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102 Cards in this Set

  • Front
  • Back
What are the parts of the central nervous system?
cerebrum
cerebellum
brain stem
spinal cord
diencephalon
basal ganglia
How many spinal and cranial nerves are there?
32 spinal (8 cervical)
12 cranial
What are the four subdivisions of the cerebrum?
frontal
parietal
temporal
occipital
What is the relationship between the spinal column and the spinal vertebra?
spinal column ends at S2
nerves continue as "cauda equina"
What are the parts of the brain stem?
midbrain
pons
medulla oblongata`
What happens when the brain stem slides down the clivus?
high intercranial pressure - brain stem herniates into foramne magnum
creation of a pressure differential between cranial and spinal cavities
What are the subdivisions of the cerebral lobes?
gyri (bulge)
sulci (small indentation)
fissures (large indentation)
What are the two main pairs of arteries that supply the brain?
2 internal carotid arteries
2 vertebral arteries
What happens with obstruction of the right carotid artery?
causes weakness and loss of sensation on the left side of the body (opposite sides)
What happens with blockage of circulation from the vertebral artery?
affects circulation to the visual area of the cerebrum, brain stem, and cerebellum
may result in visual loss, dizziness, and other problems
Where do the anterior, middle, and posterior cerebral arteries flow to?
anterior (entire midline of cerebral hemisphere)
middle (lateral surface of cerebrum, above dividing line)
posterior (below dividing line)
What is the functional representation on the cerebral cortex?
upsidedown HAL
H-head
A-arm
L-leg
What happens in an occlusion of the anterior cerebral artery?
loss of strength and sensation in the lower part of the body
What happens in an occlusion of the middle cerebral artery?
loss of strength and sensation in upper regions of body
Radiological injection into the right brachial artery contrasts which vessels?
right common carotid artery
right vertebral artery
Radiological injection into the left subclavian artery contrasts which vessels?
vertebral artery
(left common carotid arises from middle aortic arch)
Draw and name the sections of the circle of Willis
drawing
What happens with an occlusion of the basilar artery at the junction of the two posterior cerebral arteries?
total blindness (arteries supply visual cortex)
What happens with an occlusion of a vertebral artery?
little or no deficit (opposite vertebral artery can supply)
Which subclavian artery would you inject with contrast to demonstrate both carotid and vertebral cirvulations?
right subclavian vein
Contrast injection into the left vertebral artery shows up which side of the brain, left or right?
both sides
What are the layers of meninges in increasing superior order?
PAD
P-pia
A-arachnoid
D-dura
What are the structures of the meninges?
pia-thin, vascular, hugs brain and willis
arachnoid-avascular spider web
dura-against bone, thick, durable, double layer of connective tissue
What is the location of the dura membrane?
dura-periosteum inbetween are 'sinouses'
falx cerebri (between hemispheres
tentorium cerebelli (between cerebrum and cerebellum)
What is the location of the meninges?
surrounds entire CNS
spinal cord
optic nerve
What is the path of blood drainnage from the brain?
spinal fluid drains into superior sagittal sinus
to the cavernous sinus
to transverse sinus
into the internal jugular vein
What are the structures that drain blood into the cavernous sinus, and possible infections?
eye (orbital, facial infections)
carotid breaks open and releases blood back into veins (fistula, dialated eye vessels)
What are the structures that drain blood into the transverse sinus, and possible infections?
ear (inner ear infections)
An occlusion of which area of the circle of willis will result in total unilateral blindness?
ophtalmic artery
What happens to the blood vessels and CNS from a leaking aneurysm in the region of Willis?
subarachnoid hemorrahge
severe neckache or backache by blood down spinal cord
(spinal tap shows bleeding)
What happens in subdural hemorrhage?
tearing the bridging veins that connect brain and dual sinuses
What happens to the blood vessels and CNS in a skull fracture?
epidural hemorrhage
tearing of arteiries and commprssion of brain
What happens in a hemorrhage of the anterior choroidal artery and striate arteies, from hypertension?
creasion of tiny lesions on internal capsule (funnel of motor and sensory fibers from cerebrum to brain stem)
What is containned in the grey matter?
contains neuronal cell bodies synapses
What is containned in the white matter?
contains assending and descending fiber pathways
What are the three main sensory systems entering the spinal cord?
pain-temperature
proprioception-stereognosis
light touch
Where do sensory fibers synapse?
just prior to crossing over
What is the pathway of the pain-temperature sensory CNS system?
from the dorsal horn the pathway crosses immediately to the ventral horn (opposite side) and ascends to the thalamus and cerebral cortex
A lesion of the spinothalamic tract results in what?
loss of pain-temperature sensation contralaterally below lesion
What is the pathway of the proprioception-stereognosis sensory CNS system?
from the dorsal white matter the pathway remains on the same side through the posterior columns, then crosses over at the nucleus cuneatus (upper body proprioception) and nucleus gracilis (lower body) in the brain stem
A lesion of the posterior colums results in what?
a decrease in conscious proprioception and steregnosis ipsilaterally below lesion
What is the pathway of light touch sensory CNS system?
combines pathways of proprioception and pain-temp. crosses over immediately and at brain stem
A lesion of the sensory area of the cerebral cortex may result in?
a contralateral deficit of all sensory modalities
What are the types of proprioception-stereognosis?
conscious pathway (connects thalamus and cortex, describe position of limb)
unconscious pathway (connects with cerebellum, subconscious movement)
What is the difference in lesion affect between the cerebrum and cerebellum?
cerebrum lesion produces contralateral defects
cerebellar lesion produces ipsilateral lesion
What are the connections between the cerebellum and the brain stem?
SMI
superior (midbrain), middle (pons), and inferior (medulla) cerebellar peduncles
What is the motor neuron pathway in the CNS?
corticospinal pathway extends from cerebral cortex through brain stem crossing at medial lemniscus
What are the differences between the upper motor neurons and lower motor neurons?
UMN-above anterior horn synapse (2st order)
LMN-peripheral nerve neurons (2nd order)
both contain axons in upper and lower body
What are the UMN defects?
spastic paralysis
no muscle atrophy
no fasciculations and fibrillations
hyperreflexia
Babinski reflex
What are the LMN defects?
flaccid paralysis
significant atrophy
fasciculations and fibrilations
hyporeflexia
Babinski reflex not present
What is the Babinski reflex?
UMN defect where big toe extends up and toes fan out
What happens in a lesion of the anterior horns of grey matter and cortico spinal tracts?
amyotrophic lateral sclerosis
muscle weakness, atrophy, fibrillations, and fasciculations with hyperflexia
What happens in a lesion of the posterior columns of white matter and posterior ganglion/root?
tertieary syphilis
proprioceptive loss and pain particullarly in lower extremities
What happens in a lesion of the posterior columns and corticospinal tracts?
pernicious anemia
prorpioceptive loss and UMN weakness
Waht happens in a lesion of the anterior horn cells?
polio
LMN weakness, atrophy, fasiculations, fibrillations, and hyporeflexia
What happens in a cerebral hemisphere stroke?
carotid artery occlusion
decoritcate posturing (flexion of wrist and elbow, extension of ankle and knee)
What happens in a midbrain stroke?
decerebrate posturing (flexion of wrist, extension of elbow, ankle, and knee)
What happens in a 'pure' lesion of the corticospinal tract?
difficultly with skilled movements of distal aspects of extremities
What do somatic motor and sensory fibers innervate?
motor-striated skeletal muscle
sensory-skin, muscle, and tissue
What are the functions of CN1?
mediates sense of smell (olfaction)
What are the functions of CN2
subserves vision and pupillary light reflexes
What are the functions of CN3?
GSE moves eye (medial rectus muscle, superior rectus muscle, inferior rectus muscle, inferior oblique muscle, levator palperbare
CN3 constricts pupil
accomidates
postganglionic parasympathetic fibers to sphincter muscle of iris (miosis) and ciliary muscle (accomodation)
What are the general functions of CN5
GSA – provides sensory innervation to the face, mucous membranes of the nasal and oral cavities and frontal sinus, teeth, hard palate, and deep structures of the head (proprioception from muscles and the temporomandibular joint). SVE – innervates muscles of mastication, the tensors tympani and veli palatini, the mylohyoid, and the anterior belly of the digastric muscles.
What are the general functions of CN7
GSA – has cell bodies located in the geniculate ganglion; innervates the posterior surface of the external ear via posterior auricular branch of the facial nerve.
SVA – has cell bodies in the geniculate ganglion; innervates the taste buds from the anterior 2/3 of the tongue via : intermediate nerve, chorda tympani and lingual nerve.
GVA – has cell bodies in the geniculate ganglion, innervates the soft palate and adjacent pharyngeal wall.
GVE – is a parasympathetic component that innervates the lacrimal, submandibular and sublingual glands. Contains preganglionic neurons located in the superior salivatory nucleus of the caudal pons.
SVE – arises from facial nucleus of the caudal pons and exits the brainstem in the cerebellopontine angle; innervates the mm. of facial expression, the stylohyoid muscle, the post. belly of the digastric m., and the stapedius
What are the general functions of CN8
serves to maintain balance and mediates hearing
What are the general functions of CN9
SVA– innervates the taste buds of the posterior third of the tongue (cell b. in the petrosal ggl.).
SVE – innervates the stylopharyngeus muscle
GVE – is a parasympathetic component that innervates the parotid gland. Consists of preganglionic neurons located in the inferior salivatory nucleus of the medulla that project via the tympanic nerve and via the lesser petrosal nerve to the otic ganglion. Postggl. fibers project to the parotid gland via the auriculotemporal n.
What are the general functions of CN10
GSA– innervates the infratentorial dura, posterior surface of the external ear, external auditory meatus, tympanic membrane. Has cell bodies in the superior (jugular) ganglion.
GVA – innervates mucous membranes of the pharynx, larynx, oesophagus, trachea, thoracic and abdominal viscera to the left colic flexure. Has cell bodies in the inferior (nodose) ggl. SVE – innervates pharyngeal arch muscles of the larynx and pharynx, striated muscle of the upper oesophagus, muscle of the uvula, levator veli palatini and palatoglossus muscles. Receives SVE input from the cranial division of the CN XI. GVE – innervates the viscera of the neck and of the thoracic and abdominal cavities as far as the left colic flexure.
What are the general functions of CN11
SVE– mediates head and shoulder movement and innervates laryngeal muscles
What are the general functions of CN12
mediates tongue movement
Draw the functional chart of the cranial nerves
chart
What are the location of the cranial nerves and their nuclei around the midbrain ?
diencephalan (1,2)
midbrain (3,4,5 sensory)
pons (5 sensory and entry,6,7,8)
medulla (5 sensory,7,8,9,10,11,12)
How do the cranial nerves exit the brain stem?
all exit relatively anteriorly
except CN4 crosses over and passes around the roof of brain stem from posterior
What is the location of CN3 around the brain stem, includding nuclei?
oculomotor and Edinger-Westphal (closer to midline) nuclei are located in rostal midbrain near aqueduct
axons exit anterolaterally without crossing over
What is the location of CN4 around the brain stem, includding nuclei?
trochlear nucleus is located in the caudal midbrain and is the only nerve with axons that cross over and exits posteriorly
What is the location of CN6 around the brain stem, includding nuclei?
abducens nuclei located in caudal pons near the fourth ventricle
axons exit anterolaterally without crossing over
What is the location of CN11 around the brain stem, includding nuclei?
nucleus ambiguus creeps up spinal column
axons leave anteriorally and pass through jugular foramen
What is the location of CN12 around the brain stem, includding nuclei?
hypoglossal nucleus located in medulla
axons exit anterior to inferior olivary nucleus
What is the inferior olivary nucleus?
a structure functioning in communication between cerebellum and other CNS areas
What is the location of CN5 around the brain stem, includding nuclei?
from the trigeminal ganglion all motor and sensory fibers enter the brain stem at pons
three major parts inline from pons to C2
mesenchephalic nucleus (proprioception)
main sensory nucleus (ligh touch)
spinal nucleus (pain-temperature)
What is the location of CN7 around the brain stem, includding nuclei?
4 compartments
pons-facial nucleus (axon wraps around CN6 on exit)
most rostral medulla-superior salivatory nucleus (lacrimates and salivates), nucleus solitarius, spinal nucleus CN5
What is the location and function of nucleus solitarius?
visceral sensory nucleus in medulla
sensory meodalities include taste, carotid sinus and carotid body, and sensory return along vagus
What is the location and function of the nucleus ambiguus?
located in medulla
swallowing and speech
What is the location of CN9 around the brain stem, includding nuclei?
most rostral medulla-inferior salivatory nucleus (parotid), nucleus solitarius, spinal nucleus CN5, nucleus ambiguus
superior and inferior ganglion
What is the location of CN10 around the brain stem, includding nuclei?
most rostral medulla-dorsal motor nucleus, nucleus solitarius, spinal nucleus CN5, nucleus ambiguus
superior and inferior ganglion
What is the location of CN8 around the brain stem, includding nuclei?
after synapsing in the medulla auditory fibers travel to both inferior colliculi
synapse and extend to medial geniculate bodies
synapse again and travel to both cerebral hemispheres
What are the central connections of CN5?
sensory fibers enter brainstem at pons synapse ipsillaterally then cross over to form tigeminal lemiscus
What happens if CN7 is severed?
one entire side of the face, including eyelids and eyebrows, becomes paralyzed
ironed out forehead
eye will not close
Which cranial nerves open and close the eyelids?
CN7 a hook pulls down the eyelid
CN3 a pillar opens the eyelid
What happens if there is a lesion above the nucleus 7, upper motor neuronal lesion?
only the area below the eyes is paralyzed
bilateral innervation of upper face by both hemispheres
What is Bell's palsy?
a spontaneous peripheral nerve 7 palsy
difficulty in closing eye
facial canal injury (internal acoustic meatus, stylomastoid foramen)
Clinically what are the most important nerve pathways through the brain stem?
corticospinal tract
medial lemiscus
spinothalmic tract
spinocerebellar tract
What are the motor innervations of CN7?
from pons through internal acoustic meatus
innervating lacrimal gland, stapedius, anterior 2/3 taste of tongue, submaxillary and sublingual glands
through tylomastiod foramen
innervating facial musculature
What sensory systems are located along the spinthalamic tract?
pain-temperature
light touch
What sensory systems include the medial lemniscus?
proprioception-stereognosis
light touch
What sensory systems include the fasciculus cuneatus and fasciculus gracilis?
proprioception-stereognosis
light touch
What is the structure of the optic nerve from the eye to the brain stem?
retina
fovea
optic nerve
optic chiasm
optic tract
lateral geniculate body
parietal lobe optic radiaton
temporal lobe optic radiation
calcarnie fissue
Where and what parts of the retina do the optic fibers innervate?
fibers temporal to fovea connect with brain ispilaterally
fibers nasal to fovea cross over at optic chiasm
What does the visual field look like from the cortex?
upside down and backwards same way in both eyes
What is optic reflex pathway of pupillary constriction to light?
direct pathway to the midbrain
optic nerve
optic tract
Edinger-Westphal nucleus
CN3
What is optic reflex pathway of accomodation?
optic nerve
optic tract
lateral geniculate body
optic radiation
visual cortex
lens focus and pupil constriction by parasympathetic components of CN3
What is the function of CN4?
pure GSE nerve that innervates the superior oblique muscle (depresses, intorts, and abducts the eye). Arises from contralateral trochlear nucleus of the midbrain. Decussates within the midbrain and exits the brainstem on its dorsal surface, caudal to the inferior colliculus. Encircles the midbrain in the subarachnoid space, passes through the lateral wall of the cavernous sinus, and enters the orbit via superior orbital fissure
What is the function of CN6
is a pure GSE nerve that innervates the lateral rectus muscle, which abducts the eye
arises from the abducent nucleus of the caudal pons; exits the brainstem from the inferior pontine sulcus
passes through the cavernous sinus and enters the orbit via the superior orbital fissure