Nervous System

Base of the skull

Taken from emedicine: (revise boundaries with snells) Introduction to skull base anatomy: The skull base forms the floor of the cranial cavity and separates the brain from other facial structures. This anatomic region is complex and poses surgical challenges for otolaryngologists and neurosurgeons alike. Working knowledge of the normal and variant anatomy of the skull…

Ascending & Descending tracts of spinal cord

General overview Ascending tracts Sensory Descending tracts Motor General arrangement of both tracts 1st order neuron 2nd order neuron 3rd order neuron The only difference is the different locations where each order of neuron ends. Decussation is the cross-over of the tract from one side to the other. Therefore, there are instances where the left…

Ventricular system & cerebrospinal fluid

Meninges Dura mater outer layer lining the skull Arachnoid mater Space beneath is the subarachnoid space contains cerebrospinal fluid (CSF) contains blood vessels Pia mater covers the brain _____________________________________________________________ Subarachnoid space Space between the arachnoid and pia mater contains CSF Lies over the hemispheres the space is narrow At the cerebello-medullary angle pia mater and…

Organization of the Cerebral Cortex

Organization Cortex consists of neurons Types Pyramidal (main) Stellate Fusiform Horizontal neuroglia nerve fibres blood vessels Cortex forms a gray matter covers there areas cerebral hemispheres obscures diencephalone upper brain stem Surface area of the brain has been increased multiple times to accommodate 10 billion neurons Gyri convolutions Sulci fissues Functional aspects Receives sensory information…

Development of Nervous System

Prenatal Development of Central Nervous System At the beginning of the 3rd week, developing notochord induces overlying ectoderm to become neuroectoderm. Thus forming an elongated, slipper-shaped plate of thickened ectoderm – the neural plate. Neural plate invaginates and forms neural tube Pre-requirement for folding Notochord Anterior part Forms Forebrain Midbrain Hindbrain This neural plate invaginates,…