Neuroanatomy Flashcards
What constitutes the brainstem?
The midbrain, pons, and medulla
Name and describe the types of glial cell.
Astrocytes - maintains BBB
Oligodendrocytes (CNS) and Schwann cells (PNS) - produces myelin
Microglia - similar to macrophages, immune function and antigen presentation
Ependymal cells - ‘neuroepithelium’ lines ventricles
What is grey and white matter?
Grey - neurones, cell processes, synapses, support cells
White - axons and their support cells
Where are the motor and somatosensory cortices located?
Motor - precentral gyrus
S’sensory - postcentral gyrus
Describe the blood supply of the brain.
ICA: gives MCA and ACA, as well as anterior choroidal arteries
Vertebral: combines to give basilar artery, which gives PCAs
Name the layers from skin to spinal cord.
Skin and subcut fat Supraspinous ligament Interspinous ligament Ligamentum flavuum Dura & arachnoid
What are the two primary anatomical concerns associated with LP?
Raised ICP - may cause herniation
Epidural fat contains venous plexuses - rupture can cause epidural haematoma
Describe the formation of a spinal nerve.
Anterior root (motor) + posterior root (sensory; has ganglia). Gives off anterior and posterior rami (mixed) and grey and white rami.
Describe the dorsal column pathway.
- Lower limb (fasciculus gracilis) central; upper limb (fasciculus cuneatus) ‘added on’
- synapses in medulla as nucleus gracilis / cuneatus
- decussates via internal arcuate fibres to VPL nucleus of thalamus
FG/FC -> medulla (nuclei) -> VPL -> X internal arcuate -> cortex
Describe the spinothalamic tract.
- nociceptors to dorsal horn
- decussates via Lissauer’s tract
- travels via medulla to VPL nucleus of thalamus
Describe the corticospinal tract.
Motor tract
- motor cortex, to posterior limb of internal capsule, cerebral peduncles, and basis pontis
- decussates in medullary pyramids
Name the lobes and features of cerebellum.
Anterior, posterior and flocculonodular lobes
Vermis (‘worm’) splits into lateral hemispheres, which supply lateral body.
Vermis supplies midline
Name the inputs to the cerebellum.
- spinal cord (proprioceptors)
- cerebral cortex (pons)
- vestibular apparatus
- inferior peduncle: vestibulocerebellar, spinocerebellar, olivocerebellar
- middle peduncle: corticopontocerebellar fibres, motor neurons via anterior pons
Name the outputs of the cerebellum.
Solely from PURKINJE cell layer to
- inferior peduncle (to vestibular system)
- superior peduncle (contralateral to origin to red/VLN of thalamus)
Name and describe the 3 functional divisions of the cerebellum.
- vestibulocerebellum (flocculonodular node - vestibular and eye movement)
- spinocerebellum (central, midline)
- pontocerebellum (lateral, communicates with pons)
Name the components of the basal ganglia, and their collective names.
- caudate nucleus
- putamen [striatum]
- globus pallidus [+ putamen = lenticular nucleus]
- [corpus striatum]
- subthalamic nucleus
- substantia nigra
Describe the function of the basal ganglia.
Facilitates purposeful movement, prevents unwanted movement, has a role in muscle tone and posture.
Lesions affect the contralateral side (‘talks’ to ipsilateral cerebellum).
Describe CN I’s course through the brain.
Directly to olfactory area (anteromedial temporal, posteroinferior frontal), bypassing the thalamus
Name the modalities of CN V.
- somatosensation (discriminative touch, vibration, pain, temp)
- proprioception (TMJ, mastication)
- motor (mastication, tensor tympani, mylohyoid, ant belly of digastric, tensor veli palatini)
Describe the sensory pathways associated with CN V.
- V1 ophthalmic: upper eyelid, cornea, conjunctiva, skin of root, bridge, and tip of nose
- V2 maxillary: lower eyelid, maxilla, ala of nose, upper lip
- V3 mandibular: skin over mandible/TMJ
Then travels to nuclei:
- mesencephalic (proprioception)
- pontine/principal (discriminative touch, vibration)
- spinal (/spinothalamic; pain and temperature)
Then travels to thalamus via the ventral trigeminothalamic tract; most fibres cross. Lower spinal pathology = perioral sparing
Name and describe the nuclei of CN VII.
Salivatory nucleus - parasympathetic (to submandibular and pterygopalatine ganglion)
Solitary - taste from anterior 2/3 of tongue; conveyed by chorda tympani
Spinal trigeminal - somatosensation associated with pinna/EAM
Geniculate nucleus - sensory nerve cell bodeis
Describe the motor supply of CN VII.
To Zanzibar By Motor Car:
- temporal [frontalis, orbicularis oculi]
- zygomatic [orbicularis oculi]
- buccal [buccinator, zygomaticus]
- mandibular [orbicularis oculi]
- cervical [platysma]
Name and describe the nuclei of CN IX.
- solitary [gustatory/posterior 1/3 taste tongue; commissural/baro- and chemoreceptors]
- spinal trigeminal [pinna/EAM]
- inferior salivatory [parasympathetic to parotid gland]
- nucleus ambiguus [stylopharyngeus]
Name and describe the nuclei of CN X.
- dorsal (motor) [parasympathetic except to heart]
- solitary [gustatory, commissural]
- spinal trigeminal [pain from dura, pinna/EAM]
- nucleus ambiguus [motor to pharynx / larynx, para to heart]