Autonomic Nervous System (Lec 19) Flashcards
The ANS can change visceral function rapidly and intensely. Heart rate can be increased to twice normal within ___ to ___ seconds.
3-5
The ANS can change visceral function rapidly and intensely. Arterial pressure can be doubled within ___ to __ seconds
10-15
Preganglionic neuron cell bodies are located where?
within CNS
Are preganglionic axons myelinated?
yes
What is the pregnalgionic NT?
ACH for both parasympathetics and sympathetics
Where are postganglionic neuron cell bodies located?
peripheral ganglia
Are postganglionic axons myelinated?
no
What are the postganglionic NTs?
parasympathetics - ACH
sympathetics - Norepinepherine
Terminal ends of ANS fibers usually have enlarged ___ where NT and large numbers of _____ are stored
varicosities; mitochondria
In regards to the physiologic anatomy of the sympathetic system, the cell body of each sympathetic preganglionic neuron lies in the _____ horn of the spinal cord
intermediolateral
In regards to the physiologic anatomy of the sympathetic system, preganglionic fiber can synapse with postganglionic neurons upward or downward in the ____ ___
paravertebral chain
In regards to the physiologic anatomy of the sympathetic system, preganglionic fiber can pass for variable distances through the chain and then through one of the sympathetic nerves to synapse in a what?
peripheral sympathetic ganglion
The following describe what fibers:
pass through the gray rami; are C fibers; make up about 8 percent of fibers in the average nerve; control blood vessels; sweat glands, piloerector muscles
Postganglionic sympathetic fibers
Lateral horns are output source for what?
sympathetics
What lies against neck of ribs and costovertebral junctions; has 12 thoracic ganglia pairs; and has cervical ganglia?
thoracic sympathetic chain
The first thoracic ganglia pair is often fused with what?
inferior cervical ganglion
note: referred to as stellate ganglion collectively
The preganglionic sympathetic supply to the thoracic viscera are from what region of vertebrae? How do they exit?
T1-5; exit as direct fibers and travel downwards to enter the thorax as cardiopulmonary splanchnic nerves
True or false?
The cardiopulmonary splanchnic nerves travel on their own and do not accompany other nerves or vessels.
true
What is the function of the cardiopulmonary splanchnic nerves?
coronary artery dilation; increase heart rate; bronchodilation
Splanchnic nerves are composed of what fibers?
preganglionic fibers and visceral sensory fibers
What do splanchnic nerves supply?
abdominal viscera
Where do splanchnic nerves synapse?
in prevertebral ganglia
Name the splanchnic nerve:
T5-T9; synapses in celiac ganglion
greater
Name the splanchnic nerve:
T10-11; synapses in the superior mesenteric ganglion
lesser
Name the splanchnic nerve:
T12; synapses in the aorticorenal ganglion
least
The following structure is stimulated by the sympathetic system and secretes 80% epinephrine and 20% norepinephrine
adrenal medullae
The hormones secreted by the adrenal medullae last __ to __ times longer than NT versions
5-10
Describe the effects of the circulating norepinephrine that is secreted by adrenal medullae
constricts most of blood vessels in body; increases heart activity; inhibits GI tract; dilates pupil
The secretory cells of the adrenal medulla are what type of neurons?
postganglionic
____ fibers of the adrenal medulla are responsible for secreting epinephrine and norepinephrine
rudimentary
What are the effects of circulating epinephrine that is secreted by adrenal medullae
raises arterial pressure to a lesser extent than norepinephrine; increases cardiac output more than norepinephrine; has a 5-10 times as great effect on metabolism as norepinephrine; can increase metabolic rate of whole body by as much as 100%
The following are affects of what response?
Increased arterial pressure, rerouting of blood flow to active muscles, increased rates in cellular metabolism, increased blood glucose concentration, increased glycolysis in liver and muscle, increased muscle strength, increased mental activity, increased blood coagulation rate
alarm or stress response
In regards to physiologic anatomy of the parasympathetic system, about ___ % of all parasympathetic fibers are in the ___ nerve
75; vagus
In regards to physiologic anatomy of the parasympathetic system, most preganglionic fibers pass all the way to what?
the organ that is to be innervated
In regards to physiologic anatomy of the parasympathetic system, postgalngionic parasympathetic fibers are located where? and use what NT?
located in wall of organ; use Ach
Name the parasympathetic cranial nerves
oculomotor, facial, glossopharyngeal, vagus
The following is a function of what nerve:
supplies four of the six extrinsic muscles of the eye and the levator palpebral superioris
occulomotor
In regards to parasympathetic function, Where do the preganglionics of the oculomotor nerve travel?
from edinger-westphal nucleus to the ciliary ganglion
In regards to parasympathetic function, where do the postganglionics of the oculomotor nerve travel?
from the ciliary ganglion to the sphincter papillae muscle
The following is a function of what nerve:
primary motor to muscles of facial expression; carries sensation of taste from anterior two-thirds of the tongue
facial nerve
In regards to parasympathetic function, where do the preganglionics of the facial nerve travel?
from superior salivary and lacrimal nuclei to submandibular/sublingual ganglia
In regards to parasympathetic function, where do postganglionics of the facial nerve travel?
to lacrimal gland, submandibular gland, sublingual gland, and mucous glands of mouth and nose
The following is a function of what nerve:
carries general sensation and sensation of taste from posterior one-third of tongue
glossopharyngeal nerve
In regards to parasympathetic function, where do preganglionics of the glossopharyngeal nerve travel?
from inferior salivary nucleus to otic ganglion
In regards to parasympathetic function, where do postganglionics of the glossopharyngeal nerve travel?
to parotid gland
The following is a function of what nerve:
motor supply to muscles of the fourth and fifth pharyngeal arches and is important in swallowing and speaking
vagus nerve
True or false?
The vagus nerve is the major sympathetic supply to thoracic and abdominal organs
true
In regards to parasympathetic function, where do preganglionics of the vagus nerve travel?
from dorsal motor nucleus
In regards to parasympathetic function, where do postganglionics of the vagus nerve travel?
myenteric plexus of wall of gut tube all the way to the left colic flexure
The vagus nerve runs parallel to what structure in body?
esophagus
note: also innervates esophagus
The vagus nerve passes ___ to root of lung on each side and pierces ___ with esophagus, where it becomes the ___ nerve
posterior; diaphragm; gastric
Where does the left recurrent laryngeal nerve from left vagus travel?
hooks around arc of aorta to left of ligament arteriosum
Where does the right recurrent laryngeal nerve from right vagus arise?
in neck
What is the enzyme used in the following reaction:
Acetyl-CoA + Choline -> acetylcholine
choline acetyl-transferase
What is the enzyme used in the following reaction:
Acetylcholine –> choline + acetate ion
acetylcholinesterase
List the series of events in norepinephrine synthesis
hydroxylation of tyrosine to dopa; decarboxylation of dopa to dopamine; transport of dopamine into vesicles; hydroxylation of dopamine to norepinephrine
In regards to removal of norepinephrine, destruction by monamine oxidase is found where?
nerve endings
In regards to removal of norepinephrine, destruction by catechol-O-methyl transferase is present where?
all tissues
When norepinephrine is secreted into tissues is active for how long? when it is secreted into blood?
tissue = few seconds blood = remains active until destroyed by COMT
What type of acetylcholine receptor utilizes poison from toadstools and is found on all effector cells stimulated by postganglionic cholinergic neurons?
muscarinic
What type of acetylcholine receptor is found in autonomic ganglia at synapses between preganglionic and postganglionic neurons and is present in neuromuscular junctions in skeletal muscles
nicotinic
In regards to adrenergic receptors, norepinephrine excites mainly ___ receptors but also ___ receptors to a lesser extent
alpha; beta
True or false?
epinephrine excites beta receptors more than alpha receptors (adrenergic)
false; excites both equally
What receptors are associated with the following:
vasoconstriction; iris dilation; intestinal relaxation; intestinal sphincter contraction; pilomotor contraction; bladder sphincter contraction; inhibition of NT release
alpha adrenergic receptors
What receptors are associated with the following:
cardioacceleration; increased myocardial strength; lipolysis
beta1 adrenergic receptors
What receptors are associated with the following:
vasodilation; intestinal relaxation; uterus relaxation; bronchodilation; calorigenesis; glycogenolysis; bladder wall relaxation
beta2 adrenergic receptors
What receptor is associated with thermogenesis?
beta3 adrenergic receptors
Phenylephrine is a sympathomimetic drug associated with what receptor?
alpha
Isoproterenol is a sympathomimetic drug associated with what receptor?
beta
Albuterol is a sympathomimetic drug associated with what receptor?
beta2
What is ephedrine prescribed for?
note: it is a drug that causes release of norepinephrine
decongestant and bronchodilator
What is amphetamine used to treat?
ADHD (CNS stimulant)
Reserpine blocks synthesis and storage of what?
norepinephrine
Guanethidine blocks release of what?
norepinephrine
Phenoxybenzamine/phentolamine blocks what receptors?
sympathetic alpha receptors
Propanolol blocks what receptors?
sympathetic beta1 and beta2 receptors
Metroprolol blocks what receptors?
sympathetic beta1 receptors
Hexamethonium blocks transmission through what?
autonomic ganglia
Parasympathomimimetic drugs act directly on what receptors?
muscarinic
In regards to ANS stimulation; what are sympathetic and parasympathetic effects on eyes?
sympathetic: pupil dilation
parasympathetic: pupil constriction, lens focusing
In regards to ANS stimulation; what are sympathetic and parasympathetic effects on arterial pressure?
sympathetic: results in acute increase in arterial pressure but little effect long term
parasympathetic: decreases pumping of heart but little effect on blood pressure
In regards to ANS stimulation; what are sympathetic and parasympathetic effects in endodermal structures?
sympathetic: inhibits most of endodermal structures
parasympathetic: excites most of endodermal structures
