Week 1 Flashcards
1
Q
non-excitable (No AP), 50% of brain vol, 10:1 to neurons
A
Glia cells
2
Q
White matter glia cells
A
Astroglia - fibrous
3
Q
gray matter glia cells
A
Protoplasmic
4
Q
Retina glia cells
A
Muller
5
Q
myelinating cells of CNS, multiple per neuron
A
Oligodendroglia
6
Q
myelinating cells of PNS, one to one axon, also takes up excess NT and ions
A
Schwann cells
7
Q
derived from monocytes
A
microglia
8
Q
stem cells for neurons and glia cellsl synpase w/ neurons, activated in demylinating dz
A
Polydendroctyes
9
Q
Line central canal, ventricles, have cili and microvilli, epithelium that separates CSF from neurophil
A
Ependyma
10
Q
from neural crest, sussound pseudounipolar neurons of DRG modified Schwann cells or oligodendrocytes function as astrocytes in the peripheral ganglia
A
Satellites
11
Q
determines the membrane potential
A
Nernst
12
Q
estimates the resting membrane potential
A
Goldmann
13
Q
gap junction composed of 6 … to make a …
A
6 connexins > connexon
14
Q
Excitatory chemical synapse
A
Gray’s Type I, asymmetric post-syn density
15
Q
Inhibitory chemical synapse
A
Gray’s Type II, symmetric, pre/post density
16
Q
EPSP
A
Na channel opens to bring closer to threshold
17
Q
IPSP
A
Cl channel opens to bring further from potential
18
Q
2 types of neurotransmitter receptors
A
ionotropic (opens ion channel) or metabotropic (activates G protein)
19
Q
excitatory NT made from glutamine by astroytes
Ionotropic receptors: NMDA, AMPA, Kainate
Metabotropic: mGluRs
A
Glutamate
Aspartate is also excitory
20
Q
Inhibitory NTs
A
Glycine - spinal cord, Cl- influx
GABAa,c: CNS, Cl- influx OR
GABAb K+influx, calcium eflux, net inhibitory
21
Q
Nicotinc
A
ionotropic, non-specific cation channel
22
Q
Muscarinic
A
Metabotropic coupled to G proteins
M1/3 - Gq
M2= Gi
23
Q
Includes DA, NE, HIST, 5HT
metabotropic
A
Biogenic Amines
24
Q
Resistance equation
A
1/g = R
g = conductance
limits ion flow
25
active response; no decrement over distance, regenerative, large, binary, voltage-sensitive, refractory period
AP
26
passive response, no theshold, small, not voltage sensitive, no refractory period
graded potential
27
Sodium channel mutation, decreased inactivation of the sodium channels increases excitability
Generalized Epilepsy w/ Febrile Sickness
28
Familial Hemiplegic Migraine
Episodic Ataxia 2
Congential Stationary Night Blindness
Lambert Eaton
Calcium channelopathies
29
Sodium channel mutation in skeletal muscle, more excitable
Myotonia/ paralysis
30
Episodic Ataxia type I
K mutation in Purkinje cells
31
Benign Familial Neonatal Seizures
K+ channel mutation
32
antibodies to the Ach receptor in NMJ
Myasthenia gravis
33
serves as guide wires for neuron migration
radial glial cells
34
plate that develops int sensory nuclei, including dorsal horn, DRG, brainstem
Alar plate
35
plate that develops into motor nuclei, including ventral horn and brainstem
Basal
36
division between alar and basal plate
sulcus limitans
37
forms the cerebral hemispheres and deep structures
telencephalon
38
forms the thalamuc, hypothalamus, subthalamus
Diencephalon
39
midbrain
mesencephalon
40
forms the pons and cerebellum
metencephalon
41
forms the medulla
myelencephalon
42
failure of mesodermal cells to form vertebra around the spinal cord, no dorsal vertebrae, (tuft of hair over spinal tract)
Spina Bifida Occulta
43
Meninges outpouch
Spina Bifida Aperta meningocele
44
Meninges & spinal cord or filum terminale outpouch
Spina Bifida Aperta myelomingocele
45
displacement of cerebellar tonsils below the foramen magnum
Arnold-Chiari Type I
46
displacement of cerebellar tonsils below the foramen magnum + cervical encephalocele
Arnold-Chiari Type II
47
Lateral and medial surface of the frontal lobe
initiate and regulate voluntary behavior
48
Left lateral surface of the frontal lobe
Broca Motor Speech Area (motor to language)
49
Medal of frontal lobe emotional aspects of behavior
Cingulate gyrus
50
Lateral and medial surface of the parietal lobe
pain, touch, limb position
51
left lateral surface of the parietal lobe a/w with sensory aspects of language
Wernicke's Area
52
lobe for visual information
Occipital lobe
53
lobe to process auditory information
temporal lobe
54
temporal lobe - hear and process
superior temporal gyrus
55
temporal lobe perception of language
Lateral
56
temporal lobe: learning, memory, emotion
anterior, medial
57
outgrowth of the pons overlying the 4rth ventricle
| 2 hemispheres with central vermis, attached to the brainstem via peduncles (how they carry info)
Cerebellum
58
CSF, made at 20ml/h from later ventricles to the 3rd ventricle
Foramen of Monroe
59
CSF from 3rd to the 4rth ventricle?
from the 4rth ventricle -
to subarachnoid?
to central canal?
3rd to the 4rth: Cerebral aqueduct / aqueduct of sylvius
lateral foramina of Luschka, medial foramen of Magendie
direct narrowing of 4th ventricle
10% reabsorbed at the egress of the nerves and 90% at the venous sinuses via subarachnoid granulations
60
blood:csf triple lining
capillary, pia, choroid epithelium
61
BBB
tight junctions in capillaries and astrocytes
62
Circumventricular organs?
Lack a BBB, sample blood
63
monitor electrolyte balance
organ vasculosum
64
monitors hormones
Neurohypophysis
65
traumatic head injury with skull fracture, rupture of middle memningeal artery, pressure from bleed seperates the dura from the bone
Epidural hematoma
66
Shaken baby syndrome, ruptures the bridging veins between the sinus and cerebral vein
Subdural hematoma
67
Hematoma a/w arterial aneurism
Subarachnoid hematoma
68
Meningeal layer as perineureum
| layer as epineureum
Arachnoid - peri
| Dura - epi
69
Enters via carotid formain --> carotid canal, cavernous sinus, gives off opthalmic artery (anterior circulation)
internal carotid artery
70
Subclavian > C6-C1 transverse foramen > foramen magnum > Basilar artery
Vertebral artery
71
purely motor pathway?
Corticospinal tract
72
Corticospinal tract, Betz cell in forebrain cortex, travels via ....
deccussates .....
synapses.....
travels thru the posterior limb of the internal capsule, decussates w/ pyramids in the brainstem, synpases w/ lower motor neurons in anterior horn
73
Sensory for pain and temperature?
| Alpha delta - fast, localized, first pain
Spinothalamic
74
Spinothalamic sensory nerve endings?
Synpase 1
decussates?
synpase 2?
Alpha delta and C fibers
dorsal horn of spinal cord
deccussates at the anterior white commissure and ascends contralaterally
VPL of the thalamus
75
pathway for pressure, vibration, propioception, fine touch?
posterior column, medial lemnisus
76
dorsal column pathway:
DRG to first synpase?
decussates where?
second synpase?
synpases in the nucleus cuneatus or gracilus (T6)
decussates at the medulla, travels contralaterally via the medial lemniscus
VPL of the thalamus
77
Type I - Displacement of the cerebellar tonsils below the foramen magnum
Type II – also includes cervical or occipital encephalocele
Arnold-Chiari Malformations
78
separates the lateral ventricles
septum pellucidum
79
SNS: dilator muscles of iris and the tarsal muscle of eye lids; travels along the long ciliary nerves (exits spinal cord at T1-T2 level superior chain ganglion (lesion between hypothalamus & long ciliary nerve Horner’s on same side as lesion)/ if in brainstem of spinal cord, expect total left anhydrosis but if over the peripheral nerve, only facial anhydrosus
Horner's
80
-In substantia nigra corpus striatum: DA neurons ..... GABA and cholinergic neurons .... GABA (Parkinson’s loss of GABA neurons, tx by enhancing DOPA or decreasing muscarinic)
DA inhibit GABA
cholinergic excite GABA
81
Somesthesis: sensory for pain, temp, crude touch
Protopathic
| Spinothalamic tract
82
Protopathic fibers?
small w/ little myelin
83
Somesthesis: fine touch, position, vibration
Posterior column, epicritic
84
Epicritic fibers
large, myelinated
85
Encapsulated, concentric epithelial cells
detects gross pressure and vibrattions (250Hz)
subcut skin, joints, muscle, mesentery
Rapidly adapting: consist of free nerve endings encapsulated with Schwann cells known as lamellae – AP when these are distorted (onset and off-set of pressure)
Test with the tuning fork
posterior column
Pacinian corpuscule
86
light touch and vibration less than 50 Hz
Glabrous skin below epidermis
Rapid adapt
posterior column
Meissner's
87
Non-encapsulated
Slowly adapting mechanoreceptors in skin & mucosa
Touch domes & hair disks
Slow adapt
Merkel's
88
Mechanoreceptors only in deep labors of glabrous skin – sustained pressure and stretch / detect objects slipping along the skin
Slow adapt
Receptors have a thin capsule and longitudinally arranged collagen fibers
A beta fibers carry this sensory
Ruffinis
89
Protopathic pathway
Nail is in right foot -
ouch. -
sends opoids to decrease the pain
spinothalamic
spinoreticular
spinomesencephalic
90
A alpha neurons
motor neurons
91
A beta
Golgi Tendon and Ruffini endings
large, myelinated
Posterior column
92
B fibers
small, myelinated, pre-ganglionic visceral motor
93
C fibers
smallest, not myelinated a/w second pain - less localized, duller, synapse in substantia gelatinoasa
from free nerve endings (spinothalamic tract)
94
1a neuron
GSA Propioception
| sensory for muscle spindle
95
1b neuron
GSA propioception
sensory from Golgi tendon and ruffini endings
sensory from joints
96
2 neuron
sensory from skin receptors
97
3 neuron
sensory from free nerve endings for pain, temp, hair follicles
98
4 neuron
post-ganglionic autonomic
99
up/down tract in the spinothalamic tract
Lissauer's Tract
100
innervate the neck and trunk – motor coordination
Vestibulospinal tract & reticulospinal tract
101
travels closely with the lateral corticospinal tract and participates in control of the arms
flexor movements
Red nucleus --> LMN in spinal cord
Rubrospinal tract
102
coordinates the head movements with the eye movements
Colliculospinal tract
103
-Case 3: 74 y/o man wakes up with right half of his body numb except for his face bilaterally - where is the lesion?
Left thalamus (face preserved due to trigeminal nerve) – lacunar stroke
104
Cell bodies for visceral pain travel with
spinal ganglia?
terminate?
project where (this is where pain is interpreted)
visceral pain travels w/ SNS,
Anterolateral system on the contralateral side
cell bodies in spinal ganglia T1-L2
terminate in the VPL of the thalamus
projects to the insular cortex where visceral pain is interpreted
also bilaterally to the spinoreticular system
105
Visceral afferents for visceral reflexes arise from?
enter spinal cord from?
Ascend how?
S2-S4 pelvic nerves
| enter the ANTERIOR horn thru anterolateral system and also bilaterally thru spinoreticular system
106
where is wernicke's area
| superior temporal gyrus - auditory processing
posterior superior temporal lobe
107
Signals for visceral afferents originate in?
hypothalamus
108
Spinal cord injury rostral to the lumbosacral level
at first the bladder is areflexic, with complete urinary retention – next: automatic micturition via spinal reflex pathway, mechanoreceptors sense bladder fullness and directly activate sacral parasympathetics causing detrusor contraction, when the influence of the PMC is gone, external urethral sphincter is not relaxed during detrusor contraction, leading to incomplete emptying (detrusor-sphincter dyssnergia) – require daily catherization
109
level for a lumbar puncture?
| space?
L3/L4, subarachnoid
110
extension of pia mater that anchors the spinal cord to the dura (separates the posterior and anterior roots), pierces the arachnoid
Denticulate ligament
111
formed by joining 2 vertebral arteries
Basilar artery
112
Modulatory interneurons of the spinal cord
Renshaw neurons
113
mediates pain transmission in the posterior horn of the spinal cord; received input from the nucleus propius in laminae III and IV
Substantia gelatinosa
114
C8-L3, proprioception to the cerebellum
| Part of the spinocerebellar tract
Clark's Nucleus
115
Myotatic reflex
1a fibers in the muscle spindle synapse with alpha motor neuons which cause contraction
116
Withdrawal reflex
pain detected by A delta and C fibers in skin, synapse with alpha motor
117
Brown-Sequard Syndrome 3 things:
Spinothalamic tract
Dorsal column tract
Lateral corticospinal tract
Spinothalamic tract - decussates at spinal cord (loss of pain, temp, crude touch on contralat) , usually 2-3 segments below lesion
Dorsal column tract - decussates in medulla - loss of propioception, fine touch in the ipsilateral side)
Lateral corticospinal tract - ipsilateral spastic paralysis, Babinksi sign
118
Tabes dorsalis?
Neurosphyilis, loss of the posterior column medial lemniscus pathway; can no longer feel fine touch or have conscious propioception of the body
119
Friederreich ataxia mechanism
lesions of the spinocerebellar tract
120
Common presentation of syringomylia
loss of pain and temperature to both hands, sensory and motor intact
Cavitation begins around the central canal where the fibers are crossing over (spinothalamic)
121
Anterior horn of the spinal cord, convey information to the cerebellum about the postural stability of the lower limb
Spinal border cells
122
right medullary glioma would cause loss of sensation on the left side because?
In the rostral medualla, the dorsal column medical lemniscus (fine touch, proprioception) and the spinothalamic (pain, crude touch, temp) have already crossed over
123
motor tract to the head and face
Corticobulbar
124
extra-pyramidal; body posture in response to changes in head position detected by the inner ear (lateral vestibulospinal tract: interference on a ride that whirls child around)
Vestibulospinal
125
Extra-pyramiydal tract; originates in the red nucleus, flexion in upper extremities
(comatose patient: decerebrate posturing - arms extended and decorticate posturing, arms flexed)
Rubrospinal
126
extra-pyramidal tract; extension in upper extremities
Reticulospinal
127
cervical spine cord: head and neck movements during eye movements; originates in the superior colliculus
Tectospinal
128
Posturing: lesion is in midbrain or the rostral pons , reticulospinal intact
Decerebrate/ Extensor Posturing
129
posturing: upper arms flexed – both the rubrospinal and reticulospinal tract are intract
Decroticate posturing:
130
affects upper and lower motor neurons; oculomotor and visceral motor neurons are spared; begins as weakness in one limb (usually distal), cramping in the morning, atrophy, fasciculations; disruption to the reticular formation can leads to inappropriate motor expression: excessive crying, laughing
Amyotrohic Lateral Sclerosis
131
A delta fibers
Spinothalamic tract
| first pain - sharp well localized
132
Target of the descending motor tracts
LMN in the spinal cord
133
Principal cells
Projection neurons (one brain area to another brain area) - aka Golgi Type I long projecting axons
134
Interneurons
within the same brain area)
| Golgi Type 2 local circuit neurons
135
NMJ channel?
Nictonic, uses acetylcholine as the NT
136
High safety factor?
ensures that every time a motorneuron releases transmitter, every muscle fiber it innervates has an AP and contracts (lots of release sites for NT, high number receptors,, high quantal content (occurs at the NMJ)
137
Low safety factor?
CNS connections are simpler/ more diverse - different transmiters and receptors), lower quantal content, less secure
138
Brain development summary
begins in 3rd week: 3 vesicle brain and 5 vesicles by week 5
139
Alar plate -->
| Basal plae -->
Alar plate is dorsal (sensory)
| Basal plate is ventral (motor)
140
Post ganglionic NT exceptions
Use ACh rather than NE as their NT
| Pilo erectie, adrenal medulla, sweat glands
141
Cranial nerves w/ PNS action
5,7,9,10
142
Chemoreceptors and baroreceptors send information to what nucleus/ cranial nerves?
Solitary tract nucleus (X, XI)
143
Locus ceruleus
regulates sleep/ arrousal, vigilance (releases NE in the amygdala)
144
Effect of nictoine from smoking on the brain
a4b2 in the substantia nigra ventral tegmental area
145
Substantia gelatinosa
Lamina I and II (dorsal) site of pain modulation and temp info
146
Referred pain theory
Some of the collaterals of the epicritic system synpase on the same layer V cells as the protopathic cells
147
Thalamus nucleus - somesthesis for:
body?
face?
body - VPL
| face - VPM
148
Rexed's Laminae
| I& II
Substantia Gelatinosa
149
Laminae I-VI
Intermediate Sensory Neurons
150
VII-VIII
Local Circuit, Autonomic, Commisural Neurons
151
IX
Lower Motor Neurons
152
gamma motor neurons
innervate spindle intrafusal muscle cells
153
Clonus
UMN lesion - stretch reflex is unchecked
| plantar extension of the foot when the foot is forcibly stretched upwards
