NEUR3005 Practical Notes PDF

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Practical notes on structure identification and function...

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Fissures: • Longitudinal fissure • Lateral sulcus / Sylvian fissure Cerebrum: • Frontal lobe • Parietal lobe • Occipital lobe • Temporal lobe • Cingulate lobe • Insula lobe Corpus callosum • Septum pellucidum separating the anterior horns of the left and right lateral ventricles Peduncles • Cerebral Peduncles (x2) • Cerebellar peduncles (x6) • Superior cerebellar peduncles (x2) • Middle cerebellar peduncles (x2) • Inferior cerebellar peduncles (x2) Diencephalon • Thalamus • Hypothalamus • Mammillary bodies -- memory and direction • Anterior perforated substance Brainstem: • Midbrain • Tectum Dorsal midbrain (root of colliculus) • Tegmentum Ventral part of midbrain • Pons • Medulla • Open medulla ( separates by 4th ventricle) • Closed medulla Meninges: • Pia mater • Arachnoid mater • Dura mater • Arachnoid granulations

Dural folds: • Falx cerebri • Falx cerebelli • Tentorium cerebelli

Dural Sinuses: • Superior sagittal sinus • Inferior sagittal sinus • Straight sinus • Transverse sinuses • Confluence of sinuses • Sigmoid sinuses • Cavernous sinuses • Superior petrosal sinuses • Inferior petrosal sinuses

Ventricular system: • Lateral ventricles • Anterior horn • Body • Trigone / atrium • Posterior horn • Inferior horn • Foramina of Monro / interventricular foramen • Third ventricle • Optic recess • Cerebral / Mesencephalic aqueduct • Fourth ventricle • Foramina of Luschka / lateral aperture(s) • Foramen of Magendie / median aperture • Central canal of spinal cord • Choroid plexus Cisterns:

• Interpeduncular cistern • Pontine cistern • Superior cistern • Cerebellomedullary cistern / cisterna magna • Cistern of the lateral cerebral fossa Blood Vessels: • Internal carotid arteries → brain • Circle of Willis →  Anterior cerebral artery (left and right), Anterior communicating artery. Internal carotid artery (left and right) • Anterior and posterior perforating arteries → anterior perforated artery → internal capsule, putamen and caudate nucleus. • Anterior cerebral arteries → frontal lobes and superior medial parietal lobes • Anterior communicating artery • Middle cerebral arteries • Anterior choroidal arteries • Posterior cerebral arteries • Posterior communicating arteries • Basilar artery • Pontine arteries • Superior cerebellar arteries • Anterior inferior cerebellar arteries • Vertebral arteries • Posterior inferior cerebellar arteries • Anterior spinal artery

Olfactory system: • Olfactory bulb → It sends o  lfactory information to be further processed in the amygdala, the orbitofrontal cortex (OFC) and the hippocampus. • Olfactory tract →  connects piriform cortex, amygdala, and entorhinal cortex • Gyrus rectus • Temporal lobe → primary auditory perception • Parahippocampal gyrus → memory encoding and retrieval Piriform (or pyriform) cortex →between insula and the temporal lobe o  lfaction Entorhinal cortex → (temporal lobe) memory, navigation and the perception of time Uncus • Mediodorsal /dorsomedial thalamic nuclei • Amygdala → Emotion (anterior to hippocampus) • Anterior perforated substance → blood supply of deep grey matter structures of the brain • Medial olfactory striae • Lateral olfactory striae

Gustatory system: • Facial nerve • Glossopharyngeal nerve • Vagus nerve • Nucleus of solitary tract • Frontal operculum • Anterior insular cortex • Parabrachial region* → r elays taste info from the solitary nucleus to the ventroposteromedial nucleus of the thalamus. • Cingulate cortex → e  motion, learning, and memory. • Ventroposteromedial thalamic nuclei Auditory system: • Vestibulocochlear nerve • Dorsal and ventral cochlear nuclei • Inferior colliculus → auditory reflexes, such as turning of the head towards a sudden loud sound. • Brachium of inferior colliculus → carries auditory afferent fibers from the inferior colliculus to medial geniculate nucleus. • Superior olivary nucleus* → f irst auditory relay from cochlear nucleus to auditory cortex (localisation of sound and in reducing background noise) • Trapezoid body* → decussating auditory fibres and provides for bilateral projections to the auditory cortex. • Lateral lemniscus * → from the superior olivary and cochlear nuclei to the inferior colliculus • Medial geniculate nucleus https://brainstormneuro.net/diagram/20? • Superior temporal gyrus → a  uditory cortex • Planum temporale → l anguage • Transverse temporal gyrus (of Heschl) → process primary auditory information • Wernicke’s area → comprehension of speech

Visual system: • Optic nerves • Optic chiasm (surrounded by the circle of Willis) • Optic tract • Lateral geniculate bodies → receives input from retina • Superior colliculus → head and eye orienting reflexes to novel visual stimuli • Brachium of superior colliculus • Optic radiation → connects lateral geniculate to primary visual cortex • Cuneus → same-sided info from retina, visual processing • Lingual gyrus → processing vision (letters), encoding visual memories • Primary visual cortex • Calcarine sulcus • Stria (or band) of Gennari • Secondary visual cortex • Anterior thalamic tubercle • Suprachiasmatic nucleus → diurnal rhythm

Cranial Nerves

Brainstem surface anatomy: • Rhomboid fossa • Obex → decussation of sensory fibres • Facial colliculus • Hypoglossal trigone • Vagal trigone • Sulcus limitans → I t separates the cranial nerve motor nuclei (medial) from the sensory nuclei (lateral) Brainstem nuclei (model & images only): • Edinger-Westphal nucleus • Oculomotor nucleus • Trochlear nucleus • Spinal nucleus of trigeminal • Principal (or chief sensory) nucleus of trigeminal • Mesencephalic nucleus of trigeminal • Motor nucleus of trigeminal • Abducens nucleus • Facial motor nucleus • Superior salivatory nuclei • Inferior salivatory nuclei • Nucleus ambiguus • Nucleus of the solitary tract • Dorsal (motor) nucleus of vagus

• Vestibular nuclei (inferior, lateral, medial, superior) • Dorsal and ventral cochlear nuclei • Spinal accessory nucleus • Hypoglossal nucleus Medulla (proprioception): • Lateral cuneate nucleus* Spinal cord (proprioception): • Dorsal roots • Dorsal root ganglia • Grey matter • Dorsal horn* • Nucleus dorsalis /Clarke’s column* → give rise to the dorsal spinocerebellar tract, which relays proprioceptive and other sensory information to the ipsilateral cerebellum. C8 -L3 • White matter • Spinocerebellar tracts* → T  he spinocerebellar tracts occupy the periphery of the lateral funiculus and carry proprioceptive and cutaneous information from Golgi tendon organs and muscle spindles to the cerebellum for the coordination of movements • Anterior / ventral* • Posterior / dorsal* Cortex (somatosensory): • Postcentral gyrus/primary somatosensory cortex • Paracentral lobule → The paracentral lobule includes the primary motor and somatosensory areas for the leg and foot and is important in the control of voluntary movements and the localisation and perception of somatosensory stimuli in the leg and foot. • Secondary somatosensory cortex → p  arietal operculum on the ceiling of the lateral sulcus Brainstem (sensory): • Medial lemniscus → S  ensory axons transmitting information from the head and neck via the trigeminal nerve synapse at the ventral posteromedial nucleus of the thalamus. Ventral to dorsal → leg→ trunk→ arm • Gracile tubercle / nucleus* • Internal arcuate fibres* → second-order neurons of the posterior column-medial lemniscus system, and are important for relaying the sensation of fine touch and proprioception to the thalamus and ultimately to the cerebral cortex. • Cuneate tubercle / nucleus* https://brainstormneuro.net/xsection/4?

Spinal cord (sensory): • Dorsal roots • Dorsal root ganglia • Grey matter - Dorsal horn* - Substantia gelatinosa* → where first order neurons of the spinothalamic tract synapse. Pain of distal origin and temperature impulses - Nucleus proprius* → receives inputs from the dorsal root ganglions that carry sensory information, such as light touch, as well as pain and temperature information. • White matter - Spinothalamic tract* → transmits pain and temperature sensations from the spinal cord to the thalamus. - Dorsal columns* - Cuneate fasciculus* →  sensory modalities of proprioception, vibration and discriminative touch are transmitted from the peripheral receptors of the upper limb and trunk to the primary somatosensory area. - Gracile fasciculus* → l ower limb and trunk to the primary somatosensory cortex. Below T6 - Ventral white commissure → f ormed by the axons of tract cells crossing from one side of the spinal cord to the other, the major group being spinothalamic tract axons....