Neuroanatomy Flashcards
how many cranial nerves are there?
12
how many spinal nerves are there?
31
what is the autonomic nervous system divided into?
sympathetic and parasympathetic
where do the sympathetic nerves stem from?
thoracic and lumbar segments
where do the parasympathetic nerves stem from?
cranial nerves and sacral segments
where is the primary motor cortex located?
pre-central gyrus
what is the basal ganglia made up of?
caudate, putamen, globus pallidus
what is located below the calcarine sulcus?
visual cortex
where are the peduncles?
midbrain
which peduncle communicates with the cerebellum and the pons?
middle cerebellar peduncle
which spinal tract goes through the pyramids?
corticospinal tract
what level does the spinal cord end?
L1/2
where do the lower motor neurones synapse?
ventral horn of the grey matter
which tract conveys pain and temperature?
spinothalamic
where is the somatosensory cortex located?
postcentral gyrus
where is the internal capsule?
runs between the basal ganglia
where does the spinal cord start?
just below the medulla
how many segments are there to the spine?
31
how many cervical nerves are there?
8 pairs
how many thoracic nerves are there?
12 pairs
how many lumbar nerves are there?
5 pairs
how many sacral nerves are there?
5 pairs
how many coccygeal nerves are there?
1 pair
which part of the grey matter is dorsal?
the thinner part
what is a dermatome?
area of skin supplied by a single spinal nerve
what is a myotome?
muscle supplied by a single spinal nerve
what is in the white matter?
tracts
what do the ascending tracts carry?
mainly sensory information from peripheries to CNS
what do the descending tracts carry?
mainly motor information from the CNS to peripheries
what is in the grey matter?
termination of afferents (dorsal horn) sensory Cell bodies of motor neurones Interneurons Autonomic neurons Central canal
what is the dorsal column pathway?
dorsal, touch (fine tough), proprioception, cuneate fasciculus (UL) and gracile fasciculus (LL)
what is the spinothalamic pathway?
ventrolateral, pain, temp, crude touch, cell bodies in DRG, projects to dorsal grey horn, Synapses with 2nd neurons in grey horn, decussates via ventral white commissure then ascend, ipsilateral to the correct its meaning and contralateral to the part of body it receiving info from
what is the corticospinal pathway?
lateral is crossed (85%), ventral is uncrossed, Decussation of fibres at the pyramids, motor, UMN axons through internal capsule. 85% decussate at pyramids (lateral), LMN in ventral grey horn
which cranial nerves come from the cerebrum?
1 and 2
what type of nerves are the cranial nerves?
peripheral
which cranial nerves contain parasympathetic fibres?
3,7,9 and 10
which CN gives sensation to the anterior 2/3 of the tongue?
trigeminal
which CN innervated lateral rectus?
abducens
which CN innervates the muscles of the tongue?
hypoglossal
which CN innvervates the muscles of the pharynx and larynx?
vagus
which CN controls the parasympathetic innervation of the sphincter pupils?
occulomotor
which CN gives taste to the posterior 1/3 of the tongue?
glossophryngeal
which CN innervated the muscles of mastication?
trigeminal
which CNs control the corneal reflex?
trigeminal and facial
which CN is affected in bell’s palsy?
facial
what is CN1?
olfactory, smell, receptors in nasal cavity, cribriform plate (fracture = anosmia), olfactory bulb, tracts, temporal lobe
what is CN2?
optic nerve, Crossing over of nasa fibres, primary visual cortex, calcarine sulcus, medial aspect opf occipital lobe, test = visual acuity, fields, fundoscopy, pupillary light reflex
what is CN3?
oculomotor
Pupillary light, eye movements (deviated laterally) , test LPS/ looks for ptosis
Motor and parasympathetic
what is CN4?
trochlear
Superior oblique
Isolated lesions uncommon
Paralysis = diplopia on looking down (tilting head)
what is CN6?
abducens
Lateral rectus
Medial deviation= paralysis
what is CN5?
trigeminal
Sensory and motor
Ophthalmic, maxillary, mandibular (muscles of mastication)
Corneal reflex
what is CN7?
facial
Sensory = taste to anterior ⅔ to tongue
Muscles of facial expression
how do you distinguish between bells palsy or a stroke?
(bell's palsy or stroke = weakness of all muscles or weakness of lower face, does the forehead still work?, upper controlled by both sides, lower is from the contralateral, UMN = weakness in only lower, LMN = weakness in all face muscles) Salivary glands (parasympathetic)
what is CN8?
vestibulocochlear
Test - balance and gait, caloric test, hearing
what is CN9?
glossopharyngeal
Afferent for gag reflex
Taste to posterior ⅓ of tongue
General sensation to pharynx and eustachian tube
what is CN10?
vagus
Sensation - external auditory meatus, tympanic membrane, pharynx, larynx, oesophagus
Motor - muscles of soft palate, pharynx and larynx, swallowing and speech
Para - thoracic and abdominal viscera
Test - gag reflex, reflex contraction and elevation of soft palate
what is CN11?
accessory
Muscles of sternocleidomastoid and trapezius
what is CN12?
hypoglossal
Motor of tongue, tongue deviates towards side of injured nerve
which artery supplies the lateral parts of the hemispheres?
middle cerebral
which artery supplies the occipital lobe?
posterior cerebral
where is the circle of willis located?
in the subarachnoid space
which artery do the vertebral arteries stem from?
subclavian
where is the lower limb represented in the brain?
medial surface of the hemispheres
where is the middle meningeal artery located?
the extradural space
where is the majority of CFS absorbed into?
the superior sagittal sinus
which kind of bleed in most likely to arise from trauma?
extradural bleed
which kind of bleed is most likely to be spontaneous?
subarachnoid
which kind of bleed will be described as ‘sudden onset worst headache ever’?
subarachnoid
where would there be expansion upon occulsion of the cerebral aqueduct?
3rd ventricle and lateral ventricles
what are the 3 meninges?
dura, arachnoid and pia
what is the dura layer?
though and fibrous, 2 layers, periosteum = outer layer adhered to skull, meningeal = inner layer, folds into cranium, layers diverse = dural venous sinuses
what is the arachnoid layer?
soft, thin, loose, villi project into venous sinuses to return CFS, granulation with age
what is the pia layer?
thin cant be seen , blood vessels have pia on, blood brain barrier
what is the extradural space?
between skull and outer dura layer, (only in some spaces, potential space, meningeal vessels, e,g, middle meningeal)
what is the subdural space?
between the inner dura layer and the arachnoid, (potential space, not everywhere, bridging veins crossover)
what is the subarachnoid space?
above pia, ventricular system continuous, CSF, circle of willis and branches
what is a lumbar puncture used for?
CSF sampling - infection and subarachnoid haemorrhage
when should you not do a lumbar puncture?
In patients with raised intracranial pressure and focal neurology
where is a lumbar puncture done?
BELOW L2 (L3,4,5)
what makes up the anterior circulation of the brain?
Left and right internal carotid -(carotid canal)
what makes up the posterior circulation of the brain?
Left and right vertebral arteries -(foramen magnum)
what branches off the internal carotid artery?
anterior and middle cerebral arteries
what branches from the vertebrobasiliar system?
posterior cerebral, cerebellar vessels, supplies brainstem
what is brocas area?
motor speech, supplies by middle cerebral
what is wernicke area?
speech comprehension, supplied by middle cerebral
occlusion of which vessel would induce lower limb weakness?
anterior cerebral artery
occlusion of which vessel would induce upper limb weakness?
middle cerebral artery
what is the blood supply to the deep brain structures?
perforating arteries
what is the blood supply the the brain stem?
perforating arteries from the posterior cerebral artery
what is the blood supply to the spinal cord?
1 anterior spinal artery and 2 posterior
