
What role is the Enteric Nervous System responsible for within the ANS?
The processes of mixing, propulsion, and absorption of nutrients in the GI tract.
How does the ENS regulate digestive activity?
Via the mycenteric and the sub mucous plexi
(T/F?) Serotonin is also a neurotransmitter used by the ENS?
True
The ANS is regulated by which higher centers of the brain?
1) Hypothalamus - Acts as a signal relay and integration center
2) Medulla - Hemodynamic and ventilatory control
3) Pons - Hemodynamic and ventilatory control
Cholinergic Axon vs. Cholinergic Receptor?
1) Cholinergic Axon - A nerve fiber that secretes ACh
2) Cholinergic Receptor - A receptor that binds to ACh
Adrenergic Axon vs. Adrenergic Receptor
1) Adrenergic Axon - A nerve fiber that secretes NE
2) Adrenergic Receptor - A receptor that binds to NE or Epi
Preganglionic vs. Postganglionic?
1) Preganglionic - Cell body located CNS (brain or spinal cord) and carries msg to the autonomic ganglia, axon is myelinated, always releases ACh to a nAChR on the postganglionic cell.
2) Postganglionic - Cell body located outside the CNS (in an autonomic ganglion) and carries msg to the visceral effector organ, axon is unmyelinated, can release adrenergic or muscarinic.
Where are the sympathetic preganglionic neuronal cell bodies located?
In the intermediolateral of the spinal cord arising from T1 to L2 or L3 segments aka the Thoracolumbar outflow.
Characteristics of the sympathetic preganglionic fibers?
1) They are short
2) Myelinated
3) They synapse in the sympathetic autonomic ganglia
4) 22 pairs of ganglia that lie on either side of the vertebral column
Postganglionic fibers primarily release NE as their neurotransmitter, except for the following…?
1) Sweat glands - Release ACh to mAChr
2) Blood Vessels - ACh is released to mAChr on skeletal muscle
(T/F?) The ratio of sympathetic pre to postganglionic fibers is 1:20?
True - preganglionic fibers issuing from the spinal cord may synapse with neurons of more than one sympathetic ganglion: aka defuse innervation.
Effects of the sympathetic nervous system?
1) Increase HR, BP and CO
2) Bronchodilation
3) Shunts blood away from intestines and other organs to muscles
4) Increase Blood glucose
Where are the cell bodies of the parasympathetic preganglionic fibers located?
At the brainstem and sacral S2 to S4 spinal nerves: aka the Craniosacral outflow.
Characteristics of the parasympathetic Preganglionic fibers?
1) They are long
2) Myelinated
3) Releases ACh to nAChr
Characteristics of Parasympathetic postganglionic fibers?
1) They are short
2) They release ACh to mAChr
The ratio of parasympathetic pre to posganglionic fibers is 1:1. Whats the exception?
The ratio of preganglionic vagal fibers to ganglion cells in the myenteric plexus is 1:8000.
Function of the following Cranial Nerves:
1) CN III (Oculomotor)
2) CN VII (Facial)
3) CN IX (Glossopharengeal)
1) CN III - Innervate the eye orbit
2) CN VII - Innervate the lacrimal, nasal, submaxillary and sublingual glands
3) CN IX - Innervate the parotid gland
List of anatomies under the control of CN X (vagus)?
1) Heart
2) Lungs
3) Esophagus
4) Stomach
5) Small intestine and upper colon
6) Liver and spleen
7) Gallbladder
8) Pancreas
9) Upper portions of the uterus
(T/F?) The parasympathetic nervous system is functionally more selective, discrete, and localized than the sympathetic nervous system?
True