Neuroanatomy
| DORSAL COLUMN – MEDIAL LEMNISCAL |
| Proprioception, Fine touch Fasciculus gracilis & cuneatus Lower medulla synapse at nucleus gracilis & cuneatus Medullary decussation – internal arcuate fibers Medial lemniscus – VB thalamus – 3, 1, 2 cortex |
| ANTEROLATERAL SYSTEM – LATERAL SPINOTHALAMIC |
| Pain, Temperature & Crude Touch Ascent in dorsolateral fsciculus or synapse at dorsal horn – decussation in ant. white commissure of cord Spinothalamin/anterolateral tract – VB thal – 3, 1, 2 cortex Send collaterals to the reticular formation |
| LATERAL CORTICOSPINAL TRACT – PYRAMIDAL |
| Fractioned & independent movement/distal flexors Cerebral cortex 4, 6, 3, 1, 2, 5 – internal capsule – basis pedunculi diverge at pons – medullary pyramids – decussation of pyramids 90% – lat. corticospinal OR 10% no decussation – anterior corticospinal (cross at cord) Synapse in ventral/dorsal/intermed horns |
| Brain |
| Frontal, Parietal, Occipital and Temporal lobes Sylvian fissure: marks the upper border of the temporal lobes, separates from parietal lobes Rolando fissure: (central sulcus) separates frontal from parietal lobes; anterior to it is precentral motor cortex; posterior is postcentral sensory cortex Gyri: cerebral convolutions Folia: cerebellar convolutions Cranial nerves I and II are CNS extensions and myelinated by oligodendrocytes; III-XII are “peripheral” and myelinated by Schwann cells. Perikarya: neuronal cell bodies Line of Gennari: prominent myelinated fibers of the visual cortex Bergmann glia: elongated cerebellar astrocytes Rosenthal fibers: intracytoplasmic hyaline structure, sometimes corkscrew-shaped, found in pilocytic astrocytomas Corpora amylacea: PAS+ argyrophilic polyglucosan globules in the terminal processes of astrocytes |
| Ventricles and CSF |
| Produced by the choroid plexus in the lateral, 3rd and 4th ventricles. Foramen of Munro: lateral ventricle to 3rd Aqueduct of Sylvius: 3rd ventricle to 4th ventricle Hydrocephalus: increased volume of ventricles with increase in CSF caused by obstruction to CSF flow or cortical atrophy leading to hydrocephalus ex vacuo. |