NBio 146

NBio 146

Neurobiology of Disease

Localization:

Neuroanatomy Review

http://thalamus.wustl.edu/course/

http://web.odu.edu/webroot/instr/sci/kcarson.nsf/pages/492_592desc

http://thalamus.wustl.edu/course/



Planes of Section

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Anatomical TermsAnterior/PosteriorSuperior/InferiorLateral/MedialDorsal/VentralRostral/Caudal

Anatomical Planes of Section in the Brain

Horizontal, axial/ transverse/coronal, sagittal, midsagittal, parasagittal

Central Visual Pathways











Central Visual Pathways







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are needed to see this picture.6. Macular sparing

Homonymoushemianopia

Bitemporalhemianopia

quadrantanopia

Motor Pathways





Internal Capsule

Corticospinal and corticobulbar fibers arise from primary motor cortex.Corticobulbar axons terminate in the brainstem.85% of corticospinal axons decussate in the lower medulla.15% form the anterior corticospinal tract.

Internal capsule has anterior limb, posterior limb and genu.

Upper MN Lower MNIndividual muscles? No, groups Yes, sometimes

Atrophy? Minimal Marked

Spasticity? Yes No

Reflexes Hyper- Hypo-

Babinski? Yes No

Fasiculation? No YesNerve Conduction

Normal Slow

Tone increased decreased

Plantar Response

Scrape object on sole of foot.Babinski sign indicative of UMN lesion.

Normal in infants up to 1 yr.

General Organization of the Motor Systems

Neurological Differential Diagnosis 2

Computerized Tomography (CT)

As in conventional X-rays, bone and other calcified structuresare dense and appear white in CT scans. Less dense materialssuch as air appear black. Clear fluid such as CSF is black or dark gray.Isodense = intermediate density similar to brain tissueHyperdense = increased tissue density = much lighter than brain tissue in CTHypodense = decreased tissue density = much darker than brain tissue in CTAdipose tissue is hypodense bcz fat is less dense than water.Muscle has similar density to brain tissue.White matter is slightly darker (less dense) than gray matter due to the lipid content of myelin.

MRI Function

Comparison of CT and MRI Images

Basic MRI image shows greater anatomical detail

SPECT imaging of increased blood flow to area of seizure

Bold fMRI map of sensorimotor and language cortexBroca’s and Wernicke’s areasshown during speechSqueezing a ball with right & left hands

NBio 146

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