Neuroanatomy Flashcards
CNS
Brain and spinal cord
Grey matter
Neurones and processes
How is the cortex folded
Into gyri and sulci
White matter
Myelinated axons
3 large fibre tracts
Association fibres
Commissural fibres
Projection fibres
Association fibres
Remain within one hemisphere
Commissural fibres
2 sets
Cross between the 2 hemispheres
2 sets of Commissural fibres
Anterior commisure
Corpus callosum
Projection fibres
Move up and down brain (brain <—> brain stem)
Internal capsules
4 main lobes of cerebrum
Frontal
Parietal
Temporal
Occipital
Functions of the Insula
Disgust, emotion, homeostasis, perception, motor control, self-awareness, cognitive functioning and interpersonal experience
Damage to the cerebellum causes
Damage causes dysdiadokokinesia, ataxia, nystagmus of eyes, intention tremor, slurring of speech, heel-shin test positive (DANISH)
4 key elements of blood brain barrier
Endothelial cell tight junctions
Lack of basement membrane fenestrations
Astrocytes end feet
Pericytes
2 blood supplies of the brain
Internal carotid arteries
Vertebral arteries
Anterior circulation is supplied by
Internal carotid artery
Posterior circulation is supplied by
Vertebral arteries
What are the branches off the basilar artery called
Pontine arteries
Most common territory to be affected by a stroke
Middle cerebral artery- break off atherosclerosis from bifurcation of common carotid
Why is the circle of Willis useful
Collateral blood supply- still perfuse tissues if one artery blocked via other arteries
Hypertension and pons
Pontine arteries are particularly susceptible to damage as supplied by high pressure basilar artery
Susceptible to haemorrhaging
Posterior cerebral artery supplies
Occipital lobe
Middle cerebral artery supplies
Lateral parts of frontal lobe, parietal lobe and temporal lobes
Anterior cerebral artery supplies
Medial and superior part of frontal and parietal lobe
Watershed regions
Areas of the brain particularly susceptible to cell death/ hypoxic ischaemia as furtherest away from arteries supplying brain
Which sinus connects the dural sinuses to the internal jugular vein
Sigmoid sinus
Ventricular system
Lateral ventricles
Interventricular Foramen
3rd ventricle
Cerebral aqueduct
4th ventricle
3 pathways of CSF drainage from 4th ventricle
Median aperture of magendie
Lateral apertures of luschka
Central canal
Which cells line the ventricles
Ependymal cells
Ependymal cells
Line ventricles
Cilia
Choroid plexus
Site of CSF production
Interstitial fluid drainage
CSF via perivascukar channels
How is CSF reabsorbed
Arachnoid granulations
Peripheral nerves to lymphatics
Nasal mucosa lymphatics deep cervical lymph nodes
Anterior brainstem- olives
Communicate with the cerebellum
Anterior brainstem- decussation of pyramids
Swapping of axonal fibres
Medulla include
Olive
Pyramid
What divides the medulla and pons
Bulbopontine sulcus
Peduncles
White matter fibres
What attaches pons to cerebellum
Middle cerebellar peduncles
Crus cerebri
Connects midbrain to cerebrum
Cerebral peduncles
Rhomboid fossa
Floor of 4th ventricle
Dorsal columns
Vibration sense
Joint position sense- regulate movement
Division of dorsal columns
Fasciculus cuneatus
Fasciculus gracilis
Fasciculus gracilis
Carry nerve fibres from legs
Fasciculus cuneatus
Nerve fibres from the arms
Superior colliculus
Visual sensory area
Inferior colliculus
Auditory nucleus
What carries information from the midbrain to thalamus
Superior and inferior brachium
How is the midbrain divided
Tectum
Tegmentum
What divides the tectum and tegmentum of midbrain
Cerebral aqueduct
Substantia nigra function
Generating dopamine
Initiating movement- damaged in Parkinson’s
Neuromelanin in substantia nigra
By-product of producing dopamine
Stains reddish-brown colour
Pyramids
Carry movement information through medulla
Inferior olivary nuclei
Main input to cerebellum
Found in rostral medulla
What causes the pons to bulge
Pontocerebellar fibres
Folia
Folds in cerebellum
Fissures
Gaps in cerebellum
Fissures in cerebellum
Primary fissure
horizontal fissure
Main nucleus in cerebellum
Dentate nucleus
3 parts of cerebellum
Archicerebellum- floculonodular lobe
Paleocerebellum- vermis
Neocerebellum- cerebellar hemispheres
Floculonodular lobe
Balance
Connected to vestibular nuclei and reticular nuclei
Paleocerbellum - vermis
Muscle tone and posture
Afferent: dorsal spinocerebellar tracts via inf cerebellar peduncle and ventral SC tract via superior CP
Efferent: Globose and emboliform nuclei to red nucleus to rubrospinal tract
Neocerebellum- cerebellar hemispheres
more fancy movements, coordination, muscle tone
Afferent: Cerebral cortex to pontocerebellar fibres (decussate) via MCP
Efferent: Purks to dentate to red nucleus & ventral thalamus via SCP
Cerebellar granule cells
Form 90% of cerebellar cortex
Send axons into folium
Cerebellar purkinje cells
Send dendrites into folium
Output from granule cells goes to
Cerebellar nuclei - mostly Dentate nucleus
Formix
Output pathway of hippocampus
Synapses at mammillary bodies