Apex anesthesia: Autonomic Nervous System

___ mole (s) of ATP are able to be produced from ___ mole (s) of glucose

38 1

___ percent of NE is excreted unchanged in the urine

5%

the subtype nicotinic type N is found at these locations

ANS ganglia CNS neuromuscular junction

in NE synthesis, this enzyme converts DOPA to dopamine

DOPA decarboxylase

list the microgram per kilogram secretion of NE & EPI in the adrenal medulla at rest

EPI: 0.2 mcg/kg/min NE: 0.05 mcg/kg/min

list the excitatory subtypes of the muscarinic receptor and its' effector response list the inhibitory subtypes of the muscarinic receptor and its' effector

M1, M3, M5: stimulates phospholipase C M2, M4: inhibits adenylate cyclase

list the substances released by glomangiomas

NE serotonin & kallikrein histamine or bradykinin

explain the effect of sympathetic stimulation on the transcellular potassium shift

SNS stimulation releases glucose & potassium from hepatocytes into the systemic circulation

hypertension increases traffic to the nucleus tractus solitarius which pathway is affected

The rostral ventrolateral medulla & intermediolateral nucleus pathway is stimulated

define denervation

absence of autonomic tone to a distinct organ

the main function of an effector is to ___

activate the second messenger

signal transduction is when a cell converts ___

an extracellular signal into an intracellular response

this receptor augments NE release this receptor inhibits this action

augmentation: presynaptic beta-2 inhibition: presynaptic-alpha 2

this reflex uniquely remains intact in the denervated heart what is the rationale for this?

bainbridge SA node stretch directly increases its firing rate

stellate ganglion block is an unintended consequence of the type of block

brachial plexus block

list 3 types of environmental stimuli that can cause an extracellular signal

chemical stimuli (first messengers): neurotransmitter, hormone, drug electrical stimuli/ action potential: voltage change mechanical: pressure

muscarinic stimulation causes sphincter muscle ___ & ciliary muscle ___, leading to pupillary ___

contraction contraction miosis/ near vision

beta-2 stimulation causes ciliary muscle ___, leading to pupillary ___

contraction relaxation (far vision)

list 5 important second messengers

cyclic adenosine monophosphate (cAMP) cyclic guanosine monophosphate (cGMP) inositol triphosphate (IP3) diacylglycerol (DAG) calcium ion (Ca+2)

in NE synthesis, this enzyme converts dopamine to NE

dopamine B-hydroxylase

what is the fate of sympathetic fibers of piloerector muscles, sweat glands, & some blood vessels?

enter and exit the sympathetic chain renter the spinal nerve via the grey communicating rami reach their destination alongside somatic nerves

which drugs act directly on the SA node, and thus can be used to augment HR in the denervated heart?

epinephrine glucagon isoproterenol

T or F the stellate ganglion provides innervation to the contralateral upper extremity

false ipsilateral upper extremity

T or F in a G-protein couple receptor, the G-protein itself lies outside of the cell membrane and contains 4 subunits

false it lies inside of the cell membrane and contains 3 subunits subunits: alpha, beta, gamma

T or F acetylcholine is produced in the Golgi apparatus and released in the cytoplasm

false produced in the mitochondria

T or F sympathetic postganglionic fibers release Ach into the adrenal medulla

false there no postganglionic fibers in the adrenal medulla myelinated preganglionic fibers release Ach onto chromatin cells

T or F phosphodiesterase III inhibition is dependent on the sympathetic nervous system

false they act independently of the SNS

T or F adenylate cyclase & phospholipase C are second messengers

false they are enzymatic effectors

T or F steroids bind to intracellular receptors in the cell nucleus

false they bind to receptors in the cytoplasm thyroid hormone binds to receptors in the cell nucleus

T or F alpha-2 receptors are predominantly located in arteriole vasculature & cause vasoconstriction

false they cause vasoconstriction predominantly in venous vasculature

in the SNS, preganglionic fibers exit via the ventral root & enter the sympathetic chain through the grey communicating rami

false they exit the ventral root, & enter through the white communicating (myelinated) rami

after initial stimulation, how is glucose & potassium affected by the SNS system

glucose: decreased from insulin release by pancreatic beta cells due to SNS stimulation potassium: decreased from epinephrine binding to beta-2 receptors on skeletal muscle & erythrocytes by activating the Na+/K+ pump

these two vasodilators preserve the baroreceptor reflex

hydralazine nitroprusside

___ & ___ stimulate the chemoreceptor reflex list the presentations of this reflex

hypoxia & hypercarbia increased minute ventilation & SNS tone

list the key integration of ANS visceral reflex arcs for homeostasis list the 5 major components of ANS visceral reflex arcs for homeostasis

integration: renin-angiotensin aldosterone axis, ADH regulation, mineralocorticoids, glucocorticoids, & insulin components: sensor, afferent pathway, control center, efferent pathway, effector organ

the cushing reflex is an indication of ___ list the presentations of this reflex

intracranial hypertension hypertension, bradycardia, & irregular respirations

in a denervated heart, the heart rate is determined by the ___

intrinsic rate of the SA node

the 3 categories of membrane-bound receptors include ___ list an example of each

ion channel receptor (neuronal sodium channels) G-protein coupled receptor (M-2 receptor in SA node) enzyme-linked/ ligand receptor (skeletal muscle insulin receptors)

this volatile anesthetic impairs the baroreceptor the least what is the rationale behind this?

isoflurane mild beta-1 agonistic properties

Shy-Drager syndrome (multiple system atrophy) causes denervation of these structures

locus coeruleus intermediolateral column of spinal cord peripheral autonomic nerves

this mineral is an antagonist of calcium at cholinergic presynaptic terminals

magnesium

at which location in the CNS does alpha receptors cause a decrease in SNS tone, increase in PNS tone, sedation/ hypnosis, & analgesia

medulla vagus nerve locus coeruleus dorsal horn of the spinal cord

the celiac reflex is due to ___ list the presentations of this reflex

mesenteric/ abdominal traction bradycardia & hypotension

extraneuronal tissues metabolize NE & EPI through this mechanism

metabolized by monoamine oxidase (MAO) & catechol-O-methyltransferase (CMOT)

state the function of phosphodiesterase III

metabolizes cAMP to AMP, temporarily turning off cellular function

vanillylmandelic acid (VMA) is the end product of NE & EPI metabolism what is the chemical name of this compound

methoxy-4-hydroxymandelic acid

Alpha-1 stimulation causes radial muscle contraction, leading to pupillary ___

mydriasis (dilation)

explain the afferent innervation of the carotid sinus

nerves of herring & the glossopharyngeal nerve (CN-IX) carry afferent impulses to the tractus solitarius in the medulla

A glomangioma (gloms tumor) originates from ___ they grow in these tissues

neural crest cells carotid artery, aorta, glossopharyngeal nerve, & middle ear

list 2 nonselective and 2 alpha-1 selective alpha blockers

nonselective: phenoxybenzamine & phentolamine alpha-1 selective: doxazosin & prazosin

when tyrosine is unable to be obtained from the diet, this amino acid is converted to tyrosine

phenylalanine

this enzyme converts NE to EPI where does this predominantly occur?

phenylethanolamine-N-methyltransferase adrenal medulla

which enzyme to glomangioma tumors lack? which drug treats the s/sx of these tumors?

phenylethanolamine-N-methyltransferase ocreotide

an elevated VMA in the urine suggests ___ what is an important anesthetic consideration for these patients? why is this

pheochromocytoma **MUST ALPHA BLOCK BEFORE BETA BLOCK** beta blockade inhibits skeletal muscle vasodilation (B-2), increases SVR, & reduces ionotropy (B-1)

the preganglionic nerve fibers of the ANS are of this type postganglionic nerve fibers are of this type

preganglionic: lightly myelinated B-fibers postganglionic: nonmyelinated C fibers

list the symptoms of Horner's syndrome

ptosis anhidrosis miosis enopthalmos

80% of NE released is metabolized through this mechanism

reuptake

these three structures in the control center of ANS visceral reflex arc for homeostasis reflex most of the afferent sensory information

spinal cord brainstem (midbrain, pons, medulla) hypothalamus

list the different G stimulatory & G inhibitory proteins

stimulatory: Gs & Gq inhibitory: Gi

list 6 sympathetic ganglia that lie outside of the sympathetic chain

superior & middle cervical ganglion stellate ganglion celiac ganglion superior & inferior mesenteric ganglion

in the sympathetic nervous system, postganglionic fibers release acetylcholine to muscarinic receptors at these locations

sweat glands piloerector muscles some vessels

in the SNS, list the possible pathways of a sympathetic fiber once it's inside the sympathetic chain

synapses & exits at the same level travels up or down & synapses at a higher or lower level before exiting bypasses the chain & synapses at a collateral ganglion

when a G-protein is activated, the ___ subunit disassociates & subsequently turns an effector on or off

the alpha subunit when it unbinds, it rejoins the beta and gamma subunits

explain the afferent innervation of the transverse aortic arch

the vagus nerve (CN-X) carry afferent impulses to the tractus solitarius

name the prototypical PDE III inhibitor in which situations is this class of drugs useful?

theophylline beta-blocker induced cardiac depression acute heart failure catecholamine tachyphylaxis desirable increased ionotropy & reduced afterload

T or F the second messenger system allows for signal amplification

true

T or F the intracellular response to a second messenger is tissue specific

true ex: cAMP causes different effects in different cell types

The rate limiting step of NE synthesis is when ___ inhibits the conversion of ___ to ___

tyrosine hydroxylase tyrosine to DOPA

list the 4 key functions of the vasomotor center

vasoconstriction cardiac stimulation vasodilation cardiac inhibition