The Nervous system Neurons & Neuroglia
Two Types of Nervous Cells Neurons Nerve cells Transmit messages Neuroglia Supportive cells Do not transmit messages Never lose ability to divide Six types
Types of Neuroglia - CNS Astrocytes Guide migration of developing neurons Aid in nutrient exchange Help form blood-brain barrier Microglia Immune cells that act as macrophages for nervous system
Types of Neuroglia - CNS Ependymal cells Line cavities of CNS Oligodendrocytes Produce the myelin sheath around the CNS
Types of Neuroglia - PNS Satellite Cells – Protect & cushion Schwann Cells Form myelin sheath Help with regeneration
Neuron Structure Dendrite Cell Body Nodes of Ranvier Axon Myelin Sheath
Myelin Sheath
Other Vocabulary Nuclei – clusters of cell bodies in the CNS Ganglia - clusters of cell bodies in the PNS Tracts – bundles of axons in the CNS Nerves - bundles of axons in the PNS
Neuron Classification - Structural
Neuron Classification - Functional Sensory (afferent) Naked nerve endings Meissner’s corpuscles Pacinian corpuscles Proprioceptors Motor (efferent) Association (Interneurons)