how many pairs of cranial nerves are there off the brain stem
12 pairs
how many pairs of spinal nerves are there off the spinal cord
31 pairs
nerves to body surface and skeletal muscles
somatic nervous system
nerves to internal organs and blood vessels
ANS
PNS send ________ which give sensory input into the CNS
afferent nerve fibers
PNS send _____ which give motor input out of CNS
efferent nerve fibers
Nerve cell body groups in the CNS? PNS?
nucleus
ganglion
preganglionic fibers are short, postganglionic fibers are long
sympathetic
preganglionic fibers are long, postganglionic fibers are short
parasympathetic
what kind of nerve fibers transmit stomach pain into the CNS
Autonomic afferent
the greater splanchnic nerve is a ___________
preganglionic sypathetic nerve
- basal ganglia include:
caudate putamen globus pallidus red nucleus (of midbrain) substantial nigra (midbrain) sub thalamic nucleus (thalamus)
what are the 3 divisions of the brain
cerebrum
cerebellum
brain stem
what are the major divisions of the spinal cord
white matter
grey matter
the cerebrum contains what 2 divisions
telencephalon
diencephalon
the cerebellum contains what divisions?
cerebellar cortex
cerebellar nuclei
the brainstem is broken into what divisions?
midbrain (mesencephalon
pons
medulla oblongata
white and grey matter has what divisions
dorsal columns
latereal columns
anterior columns
the telencephalon from the cerebrum is divided into
cerebral cortex
subcortical white matter
commissures
basal ganglia
the diencephalon from the cerebrum is divided into
thalamus
hypothalamus
epithalamus
subthalamus
hypothalamus is part of the
diencephalon
substantial nigra is part of the
basal ganglia
what are the outside structures of the CNS
cerebrum cerebellum brain stem spinal cord meninges blood vessels
- which is more anterior and in frontal lobe, broca’s area or wernicke’s area?
broca’s
- which is more anterior, primary motor area or primary sensory area?
primary motor
- Which side is broca’s area located in the cerebral cortex? right or left?
left
- lesions in _______ show inability to use syntactic information and typically understand what is being said, but unable to fluently speak
broca’s area
- the corresponding area of broca’s area on the right frontal lobe controls
emotional overtones to spoken words
- What area helps dictate how you say/form words you want to speak
broca’s area
area where you have trouble understanding language and finding the correct words as if speaking another language. They can still form word sounds, but often what is spoken lack any meaning
wernicke’s area damage
A woman had a stroke that affected her speech. she gave nonsense answers that had no relationship to questions asked. She could answer questions quick, but made no sense. What area of the brain was damaged?
Wernicke’s area within temporal cortex
the primary visual cortex is in what region of the brain?
occipital
midline portion of the cerebellum is called ____ which separates 2 lateral lobes or cerebellar hemispheres
vermis
the surface of the cerebellum has narrow, ridge-like folds called ___, which are oriented transversely
folia
- what are the 3 major external divisions of the brain stem from cranial to caudal
midbrain
pons
medulla
What CN come off the CNS?
1 & 2
what CN come off the midbrain
3, 4,& 5(1)
- what CN come off the pons
5(2), 6, 7, 8
tiny part of 10
what CN come off the medulla
9, 10, 11, 12
- ___ connects the cerebrum to both medulla and cerebellum
pons
- descending fine motor control fibers mostly cross in ______, and small percentage don’t cross and go through ______
pyramidal decussation
anterior corticospinal tract
All spinal nerves exit ABOVE their vertebrae until _____ and then the nerves exit below
C7
(spinal nerve C8 exits below C7)
- ____ space is a “potential space” that appears between dura mater and outer portion of arachnoid mater
subdural space
- What are the 4 major blood vessels that supply blood to the base of the brain and what opening do they go through
2 vertebral arteries (foramen magnum)
2 internal carotid arteries (carotid canal –> foramen lacerum)
the 4 major blood vessels (2 vertebral, 2 internal carotid) to the brain then travel to the CNS via
3 cerebral arteries
3 cerebellar arteries
3 spinal arteries
the 3 cerebral arteries to the brain are
anterior and middle (INTERNAL CAROTID)
posterior (vertebral)
the 3 cerebellar arteries to the brain are
anterior inferior
posterior inferior
superior cerebellar
(All from vertebral)
the 3 spinal arteries to the brain are
1 anterior, 2 posterior
all from vertebral a
- which arteries to the CNS are from the internal carotid artery
anterior and MIDDLE cerebral arteries
which arteries to the CNS are from vertebral arteries posterior cerebellar (cerebrum)
superior, anterioinferior, posterioinferior (cerebellum)
anterior spinal, 2 posterior spinal (SC)
- the _____ and its branches course around the genu of the corpus callous to supply anterior frontal lobe and medial aspect of the hemisphere and extend far to the rear
anterior cerebral artery
- the ____ curves around the brain stem, supplying mainly occipital lobe and choroid plexuses of 3rd and lateral ventricles and lower surface of temporal lobe
posterior cerebral artery
- the ____ supplies many deep structures and much of the lateral aspect of cerebrum, branches into lateral fissure, over insula, before reaching convexity of the hemisphere
middle cerebral artery
the top of the cerebrum supplies the _____ half the body
lower
in a stroke affecting the ______, weakness and sensory loss are most severe in the contralateral face and arm and leg may be mildly affected or unaffected
middle cerebral artery
in a stroke affecting the ____ weakness is most pronounced in the contralateral leg
anterior cerebral artery
unlike systemic veins, ____ have no valves
cerebral veins
the venous drainage of the brain and coverings include
veins of brain itself
dural venous sinuses
meningeal veins
diploid veins
- drain the deep middle cerebral veins into the cavernous sinuses
sphenoparietal sinuses
- this sinus in on either side of the sella turcica
cavernous sinus
What is the CSF circulation?
Produced by choroid plexus –> lateral ventricles –> 3rd ventricle –> cerebral aqueduct –> 4th ventricle –> central canal (subarachnoid space) –> flow out either medial or lateral apertures and return to superior saggital sinus via arachnoid granulations
tearing of bridging veins between brain surface and dural sinus is the most frequent cause of
subdural hemorrhage
who are at the greatest risk for a subdural hemorrhage
aged adults and children
bleeding from a torn meningeal vessel (usually an artery) may lead to a
epidural hemorrhage
where the internal carotid drains into the cavernous sinus and jugular vein, causing ischemia in the cerebral arteries
carotid-cavernous fistula
what are the structures of the CNS inside grey and white matter
basal ganglia diencephalon brain stem nuclei spinal cord ventricles
the cell bodies are located in white or grey matter?
grey matter
fibers such as axons or dendrites are located in white or grey matter?
white matter
what is the only ganglion in the CNS
basal banglia
- associated with voluntary motor control, procedural learning relating to routine behaviors or “habits” such as bruxism (clench or grind teeth), eye movements and cognitive, emotional functions
basal ganglia
- what are the parts of the basal ganglia?
thalamus
caudate
putamen
globus pallidus
what processes memory and emotional reactions deep with the temporal lobe
amygdala
- ____ are myelinated fibers that separate thalamus and caudate nucleus from putamen and globes pallidus nuclei.
internal capsule
internal capsule myelinated fibers are part of what 2 tracts
corticospinal
corticobulbar
the globus pallidus and putamen nuclei together are called
lenticular nuclei
the caudate nucleus contains _____, which are chemicals that produce a positive emotional state
endorphins
____ infarcts of the posterior capsule can cause either pure motor or sensory deficits
lacunar
- defects in function of the _____, causes changes in muscle tone, weak voluntary muscle movement (akinesia) or abnormally slow movements (bradykinesia), or involuntary, abnormal movement (dyskinesia)
basal ganglia
- loss of normal motor function resulting in impaired muscle movement
akinesia
- slow movement
bradykinesia
- impaired ability to make voluntary movements, characterized by spasmodic or repetitive motions or lack of coordination
dyskinesia
disease characterized by debilitating abnormal movements and cognitive and psychiatric dysfunction
huntington’s disease
the pathology of Huntington’s includes striking loss of neurons in the ___ and ___ of basal ganglia
caudate and putamen
** the most common nervous system disorders of the elderly
Parkinson’s disease
Parkinson’s is characterized by a triad of symptoms such as
tremor
rigidity
akinesia/bradykinesisa
balance problems
parkinson’s is the loss of neurons in the _____.
substantia nigra
the progressive loss of dopaminergic neurons in substantial nigra causes
parkinson’s disease
Loss of GABA-ergic (inhibitory) neurons in the corpus striatum results in the chorea of
huntington’s disease
what are the components of the diencephalon (all bilateral)
thalamus
hypothalamus
subthalamus
epithalamus
the pituitary gland is controlled by the
hypothalamus
what hormones are made in the anterior (adenohypophysis) pituitary gland
LPH ACTH TSH FSH LH growth hormone prolactin
- what hormones are made in the posterior (neurohypophysis) pituitary gland
oxytocin
vasopressin (ADH)
does the anterior or posterior pituitary release hormones from the hypothalamus
posterior pituitary
what hormone is made in the hypothalamus
GRH
ADH is produced by neurons located in the
diencephalon (hypothalamus)
what CN are located in the medulla
9, 10, 11, 12
_____ has ventral, dorsal and lateral horns and ____ has ventral, dorsal and lateral columns
grey
white
- the lateral ventricles are located within the
telencephalon
- the third ventricle is between 2 halves of the
diencephalon
- the fourth ventricle is within the ___ and has 3 openings to the outside of the brain
brain stem
a tuft of hair develops over a region of the spine
spinal bifida
where does spinal bifida typically occur
lower lumbar or sacral region (can be cervical)
a protruding of the meninges posteriorly and typically occur in lumbosacral region
meningocele
protrusion of spinal cord along with CSF and meninges from vertebral canal
myelomeningocele
more than__% of disk herniation occurs at C6/7; L4/5 ; L5/S1
90
which type of spinal cord defect is least likely to cause loss of spinal cord function?
spinal bifida occulata
what 2 spinal cord defects is most likely to result in paraplegia
spina bifida and rachichisis
sensory neurons via dorsal column tracts provide what
sensation of fine touch
vibration
2 point discrimination
proprioception
what is the somatosensory pathway in dorsal column?
- DRG –> spinal cord via dorsal root –> fasciculus gracilis (medial) –> fasciculus cuneatus (lateral) –>
- lower medulla in gracile and cuneate nuclei –> cross over via lemniscal decussation –> ascend to thalamus–>
- ventral posterolateral thalamic nuclei –> cerebral sensory cortex
what is the spinothalamic tract?
- DRG –> spinal cord via dorsal root –> forms lissauer’s tract and ascend ipsilateral 2 segments –>
- synapse with dorsal horn neurons (*2 spinal segments above) –> cross to opposite side to form anterior (light touch) and lateral (pain and temp) spinothalamic tract –>
- thalamus –>somatosensory cerebral cortex
which order neuron is the only one to cross over in dorsal column pathway
secondary neuron
which pathway is for fine touch, vibration, 2 point discrimination and propioception
dorsal column tracts
which pathway is for touch (anterior), pain and temp (posterior)
spinothalamic tract
primary sensory neuron is located in the
dorsal root ganglia
secondary sensory neuron is located in the
dorsal horn of same side
which neurons have their axons decussate?
secondary sensory neuron
upper motor neuron
ipsilateral upper motor neuron paralysis (from lesion downward)
brown sequard syndrome
what is the pathway for white matter in descending corticospinal tract
cerebral cortex (upper motor neurons) –> medulla (pyramidal tract) –> lower medulla (pyramidal decussation - cross to contralateral side) –> spinal cord (LATERAL CORTICOSPINAL TRACT)
what controls voluntary, high skill and fractionated movement?
corticospinal tract (descending)
- the corticospinal tract pass through the medulla and most form ___
pyramidal decussation
what percent of fibers never decussate but still descend in lateral column
3%
what percent of fibers descend in anterior column on same side and decussate in spinal cord
10%
This lesion causes flaccid paralysis, muscle atrophy, diminished or absent deep tendon reflexes, no pathological reflexes
lower motor neuron lesion
this lesion causes spastic paralysis, little or no muscle atrophy, hyperactive deep tendon reflexes, pathological reflex (babinski)
upper motor neuron lesion
what lesion is caused by trauma, toxins, infection, diseases, tumor, etc
lower motor neuron lesion
what lesion is caused by strokes, infections, tumor, trauma to spinal cord corticospinal tract
upper motor neuron lesion
voluntary abnormal movement
dyskinesia
loss of coordination, jerking movements
ataxia or asynergy
unable to do rapidly alternating movement
dysdiadochokinesia
What is the visual pathway
optic nerve (retina) - 1st order –> optic chiasm (nasal fibers decussate, temporal doesn’t) –> optic tract (nasal and temporal) –> lateral geniculate body - 2nd order –>optic radiation to visual cortex
if you injury your optic nerve you will be
blind in one eye
if you injury your optic chiasm you will develop
bitemporal hemianopia
steps of how a signal travels through chemical synapse
- SIGNAL on presnaptic neuron reaches axon terminal
- signal trigger Ca++ ION CHANNELS OPEN, Ca++ influx
- Elevated Ca++ causes presynaptic vesicles undergo exocytosis, NEUROTRANSMITTERS RELEASED into synaptic cleft
- neurotransmitters bind to POSTSYNAPTIC MEMBRANE RECEPTORS. trigger postsynaptic neuron respond (excitatory or inhibitory)
- NEUROTRANSMITTERS DESTROYED in cleft or retaken to presynaptic neuron
preganglionic sympathetic fibers use what chemical
Ach
reganglionic and postganglionic parasympathetic fibers both use what chemical
Ach
some sympathetic postganglionic fibers use
Ach
Neuromuscular junction use
Ach
the progressive loss of dopaminergic neurons in substantial nigra causes
parkinson’s disease