Nervous System: CNS + PNS
https://www.webmd.com/brain/ss/slideshow-nervous-system-overview http://paydayloans-mo.com/anatomy-and-physiology-of-central-nervous-system/nervous- system-project-awesome-anatomy-and-physiology-of-central-nervous-system/ A “typical” neuron
• Is a cell • Has all the usual cellular components • Usually large nucleus • RER = “Nissl substance/bodies” • Neurites = cell processes
Cell body = soma = perikaryon Go to link for animation
https://en.wikipedia.org/wiki/Soma_(biology)#/media/File:Neuron_Cell_Body.png Neuron shape categories: found (mainly) in… • Bipolar: organs of special sense • Unipolar: dorsal/posterior root ganglia • Multipolar: everywhere else
http://humanphysiology.academy/Neurosciences%202015/Chapter%201/P.1.3p%20Neurone%20Micro.html A simple somatic neural circuit
https://www.studyblue.com/notes/hh/cell-bodies-sensory-neurons-gathered-dorsal-root-ganglion/26360419950789715 Neuroglia - “glue” CNS – central nervous system PNS – peripheral nervous system
• oligodendrocyte – myelination • Schwann cell – myelination • astrocyte - bind neurons to blood • satellite cell - support nerve vessels; blood brain barrier cell bodies in ganglia • microglia - small, few processes... support & phagocytosis • ependyma - line central cavity: spinal canal & ventricles; ciliated • better circulation of CSF • cell division - growth CNS – central nervous system PNS – peripheral nervous system
• nucleus – cluster of cell bodies • ganglion – cluster of cell bodies • tract – bundle of neurites • nerve – bundle of neurites • fascicles • endoneurium & perineurium • epineurium • meninges (1 meninx) • Schwann cell - neurilemmocyte • oligodendrocyte - myelination - myelination • other glial types • other glial types • astrocyte • satellite cells • ependymal cells • microglia MENINGES (sing: meninx)
• epidural space • subdural space (potential) • dura mater – cranial meninges only • endosteal layer • arachnoid • dural sinuses • arachnoid villi, granulations • meningeal layer • subarachnoid space (CSF) • septa: • falx cerebri • denticulate ligaments • tentorium cerebelli • falx cerebelli • pia mater • diaphragm sellae
• spinal meninges: dura mater is • meningitis ONLY meningeal layer Other Topics In This Section
• Myelination • General organization of neural connections • Convergent systems • Divergent systems • Lots of “etc” systems • Embryology of the nervous system