Slide 1

Pathologic Basis of Disease Neuropathology - 1 Slide 2 Major cells of the CNS Neurons Glial cells: -astrocytes -oligodendrocytes -ependymal cells -microglial cells Slide 3 Supporting structures Meninges: arachnoid cells Choroid plexus Blood vessels: blood-brain barrier Slide 4 Organization of the CNS and disease Not all cells in the CNS are equal: while some disease processes affect some groups of cells more than others (selective vulnerability), other disease processes could affect other areas more. Not all areas in the brain are equal: most areas in the brain have specific functions: a same disease process in two different areas of the brain, often give different symptoms. Some disease processes are the same in the brain as elsewhere in the body, while others are unique to the brain (eg demyelinative disease, neurodegenerations) Slide 5 NEURON Maturity: G0 phase Great metabolic activity requiring a continuous supply of O 2 and glucose Slide 6 Slide 7 Slide 8 Slide 9 Slide 10 Neuron cell death Phagocytosis by macrophages: acute neuronal death, viral infections Apoptosis simple atrophy: loss of cell volume and ultimately cell death due to metabolic derangement (often in neurodegeneration). Slide 11 Slide 12 Slide 13 Slide 14 Slide 15 Slide 16 Slide 17 Slide 18 Slide 19 Slide 20 Slide 21 Slide 22 Slide 23 Slide 24 Slide 25 Slide 26 Slide 27 Slide 28 Slide 29 Slide 30 Slide 31 Slide 32 Slide 33 Slide 34 Slide 35 Slide 36 Slide 37 Slide 38 Slide 39 Slide 40 Protection of neurons from the bad outside world Blood brain barrier: capillaries with endothelial cells with tight junctions (only active transport possible), astrocytic footplates Brain CSF barrier: ependymal cells with tight junctions, and astrocytic footplates. Slide 41 WHY BBB & BCB Controlled external milieu of neurons needed for excitability of neurons Protection against infections Protection against autoimmune responses Protection against cerebral oedema (skull is a closed box-no volume increase possible) Slide 42 CEREBRAL EDEMA Abnormal accumulation of fluids with increase in cerebral tissue volume Normal Edema Grey matter 800mg/g 820mg/g White matter 680mg/g 760mg/g Slide 43 Topography of edema Localized edema Generalized edema Slide 44 Types of edema Vasogenic edema: rupture of the blood- brain barrier Cytotoxic edema: pump failure Interstitial edema: passage through the ependymal lining of the ventricles Slide 45 Slide 46 Slide 47 Slide 48 Slide 49