BB anatomy Flashcards
Where does the middle meningeal artery enter the skull?
Foramen spinosum
Where does the middle meningeal artery branch from?
Maxillary artery
From external carotid
What makes up the nasal septum?
Ethmoid
Vomer
Nasal hyaline cartilage
What is found on the ventral surface of the brainstem?
Cerebral peduncles Pons Pyramids (where CST decussate) Olives All cranial nerves leaving the brainstem except for IV
What is found on the dorsal surface of the brainstem?
Superior colliculi (visual)
Inferior colliculi (auditory)
Trochlear nerve emerging at the midbrain-pons junction
Superior, middle and inferior cerebellar peduncles
Cuneate fasciculi laterally
Gracile fasciculi medially
Obex = 1/3 of the way up of the medulla where 4th ventricle begins
Blood supply to the dorsal brainstem
PCA
AICA
PICA
Blood supply to the ventral brainstem
Basilar
ASA
What does CN III innervate?
Extraocular muscles (except superior oblique and lateral rectus) Levator palpebrae superioris Ciliary muscle (parasympathetic) Sphincter pupillae (parasympathetic)
CN III lesion
Dilated pupil
Eye in down and out position
CN IV lesion
Double vision when looking down
2 major branches of V3
Lingual nerve
- supplies sensation to the anterior 2/3 of the tongue
- carries chorda tympani from facial nerve for taste sensation
Inferior alveolar nerve
- sensation to lower teeth
- enters mandible though mandibular foramen
- exits though mental foramen
Clinical significance of abducens damage
Long intradural course
Easily compressed when ICP is raised
CN VI lesion
Medial deviation on affected side
Loss of abduction
CN VII branches
Greater petrosal nerve –> lacrimal gland
Nerve to stapedius
Chorda tympani
Posterior belly of digastric and stylohyoid
Terminal branches
Terminal branches of CN VII
Temporal --> frontalis Zygomatic --> orbiculairs oculi Buccal --> buccinator, orbicularis oris Mandibular --> mentalis Cervical --> platysma
Bell’s palsy vs stroke
Bell’s palsy = complete unilateral paralysis
Stroke = forehead sparing
Tympanic branch of CN IX
Sensation to middle ear, tympanic membrane and Eustachain tube
Parasympathetic to parotid gland
What innervates the carotid sinus and body?
CN IX
Which muscle does CN IX supply?
Stylopharyngeus
Which tonsils does CN IX innervate?
Palatine via tonsillar nerve
What muscles are supplied by CN X?
Palate (except tensor veli palatini –> V3)
Pharynx (except stylopharyngeus –> CN IX)
Palatoglossus
Laryngeal muscles
What does the transverse fissure separate?
Occipital lobe
Cerebellum
What makes up the lentiform nucleus?
Putamen
Globus pallidus
What makes up the dorsal striatum
Caudate
Putamen
Superior cerebellar peduncle
Output from the cerebellum to the pons –> thalamus –> cortex
Middle cerebellar peduncle
Input to the cerebellum from the pons
About motor activities initiated by the cortex
Inferior cerebellar peduncle
Input to the cerebellum via the spinocerbellar tract from peripheral proprioceptors
Signs of cerebellar injury
DANISH Dysdiadochokinesia Ataxia Nystagmus Intention tremor Slurred speech Hypotonia
Thalamic nuceli
LGN = vision MGN = hearing VPL = touch, pain, pressure Anterior = memory VL = motor from BG and cerebellum VA = motor from BG
What does the epithalamus/pineal gland secrete?
Melatonin
Layers of the scalp
Skin = many sweat and sebaceous glands Connective tissue Aponeurosis = tendinous sheet Loose CT = allows movement of scalp Pericranium = dense CT that is the periosteum
T1 weighted
CSF and bone = black
Fat = white
Grey matter darker than white
T2 weighted
CSF and bone = white
Fat = black
White matter darker than grey
Which parts of the orbit are most commonly fractured?
Medial and inferior walls
Ethmoid and maxillary
Epidural haematoma
Impact to the head
Tearing a vessel running between skull and dura
Arterial bleed
Lucid interval then sudden unconsciousness
Convex shaped on scan
Subdural haematoma
Caused by an acceleration/deceleration incident
Tearing of bridging veins between dura and arachnoid
Gradual headache and confusion
Crescent shaped appearance on scan
Subarachnoid haemaorrhage
May be with small trauma or spontaneous rupture of an aneurysm
Blood within the subarachnoid space
Blood can be seen within the sulci and fissures on scan
Thundercap headache, vomiting, confusion, loss of consciousness
Common sites of brain contusion
Inferior surface of frontal lobes
Lateral and inferior temporal lobes
Region adjacent to lateral fissures
Occipital poles
Symptoms of posterior parietal damage
Sensory neglect
Constructional apraxia
Symptoms of visual cortex lesion
Contralateral homonymous hemianopia
ACA stroke
Urinary incontinence
Behaviour changes
Lower body sensorineural loss
PCA stroke
Contralateral homonymous hemianopia
Reading and writing deficits
Impaired memory
What is the anterior choroidal artery?
From the MCA
Supplies the hippocampus, amygdala and medial temporal lobe
Lateral medullary syndrome
Wallenburg syndrome PICA stroke Sudden onset Ipsilateral horner syndrome Vertigo Nystagmus Dysarthria (slurred speech) Dysphonia Loss of gag reflex
