Physiology Flashcards
(299 cards)
1
Q
<p>What is the Nerst equation?</p>
A
<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>
2
Q
<p>What is the resting membrane potential in large myelinated peripheral nerves and skeletal muscle? </p>
A
<p>-90 mV</p>
3
Q
<p>The resting membrane potential is determined largely by which ion?</p>
A
<p>K+ </p>
4
Q
<p>What is the resting membrane potential in the soma of the neuron?</p>
A
<p>-65 mV</p>
5
Q
<p>What is the resting memebrane potential in small nerve fibers and smooth muscle?</p>
A
<p>-55 mV</p>
6
Q
<p>How is the resting membrane potential maintained?</p>
A
<p>leaky K+ channels (potassium is -94 mV and 100 times more permeable than sodium)</p>
7
Q
<p>What is the mechanism of tetrodotoxin?</p>
A
<p>voltage gated Na+ channel blocker</p>
8
Q
<p>What is the mechanism of Tetraethylammonium (TEA)?</p>
A
<p>voltage gated K+ channel blocker</p>
9
Q
<p>What neurotransmitter and what ion are associated with presynaptic inhibition?</p>
A
<p>GABA and Cl-</p>
10
Q
<p>In what synapses is ACh used as a neurotransmitter?</p>
A
<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>
11
Q
<p>In what synapses is Norepi used as a neurotransmitter?</p>
A
<p>- pontine locus ceruleus</p>
<p>- postganglionic sympathetic nerve fibers</p>
12
Q
<p>Is dopamine excitatory or inhibitory? In what synapses is Dopamine used as a neurotransmitter?</p>
A
<p>inhibitory</p>
<p>substantia nigra projectionsto the putamen and caudate</p>
13
Q
<p>What is the rate limiting step in dopamine synthesis?</p>
A
<p>conversion of tyrosine to 3,4 DOPA by tyrosine hydroxylase</p>
14
Q
<p>Is glycine excitatory or inhibitory? In what synapses is glycine used as a neurotransmitter?</p>
A
<p>inhibitory</p>
<p>spinal cord (Renshaw cells)</p>
15
Q
<p>In what synapses is GABA used as a neurotransmitter?</p>
A
<p>- cortex</p>
<p>- basal ganglia</p>
<p>- cerebellum (Purkinje Cells)</p>
<p>- spinal cord</p>
16
Q
<p>Is glutamate excitatory or inhibitory? In what synapses is glutamate used as a neurotransmitter?</p>
A
<p>Excitatory</p>
<p>- cortex</p>
<p>- dentate gyrus of hippocampus</p>
<p>- striatum</p>
<p>- cerebellum (granular cells)</p>
17
Q
<p>Is serotonin excitatory or inhibitory? In what synapses is serotonin used as a neurotransmitter?</p>
A
<p>inhibitory</p>
<p>- Median raphe nucleithat projectto the hypothalamus and spinal cord (dorsal horns)</p>
18
Q
<p>What neurotransmitter serves as the precursor to melatonin?</p>
A
<p>Serotonin</p>
19
Q
<p>Where are nicotinic receptors located?</p>
A
<p>- NMJ</p>
<p>- preganglionic sympathetics and parasympathetics</p>
20
Q
<p>What are the subunits of the autonomic nicotinic receptor?</p>
A
<p>2 alpha, one beta, one gamma, and one delta</p>
21
Q
<p>Which subunit on the nicotinic autonomic receptor binds the ACh?</p>
A
<p>the alpha subunit</p>
22
Q
<p>What blocks the ACh binding receptor on the nicotinic autonomic receptor?</p>
A
<p>hexamethonium (not reversed by acetacholinesterase)</p>
23
Q
<p>What are the subunits of nicotinic receptors at the NMJ?</p>
A
<p>2 alpha subunits</p>
24
Q
<p>Where are muscarinic receptors located?</p>
A
<p>-postganglionic parasympathetic</p>
<p>-postganglionic sympathetics for sweat glands</p>
25
What intracellular messaging system is paired with muscarinic receptors?
G protein via second messahnger system
26
Muscarinic receptors are blocked by what toxin?
pertussis toxin
27
What messenger system is used by dopamine receptors?
cAMP second messenger
28
What is the competitive antagonist of glycine receptors?
Strychnine
29
Mutations in what receptor causes stiff person syndrome?
mutations in glycine receptor (loss of inhibition)
30
GABA A receptors increase _______ permeability; GABA B receptors increase _______ conductance.
Cl-
K+
31
What are the GABA A agonists? What is their function?
Barbituates (prolong duration of Cl - opening) and Benzodiazepines (increase frequency of Cl- opening)
32
What are GABA B agonists?
Baclofen
33
What toxin blocks GABA receptor activity? What is the clinical manifestation?
Picrotoxin
Causes seizure like activity
34
NMDA receptors use what type of neurotransmitter?
Glutamate (requires glycine for coactivation)
35
What blocks NMDA receptors?
Magnesium
36
Kinesin mediates _________ and dynein mediates ________.
anterograde axonal transport
retrograde axonal transport
37
Excitatory action potentials lead to _____ channels opening while inhibitory action potentials lead to _____ channels opening.
NA+
K+ and Cl-
38
Action potentials start at the _______ due to ______.
Neuronal axon hillock
Higher concentrations of Na+ channels
39
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
40
Annulospiral endings of muscle spindles have what sensory nerve fiber?
Type Ia (alpha type A)
41
What sensory fiber is found in Golgi tendons?
type Ib (alpha type A)
42
Type II sensory nerves are found where?
cutaneous tactile receptors and flower spray endings of muscle spindles
43
What are the function of type III sensory fibers?
temperature, crude touch, and pricking pain
44
What are the functions of type IV sensory nerve fibers?
unmyelinated fibers relaying pain, itch, temperature, and crude touch
45
What are the three types of motor fibers? Where are they found? Myelinated vs unmyelinated?
1. Skeletal muscle - alpha type A (myelinated, fastest)
2. Muscle Spindle - gamma type A (myelinated)
3. Sympathetic - type C (unmyelinated)
46
Rank the sensory fibers from fastest to slowest.
1. 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)
47
What is the function of Free Nerve Endings in somatic sensation?
respond to pain, touch, and pressure
48
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
49
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
50
What are Pacinian corpuscles?
rapidly adapting receptors that respond to vibration
51
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)
52
What are Hair End Organs?
rapidly adapting receptors that respond to touch; located at the base of hair follicles
53
What type of nerve fibers transmit touch?
mostly beta-type A fibers
54
What nerve fibers relay vibration?
beta-type A fibers
55
What somatic nerve fibers relay pain?
free nerve endings
56
What spinal cord laminae does crude touch originate from?
1, 4, 5, and 6
57
The anterior and posterior spinothalamic tracts terminate at which thalamic nuclei? What functions?
VPL (body)
VPM (face)
Posterior Thalamic Nuclei- touch and temperature sensations
58
The spinoreticular tract terminates at what thalamic nuclei? What function(s) does it contain?
Intralaminar thalamic nucleus- pain
59
The nucleus gracilis is located ________ and responsible for _______.
medial medulla
lower limb fine touch, vibration, proprioception
60
The nucleus cuneatus is located ________ and responsible for _______.
lateral medulla
upper limb fine touch, vibration, proprioception
61
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
62
Where does the medial lemniscus terminate?
VPL (body)VPM (face)
63
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
64
What is the pathway for lower limb proprioception?
Clark's column neurons through the dorsal spinocerebellar tract to the cerebellum
65
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
66
Cortex Layers 5 and 6 have projection fibers which project to the _____ and ______, respectively.
brainstem/spinal cord
thalamus
67
Fast pain is relayed by what fibers?
delta-type A fibers
68
Slow pain is relayed by what fibers?
type C fibers
69
What is Lissauer's tract?
tract in the spinal cord by which pain fibers ascend or descend prior to entering the dorsal horns
70
Fast pain is transmitted within the ______ tract while slow pain is through the ______ tract.
neospinothalamic
paleospinothalamic
71
Fast pain is transmitted through what spinal cord lamina?
Lamina 1 (lamina marginalis)
72
Slow pain is transmitted through what spinal cord lamina?
2 and 3 followed by 5-8
73
What areas release enkephalins?
periaquaductal gray and periventricular hypothalamus
74
How does amitryptyline decrease pain?
increase 5-HT which activates pain inhibitory complex in the spinal cord
75
How do NSAIDs decrease pain?
decrease prostaglandin production which increase pain receptor sensitivity
76
DBS of what areas have been used to treat chronic pain?
periaqueductal gray and preventricular hypothalamus
77
What is hyperalgesia?
increased sensitivity (i.e. decreased threshold) to pain
78
What is hyperpathia?
increased reaction to pain (painful stimuli causing greater than expected pain response)
79
What is allodynia?
Non-painful stimuli causing pain
80
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
81
What nerve is responsible for referred pain from supratentorial cranial structures? How does it manifest?
Trigeminal nerve; frontal headache
82
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
83
What causes post lumbar puncture headaches?
decreased CSF allows weight of the brain to stretch blood vessels bridging from the brain to the skull
84
What autonomic nerves innervate the cilliary muscle?
parasympathetics
85
What is the vascular layer of the eye?
Choroid
86
What is the blood supply to the retina?
inner layers: central retinal artery
outer layers: diffusion across the choroid
87
The rod pathway goes from rods to ______ then _______ and finally ________.
bipolar cells; amacrine cells; ganglion cells
88
The cone pathway goes from cones to _______ and then ________ .
bipolar cells; ganglion cells
89
What is the neurotransmitter for rods and cones?
glutamate
90
Amacrine cells neurotransmitters are _______ (excitatory/inhibitory).
inhibitory
91
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)
92
What are the parasympathetic functions of the eye?
accomodation and miosis
93
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
94
What are the sympathetic functions of the eye?
mydriasis and lid retraction
95
What are the characteristics of an Argyll-Robertson pupil?
intact accomodation reflex but no pupillary light reflex
96
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
97
What causes Horner syndrome?
impaired sympathetic output to the eye
98
What are the symptoms of Horner syndrome?
miosis, ptosis, anhidrosis, enophthalmos, dilated facial vessels
99
Which portion of the hypothalamus deals with circadian rhythms?
suprachiasmatic nucleus
100
What is the primary function of the superior colliculous?
control of conjugate eye movements in response to head movements
101
What part of the thalamus serves as a visual relay center?
lateral geniculate body
102
How many layers are there in the LGB?
6
103
Which layers of the LGB receive contralateral vs ipsilateral input?
Contra: 1, 4, 6Ipsi: 2, 3, 5
104
Which layers of the LGB receive black/white vs color vision?
Black/White: 1, 2 (Y cell input)Color: 3-6 (X cell input)
105
What innervates the tensor tympani?
branch of V3
106
What nerve innervates the stapedius?
CN VII
107
What is the acoustic reflex? What brain structure is associated with that reflex?
attenuation of loud sounds to protect the cochleasuperior olivary nucleus
108
Loud noises cause what type of hearing loss?
high frequency hearing loss
109
Elderly people develop what type of hearing loss?
high frequency discrimination
110
Ototoxic medications induce what type of hearing loss?
hearing loss at all frequencies
111
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)
112
What Brodmann's area is the primary auditory cortex?
41
113
Localization of sound is mediated by what brain structure?
superior olivary nucleus
114
What is the innervation of taste on the tongue?
Anterior: Chorda tympani (CN VII)Posterior: CN IXBase: CN X
115
What is the innervation of sensation on the tongue:
Anterior: CN V3Posterior: CN IXBase: CN X
116
Describe the taste pathway.
CN VII, IX, X to the nucleus solitarius > VPM > cortex
117
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
118
What composes the medial olfactory area?
septal nuclei
119
What composes the lateral olfactory area?
prepyriform and pyriform cortex, cortex over the amygdala nucelus
120
What are the types of anterior motor neurons?
a-motor neuronsg-motor neurons
121
Where are renshaw cells located?
anterior horn
122
What neurotransmitter do renshaw cells use?
glycine
123
Where are muscle spindles located?
within the muscle belly
124
What do muscle spindles detect?
detect length and velocity changes in the muscle
125
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
126
What is the fastest sensory fiber in the body?
annulospiral (type Ia) ending in muscle spindle
127
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
128
What fibers are associated with Golgi tendon organs?
Type Ib fibers
129
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
130
What are Betz cells?
large pyramidal neurons found only in primary motor cortex, mediate corticospinal output
131
What cortical layer are Betz cells located in?
Layer 5
132
How long does it take for SMA syndrome to resolve?
usually under 6 weeks
133
What is the macula?
sensory organ of the utricle and saccule
134
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)
135
What are the three semicircular canals?
anterior, posterior, lateral
136
What is the main function of the MLF?
control of eye movements
137
How many vestibular nuclei are there? What are their functions?
Superior and Medial: eye reflexesLateral (Deiter's): postureInferior: integrates vestibular and cerebellar
138
Removal of the anterior lobe of the cerebellum results in what motor finding?
Spasticity
139
Which vestibular organ detects static and linear acceleration?
macula
140
Which vestibular organ detects angular acceleration?
semicircular canals
141
What tracts lie in the inferior cerebellar peduncle? Afferent or efferent?
Juxtarestiform body (afferent and efferent)Restiform body (afferent)
142
What tracts lie in the middle cerebellar peduncle? Afferent or efferent?
Corticopontocerebellar pathway (afferent)
143
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)
144
What is the juxtarestiform body?
vestibulocerebellar pathway: vestibular nucleus to the fastigial nucleus of the flocculonodular lobethis pathway is both afferent and efferent
145
What comprises the restiform body?
Olivocerebellar PathwayReticulocerebellar pathway (reticular nucleus to the vermis)Dorsal Spinocerebellar Pathway
146
What is the center of the functional unit of the cerebellum?
Purkinje Cells
147
What are the layers of the cerebellum? What cells reside in each?
Molecular: basket and stellatePurkinje: purkinje cellsGranular: granule and Golgi type II cells
148
What are climbing fibers?
inferior olivary complex to purkinje and deep nuclear cellsexcitatory
149
What are mossy fibers?
excitatoryeverything (except inferior olivary complex) to the deep nuclear cells and granule layer
150
Which of the following are excitatory/inhibitory?Granule CellsBasket cellsStellate CellsPurkinje CellsGolgi Type II Cells
Granule cells are excitatory, all other are inhibitory
151
What is the function of the flocculonodular lobe?
mediates rapid changes in body position
152
What is the function of the intermediate zone?
movement control/fine tuning and ballistic/short/fast actions (no time for feedback)
153
What does damaging the intermediate zone lead to?
intention tremors, decreased force, slow movements, and inability to stop a movement once initiated
154
What does the lateral zone control?
motor planning and timing (in conjunction with pre motor area)
155
What does damage to the lateral zone cause?
discoordination of speech and limbs
156
What is the function of the putamen circuit?
executes motor activity patterns
157
What is the function of the caudate circuit?
cognitive control of motor patterns
158
All basal ganglia circuits to the cortex are _______ (excitatory/inhibitory).
inhibitory
159
Damage to the GP causes _______.
athetosis (slow, involuntary, convoluted, writhing movements of the fingers, hands, toes, and feet)
160
Damage to the ST causes _______.
hemiballismus
161
Damage to the caudate causes ______.
chorea
162
Damage to the putamen causes ______.
chorea
163
Damage to the SN causes _____.
rigidity and tremor
164
What causes parkinson's disease?
degeneration of the pars compacta of the SN
165
What are the four cardinal characteristcis of parkinson's disease?
Rigidity
Tremor (3-6 cycles/s)
Akinesia
Postural Instability
166
What causes the rigidity and tremor seen in Parkinson's disease?
unapposed corticospinal stimulation
167
What neurotransmitter is decreased in Parkinson's disease?
Dopamine
168
What neurotransmitter is decreased in Huntington's disease?
ACh
169
What neurotransmitter is decreased in dementia disease?
ACh
170
What neurotransmitter is decreased in depression?
NE and 5-HT
171
How do MAO inhibitors treat depression?
decrease destruction of NE and 5-HT
172
How do TCAs treat depression?
block the reuptake of NE and 5-HT
173
How does shock therapy treat depression?
increase NE transmission (which occurs after seizures)
174
What neurotransmitter is affected in schizophrenia?
increased DA
175
What are of the brain is overactive in schizophrenia?
Ventral tegmentum
176
Where is the nucelus basalis of Meynert located?
beneath GP in the substantia innominata
177
What neurotrasmitter is decreased in Alzheimer's disease?
ACh (also Substance P and somatostatin)
178
Which nucleus is affected by Alzheimer's disease?
Nucleus basalis of Mynert (75% loss of neurons)
179
Where are granular (stellate) cells more numbers in the cerebrum?
sensory areas
180
Incoming sensory information generally enters what cortical layer?
layer 4
181
Output from the cortex generally comes from what cortical layers?
Layer 5 - brainstem and spinal cordLayer 6 - thalamus
182
What Brodmann's areas compose Wernicke's area?
22, 39, 40
183
What Brodmann's area composes the angular gyrus?
39
184
Where is the angular gyrus located?
posterior inferior parietal lobe
185
What is the angular gyrus responsible for?
visual processing of words
186
Damage to the angular gyrus causes ________.
dyslexia (inability to read)
187
What B-man's areas compose Broca's?
44
188
What is prosopagnosia? A lesion where causes it?
inability to recognize facesb/l damage to the medial basal occipitotemporal cortex
189
What is habituation?
inhibition of memory of useless sensory information
190
A hippocampal lesion causes ________ amnesia while a thalamic lesion causes ________ amnesia.
retrograde and anterograde retrograde
191
Damaging the reticular activating system induces _____
coma
192
Where is the reticular activating system?
middle/lateral pons and brainstem
193
What neurotransmitter is used by the reticular activating system?
ACh
194
Where is the inhibitory reticular formation located?
lower brainstem in the medial ventral medulla
195
What neurotransmitter is used by the inhibitory reticular formation?
5-HT
196
Where is the locus ceruleus located?
bilateral posterior pontine-midbrain junction
197
Where is the raphe nucleus located?
lower pons/medulla
198
What neurotransmitter is released by the gigantocellular layer of the reticular activating system?
ACh
199
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
200
What structure does the median forebrain bundle go through?
hypothalamus
201
The lateral hypothalamus controls what functions?
regulates thirst, hunger, emotion, and sympathetic output
202
The medial hypothalamus controls what functions?
controls satiety
203
Stimulation of the anterior hypothalamus causes ________.
decreases in temperature, HR, and BP while increase parasympathetic output
204
Stimulation of the posterior hypothalamus causes ______.
increases in temp, HR, and BP while increasing sympathetic tone
205
Where is temperature mainly regulated?
anterior hypothalamus by the preoptic area
206
Where is ADH produced?
supraoptic nucleus of the hypothalamus
207
Where is oxytocin produced?
paraventricular nucleus
208
What cerebral structure controls feeding reflex?
mammillary bodies
209
What cerebral structure controls sex drive?
anterior/posterior hypothalamus
210
What regions of the cerebrum control rage?
lateral hypothalamus and periventricular region
211
What region of the hypothalamus controls fear and anxiety?
midline preoptic nucleus
212
What is the primary goal of the limbic system?
to determine whether a sensation is pleasant or unpleasant
213
Ablation of the temporal tip of the limbic cortex produces _______.
Kluver Bucy Syndrome
214
Bilateral ablation of the amygdala produces _______.
Kluver Bucy Syndrome
215
What is Kluver Bucy Syndrome characterized by?
oral fixation, tameness, fearlessness, hypersexuality, psychological blindness (inability to determine an objects function or use by sight)
216
How many layers are in the hippocampus?
three layers (paleocortex)
217
Slow wave sleep constitutes what percentage of sleep?
75 %
218
What is the theory behind sleep activation mechanism?
active inhibition of the ascending reticular activating system
219
Which of the deep cerebral nuclei when stimulated elicits sleep?
Raphe nucleus
220
Lesions of the _________ decrease REM sleep.
locus ceruleus
221
What cortical layers are brainwaves primarily derived from?
cortical layers 1 and 2
222
What are the characteristic of a-waves (EEG)?
8 to 13 waves/s and amplitude of 50 mV
223
When are a-waves (EEG) present?
during wakefulness but not with activity or intense stimulation
224
Where are a-waves (EEG) primarily located?
occipital lobes
225
What are the characteristics of B-waves (EEG)?
14 to 80 waves/s, decreased amplitude compared to a-waves
226
Where are B-waves (EEG) primarily located?
frontal and parietal lobes during activity
227
What are the characteristics of theta-waves (EEG)?
4-7 waves/s with increased amplitude
228
What are the characteristics of g-waves (EEG)?
less than 3.5 waves/s, increased amplitude
229
When are theta-waves (EEG) present?
parietal and temporal lobes in childrenmay appear during stress in adults or with brain disorders
230
When are g-waves (EEG) present?
occur with deep sleep
231
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
232
What is the overall prevalence of epilepsy in society?
1-2 %
233
Absence seizures are activated by what area of the brain?
basal forebrain
234
What EEG findings are seen with absence seizures?
3 waves/s spike and dome
235
Where do preganglionic sympathetic fibers originate?
spinal cord from a cell body in the intermediolateralcell column (extending from T1 to L2)
236
Which ramus do preganglionic fibers course through?
white ramus
237
Where do postganglionic sympathetic fibers originate?
sympathetic change ganglia or prevertebral ganglia
238
What type of fibers are sympathetic nerves?
type C
239
What are splanchic nerves?
preganglionic sympathetic fibers that pass through the sympathetic chain without synapsing and go straight to the adrenal medulla
240
Sympathetic fibers from what spinal level supply the head?
T1
241
Sympathetic fibers from what spinal level supply the neck?
T2
242
Sympathetic fibers from what spinal level supply the thorax?
T3-T6
243
Sympathetic fibers from what spinal level supply the abdomen?
T7 - T11
244
Sympathetic fibers from what spinal level supply the lower limbs?
T12-L2
245
In what nerves are parasympathetic fibers found?
CN III, VII, IX, X (75%) S1-S4
246
Preganglionic autonomic fibers are _______ (receptor type).
Cholinergic
247
Post ganglionic parasympathetic fibers are _______ (receptor type).
Cholinergic
248
Post ganglionic sympathetic fibers are ________ (receptor type).
Adrenergic except for fibers going to sweat, piloerectors, and blood vessels (Muscarinic)
249
What is the mechanism of Resperine?
blocks NE synthesis and storage; prevents DA uptake into vesicles
250
What is the effect of Gaunethidine?
decreases NE release
251
Phenylepherine stimulate _____ receptor(s).
alpha receptors
252
Name two alpha blockers.
Phentolamine and Phenoxybenzamine
253
Name three autonomic (primarily sympathetic) ganglionic blockers. What is their overall effect?
hexamethonium, TEA, Pentolinimdecrease BP
254
Name two muscarinic receptor agonists.
pilocarpine and methacholine
255
Name three muscarinic receptor blockers.
atropine, pertussis toxin, and scopolamine
256
Name three reversible acetylcholinesterase inhibitors.
neostigmine, pyridostigmine, physostigmine
257
Name the irreversible acetylcholinesterase inhibitors.
organophosphates
258
Name three ACh receptor agonists.
ACh, nicotine, and methacholine
259
What is the mechanism of tetanus?
prevents fusion of vesicle with cell membrane, such as blocking glycine release from Renshaw cells
260
What is the mechanism for Cholera toxin?
decreased GTP hydrolysis
261
What is the effect of Diptheria toxin?
inactivates tRNA transferase
262
What is the mechanism of Strychnine?
glycine antagonist
263
What is the mechanism of cocaine?
blocks DA and NE uptake
264
What is the mechanism of cyanide?
blocks Na/K pump, disrupting active transport
265
What is a sarcomere?
muscle unit that lies between two Z discs/lines
266
What composes the motor unit?
one alpha motor neuron and numerous muscle fibers (various in number)
267
How is organophophate inhibition of acetylcholinesterase treated?
2-pyridine aldoxime methochloride (PAM)
268
What is the mechanism of Curare?
blocks ACh at the NMJ
269
What is the pathologic cause of myesthenia gravis?
antibodies to the ACh receptor
270
Where is the vasomotor center located?
reticular formation of the medulla and caudal pons
271
Where is the vasoconstrictor (C1) area of the vasomotor center? What are its outputs?
anterolateral upper medullarelays NE to the spinal cord
272
Where is the vasodilator (A1) area of the vasomotor center? What are its outputs?
anterolateral lower medullaprojects to vasoconstrictor area to inhibit it
273
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
274
The medial vasomotor center relays ______ output to the heart while the lateral relays ______ output.
parasympatheticsympathetic
275
Stretching the carotid sinus stimulates what nerve?
Hering's nerve (CN IX)
276
Where does Hering's nerve synapse onto?
solitary tract which eventually proceeds to the sensory area of the vasomotor center
277
Stretching of the aorta causes stimulation of which nerve?
vagus nerve which eventually synapses onto the solitary tract
278
Which part of the hypothalamus detects serum osmolarity?
anteroventral third ventricular region (AV-3V)
279
What composes the AV-3V of the hypothalamus?
superior: subforniceal organinferior: organ vasculosum of the lamina terminalisIn between: median preoptic nucleus
280
What comprises the respiratory?
Dorsal respiratory group Ventral respiratory groupPneumotaxic center
281
Where is the dorsal respiratory group located? What are its functions?
dorsal medulla controls inspiration
282
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
283
Where is the pneumotaxic center located? What are its functions?
- dorsal superior pons in the nucleus parabrachialis- rate and pattern of breathing
284
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
285
What is Auerbach's myenteric plexus?
located between the longitudinal and circular layers of muscle; controls GI movements
286
What is Meissner's submucosal plexus?
located in the GI submucosa; controls secretions and blood flow
287
Where is the salivatory nucleus located?
pontomedullary junction
288
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
289
Name three substances that increase gastric secretions?
ACh, gastrin, histamine
290
Which pelvic nerves provide paraysmpathetics to the bladder?
S2-S3
291
Which portion of the hypothalamus detects temperature?
anterior hypothalamus and preoptic area
292
What endocrine hormones or equivalents are released by hypothalamus?
thyrotropin, corticotropin, growth hormone releasing hormone, gonadotropin releasing hormone, somatostatin, DA
293
Somatostatin inhibits _______ and _________.
growth hormone releasing hormonethyrotropin releasing hormone
294
Where is somatomedin C synthesized? What triggers its synthesis? What is its function?
LiverGHIncreases somatostatin levels which decrease GH levels
295
Prolactin is tonically inhibited by _______.
Dopamine
296
What is the effect of ADH?
increase distal tubule H2O absorption and NaCl loss
297
Which hypothalamic releasing hormone inhibits ADH?
Corticotropin releasing hormone
298
Gonadotropin releasing hormone is released mainly by the _______ of the hypothalamus.
arcuate nucleus
299
Which nerve is responsible for an erection in males/females?
nervi erigentes
