Anatomy 2 Flashcards
what are the dimples in you back landmarks of
posterior superior iliac spines
what is the first palpable spinous process
t1
70% have C7 palpable
what are the extrinsic back muscles
attach the back to the pectoral girdle
- levator scapulae
- rhomboids
- trapezius
- latissimus dorsi
what mainly innervates the external back muscles
anterior rami of the cervical nerves
what innervates the trapezius
accessory nerve
what are the intrinsic back muscles
(maintain posture and move spine) erector spinae (superficial) transversospinalis (deep)
where are transversospinalis found
between the transverse and spinous processes
attach between vertebrae and: rib, skull, another vertebra or the sacrum
what is the main role of transversospinalis
stability and rotation of the vertebrae
what is the nerve supply of the intrinsic back muscles
segmental - posterior rami branches (cervical, thoracic and lumbar)
what happens when the erector spinae contracts unilaterally
lateral flexion
what are the curvatures of the vertebral column
cervical lordosis
thoracic kyphosis
lumbar lordosis
sacral kyphosis
where in vertebra is the spinal cord
vertebral foramen
what is a facet joint
articular processes of adjacent vertebrae
what vertebrae is there no intervertebral discs between
C1-2
fused sacrum/ coccyx
what makes up the intervertaebral discs
outer fibrous ring- annulus fibrosus
inner doft pulp- nucleus pulposus
what is the ligamentum flavum
connects adjacent laminae posterior to the spinal cord
what is the posterior longitudinal ligament
narrow, weak, prevents overflexion
what does the anterior longitudinal ligament do
strong, broad, prevents over extension of the spine
which way are vertebral disc more likely to herniate
posteriorly as posterior longitudinal ligament weaker than anterior
what does the supraspinous ligament do
connects TIPS of spinous processes
strong
what does the interspinous ligament do
connects superior and inferior surfaces of adjacent spinous processes
weak
what goes through the transverse foramen
vertebral arteries (off subclavian)
which vertebrae have bifid spinal processes
cervical
describe the anatomy of C1 (atlas)
does not have a body or spinous process (post and ant arch instead)
which vertebrae has an ondontoid process
C2- axis
what movement at the atlanto-occipital joint
flexion and extension of neck
a little lateral flexion and rotation
what joint type is atlanto axial
synovial
what movement at the atlanto-axial joint
rotation mainly
where does the spinal cord start and finish
foramen magnum (continuous with medulla oblongata) ends vertebral level (L1/2) at conus medullaris
what is the cauda equina
spinal nerve roots from L2 to Co1 that descend to the numbered vertebrae
where is the epidural space
outside the dura in the spinal chord
where is anaesthesia injected in caudal anaesthesia
sacral hiatus
where is epidural anaesthesia inserted
subarachnoid space surrounding cauda equina where vertebrae arent fused (l3/4 interface)
where does the subarachnoid space end
L2
when do you not perform a lumbar puncture
when there is raised ICP
what does the needle go through in an epidural
supraspinous ligament
interspinous ligament
ligamentum flavum
epidural space (fat and veins)
what does the needle go through in a lumbar puncture
supraspinous ligament interspinous ligament ligamentum flavum epidural space (fat and veins) dura mater arachnoid mater (reaches subarachnoid space)
what is a laminectomy
removal or one or more spinous processes and the adjacent lamina
used to access spinal cord/ spinal roots or to relieve spinal cord or nerve roots (tumour, herniated disc, bone hypertrophy)
as spinal nerves pass through the intervertebral foramina why is the posterior root enlarged
by the dorsal (posterior) root ganglion
what is the conus medullaris
where the spinal cord terminates
why is the posterior root enlarged as it leaves the intervetebral foramina
enlarged by dorsal root ganglion
what suspends the spinal cord in the canal
denticulate ligament
what is in the white matter of the spinal cord
axons, glial cells, blood vessels
what is in the grey matter of the spinal cord
soma, cell processes, synapses, glia and blood vessels
what is the lateral horn
at levels T1-L2 there is a smaller horn which contains the preganglionic sympathetic neurones
what is the blood supply of the spinal cord
3 longitudinal arteries (1 ant 2 post) that original from vertebral arteries segmental arteries radial arteries (travel along roots)
venous has longitudinal and segmental vessels also in epidural space
the right side of the cortex represents which side of the body
left
where is the primary somatosensory cortex
post central gyrus (poSt = Sensory)
describe the dorsal column/ medial lemniscus
ascending tract for fine touch and proprioception
enter dorsal column
sypanse in medulla @ nucleus gracillus- where it crosses to midline
goes to thalamus
the PostCG
describe the spinothalamic tract
ascending tract for pain, temp and deep pressure
synapse immediately in posterior horn and ascended on CONTRAlateral side
synapses in thalamus
PostCG
fibres cross Segmentally= Switch Sides Straight away as they enter cord= Spinothalamic
what is the primary motor cortex
pre central gyrus
describe the corticospinal tract
descending tract for fine precise movement (esp digits)
cortex PreCG
85% of fibres cross at the decussation of the pyramids in the medulla (forming the lateral CST)
other 15% form ventral CST which cross segmentally (at level they leave cord)
what are pyramidal tracts
corticospinal tract forms these on the anterior surface of the medulla- 85% of fibres cross here in medulla
what is the internal capsule
white matter strip where lots of sensory information (e.g. CST) travels through)
what happens if there is a CVS in the internal capsule
lack of descending control of the corticospinal tract which results in a spastic paralysis with hyperflexion of the upper limbs = decorticate posturing.
describe the tecto spinal tract
begins in tectum (post. mid brain)
dorsal tegmental decussation
mediates head and neck reflec to visual stimuli
decsribe the reticulospinal tract
Network of nuclei in the brainstem that control breathing, cardiac
describe the vestibulospinal tract
Fibres originate in the vestibular nuclei of pons and medulla
project down cord ipsilaterally
excite anti gravity extensor muscles
in general what motor influence do fibres from the pons and medulla do
Fibres originating in pons facilitate extensor movements and inhibit flexor movements, while those originating in the medulla do the opposite
when do you get decerebrate regidity and paraplegia in extension
Lesions of the brainstem at the level of the midbrain can result in a lack of descending cortical control of the vestibulosponal tract. This leads to domination of extensor muscle tone and hyperextended spastic paralysis.
how would a lateral hemisection of the cors (brown sequard) affect:
motor
reflexes
sensation
motor- ipsilateral paralysis (CST crosses (85%) at medulla)
reflexes- ipsilateral
sensation:
- ipsilateral loss vibration and proprioception (MLS crosses at medulla)
- contralateral loss pof pain and temp (STT crosses segmentally)
how are the cranial nerves numbered
form anterior to posterior and medial to lateral on where they connect with CNS
what is in the optic canal
optic nerve and ophthalmic artery
what is the path of CN I
olfactory mucosa cribiform plate of ethmoid anterior cranial fossa olfactor bulb (synapse) olfactory tract cortical areas
what is the path of CN II
retina optic nerve optic canal (middle cranial fossa) around pituitary stalk optic chiasm forms optic tract diencephalon
how do you test CN I
smell a familiar smell while covering the contralateral nostril
how do you test CN II
acuity (snellens) colour (ishihara) fields relfexes (pupillary light) fundoscopy
what is the path of CN III
midbrain (mesencephalon) lateral wall of cavernous sinus superior orbital fissure orbit (parasympathetics (pupil constriction) synapse in cilliary ganglion)
how do you test CN III parasympathetics
pupillary constriction
what is the path if CN IV
midbrain (mesencephalon) (exits via dorsal surface) lateral wall of the cavernous sinus superior orbital fissure orbit (superior oblique)
what is the path of CN VI
pontomedullary junction within cavernous sinus superior orbital fissure orbit (lateral rectus muscle)
what is in the cavernous sinus
internal carotid artery
CN III, IV, V (V1 and V2) and VI
how do you test the SO
look down and IN
how do you test IO
look up and in
how do you test superior and inferior rectus
SR up and out
IR down and out
what is the path of CN VIII
axons from cochlear and vestibular apparatus
internal accoustic meatus (post cranial fossa)
travels posteromedially to the pontomedullary junction
how do you test CN VIII
rinne and weber tests
what is the function of CN XI
motor to sternocleidomastoid and trapezius
what is the path of CN XI
cervical spinal cord ascends through foramen magnum jugular foramen in post cranial fossa SCM (deep surface) posterior triangle trapezius and SCM
how do you test CN XI
shrug shoulders
flex neck and tern to opposite side
what is the path of CN XII
rootlets lateral to the pyramids of the medulla oblongata
hypoglossal canal (posterior cranial fossa)
descends lateral to carotid sheath
at hyoid turns anteriorly towards tongue
what does CN XII innervate
all the nerves ending in glossus except palatoglossus (vagus)
how do you test CN XII
Ask patient to stick tongue straight out
If both CNXII’s are functioning normally the tongue tip remains in the midline on protrusion
If there is unilateral CN XII pathology the tongue tip will point towards the side of the injured nerve
what are the modalities of CN V
V1 sensory
V2 sensory
V3 sensory and motor
what is the path of CN V
pos inferior to tentorium cerebelli cranial foramina: -V1 SOF -V2 foramen rotundum -V3 foramen ovale
what does CN V1 supply
- The upper eyelid
- The cornea (corneal reflex)
- All the conjunctiva
- Skin of the root/bridge/tip of the nose
deep sensory:
Bones & soft tissues of the orbit (except the orbital floor & lower eyelid)
Upper anterior nasal cavity
Paranasal sinuses (except the maxillary sinus)
Anterior & posterior cranial fossae
what does CN V2 supply
- The skin of the lower eyelid
- The skin over the maxilla
- The skin of the ala of the nose
- The skin/mucosa of the upper lip
deep sensory: Lower posterior nasal cavity Maxilla & maxillary sinus Floor of the nasal cavity/palate Maxillary teeth & associated soft tissues (gingivae & mucosae)
what does CN V3 supply
- Skin over the mandible and temporomandibular joint
(apart from the angle of the mandible – supplied by C2,3 spinal nerves)
deep sensory: Middle cranial fossa Mandible Anterior 2/3rds of the tongue Floor of the mouth Buccal mucosa Mandibular teeth & associated soft tissues
what is the great auricular nerve and what does it do
(C2,3) – a sensory branch of the cervical plexus
Supplies: - The skin over the angle of the mandible & some of the external ear
what motor action does CN V3 have
jaw closing- masseter, temporalis, medial pterygoid
jaw opening- lateral pterygoid
tensor veli palatini
tensor tympani
how do you test CN V
sensory
Ask the patient to close their eyes
Gently brush the skin in each dermatome with a fine tip of cotton wool
Ask the patient to tell you when they feel their skin being touched
Compare the 2 sides
motor
Palpate the strength of contraction of the masseter & temporalis by asking patient to clench their teeth
Ask the patient to open their jaw against resistance
what is the path of CN VII
pontomedullary junction
internal acoustic meatus (into petrous part of temporal bone)
stylomastoid foramen
parotid gland/ muscles of facial expression
what does the chorda tympani do
Taste buds of the anterior 2/3rds of the tongue
Parasympathetic supply to the submandibular & sublingual glands (salivation).
(branch of CN VII)
what supplies the stapedius
CN VII
what does stapedius do
Reduces stapes movement to protect the internal ear from excessive noise
what does CN VII do
sensory, motor, parasymp
motor- muscles of facial expression, stapedius
sensory- taste ant 2/3rds of tongue (c. tympani)
para- sublingual, submandibular, lacrimal and mucous glands
how do you test CN VII
raise eyebrows- frontalis
close eyes tightly- orbicularis oculi
smile- elevators of lips
puff out cheeks and hold air- orbicularis oris
what is the path of CN IX
medulla oblongata
jugular foramen
descends towards pharynx and mouth
To the : stylopharyngeus muscle parotid gland pharyngeal mucosa carotid body and sinus posterior 1/3rd of tongue
what does CN IX do
General sensory to:
The posterior 1/3rd of the tongue
The mucosa of most of the nasopharynx and oropharynx
The mucosa of some of the laryngopharynx (some overlap with CN X territory)
The palatine tonsil
The eustachian tube
The middle ear cavity
Special sensory to:
The vallate papillae (with taste buds) of the posterior 1/3rd of the tongue
Visceral afferent to the carotid sinus baroreceptors & the carotid body chemoreceptors
Somatic motor
(Stylopharyngeus)
Parasympathetic (secretomotor) to the parotid gland (salivary)
how can you test CN IX
gag reflex
what is the path of the vagus nerve
lateral aspect of medulla oblongata
jugular foramen
supplies between palate and midgut
-runs within carotid sheath
-posterior to and between the common carotid artery and IJV
-gives of recurrent laryngeal branch
-right CN X lies on trachea
-left CN X lies on aortic arch
-both pass posterior to lung root and onto oesophagus
-pass through diaphragm with oesophagus at T10
both pass onto surface of stomach
branches pass to celiac and superior mesenteric ganglia follows GI arteries
what is the path of the two recurrent laryngeal nerves
Left recurrent laryngeal nerve curves under arch of the aorta
Right recurrent laryngeal curves under the right subclavian artery
how do you test CN X
Ask patient to say ‘ahhhhh’ – also tests CNV3
(MUSCLES OF PALATE)
Motor function
Uvula should lift straight up in midline
Unilateral pathology will pull uvula away from the non-functioning side
swallow water
listen to speech
what are the five layers of the scalp
SCALP s= skin C= connective tissue (contains arteries) A= aponeurosis L= loose connective tissue P= pericranium (periosteum of the skull)
what do skull sutures do in skull fractures
help prevent fractures spreading
what bones make up the pterion
frontal, parietal, temporal, sphenoid
what artery courses over the deep aspect of the pterion
the middle meningeal artery
what is meningitis
inflammation (usually bacterial or viral infection) of the meninges
what supplies the sensory innervation to the dura mater
CN V
what meninges enlcoses the dural venous sinuses
dura mater
what is the diaphragm sellae
sheet of dura mater that forms a roof over the pituitary fossa
what is the tentorium cerebelli
sheet of dura mater that tents over the cerebellum
attaches to the ridges of the petrous temporal bones
has a central gap to allow the brainstem to pass through
what is the falx cerebri
dura mater midline structure that attaches to deep aspect of skull:
- from crista galli of the ethmoid bone anteriorly
- internal aspect of the sagittal suture
- to internal occipital protuberance posteriorly
it separates the left and right cerebral hemispheres
blends with tentorium cerebelli
what do cerebral veins do
drain venous blood from the brain into the dural venous sinuses
where is the confluence of dural venous sinuses
midline at internal occipital protuberance
what lines dural venous sinuses
endothelium
what is the danger triangle
are if face where there is connection between superficial facial veins and deep facial veins - infection here can spread backwards to cranium
what foramen does the vertebral artery go through
transverse foraminae in vertebrae then foramen mangum
how does the internal carotid enter the cranial cavity
cranial canal
what does the external carotid supply
neck face and scalp
what does the right anterior cerebral artery supply
medial aspect of the right cerebral hemisphere
what links the anterior cerebral arteries
anterior communicating artery
what does the left middle cerebral artery supply
lateral aspect of the left cerebral hemisphere
what does the right posterior cerebral artery supply
posterior aspect of the right cerebral hemisphere including the visual cortex
what links the posterior cerebral arteries to the middle cerebral arteries
posterior communicating arteries
where is the circle of willis
in subarachnoid space
inferior to midbrain- close to pituitary stalk and optic chiasm
how much CSF is made each day and where
400-500mls
choroid plexus of the ventricles
reabsorbed via arachnoid granulations
what level does the subarachnoid space end
S2
where is the 3rd venticle
midline within the diencephalon
where is the 4th ventricle
between the cerebellum and pons
how does the CSF get from the lateral ventricles to the 3rd ventricle
foraminae of munro
where is CSF in the spinal cord
in subarachnoid space around it ans in central canal
what is hydrocephalus
when excessive production, obstruction to flow or inadequate reabsorption causes increased CSF volume
what is a ventricular peritonieal shunt
when a shunt catheter is tunnelled beneath the skin of the neck and chest and then sited within the peritoneal cavity to help hydrocephalus
where do cerebral arteries go between
brain to dural sinuses
where are the middle meningeal arteries
between bone and dura
what is an extradural haemorrhage
bleed between brain ans dura (middle meningeal artery- trauma to pterion)
what is a subdural haemorrhage
a bleed separates the dura from the arachnoid (cerebral veins- falls in the elderly)
what is a subarachnoid haemorrhage
bleed in to the csf of the subarachnoid space (ruptured circle of willis ‘berry aneurysm’- congenital)
what is an uncal herniation
the uncus (medial part) of the temporal lobe herniates inferior to the tentorium cerebelli
describe an infratentorial herniation
can be upward, downward or tonsillar:
-the cerebellar tonsils herniate into the foramen magnum
what does compression of the oculomotor nerve by an uncal herniation cause
ipsilateral fixed dilated pupil (blown pupil)
what is the basic function of the cerebellum and basal ganglia
adjust and coordinate movement
what is the flocculonodular lobe
ear like lobe on the cerbellum
how is the cerebellum attached to the brainstem
via 3 penduncles- middle, superior and inferior- made of white matter
what is the vermis
centre of the cerebellum
how does the cerebellum talk to the brainstem and thalamus
via deep cerebellar nuclei (deep grey matter)
what are the three layers of the cerebellum
outer- molecular (lots of neurones)
middle- purkinje (output cells- talks to brainstem)
inner- granular (>50% of neurones)
what are the afferet projections to the cerebellum (inputs)
spinal cord (from somatic proprioceptors and pressure receptors) cerebral cortex (relayed via the pons) vetsibular apparatus (via vestibular nuclei)
all enter via cerebellar peduncles and project mainly to granular layer
what are the efferent projections of the cerebellum (outputs)
(only output is via axons of purkinje cells which synapse at deep cerebellar nuclei and contribute to coordinating the functions of all the motor tracts of brain stem and spinal cord)
- corticospinal
- vestibulospinal
- rubrospinal
where do most efferent axons of the deep cerebellar nuclei cross the midline and synapse
in the thalamus- which in turns send fibres to the motor cortex
what side if the body do the cerebral hemispheres influence
ipsilateral (lesions will have ipsilateral affects)
what will a unilateral hemispheric lesion cause
intention tremor, unsteady gait
NO weakness or sensory loss
what does bilateral cerebellar dysfunction cause
slowed, slurred speech (dysarthia)
bilateral incoordination of arms
staggering, wide based gait (cerebellar ataxia)
how does alcohol affect the cerebellar
causes bilateral cerebellar hemisphere dysfunction
what will a midline lesion in the cerebellum cause
disturbance of postural control
what does the vermis control
automonic information
what are the functions of the basal ganglia
facilitate purposeful movement
inhibit unwanted movement
role in posture and muscle tone
what are the 5 basal ganglia
- caudate nucleus
- putamen
- globus pallidus
- subthalamic nucleus
- substantia nigra
1+2 = striatum 1+2+3 = corpus striatum 2+3 = lenticular nucleus
what are basal ganglia
a number of small masses of grey matter located near the base of each cerebral hemisphere
what is the direct pathway of the basal ganglia
Enhances outflow of thalamus, enhancing the desired movement
what is the indirect pathway of the basal ganglia
inhibits outflow of thalamus
prevents movement you don’t want
what side of body to basal ganglia lesoins affect
in contrast to cerebellar lesions affect the contralateral side of the body
what DONT lesions of the basal ganglia cause
paralysis
sensory loss
loss of power
ataxia
what DO basal ganglia lesions cause
changes in muscle tone
dyskinesias (abnormal involuntary movements):
-temor (sinusoidal movements)
-chorea (rapid, asymmetrical movements, usually distal limb)
-myoclonus (muscle jerks)
where is the pathology in parkinsons
generation of dopaminergic neurones of the substatia nigra (direct pathway affected)
what are the signs of parkinsons
akineasia, rigidity and resting tremor
where is the pathology in huntingtons disease
autosomal dominant disorder causes progressive degeneration of the basal ganglia and cerebral cortex (indirect pathway affected- no inhibition of movement)
what are the signs of huntingtons
chorea and progressive dementia
list the modality, central connection and function of CN I
sensory
olfactory bulb (only CN to not synapse in thalamus before going to cortex)
innervates olfactory epithelium- olfaction
list the modality, central connection and function of CN II
sensory
cc=lateral geniculate nucleus, prectal nucleus
f= vision (innervates retina), pupillary light reflex
list the modality, central connection and function of CN III
motor and parasympathetics
motor
CC=oculomotor nucleus
f= eye movements (sup., inf,. medial rectus, inf. oblique), elevate eyelid (LPS)
para
cc=EWN
f= pupillary constriction and accommodation (innervates sphincter pupillae + cilliary muscle via ciliary ganglion)
list the modality, central connection and function of CN IV
motor
cc-trochlear nucleus
f- moves up (SO- down and out)
(only CN to exit posteriorly)
list the modality, central connection and function of CN V
sensory and motor
sensory
cc- trigeminal sensory nucleus
f- somatosensation (discriminative touch, vibration, pain, temp of face, scalp, cornea, nasal and oral cavities and cranial dural mater) via pontine trigeminal nucleus
proprioception of chewing via mesencephalic nucleus
motor
cc- trigeminal motor nucleus
f- opening and closing mouth (muscles of mastication)
tensor tympani
list the modality, central connection and function of CN VI
motor
cc- abducens nucleus
f- move eye (LR)
list the modality, central connection and function of CN list the modality, central connection and function of CN
sensory, motor, parasympathetics
sensory
cc- nucleus solitarius
f- taste of ant 2/3rds of tongue (via c. tympani)
motor
cc- facial nucleus
f- facial expression muscles, tenses stapedius
para
cc- superior salivatory nucleus
f- salivation and lacrimation (via submandibular and pterygopalatine ganglia)
list the modality, central connection and function of CN list the modality, central connection and function of CN
sensory
cc- vestibular nuclei, cochlear nuclei
f- vestibular sensation and hearing
list the modality, central connection and function of CN IX
sensory, motor and para
sensory (2)
1. f- general sensation for pharynx, posterior 1/3rd of tongue, eustachian tube, middle ear
cc- trigeminal sensory nucleus
- f- taste to post 1/3rd of tongue (chemo and baroreception)
cc- nucleus solitarus
motor
cc- nucleus ambiguus
f- stylopharyngeus muslces (swallowing)
para
cc- inferior salivatory nucleus
f- salivation (parotid gland via otic ganglion)
list the modality, central connection and function of CN X
sensory motor and para
sensory (2)
1. general sensation for pharynx, larynx, trachea, oesophagus, external ear
cc- trigeminal sensory nucleus
- visceral sensation, chemo and baro reception for thoracic and abdominal viscera, aortic bodies and aortic arch
cc- nucleus solitarius
motor
cc- nucleus ambiguis
f- speech and swallowing (soft palate, pharynx, larynx, upper oesophagus)
para
f- innervation of cardiac muscle, smooth muscle and glands or cardiovascular system, resp and GI tracts (thoracic and abdo viscera)
cc- dorsal motor nucleus of vagus
list the modality, central connection and function of CN XI
motor
cc- cervical spinal cord
f- SCM and trapezius- movement of head and shoulder
list the modality, central connection and function of CN XII
motor
cc- hypoglossal nucleus
f- intrinsic and extrinsic muscles of the tongue (expect palato)
what CN dont exit brainstem anteriorly
IV (posterioly) and VIII (laterally)
what is the motor input to CNs
corticobulbar tract (part of pyramidal tract)
what is the parasymp input into CNs 1973
hypothalamus
what are the functions of the reticular formation
Integrate cranial nerve reflexes.
Participate in conduction and modulation of pain.
Influence voluntary movement.
Regulate autonomic activity.
Integrate some basic functions, like respiration and sleep.
Activate the cerebral cortex
what CN in myelinated
CN II (optic)
where are the nuclei of the motor CNs
midline of the brainstem
what CNs share the solitary nucleus
VII, IX, X
taste and visceral sensory information
what CNs share the superior and inferior salivatory nucleus
CN VII and IX
parasymp to ganglia of salivary glands and pterygopalatine ganglion
what CNs share the nucleus ambiguus
CN IX and X
motor efferents to muscles of pharynx, larynx and upper oesophagus
where is the solitary nucleus
extends in a V shape from upper to lower medulla
where is the nucleus ambiguus
lower pons/ upper medulla
what is the auditory pathway
- cochlear nerve (spiral ganglion- carries APs from organ of corti to cochlear nuclei in pons)
- internal accoustic meatus
- pontomedullary junction (bilateral now)
- ventral and dorsal cochlear nuclei
- olivary nucleus (1st synapse- not all synapse here tho for localisation)
- inferior colliculus (all synapse here)
- medial geniculate body in thalamus
- primary auditory cortex
why are the suprior olivary and lateral lemniscus nuclei important in the auditory pathway
for locaisation and relays for stapedius and tensor tympani reflexes
where is the auditory cortex
temporal superior gyrus
what is the vestibular pathway
vestibular nerve vestibular ganglion vestibular nuclei thalamus cerebral cortex (no primary cortex area) medial longitudinal fasciculus to CN 3,4,6 6. cerebellum 7. spinal cord via vestibulospinal tract
what is the medial longitunidal fasciculus
white matter tract that allows vestibular nuclei to coordinate eye movements
carries both ascending and descending tracts
what is tonotopic organisation in the auditory cortec
Fibres carrying information regarding low frequency sound end in the anterolateral part of the auditory cortex
Fibres carrying information regarding high frequency sound end in the posteromedial part of the auditory cortex.
what is aphasia
inability to use language
what happens if there is damage to brocas area
difficulty in producing language
what happens if there is damage to wernickes area
difficulty comprehending language
what is the optic pathway
optic nerve chiasm optic tract lateral geniculate nucleus (+superior colliculi) optic radiation (meyers loop) visual cortex
what part of visual cortex does the lower visual field go to
gyrus superior to the calcarine sulcus
what part of visual cortex does the upper visual field go to
gyrus inferior to the calcarine sulcus
which visual field goes around meyers loop
upper
what part of vision responds to visual stimuli (tracking)
visual cortex
what part of vision does movements of command (saccadic)
frontal eye fields
what is affected in internuclear ophthalmoplegia
medial longitudinal fasciculus
what are the steps of the pupillary light reflex
- light shone in eye
- APs reach pretectal nuclei (both sides)
- edinger-westphal nucleus
- oculomotor nerves
- ciliary ganglion
- pupil constriction (pupillary sphincter)
why is the accomoationd reflex different from the pupillary light refelx
as accomodation needs input to EWN and occulomotor nucleus from the visual cortex not just direct pathway
what are the steps of the accomodation reflex
optic nerve lateral geniculate nucleus visual cortex pretectal area EWN occulomotor nerve muscles of accomodation (medial rectus, cilliary muscle, sphincter pupillae)
for most right handed people where in the brain is dominant for language
left hemisphere
what are association fibres
connect cortical sites lying in the same hemisphere
what are commisural fibres
connext one hemisphere to the other, usually connecting areas with similar function
what are projection fibres
connect hemispheres to deeper structures including thalamus, corpus striatum, brain stem and spinal cord
