Flashcards in T3 Autonomic NS Deck (97)
Efferent activity of the ANS is largely regulated by what?
What is the baroreceptor reflex?
located in the major systemic arteries sensing blood pressure.
What happens if BP decreases?
sensory impulses to the vasomotor center of the brainstem decreases. Heart rate increases and vascular resistance increases.
Preganglionic neurons of ANS cell bodies are located where?
within the CNS
Postganglionic neurons of ANS cell bodies are located where?
Preganglionic neurons of the ANS are myelinated or unmyelinated?
Postganglionic neurons of the ANS are myelinated or unmyelinated?
Preganglionic neurons use what neurotransmitter?
Postganglionic neurons use what neurotransmitter?
ach (parasympathetic) and norepinephrine (sympathetic)
What is the result of the sympathetic stimulation of ANS on glands?
secretion of large amounts of sweat
What is the result of the parasympathetic stimulation of ANS on glands?
strongly stimulates lacrimal, nasal, salivary and GI glands of upper tract.
What is the result of the sympathetic stimulation of ANS on heart?
increase in heart rate and strength of contraction
What is the result of the parasympathetic stimulation of ANS on heart?
decrease in heart rate and strength of contraction
What is the result of the sympathetic stimulation of ANS on systemic blood vessels?
constricts most blood vessels
What is the result of the parasympathetic stimulation of ANS on systemic blood vessels?
has almost no effect
What is the result of the sympathetic stimulation of ANS on arterial pressure?
results in acute increase in arterial pressure but little long term
What is the result of the parasympathetic stimulation of ANS on arterial pressure?
decreases pumping of heat but little effect on bp
What is the result of the sympathetic stimulation of ANS in general?
inhibits most ectodermal structures (GI, respiratory, endocrine, auditory, urinary)
What is the result of the parasympathetic stimulation of ANS in general?
excites most endodermal structures
What is the result of the sympathetic stimulation of ANS on eyes?
What is the result of the parasympathetic stimulation of ANS on eyes?
pupil constriction and lens focusing
What is the result of the sympathetic stimulation of ANS on GI tract?
strong stimulation inhibits peristalsis. GI tract is not normally dependent on sympathetic stimulation
What is the result of the parasympathetic stimulation of ANS on GI tract?
promotes peristalsis and relaxes sphincters
Where do the cell bodies of each sympathetic preganglionic neuron lie?
in the intermediolateral horn of the spinal cord
All preganglionic neurons are _______.
Where doe post-ganglionic sympathetic neurons pass?
through the gray rami
What type of fibers are postgang sympathetic?
Post gang symp fiber innervate muscles that...?
constrict blood vessels, piloerect hair, and change heart rate and force of contraction
Cervical sympathetics supply the face and thoracic viscera and are considered _________.
What are the functions of the cervical/thoracic sympathetic chain?
-coronary artery dilation
-increase heart rate
What is the location of the thoracic sympathetic chain?
lies against neck of ribs and costovertebral junction
There are 12 pairs of thoracic ganglia. T2 goes where?
There are 12 pairs of thoracic ganglia. T3-6 go where?
There are 12 pairs of thoracic ganglia. T7-11 go where?
There are 12 pairs of thoracic ganglia. T12-L2 go where?
Splanchnic nerves are composed of _______ fibers and visceral sensory fibers.
What do the splanchnic nerves supply?
Where do the splanchnic nerves synapse?
All preganglionic neurons are __________.
Where do the greater splanchnic nerves synapse?
Where do the lesser splanchnic nerves synapse?
superior mesenteric ganglion
Where do the least splanchnic nerves synapse?
Where do the lumbar splanchnic nerves synapse?
superior and inferior mesenteric ganglion
What are the steps of NE synthesis
-hydroxylation of tyrosine to dopa
-decarbox of dopa to dopamine
-transport of dopamine into vesicles
-hydroxylation of dopamine to NE
-once neuron is stimulated, NE is released where it binds receptor depending on affinity
What happens after NE is released?
-broken down in cleft
-recycled via NE transporter
-taken up in to circulation
-small amount is returned to vesicles
-most is metabolized and metabolites are released into circulation
-metabolites broke down to COMT, which is found in all tissues.
NE excites mainly _____ receptors
Epinephrine excites ______ and _______ receptors.
alpha and beta adrenergic
What type of functions are alpha adrenergic receptors associated with?
sympathetic functions like iris dilation, vasoconstriction, bladder sphincter contraction and inhibition of neurotransmitter release
what are the functions of beta 1 adrenergic receptors?
cardioacceleration, increased myocardial strength, lipolysis
what are the functions of beta 2 adrenergic receptors?
vasodilation, intestinal relaxation, uterus relation, bronchodilation, calorigenesis, glycogenolysis, bladder wall relaxation
what are the functions of beta 3 adrenergic receptors?
What are the drugs that block adrenergic activity?
reserpine, propranolol, and metoprolol
What is the function of reserpine?
block synthesis and storage of NE
What is the function of propranolol?
block sympathetic beta 1 and beta 2 receptors
What is the function of metoprolol?
block mostly sympath beta 1 receptors
What is the function of beta blockers?
block beta adrenergic receptors, and attenuate the actions of the sympathetic system by decreasing heart rate
What are the side effects of beta blockers?
fatigue, hypotension, bradycardia, associated with negative changes in blood lipid profiles, and associated with higher glucose and insulin levels.
What is the effect of alpha 1 blockers?
decrease blood pressure
The adrenal medulla is stimulated by what?
What is secreted from the adrenal medulla?
80% epinephrine and 20% NE
Are secreting cells of the adrenal medullar pre or post gang?
What are the functions of circulating NE?
constricts blood vessels of body, increases heart activity, inhibits GI tract, dilates pupil
What are the functions of circulating epinephrine?
raises arterial pressure to a lesser extent than NE, increases CO more than NE, 5-10x great effect on metabolism as NE, increases metabolic rate of whole body (up to 100% above normal).
Alarm or stress response occurs when there is a mass discharge of the entire sympathetic system. What are the results?
-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
What is the location of the post gang parasympath fibers, and what neurotransmitter do they use?
located in the wall of the organ; ach
What are the cranial nerves that carry parasympathetic signals?
oculomotor, facial, glossopharyngeal, and vagus
What is the path of the sacral parasymp nerves and what do they supply?
pass through the spinal nerve sacral plexus on each side of S2 and S3, and supply the colon, rectum, urinary bladder, and external genitalia
What is the preganglionic pathway of the oculomotor nerve?
from edinger-westphal nucleus to the ciliary ganglion
What is the postganglionic pathway of the oculomotor nerve?
from the ciliary ganglion to the pupillae muscle
What is the motor function of the oculomotor nerve?
innervate the skeletal muscles of the eyes
What is the parasympath function of the oculomotor nerve?
constrict pupillae of the iris and the ciliary muscles
What is the preganglionic pathway of the facial nerve?
from the superior salivatory and lacrimal nuclei to the submandibular/sublingual ganglia
What is the postganglionic pathway of the facial nerve?
to lacrimal gland, submandibular gland, sublingual gland, and mucous gland
What is the motor function of the facial nerve?
primary nerve to the muscle of facial expression, innervates muscles of the inner ear
What is the sensory function of the facial nerve?
carries sensation of taste from anterior 2/3 of the tongue
What is the parasymp function of the facial nerve?
stimulates mandibular and sublingual glands to increase the flow of saliva, stimulates the nasal mucosa
What is the preganglionic pathway of the glossopharyngeal nerve?
from inferior salivatory nucleus to otic ganglion
What is the postganglionic pathway of the glossopharyngeal nerve?
to parotid gland
What are the functions of the glossopharyngeal nerve?
-carried general sensation and sensation of taste from posterior 1/3 of tongue
-skeletal muscle to stylopharyngeus muscle
-injury can result in impaired swallowing
What is the longest nerve in the human body?
vagus nerve pierces diaphragm and becomes what nerve?
What are the functions of the vagus nerve regarding the heart?
lowers heart rate
What are the functions of the vagus nerve regarding the GI tract?
-controls taste and saliva
-increases stomach acidity, digestive secretions and gut flow
-role in controlling blood glucose balance
-assists in releasing bile
What are the functions of the vagus nerve regarding the kidneys?
promotes general function (filtration)
What are the functions of the vagus nerve regarding the repro sys?
helps control fertility
What are some effects of vagus nerve dysfunction?
IBS, anxiety, depression, high/low HR, difficulty swallowing, esophageal reflux, migraines
What enz catalyzes the reaction of acetyl coa and choline to acetylcholine?
What enz catalyzes the breakdown of acetylcholine to choline and acetate ion?
________ is a poison from toadstools, and receptors are found on all effector cells stimulated by postgang cholinergic receptors.
What adrengeric receptors are found in autonomic ganglia at synapses between pre and post gang neurons, and are present in NMJ in skeletal muscles>
What is the mechanism of muscarinic receptors?
What is the mechanism of nicotinic receptors?
What are direct parasymp cholinergic drugs that bind to ACH receptors?
nicotinic or muscarinic
What is an indirect parasymp drug function?
Tear gas and sarin are ______ drugs