Lecture 8 Flashcards
autonomic nervous system is stimulated by centers located in the _____,_____,______, and ________
spinal cord
brainstem
hypothalamus
portions of the cerebral cortex
the autonomic nervous system often operates by means of ______, which involves ________
visceral reflexes
subconscious sensory signals from visceral organs
in the autonomic nervous system, these visceral reflex loops can return an ______reflex motor response back to the visceral organ to control _____
involuntary
its activity
two major subdivisions of autonomic nervous system
sympathetic NS
parasympathetic NS
most organs receive intervention from _____NS
both sympathetic and parasympathetic
the autonomic NS receives input from the brainstem. this input including _____________________.
brainstem
-arterial pressure
-heart rate
-respiratory rate
the ______ and _____ also play a large role in regulating the activity of the autonomic NS
hypothalamus
cerebral cortex
parasympathetic located in the ______ and sympathetic in the _______
anterior of hypothalamus
posterior of hypothalamus
skeletal muscle stimulation requires _____ impulses per second to fire a muscle.
in contrast, the ANS only requires ___ impulses every ______.
Full activation of either Sympathetic or parasympathetic require _____ per second
50-500
1 every few seconds
10-20
autonomic tone
not a lot of impulses needed to activate
the sympathetic nervous system has the capability to simultaneously ______
dilate some arterioles and constrict others
what are some important nerves in the ANS
the vagus nerve (cranial nerve X)
role of the vagus nerve
important parasympathetic ton activity : GI peristalsis
cutting almost any sympathetic nerve to a specific organ will often result in significant ______ in less than ______ to that organ. this is how we know ____ muscle has some ability to control itself
vasodilation
less than a minute
smooth muscle
what is secreted into the bloodstream at all times to provide a baseline tone?
- epinephrine (0.2 mcg/kg/min)
- norepinephrine (0.05 mcg/kg/min)
what makes and secretes epinephrine and norepinephrine?
adrenal medulla
- adrenal gland is on top of kidneys
the baseline tone allows ______ to remain at normal levels even without direct ________ nerve activity
blood pressure
sympathetic
sensitivity to norepinephrine and ________ is unregulated after a ______ event, or trauma, causing super sensitivity. the response of _____ is magnified
acetylcholine
denervation
vasoconstriction
Within _______ seconds, HR can be doubled by the ANS
Within _______ seconds, Arterial Pressure can be doubled, or it can be lowered enough to cause ______
Sweating can begin within seconds
3-5 seconds
10-15 seconds
syncope
Stretch sensors in the bladder causes signals to be sent to the __________, which causes the bladder to contract, and the __________ to relax
Voluntary control may need to be exerted to prevent this.
sacral spinal cord
urinary sphincters
________ can send signals up, down, or out to the organs. to is located ______. this involves _____ synapse
sympathetic trunk ganglia
slightly in front of spinal cord on the sides
chemical
sympathetic NS’s general peripheral organization contains ___________ sympathetic ganglia that are interconnected with spinal nerves on each Side of the cord (bilateral)
2 paravertebral chains of ganglia
each paravertebral ganglia consist of _ ________
3 prevertebral ganglia
the 3 prevertebral ganglia lie ____ to the vertebral column and close to __________
anterior
large abdominal arteries
what are the 3 prevertebral ganglia
celiac
superior mesenteric
inferior mesenteric
the ________ axons leave the ______ ganglia to travel to the visceral organ
prostganglionic axon
prevertebral
the sympathetic NS is a _____ neuron system, which include _____ and ______
two
- preganglionic
-postganglionic
the preganglionic nerve are ____ that pass through the _____ root of the cord to the corresponding spinal nerve.
Enter the sympathetic trunk by way of _________.
fibers
anterior
white ramus communicans
what is the white ramus communicans
axons entering the sympathetic trunk in one of these three routes
- synapse with postganglionic sympathetic neurons in the ganglion at the level it enters
- pass upward or downward in the chain and synapse with ganglia at those levels
- pass through the sympathetic chain and synapse in prevertebral ganglia, or postganglionic cell bodies in the adrenal medulla (leave the ganglia)
the postganglionic neuron in sympathetic NS are located where?
cell bodies are either located in sympathetic chain, prevertebral ganglia, or in the wall of the adrenal medulla
Path of postganglionic neurons?
some fibers pass back into the spinal nerves through the gray humus communicans to supply smooth muscle in blood vessels, sweat glands, and erector pills muscles of the hairs
blood vessels are_______
vasomotor
sweat glands are______
sudomotor
erector pilli is _______
pilomotor
gray ramus is ___% of the spinal nerve fibers
8%
more than one ramus is a _____
rami
these rami exit all spinal levels after doubling back at the ______ through the _______
postganglionic level
gray ramus
rami are _____ fibers
they control __________, ________, and ________. these are ________ system only.
C fibers
- vasoconstriction and dilation (vasomotor)
- sweat gland production (sudomotor)
- piloerector muscles (pilomotor)
sympathetic only
parasympathetic comes through ____ and ____ of spinal cord
very top and very bottom
preganglionic fibers in parasympathetic nervous system cell bodies are located in CN nuclei ________. also located in ______matter of ____.
III, VII, IX and X
lateral most gray matter of S2-S4
Most (____%) of all parasympathetic preganglionic fibers are carried in the ____ nerves (____)
75%
vagus
CN X
CN X
supplies heart, lungs, esophagus, stomach, entire small intestine, proximal half of colon, liver, gallbladder, pancreas, kidneys, and upper ureters
typically parasympathetic preganglionic axons are _____ and sympathetic ones are ____
long
short
CN III
supplies pupillary sphincter and colliery eye muscles
CN VII
supplies the parotid gland
sacral nerves
fibers are in pelvic splanchnic nerves which pass through spinal sacral plexus and supply…
-descending colon
-rectum
-urinary bladder
-lower ureters
-external genitalia
parasympathetic postganglionics are located in _________.
can also be located within the _____.
therefore, postganglionic axons here are relatively ____ where sympathetics are ____.
terminal ganglia right outside the organ being supplies
wall of the organ itself
short
long
what are the parasympathetic post ganglions
cilliary ganglion
pterygopalatine ganglion
submandibular ganglion
otic ganglion
Function of sympathetic pre ganglion fibers?
secrete acetylcholine at synaptic end bulb (cholinergic; excitatory)
Function of sympathetic postganglion fibers?
secrete norepinephrine to the organ receptor (adrenergic)
Function of parasympathetic preganglion fibers?
secrete acetylcholine at synaptic end bulb
(cholinergic; excitatory)
Function of parasympathetic postganglion fibers?
secrete acetylcholine to the organ receptor (cholinergic)
in the sympathetic side ___________ is synthesized in the ______ from the ______. it is removed form synaptic cleft by reuptake, diffusion into body fluids and blood.
norepinephrine
adrenal medulla
amino acid tyrosine
in the parasympathetic side _____+_____=______
its broken down in the synaptic cleft by ________________ and the _____ undergoes reuptake back into synaptic terminals
acetyl CoA + choline =
Acetylcholine
acetylcholinesterase
choline
excitation vs inhibition of effector cell is dependent upon the ______
nature of the receptor
basically sympathetic or parasympathetic can be either excitatory or inhibitory
two types of receptors activated by acetylcholine
muscarinic receptors
nicotinic receptors
muscarinic receptors
named after?
found where?
named after muscarine, a poison from toadstools that activates only muscarinic receptors
- found on effector cells that are stimulated by cholinergic axons of parasympathetic and few from the sympathetic NS
nicotinic receptors
named after?
found where?
named after nicotine which only activates nicotine receptors
- found in autonomic ganglia at synapses between preganglionic and postganglionic neurons of both parasymathetic and sympathetic systems
- also found In non automatic nerve ending such as skeletal muscle
two principal types of adrenergic receptors
Alpha (alpha1 and alpha2)
Beta (beta1, beta2, beta3)
adrenergic receptor Alpha (alpha1 and alpha2) excited by?
excited by norepinephrine and epinephrine equally
adrenergic receptor Beta (beta1, beta2, beta3) excited by?
most excited by epinephrine, excited to a lesser degree by norepinephrine
sympathetic and parasympathetic cause excitatory in some organs and inhibitory effects in other organs. therefore some of the time they act reciprocally to each other, however most of our organs in our body are controlled by ______
either sympathetic or parasympathetic
sympathetic vs. parasympathetic stimulation on effector organ : blood vessels
sympathetic
- vasoconstriction most arterioles (except heart) which increases BP
parasympathetic
- vasodilation of arterioles (except in the heart) which decreases BP
sympathetic vs. parasympathetic stimulation on effector organ : glands (nasal, lacrimal, salivary)
sympathetic
- decreased secretion
parasympathetic
- increased secretion
sympathetic vs. parasympathetic stimulation on effector organ : eyes
sympathetic
- pupillary dilation
parasympathetic
- pupillary constriction
sympathetic vs. parasympathetic stimulation on effector organ : heart
sympathetic
- increase heart rate
- vasodilation of coronary vessels
parasympathetic
- decreased heart rate
- vasoconstriction of coronary vessels
sympathetic vs. parasympathetic stimulation on effector organ : sweat glands
sympathetic
-increased secretion
Parasympathetic
- no known effect
sympathetic vs. parasympathetic stimulation on effector organ : GI Tract
sympathetic
-decreased digestion
Parasympathetic
- increased digestion
sympathetic vs. parasympathetic stimulation on effector organ : kidneys
sympathetic
-decreased urine production
Parasympathetic
- increased urine production
sympathetic vs. parasympathetic stimulation on effector organ : liver
sympathetic
-increased glycogenolysis to mobilize glucose for energy
Parasympathetic
- glycogen synthesis
sympathetic vs. parasympathetic stimulation on effector organ : lungs
sympathetic
- dilation of bronchial muscle
Parasympathetic
- constriction of bronchial muscle
- constriction of airway
sympathetic vs. parasympathetic stimulation on effector organ : adipose tissue
sympathetic
- increases lipolysis for energy
Parasympathetic
- …nothing ig
in Sympathetic Nervous system, all portions of the sympathetic nervous system can discharge simultaneously as a complete unit called “________.” when does this occur?
This is commonly called ___________
mass discharge
when the hypothalamus is activated by fright, fear, severe, pain, emotional stress, or rage
fight or fight
as a result of fight or flight…
1. _____ HR
2. _____ BP
3. _____ rates of cellular metabolism for ATP
4. _____ glucose concentration
5. _____ glycolysis in the liver
6. _____ muscle strength
7. _____ mental activity
8. _____ rate of blood coagulation
increased everything
what drugs can act on adrenergic effector organs (sympathomimetic drugs)
injection of norepinephrine, which causes the same effect as sympathetic stimulation
- norepinephrine
- epinephrine
- methoxamine
different drugs differ in the specific _____ they activate as well as the _____ of their activation
receptors
duration
important drugs that stimulate adrenergic receptors
phenylephrine (cold medicine)
- alpha receptors
albuterol (inhalers)
- beta2 receptors
these drugs that cause release of norepinephrine……
cause release of norepinephrine from storage vesicles in _______.
examples?
sympathetic nerve endings
- ephedrine (cold medicine)
- amphetamine (abused lol)
drugs that block adrenergic activity…
activity can be blocked at these several points…
1.Blockage of the synthesis and storage of Norepinephrine in nerve endings.
2.Blockage of the release of norepinephrine from sympathetic endings
3.Blockage of sympathetic alpha receptors
4.Blockage of sympathetic beta receptors
[e.g. propranolol (both beta1 and beta2) and metoprolol (beta1)]
acetylcholine stimulates pre ganglions of ________ system.
these can contain _____ receptors, therefore it stimulates in the same way as _______, and are called _____
both sympathetic and parasympathetic
nicotinic
acetylcholine
nicotinic drugs
