AUTONOMIC NERVOUS SYSTEM Part I Flashcards
Anesthesiology define as ________
Goal of anesthesia: ______
The practice of ANS medicine
Keep ANS stable
Division of ANS 3 anatomic divisions are:
Sympathetic
Parasympathetic
Enteric GI
The ANS Is (vol/invo) and conducts impulse from ______ or _______to _____, ______, and _______Tissues
involuntary division of the PNS (conducts impulses from the brain stem or spinal cord to cardiac, smooth and glandular tissues)
ANS also called (Not in control); 3 other names
Visceral, vegetative and involuntary NS
ANS periphery involces
nerves, ganglia, plexuses
ANS is accompanied by sensory (afferent) nerve fibers - visceral afferent system
send input from viscera
**ANS is a ______ innervation. most organs have input for ______ and ______pathways
Dual innervation system: PNS and SNS
ANS function
regulates structures that are NOT VOLUNTARY CONTROL and that function below the consciousness.
Enteric Nervous system
Mixing, propulsion and absorption of nutrients in the GI tract.
Neurons located in wall of GI tract, link to pancreas and gallbladder function.
It is the ENS through the _______ and __________that regulates _______activity
Myenteric, SUBMUCOUS PLEXI regulates the DIGESTIVE ACTIVITY
***IMPORTANT: Main neurotransmitter in GI Nervous system
SEROTONIN
HYPOTHALAMUS (CNS) act as a ____ ____ and _________ for the ANS FUNCTION
SIGNAL RELAY and integration center for ANS functions
What are the 2 VITAL CENTERS FOR hemodynamics and ventilatory control
MEDULLA
PONS
Adrenergic Axon is a
Cholinergic Axon is a
nerve fiber that secretes norepinephrine
nerve fiber that secretes acetylcholine
Adrenergic Receptor
Cholinergic Receptor
receptor Binds to catecholamines: Norepinephrine and epinephrine, dopamine
Receptor that binds to Acetylcholine
ANS is a 2 neuron pathway
Pre-ganglionic
and post ganglionic
the cell body of the Pre-ganglionic neuron is located in 2 places: the ______(____nerves) and the ________ _____ (___Nerves)
Cell body is in brain (cranial nerves) or spinal cord (spinal nerves)
Pre-ganglionic neuron does what?
Carries message to the autonomic ganglia
the neurotransmitter released from the PREGANGLIONIC NEURON at the autonomic ganglion is ALWAYS
ACETYLCHOLINE
The receptor that ACh binds on the POST GANGLIONIC NEURON Cell body is ALWAYS
a NICOTINIC CHOLINERGIC RECEPTOR (nAChR)
Where does the cell body lies in the POST GANGLIONIC neuron? and where does it carry the message to? ______ _____
lies outside the CNS - CARRIES MESSAGE TO THE VISCERAL EFFECTOR ORGAN
AXON in the POST ganglionic is (myelinated /unmyelinated)
UN-myelinated fiber.
Axon is a myelinated fiber in a ____ ______neuron
PRE-GANGLIONIC Neuron
Where is the cell body in post ganglionic? Where does it terminates _______
OUTSIDE of the CNS; In the visceral effector organ.
SNS pre-ganglionic comes from ________horn of the _________ from ___ -____segments
Intermediolateral horn of the spinal cord arising form T1-L2 or L3 segments
The preganglionic fibers are short, _______ and synapses Sympathetic autonomic ganglia
MYELINATED
PREGANGLIONIC fibers always release
ACh
SYMPATHETIC Post ganglionic fibers release primarily ________
The neurotransmitter release depends on the_______ ______
ANS the receptor can be either : _______Or ________/______
Norepinephrine ; effector organs
adrenergic; muscarinic/ Cholinergic
Sweat glands SYMPATHETIC post-ganglionic EXCEPTION post ganglionic releases _____and binds to _____
release Ach which binds to muscarinic cholinergic receptors
Skeletal muscles and blood vessels are an EXCEPTION post ganglionic releases ____and binds to ______
release Ach bind to muscarinic cholinergic receptors
NE released from sympathetic postganglionic bind to adrenergic receptors
located on the effector organ
Pre-ganglionic fibers issuing from the spinal cord may synapse with the neurons of more than one
sympathetic ganglion
where are the cell bodies of the preganglionic neurons located? ____________ horn of the spinal cord and fibers from these pre-ganglionic cell bodies leave the spinal cord through what? the (anterior/posterior) nerve roots and pass via _________ to 3 different fates.
Intermediolateral horn of the spinal cord; anterior T1 to L2 - L3; WHITE RAMI
3 fates once passed through WHITE RAMI
1: preganglionic fibers will synapse with the paravertebral ganglia with a sympathetic post-ganglionic neuron and these post-ganglionic fibers pass through the grey rami to reach the spinal nerves.
2. Some PreGF will ascend or descend in the paravertebral ganglia to synapse with post ganglionic neurons in OTHER paravertebral ganglia
3. some PreGF will pass through the paravertebral ganglia WITHOUT synapsing and synapse in EITHER the prevertebral ganglia or terminal ganglia.
Function of sympathetic nervous system (fight or flight): effect:HR, BP, CO , bronchial tree, effect on Blood sugar? where does it shunt blood away from ____to better supply.
when activated: Increased HR , CO Increase BP DILATE BRONCHIAL TREE Shunt blood away from the intestine to better supply skeletal muscle Increase BLOOD GLUCOSE concentration
Cell bodies of pre-ganglionic are located in the PARASYMPATHETIC system
brainstem
and sacral nerves
Nerves arise from ___ ___ ___ __ ___ and _______-____ of sacral portion of the spinal cord.
CN III, VII, IX and X and S2-S4 sacral portion of the spinal cord.
What is the only neurotransmitter in the PNS system
ACh
The ration of pre to post for Parasympathetic
1:1
Exception: The ratio of preganglionic VAGAL fibers to Ganglion CELLS in the _________ _________is
MYENTERIC PLEXUS 1:8000
The receptor located on the postganglionic cell body is always
nACh R
Preganglionic fibers or the Parasympathetic NS is Long, myelinated and pass
UNINTERRUPTED
CN III innervates
Eye/orbit
** CN X most important of PARASYMPATHETIC . why :
Vagus NERVE: becomes it transmits 75% of parasympathetic outflow.
CN VII innervates
lacrimal, nasal and SL, submaxillary glands
A massive parasympathetic response only prostrate and organism leaving it :
helplessly, salivating, wheezing, weeping, vomiting, urinating, defecating and seizing.
PNS Is_______
essential for the Maintenance of life.
Essential for the Maintenance of life which nervous system
PNS
Sympathetic ____pupils, para sympathetic ___pupils
dilate pupils
Constrict pupils
Sympathetic ____bronchi, para sympathetic ___bronchi
Dilate bronchi
Constrict
Length of the preganglionic nerve in Parasympathetic is
LONG
Length of the preganglionic nerve in sympathetic is
short
Effects of Sympathetic on heart
- CO
- HR Automaticity and conduction velocity
- SA and AV
- His purkinje
- Ventricle
- Increase HR (Beta 1)
- AV and SA node Increased (beta 1)
- Increased automaciticy and conduction velocity (Beta 1)
- his: increased automaticity and conduction velocity (Beta1)
- increased forces on contraction (Beta 1)
Effects of ParaSympathetic on heart
Decrease HR
- AV and SA node decreased
- decreased automaticity and conduction velocity
- his: minimal effect
- Slight decreases in forces on contraction.
In Parasympathetic, at the heart, AcH binds to
MUSCARINIC 2 receptors.
Effects of Sympathetic on ARTERIES:
Vasoconstriction (alpha 1)
Vasodilation (Beta 2)
Effects of ParaSympathetic on ARTERIES
No direct innervation of the vasculature.
Effects of ParaSympathetic on VEINS
No direct innervation of the vasculature.
Effects of Sympathetic on VEINS
Vasoconstriction (alpha 1)
Vasodilation (Beta 2)
Blood vessels do have _______ receptors : are they innervated from PNS?
muscarinic receptors; NO
Acetylcholine is a __________>
neurotransmitter
Synthesis of ACH
- occurs where?
- what is the EXCEPTION of post ganglionic
occurs in cytoplasm
Pre-ganglionic of SNS and PNS
Post-ganglionic PNS
Post-nganglinonic of SNS for innervation of sweat glands and skeletal muscles.
How is ACH synthesized
4 steps : What is the rate limiting step?
wher is Acetyl CoA synthesized?
-choline taken up by active transport from the ECF into the Axoplasm
- Choline acetyltransferase catalyzes the final step in the synthesis of ACH –>the acetylation of choline with AcetylCoA enzymes
-
ACH is packaged RAPIDLY into synaptic vesicles.