General Histology Lecture 17: Nervous Tissue PDF

General Histology Lecture 17 Nervous Tissue/Nervous System Ahmed Abdul-Aziz Muhammad. PhD Nervous System Lecture Outline Organization of the nervous system Cells of the nervous system Central nervous system  Organization of Nervous System Central nervous system (CNS)...

General Histology Lecture 17 Nervous Tissue/Nervous System Ahmed Abdul-Aziz Muhammad. PhD Nervous System Lecture Outline Organization of the nervous system Cells of the nervous system Central nervous system  Organization of Nervous System Central nervous system (CNS) = brain + spinal cord Peripheral nervous system (PNS) = peripheral nerves + nerve ganglia (groups of nerve cell bodies outside the CNS) Peripheral nervous system has motor and sensory components. Nervous System Lecture Outline Organization of the nervous system Cells of the nervous system Neurons Glial cells Neurons  Cell body maintains the cell; can receive synaptic input Tons of Nissl substance (rough ER) Multiple dendrites (receive impulses) One axon (sends out impulses) – originates at “axon hillock” Cytoskeleton contains neurofilaments (for structure) and microtubules (for transport along axons) Large pale nucleus Nucleolus Nissl substance Neuron cell body neuron and neuropil Nervous System Lecture Outline Organization of the nervous system Cells of the nervous system Neurons Glial cells  Glial Cells 10x more abundant than neurons in brain Support and protect neurons Five types, each with different functions: Astrocyte Oligodendrocyte Schwann cell Ependymal cell Microglial cell  Location and Function of Glial Cells Glial cell type Location Main functions Astrocyte CNS Provides structural support, participates in blood-brain barrier Oligodendrocyte CNS Makes myelin Schwann cell PNS Makes myelin Ependymal cell CNS Lines cavities of CNS Microglial cell CNS Eats up debris and dead cells Neuropil and an astrocyte Astrocyte foot processes bind to capillaries and neurons Oligodendrocytes are smaller and darker than astrocytes. Oligodendrocytes produce myelin in the CNS.  Schwann Cells Schwann cells produce myelin in the PNS. Ependymal cells Microglial cells Nervous System Lecture Outline to be completed Organization of the nervous system Cells of the nervous system Central nervous system Cerebrum Cerebellum Spinal cord Meninges Glymphatics and blood brain barrier Thank you