AIgen checklist

Nervous System – Concept Checklist

Self-study checklist of concepts touched on across the module lectures. Grouped by lecture in chronological order. Tick each once you can explain it from memory.

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1. Physiology Introduction (Bevin, 16 Feb)

• Nervous system as a communication and control system (sensing, integration, homeostasis, reflex/voluntary action)
• CNS vs PNS organisation
• Grey matter vs white matter; tracts
• Neuron structure: soma, dendrites, axon, synapses
• Nissl substance (RER/ribosomes) and protein synthesis
• Diversity of neuron size and form
• Synapses and neurotransmitter release
• Glial cells: roles in support, protection, structure
• Metabolic demand of the brain (~20% of metabolism)
• Meninges – the 3 protective layers
• CSF and the subarachnoid space (overview)
• Overview of the 12 cranial nerves and their basic functions
• Levels of organisation: neuronal, regional, system

2. Neuroanatomy 1–2 (Liu, 17 Feb) L2 Nervous System Neuroanatomy 1 & 2

• Cranium (8 bones), vault and base
• Sutures
• Dural folds: falx cerebri, tentorium cerebelli (tentorial incisure)
• Hypophyseal fossa / pituitary
• Dural venous sinuses (sigmoid, etc.) – naming
• Ventricular system: lateral → 3rd → cerebral aqueduct → 4th
• CSF flow pathway and return to venous sinuses (arachnoid granulations)
• Corpus callosum, internal capsule, striatum/corpus striatum
• Cerebral arterial supply: ACA, MCA, PCA
• Circle of Willis (ICA, PCA, communicating arteries)
• Anatomical views: lateral, anterior, midsagittal

3. Neuroanatomy 3–4 (Liu, 18–20 Feb) L4 Nervous System Neuroanatomy 3 & 4

• Cerebral cortex lobes: frontal, parietal, temporal, occipital
• Functional areas of the cortex (primary motor, sensory, auditory, visual)
• Visual association area
• Dominant vs non-dominant hemisphere
• Language areas; aphasia; arcuate fasciculus
• Cerebellum: structure, deep nuclei, cortical inputs/outputs
• Vestibulocerebellum
• Cerebellar information flow (cortex → brainstem → spinal cord)
• Cerebrovascular accident (CVA/stroke) and arterial territories
• Conscious sensation pathways overview

4. Neuroanatomy 5 (Liu, 23 Feb) – Neurodegeneration

• Anatomy of memory / affected regions
• Alzheimer’s: Aβ (amyloid) toxin accumulation
• Braak & Braak staging
• Initial insult and self-propagating neurodegeneration
• Biomarkers
• Early detection / early diagnosis
• Prognosis and interventions

5. Neurons to Networks (Bevin, 23 Feb)

• Resting membrane potential and concentration gradients
• Differential ion permeability; K+ efflux
• Equilibrium of concentration and electrical gradients
• Graded (local) potentials – decremental spread
• Magnitude depends on stimulus strength
• Action potential generation and propagation along axons
• Axon initial segment / trigger zone
• Spatial summation; temporal summation
• Hyperpolarising vs depolarising inputs
• Chemical synaptic transmission
• Glia in network function
• Cortical regions and network organisation

6. Introduction to Cranial Nerves and their Nuclei (Reynolds, 23 Feb)

• The 12 cranial nerves – names and numbers
• Functional columns of cranial nerve nuclei
• Location of nuclei within the brainstem (midbrain, pons, medulla)
• Sensory vs motor vs parasympathetic components
• Relationship of nuclei to ventricular system

7. CNS Control of the ANS (Bevin, 25 Feb)

• Autonomic nervous system overview
• Sympathetic vs parasympathetic divisions
• CNS centres controlling autonomic output
• Micturition reflex and control
• Continence
• Autonomic regulation of organs

8. Epilepsy (Bevin, 27 Feb)

• Definition of epilepsy (ILAE criteria: ≥2 unprovoked seizures, etc.)
• Seizure classification by symptoms/signs
• Focal (partial) vs generalised seizures
• Awareness as a classifier
• Seizure semiology: motor (tonic, clonic, myoclonus, atonic, spasm), autonomic, sensory, cognitive, emotional automatisms
• Focal to bilateral tonic-clonic seizures
• EEG: scalp electrodes detecting cortical activity
• Mechanisms: Na+ channels, glutamate, GABA
• Antiepileptic drugs (AEDs) by mechanism
• AED polytherapy and co-morbidities
• SUDEP (sudden unexpected death in epilepsy)
• Reflex epilepsy

9. Consciousness, Coma, Sleep (Bevin, 2 Mar)

• Definition of consciousness (arousal + awareness)
• Awareness of self, person, place, time
• Reticular activating system / arousal
• Coma and reduced level of consciousness
• Sleep as an active brain state (not rest)
• Sleep stages / patterns (2 basic patterns – REM vs NREM)
• EEG in sleep and consciousness

10. Traumatic Brain Injury (Bevin, 2 Mar)

• Glasgow Coma Scale (GCS): E, V, M scoring
• Primary vs secondary brain injury
• Diffuse axonal injury (DAI)
• Subdural haematoma (SDH) and midline shift
• Contusions and petechial haemorrhage
• Raised intracranial pressure (ICP) and management
• Brainstem injury and extensor (decerebrate) responses
• Pupillary signs (fixed and dilated pupil)
• Surgical management: craniotomy, evacuation, lobectomy/decompression
• Outcome categories (Glasgow Outcome Scale: death → disability levels)

11. Neuroimaging (Doyle, 2 Mar)

• CT physics (ionising radiation, Hounsfield density)
• Hyperdense (white) vs hypodense (dark) on CT
• Windows: soft tissue vs bone
• MRI physics (hydrogen protons, magnet, radio pulse)
• T1 vs T2 vs FLAIR; diffusion-weighted imaging (DWI) and ADC
• Gadolinium contrast enhancement
• When to choose CT vs MRI
• Stroke imaging: loss of grey/white differentiation, sulcal effacement, swelling
• Haemorrhage types: extradural, subdural, subarachnoid, parenchymal
• Middle meningeal artery rupture (extradural)
• Aneurysm and vascular malformation
• Cerebral atrophy (widened subarachnoid space)
• CT/MR/catheter angiography
• Tumour appearance and contrast enhancement

12. Motor Systems 1–4 (Bevin, 6–9 Mar)

• Lower motor neuron = α-motor neuron; the motor unit
• LMN signs: ↓tone, ↓reflexes, muscle atrophy, fasciculations, ↓power
• Spinal reflexes and the stretch (tendon) reflex
• Spinal cord role in processing voluntary commands
• Central pattern generators / rhythmic motor patterns (locomotion)
• Upper motor neuron concept (anatomical/physiological basis)
• UMN signs: ↑tone, clonus, hyperreflexia, extensor plantar (Babinski), no atrophy
• Contrasting UMN vs LMN signs
• Brainstem motor structures and descending tracts (e.g. rubrospinal/red nucleus)
• Corticospinal and corticobulbar tracts
• Motor cortex organisation: primary motor, premotor (PMC), supplementary motor area (SMA)
• Medial vs lateral motor system organisation
• Basal ganglia: striatum, medium spiny neurons, dopamine
• Dopamine roles: reward-mediated learning, attention
• Basal ganglia disorders: Parkinson’s, Huntington’s disease
• Cerebellum in motor control; signs of cerebellar damage
• Example disorders: stroke, trauma, multiple sclerosis, poliomyelitis

13. Somatic Sensations 1–2 (Bevin, 11 Mar)

• Sensory submodalities (modality/type of sensation)
• Receptor types and receptors activated per modality
• Intensity coding (frequency/population)
• Location coding and cortical mapping (somatotopy)
• Dorsal column–medial lemniscus pathway (gracile/cuneate nuclei)
• Spinothalamic pathway
• Proprioceptive neurons; Clarke’s nucleus; spinocerebellar projection
• Thalamic relay to cortex
• Projections to cingulate gyrus (emotional component)
• Intralaminar nuclei
• Primary somatosensory cortex and higher interpretation

14. Motor and Sensory Dysfunction (Bevin, 13 Mar)

• Stroke / cerebrovascular accident (CVA) – clinical
• “1.9 million neurons die per minute” – time-critical ischaemia
• Hemisensory deficit localisation
• Distribution of motor/sensory loss (upper vs lower extremity)
• Extensor toe signs (bilateral)
• Clinical case-based localisation of lesions
• Multiple sclerosis features (fatigue, vertigo)

15. Pain / Nociception 1–2 (Bevin, 13 Mar)

• Purpose of the pain system (prevent injury)
• Nociceptor fibre types: Aδ (fast, myelinated) vs C (slow, unmyelinated)
• First vs second pain
• Spinothalamic projection and brainstem reticular formation
• Periaqueductal grey (PAG) and descending modulation
• Pain tolerance
• Chronic pain issues
• Congenital insensitivity to pain (absence of C fibres) – clinical consequences

16. Organisation of the Cranial Nerves (Reynolds, 16 Mar)

• Position of cranial nerve nuclei on a brainstem section
• Course of each cranial nerve within the brainstem
• Brainstem blood supply by region
• Stroke targets and effects per brainstem area
• Trigeminal (V) relations within brainstem

17. Cranial Nerves of the Medulla (Reynolds, 16 Mar)

• Nucleus ambiguus (branchial motor – IX, X)
• Nucleus tractus solitarius (general visceral + taste)
• Inferior salivatory nucleus
• Dorsal motor nucleus of vagus
• Hypoglossal nucleus (XII)
• Functional columns at medullary level
• Clinical effects of medullary cranial nerve lesions

18. Nervous System Development (Liu, 18 Mar)

• Neurulation
• Ectoderm → neural plate → neural tube (~14–16 days)
• Anterior and posterior neuropore closure (~26–28 days)
• Timeline of nervous system development
• Neural tube defects (NTDs); NZ occurrence rate
• Folate (vitamin B9) and prevention
• Regionalisation of the developing CNS

19. Facial Sensation (Reynolds, 18 Mar)

• Trigeminal nuclear complex (three nuclei)
• Discriminative (fine) touch component
• Pain & temperature, crude touch – spinal trigeminal nucleus
• Proprioception – mesencephalic nucleus of V
• Chief (principal) sensory nucleus
• Ventral trigeminothalamic tract
• Cranial nerves carrying facial sensation (V, VII, IX, X)
• Comparison with limb pathways (gracile fasciculus)

20. Motor Function of Face & Head; Pupillary Reflexes & Eye Movements (Reynolds, 20 Mar)

• Trigeminal motor nucleus (branchial motor, mastication)
• Facial nerve (VII) motor – muscles of facial expression
• Cortical input to facial motor nucleus (upper vs lower face)
• UMN vs LMN facial weakness (forehead sparing)
• Hypoglossal nerve (XII) and tongue deviation
• Sternomastoid / accessory nerve
• Corneal (blink) reflex – afferent V, efferent VII, orbicularis oculi
• Pupillary light reflex; accommodation reflex
• Pupillary dilation (sympathetic) vs constriction (parasympathetic)
• Extraocular muscles and innervation (III, IV, VI)
• Superior oblique (IV) palsy – diplopia, problems descending stairs
• Lateral rectus (VI) and gaze defects
• Diplopia
• Reflex pathways (stimulus → afferent → efferent)

21. Vision 1–2 (Bevin, 23 Mar)

• Eye optics: cornea (main focusing) and lens
• Accommodation and the ciliary body
• Refractive errors and correction (glasses/contacts)
• Retinal layers; light passes through retina to receptors
• Photoreceptors: rods vs cones; cone opsins (3 types)
• Phototransduction (single photon closes channel)
• Retinal circuitry: bipolar, horizontal, amacrine, ganglion cells
• Colour vision and colour blindness (X-linked, ~10% males)
• Ganglion cell axons → optic disc → optic nerve
• Visual pathway: optic nerve, chiasm, tract, LGN, radiations, V1
• Nasal vs temporal hemiretina and decussation
• Visual field defects: hemianopia, quadrantanopia, homonymous hemianopia
• Pupillary light reflex and pupil responses
• Superior colliculus / pulvinar; retino-hypothalamic tract
• Ventral temporal stream and emotional context
• Clinical examination: ophthalmoscopy
• Glaucoma; retinopathy

22. Clinical Ophthalmology (March-Deribot, 23 Mar)

• Burden of blindness and low vision (global and NZ figures)
• WHO definitions of blindness and low vision
• Sudden painless vs gradual painless vision loss
• Refractive errors
• Diabetic retinopathy: DM1 vs DM2; NPDR → PDR progression
• Risk factors for progression
• Treatment: laser and anti-VEGF injections
• Amsler grid
• Fluorescein staining
• Clinical eye examination
• Access and cost of eye care

23. Vestibular System and Hearing (Bevin, 30 Mar)

• Components and functions of external, middle, inner ear
• Vestibular apparatus structures
• Detection of rotational (semicircular canals) and linear (otolith) acceleration
• Hair cell transduction
• Conversion of air movement into auditory nerve impulses
• Auditory transduction in the Organ of Corti
• Cochlear tonotopy
• Forms of hearing loss (conductive vs sensorineural)
• Central auditory pathways (cochlear nucleus onward)

Associated material: Assisted Self-Learning – Brainstem (Reynolds)

• Functional components of cranial nerves (somatic afferent, special visceral afferent/taste, general visceral, branchial motor, somatic motor)
• Trigeminal nuclear complex connections and cortical projection
• Spinal trigeminal nucleus – somatic afferents
• Solitary nucleus – taste and general visceral sensation
• Nucleus ambiguus – branchial motor (IX, X)
• Dorsal motor nucleus of vagus
• Hypoglossal nerve (XII) – somatic motor
• Facial nerve (VII): geniculate ganglion, facial colliculus, relation to abducens
• Pterygopalatine ganglion and parasympathetic pathways
• Corticobulbar fibres and cortical input to brainstem motor nuclei
• Effects of peripheral (LMN) vs central (UMN) facial nerve lesions
• Branchial arch origins of facial/masticatory muscles
• Clinical tests of cranial nerve function
• Lateral corticospinal vs other tracts (comparison)