3. The Neuron Dendrites Cell body (perikaryon, soma)

4. Axon

5. Support cells (neuroglia) - more abundant than neurons - more mitotic capability

7. Axon hillock

8. Gaps between Schwann cells called nodes of Ranvier axolemma

9. Myelinated axons: sheath of Schwann and myelin sheath one Schwann cell myelinates a single axon multiple Schwann cells needed to cover entire length of an axon

10. Oligodendrocytes myelinate CNS axons (if myelinated)

12. Central Nervous System 1. brain 2. spinal cord - ganglia associated

13. 3. axons project to and from the body (CNS  PNS) 4. cell bodies in CNS except some in ganglia

15. Transmission 1. innervation - cell body as integrator 2. action potentials (impulses) - axon hillock 3. myelin sheath

16. Synapses - presynaptic terminal - postsynaptic terminal - neurotransmitters - ligand-gated ions channels on postsynaptic membrane

18. Gap junction (nexus) - is an electrical synapse

19. Nervous System Organization of neurons 1. circuits for stimulus-response 2. exchange of information

20. Neuron signaling 1. afferent vs. efferent 2. interneurons 3. circuits

33. Anencephaly

35. Spina bifida occulta with meningocoele

36. Spina bifida with failure of neuropore closure

37. Cortical dysplasia