Neuro exam 1
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- Describe brain laterailty in terms of organization
-
-bilateral anatomical symmetry: 2 hemispheres essentially same shape
-unilateral functional differences: left for language, right for emotions/music etc
-contralateral sensorimotor control: left controls rt movement, vice versa - Describe structural and functional organization in the brain
- -sensory and motor systems have specialized nerve cells for their own sensations
- Describe topographical organizaion in the brain
-
-precentral gyrus: motor
-postcentrl gyrus: sensory
-auditory and visual cortices
-subcortical: interal capsule, BG, thalamus -
Describe these brain sections:
-coronal
-sagital/midsagital
-horizontal -
c--vertical slice, separates anterior and posterior
s--vertical slice, seperates right and left (midsag, exact middle)
h-horizontal slice, seperates top and bottom -
From BODY perspective, describe:
-caudal
-rostral
-anterior
-posterior
-dorsal
-ventral -
caud-toward the head
rost-toward the tailbone
ant/vent-toward font of bodu
post/dors-toward back -
From the CEREBRAL perspective, describe:
-caudal
-rostral
-anterior
-posterior
-dorsal
-ventral -
caud/post--back of brain/head
rost/ant--front of head
dorsal--top of brain
ventral--botton of brain -
From the BRAINSTEM perspective, describe:
-caudal
-rostral
-anterior
-posterior
-dorsal
-ventral -
caud--coccygeal end of spinal cord
rost-toward brain
dors-back of BS/SC
vent-toward front of body - Main structures in the CNS
-
Brain: cerebrum, brainstem (midbrain, pons, medulla), cerebellum
Spinal cord - Main structures in the PNS
- motor and sensory nerves
- Name the 6 layers of the cerebral cortex
-
1. molecular (interconnections)
2. external granular (cortex)
3. external pyramidal (cortex)
4. internal granular (thal. & subcort.)
5. internal pyramidal (Betz cells, motor cortex, BS, cerebellum, SC)
6. multiform (thalamus)
--MEgEpIgIpM - Name the primary vessicles, and what they mature into (brain divisions)
-
1. Prosencephelon--> Telencephalon, Diencephalon
2. Mesencephalon--> Mesencephalon
3. Rhombencephalon--> Metencephalon, Myelencephalon -
Gross anatomical structures that arise from...
...telencephalon
...diencephelon
...mesencephalon
...metencephalon
...myelencephelon -
tele: cerebrum, limbic lobe, BG
dien: thalamus, hypothal.
mesen: midbrain structures
mete: cerebellum, pons
myel: medula oblongtata - Describe embryonic development during 3rd week gestation
-
-neuro structures laid down
-neuroectodermal layer--> CNS & PNS
-neural tube--> BS & SC
-neural crest--> sensory ganglia, autonomic nerves - What are the major lobes of the brain?
- Frontal, parietal, occipital, temporal
-
what are the functions of the...
...precentral gyrus
...postcentral gyrus -
pre: motor homunculus
post: sensory homunculus - Name the classification of neurons
-
-unipolar (T-shaped, only one process)
-bipolar (peripheral process and central process)
-multipolar (many dendrites, one axon)
-golgi type I (LONG axon)
-golgi type II (short axon) -
Describe locations of...
...unipolar
...bipolar
...multipolar
...Golgi I
...Golgi II -
Uni: posterior root ganglia, cranial nerves, CNS & PNS connections
Bi: retina, sensory cochlear, vestibular ganglion
Multi: CNS nerve tracts, PNS - What is myelin? What cells produce it in the CNS and PNS?
-
-fatty sheath insulating nerve for better impulse conduction
-CNS: oligodendroglia cells
-PNS: Schwann cells - Factors influencing neural regeneration in CNS and PNS
-
CNS: poor, can't cross scars, may be influenced by growth hormones
PNS: good, 3-4 days, endoneurial membrane and neurilemma help sprout protien -
Describe:
--astrocytes
--oligodendrocytes
--microglea
--ependyma
--Schwann cells -
ast: CNS, grey/white matter; form lining around ext. surface of brain & blood vessels
--olig: CNS, produce myelin
--micro: CNS, engulf debris
--epend: Ventricular Cavity; lining of ventricular surface
--Schwann: PNS; produce myelin - Describe major componants of a single neuron
-
-cell body (soma)
-dendrites (receptors, transmit toward cell body)
-axons (effector, transmit away from cell body) -
Describe...
...Excitatory Impulses (EPSPs)
...Inhibitory Impulses (IPSPs) -
E: lowers post-synaptic membrane potential
I: Makes post-synaptic membrane hyperpolarized (inside more negative) - Describe the function and location of acetylcholine, as well as pathologies resulting from a breakdown
-
-CNS & PNS
-reticular formation, forbrain, cortex
-controls circadian cycles, excitation/inhibition, stereotypical movements
-MG, Alzheimers, myasthenia gravis can result if not enough - Describe the function and location of Dopamine, as well as pathologies resulting from a breakdown
-
-cortex, midbrain (substantia nigra)
-controls voluntary movement
-Parkinson's disease can result if not enough - Describe the function and location of Norepinephrine, as well as pathologies resulting from a breakdown
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-pons, medulla, limbic, thalamus, cortex
-conrols sleep, sustained memroy and vigilance - Describe the function and location of Serotonin, as well as pathologies resulting from a breakdown
-
-GI tract, blood, BS, subcortical and cortical
-controls arousal, sleep, pain control
-depression can result from low levels - Describe the function and location of GABA, as well as pathologies resulting from a breakdown
-
-CNS (inhibitory)
-Huntinton's chorea can result from low levels - Describe the function and location of Glutamate, as well as pathologies resulting from a breakdown1
-
-major excitatory
-creates links between neurons for learning and long term memory - Describe the function and location of Noradrenaline, as well as pathologies resulting from a breakdown
-
-excitatory
-induces physical and mental arousal, elevated mood
-produced in locus coreuleus - Describe the meninges, what is in the space between them, and how they are layered
-
-covers CNS from top of brain to tip of spinal cord
-between the two inner "diapers" is cerebrospinal fluid
-3 layers - Where is the efferent system in the cortex, and what comprises the tracts?
-
-direct activation pathways: pyramidal system (coticobulbar and cortico spinal tracts)
-indirect activation pathway: extrapyramidal system
-final common pathway (FCP): LMN system, cranaial and spinal nerves go to striated muscle - Where is the afferent system and what comprises the system tracts?
-
-post-central gyrus
-dorsal column-medial lemniscal system
-antero-lateral system -
Decribe what these conditions are any why they result:
--anencephaly
--cranium bifidum
--spina bifida
--hydrocephalus
--microsephalus -
an: missing cerebral hemispheres (defect of neural tube inutero)
CB: protrusion of brain & SC (inc. fusion of rostral neural tube)
SB: post. vertebral arches don't fuse, post. skin epithelialized (caudal neural tube doen'st fuse)
hyd: enlarged cerebral ventricles, too much CSF
micro: small brain, MR (environment, genes, radiation) -
Describe functions of...
...nissl substance
...golgi apparatus
...mitochondria
...neurofibrils
...microtubules
...lysosomes
...centrioles
...librofuscin
...melanin -
nissl: protien synthesis
golgi: cell membrane production
mito: chemical energy
neurofib: cell transport, cytoskeleton makeup
mirco: cell transport, motor movement
lyso: cleaning waste
centr: cell division
lipo: metabolic by-product
mel: formation of dopa - Describe what happens in a synapse
-
-presynaptic cell transmits neurotransmitter via terminal bouton to synaptic cleft
-postsynaptic cell receives it and generated impulse -
Describe...
...hyperpolarized
...depolarized
...repolarized
...polarized
...absolute refactory period -
hyp: period after impulse where potential < -70mV
dep: impulse becomes less negative as Na+ added
rep: impulse becomes more negative as K+ added
pol: at -70mV
ARP: period during hyperpolarization - Describe the process of nerve excitability
-
1. stimuli to nerves
2. Na+ depolarizes cell
3. action potential elicited
4. K+ repolarizes cell
5. cell becomes hyperpolarized briefly
6. cell returns to resting potential - Describe how Na+ and K+ influence nerve conduction
-
Na+: rush into cell to depolarize it before action potential
K+: rush into cell to repolarize after action potential -
What are...
...epicritic senses
...protopathic senses -
e: discriminate slight differences in senses
p: sensing pain/pressure/temperature in non-localized fashion -
Describe the following kinds of neurological breakdowns:
-neoplastic
-vascular
-degenerative
-motoric
-bacterial -
n: slow presenation
v: of the blood vessels
d: progressively worsening
m: movement disorder
b: caused by bacteria - Functions of the cerebral hemisphere
- -mental functions, multimodal processing, initiate motor acts, language/vision/hearing, organization/planning, memory, executive functions
- Functions of the Limbic Lobe
-
emotional behavior, body regulation, survival functions
-driven by hormones - Functions of the Basal Ganglia
-
-motoric precisions, initiation of movement dynamics/force/speed, templates for redundant verbal/motor acts, new verbal/motor training
-CSF by lateral ventricles - Functions of the Thalamus
- sensory/motor gateway, 30+ nuclei fused together (independant of brain), interconnection b/w cortex and subcortical
- Functions of the Hypothalamus
-
hormone secretion (regulates behavior), ANS functions, fight/sex/thirst/body temp
-3rd ventricle gives CSF - Functions of the midbrain
-
-made of tegmentum, red nucleus, substantia nigra, reticular formation, cranial nuclei
-funnels/monitors CNS/PNS sentory and motor input/output
-cerebral aqueduct gives CSF - Functions of the Pons
- sensory and motor pathways, cranial nerve nuclei
- Functions of the Cerebellum
-
control circuit, feedback used to regulate body
info from SC->BS->cortex (and back)
-4th ventricle gives CSF - Functions of the Medulla
-
pyramidal tracts and ascending sensory tracts, major point of decussation, cranial nerve nuclei
(no ventricles) - In general, where are the sig. structures for s/l/h in each major lobe?
-
-Brocca's area: Left Frontal lobe
-Wernicke's: Left Temporal
-Heschels gyrus: Left upper temporal lobe (near frontal)
-supramarginal/angular gyri: parietal lobe - Name major tracts that connect neuronal areas and cerebral cortex
-
-association fibres: superior longitudinal fassiculus, cinglulum, superior occipito-frontal fassiculus, inferior long.fassic, uncinate fasic.
-commisural fibres: corpus collosum
-projection fibres: corona radiata (decending motor tract of pyr. syst.) - Describe the connection of the corpus collosum
- connexts L&R hemispheres via assiciation areas, NOT the primary sensory, motor, auditory or visual centers
- Describe the tracts of the internal capsule
-
Anterior limb: anterior thalamic radiation, corticopontine
Genu: coticobulbar, coticoreticular
Posterior limb: corticospinal, frontopontine, superior thalamic, corticotectal, corticorubral, corticoreticular - what are the major cortical sulci?
-
-central sulcus
-lateral fissure
-parieto-occipital - Structures of the parietal lobe
-
-post-central gyrus/sensory cortex
-superior and inferior parietal lobules
-supramarginal and angular gyri - structures of the frontal lobe
-
-primary motor cortex
-premotor cortex
-prefrontal cortex - Major structures of the occipital lobe
- visual cortex
- major structures of the temporal lobe
-
-angular gyrus
-Heschel's gyrus
-Wenicke's area - where does the Corona Radiata merge?
- -subcortially near BG/Thal. region, thru internal capsule
- Characteristics of an axon
-
-aka nerve fiber
-efferent (motor), transmit AWAY from body
-extend long distances
-collaterals (extensions)
-terminal boutons release neurotransmitters - Characteristics of a dendrite
-
-afferent (receptive)
-transmit TOWARD cell body
-short with branches - Brain injury effects
-
-axonal retrograde: injury of axon
-Wallerian degeneration: axon cut, inflames, degenerates, atrophies
-Chromatolysis: degeneration, discoloration
-neuroglial response: increase of # of nerve cells and cell size - Lesion classification by levels
-
-supratentorial: brain
-posterior fossa: cerebellum, BS, medula
-spinal: below medulla
-peripheral: final common path of nerve - Supratentorial level
-
-derivitives of telen/diencephalons
-cerebral hemispheres, BG, thal., hypthal, cranial nerves I & II - Posterior fossa level
-
-structures b/w tentorium cerebelli and foramen magnum
-midbrain, pons, medulla, cerell., cran. nerves III->XII - Spinal level
-
-below foramen magnum, in vertebral column
-dorsal root ganglia (sensory), ventral root ganglia (motor) - peripheral level
-
-cranial/peripheral nerves
-ANS & ganglia, striated muscles - Efferent Tract:
-
-from motor cortex-->OUT
-motor homunculus, internal capsule, BS, SC
(H, IC, BS, SC) - Afferent Tract
-
-from periphery-->IN!
-dosal spinal ganglia, contralateral parietal lobes, sensory homunculus
(DSG, P, H) -
Label -
1. Dorsal
2. Rostral, anterior
3. Ventral
4. Caudal, posterior
5. Dorsal -
Label -
1. molecular
2. external granular
3. external pyramidal
4. internal granular
5. internal pyramidal / Betz cells
6. multiform -
Label -
1. dendrites
2. cell body
3. axon
4. nodes of ranvier
5. myelin sheath
6. terminal boutons -
Label -
1. neurons
2. oligodendrocyte
3. axon
4. microclian cell
5. ependymal cell
6. astrocyte
7. capillary -
Describe the following terms and if they're CNS or PNS
-Nucleus
-Tract
-Fasiculus
-Ganglion
-nerve -
nuc: mass of neurons (CNS)
trac: bundle of parallel axons a/common origin and termination (CNS)
fas: several // running tracts (CNS)
gang: collection of neurons (PNS)
nerve: bundle of axons (PNS) (optic nerve=CNS) -
Describe the 6 layers of gray matter
-mollecular
-ext. granular
-ext. pyramidal
-int. granular
-int. pyramidal
-multiform -
I-terminal denrdites and axons from cortex form interconnections
II-small granular interneurons recieve input from cerebrum
III-small pyramidal neurons with projections to other cereb. regions
IV-small granular interneurons receive input from thal. and other subcort. nuclei
V-Lg pyramidal cells (Betz cells) axons project to BS, cebell., and SC
VI-fusifrom neurons with projections to thalamus -
Important Brodmann areas:
-primary sensory cortex
-primary motor cortex
-primary visual cortex
-prim. auditory cortex
-2ndary association cortex
-Wernicke's
-Broca
-Supramarginal gyrus
-angular gyrus -
-1, 2, 3 (post central gyrus)
-4 (precentral gyrus)
-17 (med. occipital lobe)
-41, 42 (Heschl's gyrus)
-5, 7 (superior parietal lobule)
-22 (superior temporal gyrus)
-44 (lower 3rd frontal convulution
-40
-39