Physiology Flashcards
<p>What is the Nerst equation?</p>
<p>used to determine the electrical potential of a cell membrane in regards to one type of ionNernst potential = 61 Log C intra/C extra </p>
<p>What is the resting membrane potential in large myelinated peripheral nerves and skeletal muscle? </p>
<p>-90 mV</p>
<p>The resting membrane potential is determined largely by which ion?</p>
<p>K+ </p>
<p>What is the resting membrane potential in the soma of the neuron?</p>
<p>-65 mV</p>
<p>What is the resting memebrane potential in small nerve fibers and smooth muscle?</p>
<p>-55 mV</p>
<p>How is the resting membrane potential maintained?</p>
<p>leaky K+ channels (potassium is -94 mV and 100 times more permeable than sodium)</p>
<p>What is the mechanism of tetrodotoxin?</p>
<p>voltage gated Na+ channel blocker</p>
<p>What is the mechanism of Tetraethylammonium (TEA)?</p>
<p>voltage gated K+ channel blocker</p>
<p>What neurotransmitter and what ion are associated with presynaptic inhibition?</p>
<p>GABA and Cl-</p>
<p>In what synapses is ACh used as a neurotransmitter?</p>
<p>- motor cortex</p>
<p>- skeletal muscle</p>
<p>- preganglionic autonomic nerves</p>
<p>- postganglionic parasympathetic nerves</p>
<p>- postganglionic sympathetic nerves for sweat glands</p>
<p>In what synapses is Norepi used as a neurotransmitter?</p>
<p>- pontine locus ceruleus</p>
<p>- postganglionic sympathetic nerve fibers</p>
<p>Is dopamine excitatory or inhibitory? In what synapses is Dopamine used as a neurotransmitter?</p>
<p>inhibitory</p>
<p>substantia nigra projectionsto the putamen and caudate</p>
<p>What is the rate limiting step in dopamine synthesis?</p>
<p>conversion of tyrosine to 3,4 DOPA by tyrosine hydroxylase</p>
<p>Is glycine excitatory or inhibitory? In what synapses is glycine used as a neurotransmitter?</p>
<p>inhibitory</p>
<p>spinal cord (Renshaw cells)</p>
<p>In what synapses is GABA used as a neurotransmitter?</p>
<p>- cortex</p>
<p>- basal ganglia</p>
<p>- cerebellum (Purkinje Cells)</p>
<p>- spinal cord</p>
<p>Is glutamate excitatory or inhibitory? In what synapses is glutamate used as a neurotransmitter?</p>
<p>Excitatory</p>
<p>- cortex</p>
<p>- dentate gyrus of hippocampus</p>
<p>- striatum</p>
<p>- cerebellum (granular cells)</p>
<p>Is serotonin excitatory or inhibitory? In what synapses is serotonin used as a neurotransmitter?</p>
<p>inhibitory</p>
<p>- Median raphe nucleithat projectto the hypothalamus and spinal cord (dorsal horns)</p>
<p>What neurotransmitter serves as the precursor to melatonin?</p>
<p>Serotonin</p>
<p>Where are nicotinic receptors located?</p>
<p>- NMJ</p>
<p>- preganglionic sympathetics and parasympathetics</p>
<p>What are the subunits of the autonomic nicotinic receptor?</p>
<p>2 alpha, one beta, one gamma, and one delta</p>
<p>Which subunit on the nicotinic autonomic receptor binds the ACh?</p>
<p>the alpha subunit</p>
<p>What blocks the ACh binding receptor on the nicotinic autonomic receptor?</p>
<p>hexamethonium (not reversed by acetacholinesterase)</p>
<p>What are the subunits of nicotinic receptors at the NMJ?</p>
<p>2 alpha subunits</p>
<p>Where are muscarinic receptors located?</p>
<p>-postganglionic parasympathetic</p>
<p>-postganglionic sympathetics for sweat glands</p>
<p>What intracellular messaging system is paired with muscarinic receptors?</p>
<p>G protein via second messahnger system</p>
<p>Muscarinic receptors are blocked by what toxin?</p>
<p>pertussis toxin</p>
<p>What messenger system is used by dopamine receptors?</p>
<p>cAMP second messenger</p>
<p>What is the competitive antagonist of glycine receptors?</p>
<p>Strychnine</p>
<p>Mutations in what receptor causes stiff person syndrome?</p>
<p>mutations in glycine receptor (loss of inhibition)</p>
<p>GABA A receptors increase \_\_\_\_\_\_\_ permeability; GABA B receptors increase \_\_\_\_\_\_\_ conductance.</p>
<p>Cl-</p>
<p></p>
<p>K+</p>
<p>What are the GABA A agonists? What is their function?</p>
<p>Barbituates (prolong duration of Cl - opening) and Benzodiazepines (increase frequency of Cl- opening)</p>
<p>What are GABA B agonists?</p>
<p>Baclofen</p>
<p>What toxin blocks GABA receptor activity? What is the clinical manifestation?</p>
<p>Picrotoxin</p>
<p></p>
<p>Causes seizure like activity</p>
<p>NMDA receptors use what type of neurotransmitter?</p>
<p>Glutamate (requires glycine for coactivation)</p>
<p>What blocks NMDA receptors?</p>
<p>Magnesium</p>
<p>Kinesin mediates \_\_\_\_\_\_\_\_\_ and dynein mediates \_\_\_\_\_\_\_\_.</p>
<p>anterograde axonal transport</p>
<p></p>
<p>retrograde axonal transport</p>
<p>Excitatory action potentials lead to \_\_\_\_\_ channels opening while inhibitory action potentials lead to \_\_\_\_\_ channels opening.</p>
<p>NA+</p>
<p></p>
<p>K+ and Cl-</p>
<p>Action potentials start at the \_\_\_\_\_\_\_ due to \_\_\_\_\_\_.</p>
<p>Neuronal axon hillock</p>
<p></p>
<p>Higher concentrations of Na+ channels</p>
What are phasic vs tonic sensory receptors? Which receptors fall into each category?
Phasic (Rapidly adapting)- Pacinian and Hair receptors
Tonic (Slowly adapting)- everything else
Annulospiral endings of muscle spindles have what sensory nerve fiber?
Type Ia (alpha type A)
What sensory fiber is found in Golgi tendons?
type Ib (alpha type A)
Type II sensory nerves are found where?
cutaneous tactile receptors and flower spray endings of muscle spindles
What are the function of type III sensory fibers?
temperature, crude touch, and pricking pain
What are the functions of type IV sensory nerve fibers?
unmyelinated fibers relaying pain, itch, temperature, and crude touch
What are the three types of motor fibers? Where are they found? Myelinated vs unmyelinated?
- Skeletal muscle - alpha type A (myelinated, fastest)
- Muscle Spindle - gamma type A (myelinated)
- Sympathetic - type C (unmyelinated)
Rank the sensory fibers from fastest to slowest.
- Ia (a-type A)2. Ib (a-type A)3. II (B and g-type A)4. III (d-type A)5. IV (type C)
What is the function of Free Nerve Endings in somatic sensation?
respond to pain, touch, and pressure
What are Meissner Corpuscles? What type of nerve fibers do they use?
rapidly adapting receptors that respond to touch (end of finger tips)
large myelinated beta type A fibers
What are Merkel Disks? What type of nerve fibers do they use?
slowly adapting receptors for touch and pressure (hairy and non hairy skin)myelinated beta type A fiber
What are Pacinian corpuscles?
rapidly adapting receptors that respond to vibration
What are Ruffini end organs? Where are they generally located?
slowly adapting receptors that respond to heavy touch and pressure (located in deep layers of the body)
What are Hair End Organs?
rapidly adapting receptors that respond to touch; located at the base of hair follicles
What type of nerve fibers transmit touch?
mostly beta-type A fibers
What nerve fibers relay vibration?
beta-type A fibers
What somatic nerve fibers relay pain?
free nerve endings
What spinal cord laminae does crude touch originate from?
1, 4, 5, and 6
The anterior and posterior spinothalamic tracts terminate at which thalamic nuclei? What functions?
VPL (body)
VPM (face)
Posterior Thalamic Nuclei- touch and temperature sensations
The spinoreticular tract terminates at what thalamic nuclei? What function(s) does it contain?
Intralaminar thalamic nucleus- pain
The nucleus gracilis is located ________ and responsible for _______.
medial medulla
lower limb fine touch, vibration, proprioception
The nucleus cuneatus is located ________ and responsible for _______.
lateral medulla
upper limb fine touch, vibration, proprioception
The axons from the nucleus gracilis and cuneatus cross through arcuate fibers to form _______. What other fibers do they join?
medial lemniscus
main sensory nucleus of Trigeminal nerve and Upper Spinal Nucleus of V
Where does the medial lemniscus terminate?
VPL (body)VPM (face)
What is the somatotopic organization at the spinal cord, thalamus, and cortex?
lower limbs are medially in the spinal cord, laterally in the thalamus, and medially in the cortex
What is the pathway for lower limb proprioception?
Clark’s column neurons through the dorsal spinocerebellar tract to the cerebellum
What is the pathway for upper limb proprioception?
fasciculus cuneatus fibers synapse on accessary cuneate nucleus in the caudal medulla and then enter the cuneocerebellar tract before entering the cerebellum
Cortex Layers 5 and 6 have projection fibers which project to the _____ and ______, respectively.
brainstem/spinal cord
thalamus
Fast pain is relayed by what fibers?
delta-type A fibers
Slow pain is relayed by what fibers?
type C fibers
What is Lissauer’s tract?
tract in the spinal cord by which pain fibers ascend or descend prior to entering the dorsal horns
Fast pain is transmitted within the ______ tract while slow pain is through the ______ tract.
neospinothalamic
paleospinothalamic
Fast pain is transmitted through what spinal cord lamina?
Lamina 1 (lamina marginalis)
Slow pain is transmitted through what spinal cord lamina?
2 and 3 followed by 5-8
What areas release enkephalins?
periaquaductal gray and periventricular hypothalamus
How does amitryptyline decrease pain?
increase 5-HT which activates pain inhibitory complex in the spinal cord
How do NSAIDs decrease pain?
decrease prostaglandin production which increase pain receptor sensitivity
DBS of what areas have been used to treat chronic pain?
periaqueductal gray and preventricular hypothalamus
What is hyperalgesia?
increased sensitivity (i.e. decreased threshold) to pain
What is hyperpathia?
increased reaction to pain (painful stimuli causing greater than expected pain response)
What is allodynia?
Non-painful stimuli causing pain
What is Dejerine-Roussy syndrome? What is it caused by?
usually caused by posteroventral thalamic strokes
beginning symptoms are ataxia and contralateral hemianesthesia, with eventual return of crude sensation but also increased pain and discomfort on that contralateral side
What nerve is responsible for referred pain from supratentorial cranial structures? How does it manifest?
Trigeminal nerve; frontal headache
What nerves are responsible for the referred pain from infratentorial cranial structures? How does it manifest?
C2, CN IX, CN X
occipital and retroauricular headache
What causes post lumbar puncture headaches?
decreased CSF allows weight of the brain to stretch blood vessels bridging from the brain to the skull
What autonomic nerves innervate the cilliary muscle?
parasympathetics
What is the vascular layer of the eye?
Choroid
What is the blood supply to the retina?
inner layers: central retinal artery
outer layers: diffusion across the choroid
The rod pathway goes from rods to ______ then _______ and finally ________.
bipolar cells; amacrine cells; ganglion cells
The cone pathway goes from cones to _______ and then ________ .
bipolar cells; ganglion cells
What is the neurotransmitter for rods and cones?
glutamate
Amacrine cells neurotransmitters are _______ (excitatory/inhibitory).
inhibitory
Describe the parasympathetic innervation pathway of the eye.
begins at Edinger-Westphal nucleus, transmits via the third nerve to the ciliary ganglion -> short ciliary nerve to then the ciliary muscle (accomodation) and iris sphincter (miosis)
What are the parasympathetic functions of the eye?
accomodation and miosis
Describe the sympathetic innervation pathway of the eye.
T1 level to the sympathetic chain - > super cervical ganglion, continue to head up along the carotid artery, as long and short ciliary nerves to the iris radial fibers (mydriasis), Muller muscle of the eyelid, and weakly ciliary muscle
What are the sympathetic functions of the eye?
mydriasis and lid retraction
What are the characteristics of an Argyll-Robertson pupil?
intact accomodation reflex but no pupillary light reflex
What is the pathway of the light reflex?
impulses in retina > optic tract > pretectal nucleus > Edinger Westphal nucleus > third nerve > ciliary ganglion > short ciliary nerve > iris sphincter
What causes Horner syndrome?
impaired sympathetic output to the eye
What are the symptoms of Horner syndrome?
miosis, ptosis, anhidrosis, enophthalmos, dilated facial vessels
Which portion of the hypothalamus deals with circadian rhythms?
suprachiasmatic nucleus
What is the primary function of the superior colliculous?
control of conjugate eye movements in response to head movements
What part of the thalamus serves as a visual relay center?
lateral geniculate body
How many layers are there in the LGB?
6
Which layers of the LGB receive contralateral vs ipsilateral input?
Contra: 1, 4, 6Ipsi: 2, 3, 5
Which layers of the LGB receive black/white vs color vision?
Black/White: 1, 2 (Y cell input)Color: 3-6 (X cell input)
What innervates the tensor tympani?
branch of V3
What nerve innervates the stapedius?
CN VII
What is the acoustic reflex? What brain structure is associated with that reflex?
attenuation of loud sounds to protect the cochleasuperior olivary nucleus
Loud noises cause what type of hearing loss?
high frequency hearing loss
Elderly people develop what type of hearing loss?
high frequency discrimination
Ototoxic medications induce what type of hearing loss?
hearing loss at all frequencies
Describe the auditory pathway.
Spiral Ganglioin (1st order) > Dorsal and ventral cochlear nuclei (2) > contralateral (some ipsilateral) superior olivary nucleus (3) > lateral lemniscus (4) > inferior colliculus (5) > medial geniculate body (6) > auditory cortex (7)
What Brodmann’s area is the primary auditory cortex?
41
Localization of sound is mediated by what brain structure?
superior olivary nucleus
What is the innervation of taste on the tongue?
Anterior: Chorda tympani (CN VII)Posterior: CN IXBase: CN X
What is the innervation of sensation on the tongue:
Anterior: CN V3Posterior: CN IXBase: CN X
Describe the taste pathway.
CN VII, IX, X to the nucleus solitarius > VPM > cortex
Describe the olfactory pathway.
Axons from olfactory cells (1st order) > glomeruli in olfactory bulb (2) which travels along the CN I > divide into the medial and lateral olfractory striae which go to the medial and lateral olfactory areas
What composes the medial olfactory area?
septal nuclei
What composes the lateral olfactory area?
prepyriform and pyriform cortex, cortex over the amygdala nucelus
What are the types of anterior motor neurons?
a-motor neuronsg-motor neurons
Where are renshaw cells located?
anterior horn
What neurotransmitter do renshaw cells use?
glycine
Where are muscle spindles located?
within the muscle belly
What do muscle spindles detect?
detect length and velocity changes in the muscle
What are the sensory endings for the muscle spindle? What sensory fibers are they associated with?
Annulospiral ending - type Ia fiberFlower-spray ending - type II fiber
What is the fastest sensory fiber in the body?
annulospiral (type Ia) ending in muscle spindle
What is the myotatic (muscle stretch) reflex?
when the muscle is stretched, impusles travel from the spindle’s type Ia fibers to the a-motor neuron; induces contraction
What fibers are associated with Golgi tendon organs?
Type Ib fibers
What is the function of the dorsal spinocerebellar tracts?
transmit signals from the muscle spindles and Golgi’s tendon organs to the reticular formation and cortex and cerebellum
What are Betz cells?
large pyramidal neurons found only in primary motor cortex, mediate corticospinal output
What cortical layer are Betz cells located in?
Layer 5
How long does it take for SMA syndrome to resolve?
usually under 6 weeks
What is the macula?
sensory organ of the utricle and saccule
In what planes do the utricle and saccule sense gravitational force?
Utricle - upright (macule in horizontal plane)Saccule - when lying down (macule in verticle plane)
What are the three semicircular canals?
anterior, posterior, lateral
What is the main function of the MLF?
control of eye movements
How many vestibular nuclei are there? What are their functions?
Superior and Medial: eye reflexesLateral (Deiter’s): postureInferior: integrates vestibular and cerebellar
Removal of the anterior lobe of the cerebellum results in what motor finding?
Spasticity
Which vestibular organ detects static and linear acceleration?
macula
Which vestibular organ detects angular acceleration?
semicircular canals
What tracts lie in the inferior cerebellar peduncle? Afferent or efferent?
Juxtarestiform body (afferent and efferent)Restiform body (afferent)
What tracts lie in the middle cerebellar peduncle? Afferent or efferent?
Corticopontocerebellar pathway (afferent)
What tracts lie in the superior cerebellar peduncle? Afferent or efferent?
Ventral spinocerebellar pathway (afferent)Int. Zone to VL/VPL to red nucleus (and other grey matter) (efferent)Lat. Zone to dentate nucleus to VL/VPL to Area 4 (efferent)
What is the juxtarestiform body?
vestibulocerebellar pathway: vestibular nucleus to the fastigial nucleus of the flocculonodular lobethis pathway is both afferent and efferent
What comprises the restiform body?
Olivocerebellar PathwayReticulocerebellar pathway (reticular nucleus to the vermis)Dorsal Spinocerebellar Pathway
What is the center of the functional unit of the cerebellum?
Purkinje Cells
What are the layers of the cerebellum? What cells reside in each?
Molecular: basket and stellatePurkinje: purkinje cellsGranular: granule and Golgi type II cells
What are climbing fibers?
inferior olivary complex to purkinje and deep nuclear cellsexcitatory
What are mossy fibers?
excitatoryeverything (except inferior olivary complex) to the deep nuclear cells and granule layer
Which of the following are excitatory/inhibitory?Granule CellsBasket cellsStellate CellsPurkinje CellsGolgi Type II Cells
Granule cells are excitatory, all other are inhibitory
What is the function of the flocculonodular lobe?
mediates rapid changes in body position
What is the function of the intermediate zone?
movement control/fine tuning and ballistic/short/fast actions (no time for feedback)
What does damaging the intermediate zone lead to?
intention tremors, decreased force, slow movements, and inability to stop a movement once initiated
What does the lateral zone control?
motor planning and timing (in conjunction with pre motor area)
What does damage to the lateral zone cause?
discoordination of speech and limbs
<p>What is the function of the putamen circuit?</p>
<p>executes motor activity patterns</p>
<p>What is the function of the caudate circuit?</p>
<p>cognitive control of motor patterns</p>
<p>All basal ganglia circuits to the cortex are \_\_\_\_\_\_\_ (excitatory/inhibitory).</p>
<p>inhibitory</p>
<p>Damage to the GP causes \_\_\_\_\_\_\_.</p>
<p>athetosis (slow, involuntary, convoluted, writhing movements of the fingers, hands, toes, and feet)</p>
<p>Damage to the ST causes \_\_\_\_\_\_\_.</p>
<p>hemiballismus</p>
<p>Damage to the caudate causes \_\_\_\_\_\_.</p>
<p>chorea</p>
<p>Damage to the putamen causes \_\_\_\_\_\_.</p>
<p>chorea</p>
<p>Damage to the SN causes \_\_\_\_\_.</p>
<p>rigidity and tremor</p>
<p>What causes parkinson's disease?</p>
<p>degeneration of the pars compacta of the SN</p>
<p>What are the four cardinal characteristcis of parkinson's disease?</p>
<p>Rigidity</p>
<p>Tremor (3-6 cycles/s)</p>
<p>Akinesia</p>
<p>Postural Instability</p>
<p>What causes the rigidity and tremor seen in Parkinson's disease?</p>
<p>unapposed corticospinal stimulation</p>
What neurotransmitter is decreased in Parkinson’s disease?
Dopamine
What neurotransmitter is decreased in Huntington’s disease?
ACh
What neurotransmitter is decreased in dementia disease?
ACh
What neurotransmitter is decreased in depression?
NE and 5-HT
How do MAO inhibitors treat depression?
decrease destruction of NE and 5-HT
How do TCAs treat depression?
block the reuptake of NE and 5-HT
How does shock therapy treat depression?
increase NE transmission (which occurs after seizures)
What neurotransmitter is affected in schizophrenia?
increased DA
What are of the brain is overactive in schizophrenia?
Ventral tegmentum
Where is the nucelus basalis of Meynert located?
beneath GP in the substantia innominata
What neurotrasmitter is decreased in Alzheimer’s disease?
ACh (also Substance P and somatostatin)
Which nucleus is affected by Alzheimer’s disease?
Nucleus basalis of Mynert (75% loss of neurons)
Where are granular (stellate) cells more numbers in the cerebrum?
sensory areas
Incoming sensory information generally enters what cortical layer?
layer 4
Output from the cortex generally comes from what cortical layers?
Layer 5 - brainstem and spinal cordLayer 6 - thalamus
What Brodmann’s areas compose Wernicke’s area?
22, 39, 40
What Brodmann’s area composes the angular gyrus?
39
Where is the angular gyrus located?
posterior inferior parietal lobe
What is the angular gyrus responsible for?
visual processing of words
Damage to the angular gyrus causes ________.
dyslexia (inability to read)
What B-man’s areas compose Broca’s?
44
What is prosopagnosia? A lesion where causes it?
inability to recognize facesb/l damage to the medial basal occipitotemporal cortex
What is habituation?
inhibition of memory of useless sensory information
A hippocampal lesion causes ________ amnesia while a thalamic lesion causes ________ amnesia.
retrograde and anterograde retrograde
Damaging the reticular activating system induces _____
coma
Where is the reticular activating system?
middle/lateral pons and brainstem
What neurotransmitter is used by the reticular activating system?
ACh
Where is the inhibitory reticular formation located?
lower brainstem in the medial ventral medulla
What neurotransmitter is used by the inhibitory reticular formation?
5-HT
Where is the locus ceruleus located?
bilateral posterior pontine-midbrain junction
Where is the raphe nucleus located?
lower pons/medulla
What neurotransmitter is released by the gigantocellular layer of the reticular activating system?
ACh
What is the median forebrain bundle?
bidirectional tract that connects the septal nuclei and orbitofrontal gyrus to the reticular formationAlso connects the reticular formation to the thalamus, hypothalamus, and cortex
What structure does the median forebrain bundle go through?
hypothalamus
The lateral hypothalamus controls what functions?
regulates thirst, hunger, emotion, and sympathetic output
The medial hypothalamus controls what functions?
controls satiety
Stimulation of the anterior hypothalamus causes ________.
decreases in temperature, HR, and BP while increase parasympathetic output
Stimulation of the posterior hypothalamus causes ______.
increases in temp, HR, and BP while increasing sympathetic tone
Where is temperature mainly regulated?
anterior hypothalamus by the preoptic area
Where is ADH produced?
supraoptic nucleus of the hypothalamus
Where is oxytocin produced?
paraventricular nucleus
What cerebral structure controls feeding reflex?
mammillary bodies
What cerebral structure controls sex drive?
anterior/posterior hypothalamus
What regions of the cerebrum control rage?
lateral hypothalamus and periventricular region
What region of the hypothalamus controls fear and anxiety?
midline preoptic nucleus
What is the primary goal of the limbic system?
to determine whether a sensation is pleasant or unpleasant
Ablation of the temporal tip of the limbic cortex produces _______.
Kluver Bucy Syndrome
Bilateral ablation of the amygdala produces _______.
Kluver Bucy Syndrome
What is Kluver Bucy Syndrome characterized by?
oral fixation, tameness, fearlessness, hypersexuality, psychological blindness (inability to determine an objects function or use by sight)
How many layers are in the hippocampus?
three layers (paleocortex)
Slow wave sleep constitutes what percentage of sleep?
75 %
What is the theory behind sleep activation mechanism?
active inhibition of the ascending reticular activating system
Which of the deep cerebral nuclei when stimulated elicits sleep?
Raphe nucleus
Lesions of the _________ decrease REM sleep.
locus ceruleus
What cortical layers are brainwaves primarily derived from?
cortical layers 1 and 2
What are the characteristic of a-waves (EEG)?
8 to 13 waves/s and amplitude of 50 mV
When are a-waves (EEG) present?
during wakefulness but not with activity or intense stimulation
Where are a-waves (EEG) primarily located?
occipital lobes
What are the characteristics of B-waves (EEG)?
14 to 80 waves/s, decreased amplitude compared to a-waves
Where are B-waves (EEG) primarily located?
frontal and parietal lobes during activity
What are the characteristics of theta-waves (EEG)?
4-7 waves/s with increased amplitude
What are the characteristics of g-waves (EEG)?
less than 3.5 waves/s, increased amplitude
When are theta-waves (EEG) present?
parietal and temporal lobes in childrenmay appear during stress in adults or with brain disorders
When are g-waves (EEG) present?
occur with deep sleep
What are the EEG findings during sleep at each stage?
Stage 1: very light sleep w/ elimination of a-wavesStage 2: sleep spindles (short a-wave bursts) and K complexes; may exhibit theta-wavesStage 3: g-waves, may exhibit theta-wavesStage 4: g-wavesREM: B-waves
What is the overall prevalence of epilepsy in society?
1-2 %
Absence seizures are activated by what area of the brain?
basal forebrain
What EEG findings are seen with absence seizures?
3 waves/s spike and dome
Where do preganglionic sympathetic fibers originate?
spinal cord from a cell body in the intermediolateralcell column (extending from T1 to L2)
Which ramus do preganglionic fibers course through?
white ramus
Where do postganglionic sympathetic fibers originate?
sympathetic change ganglia or prevertebral ganglia
What type of fibers are sympathetic nerves?
type C
What are splanchic nerves?
preganglionic sympathetic fibers that pass through the sympathetic chain without synapsing and go straight to the adrenal medulla
Sympathetic fibers from what spinal level supply the head?
T1
Sympathetic fibers from what spinal level supply the neck?
T2
Sympathetic fibers from what spinal level supply the thorax?
T3-T6
Sympathetic fibers from what spinal level supply the abdomen?
T7 - T11
Sympathetic fibers from what spinal level supply the lower limbs?
T12-L2
In what nerves are parasympathetic fibers found?
CN III, VII, IX, X (75%) S1-S4
Preganglionic autonomic fibers are _______ (receptor type).
Cholinergic
Post ganglionic parasympathetic fibers are _______ (receptor type).
Cholinergic
Post ganglionic sympathetic fibers are ________ (receptor type).
Adrenergic except for fibers going to sweat, piloerectors, and blood vessels (Muscarinic)
What is the mechanism of Resperine?
blocks NE synthesis and storage; prevents DA uptake into vesicles
What is the effect of Gaunethidine?
decreases NE release
Phenylepherine stimulate _____ receptor(s).
alpha receptors
Name two alpha blockers.
Phentolamine and Phenoxybenzamine
Name three autonomic (primarily sympathetic) ganglionic blockers. What is their overall effect?
hexamethonium, TEA, Pentolinimdecrease BP
Name two muscarinic receptor agonists.
pilocarpine and methacholine
Name three muscarinic receptor blockers.
atropine, pertussis toxin, and scopolamine
Name three reversible acetylcholinesterase inhibitors.
neostigmine, pyridostigmine, physostigmine
Name the irreversible acetylcholinesterase inhibitors.
organophosphates
Name three ACh receptor agonists.
ACh, nicotine, and methacholine
What is the mechanism of tetanus?
prevents fusion of vesicle with cell membrane, such as blocking glycine release from Renshaw cells
What is the mechanism for Cholera toxin?
decreased GTP hydrolysis
What is the effect of Diptheria toxin?
inactivates tRNA transferase
What is the mechanism of Strychnine?
glycine antagonist
What is the mechanism of cocaine?
blocks DA and NE uptake
What is the mechanism of cyanide?
blocks Na/K pump, disrupting active transport
<p>What is a sarcomere?</p>
<p>muscle unit that lies between two Z discs/lines</p>
<p>What composes the motor unit?</p>
<p>one alpha motor neuron and numerous muscle fibers (various in number)</p>
<p>How is organophophate inhibition of acetylcholinesterase treated?</p>
<p>2-pyridine aldoxime methochloride (PAM)</p>
<p>What is the mechanism of Curare?</p>
<p>blocks ACh at the NMJ</p>
<p>What is the pathologic cause of myesthenia gravis?</p>
<p>antibodies to the ACh receptor</p>
Where is the vasomotor center located?
reticular formation of the medulla and caudal pons
Where is the vasoconstrictor (C1) area of the vasomotor center? What are its outputs?
anterolateral upper medullarelays NE to the spinal cord
Where is the vasodilator (A1) area of the vasomotor center? What are its outputs?
anterolateral lower medullaprojects to vasoconstrictor area to inhibit it
Where is the sensory (A2) area of the vasomotor center? What are its inputs?
located in the tractus solitarius in the posterolateral pons and medullareceived input from CN IX and X
The medial vasomotor center relays ______ output to the heart while the lateral relays ______ output.
parasympatheticsympathetic
Stretching the carotid sinus stimulates what nerve?
Hering’s nerve (CN IX)
Where does Hering’s nerve synapse onto?
solitary tract which eventually proceeds to the sensory area of the vasomotor center
Stretching of the aorta causes stimulation of which nerve?
vagus nerve which eventually synapses onto the solitary tract
Which part of the hypothalamus detects serum osmolarity?
anteroventral third ventricular region (AV-3V)
What composes the AV-3V of the hypothalamus?
superior: subforniceal organinferior: organ vasculosum of the lamina terminalisIn between: median preoptic nucleus
What comprises the respiratory?
Dorsal respiratory group Ventral respiratory groupPneumotaxic center
Where is the dorsal respiratory group located? What are its functions?
dorsal medulla controls inspiration
Where is the ventral respiratory group located? What are its functions?
ventrolateral medulla in the nucleus ambiguus and retroambiguuscontrols inhalation and exhalation when large efforts needed
Where is the pneumotaxic center located? What are its functions?
- dorsal superior pons in the nucleus parabrachialis- rate and pattern of breathing
What is the Herin-Breur inflation reflex?
stretch receptors in the bronchi and bronchioles sent afferent signals via the vagus to the dorsal respiratory nucleus to stop inhalation
What is Auerbach’s myenteric plexus?
located between the longitudinal and circular layers of muscle; controls GI movements
What is Meissner’s submucosal plexus?
located in the GI submucosa; controls secretions and blood flow
Where is the salivatory nucleus located?
pontomedullary junction
What are the associated nerves and ganglion with each of the following glands:- submandibular- sublingual- parotid
Submandibular - CN VII - submandibular ganglionSublingual - CN VII - submandibular ganglionParotid - CN IX - otic ganglion
Name three substances that increase gastric secretions?
ACh, gastrin, histamine
Which pelvic nerves provide paraysmpathetics to the bladder?
S2-S3
Which portion of the hypothalamus detects temperature?
anterior hypothalamus and preoptic area
What endocrine hormones or equivalents are released by hypothalamus?
thyrotropin, corticotropin, growth hormone releasing hormone, gonadotropin releasing hormone, somatostatin, DA
Somatostatin inhibits _______ and _________.
growth hormone releasing hormonethyrotropin releasing hormone
Where is somatomedin C synthesized? What triggers its synthesis? What is its function?
LiverGHIncreases somatostatin levels which decrease GH levels
Prolactin is tonically inhibited by _______.
Dopamine
What is the effect of ADH?
increase distal tubule H2O absorption and NaCl loss
Which hypothalamic releasing hormone inhibits ADH?
Corticotropin releasing hormone
Gonadotropin releasing hormone is released mainly by the _______ of the hypothalamus.
arcuate nucleus
Which nerve is responsible for an erection in males/females?
nervi erigentes