Nerve Review PDF

## Nerve Review 1. **Efferent** - from brain to effectors (muscle), **Afferent** - from body to brain 2. **Neurons** - excitability, conductivity, signal transmission - Nissl body are composed of RER for protein synthesis such as lysosomal enzymes, secreted (neurotransmitters), membrane (ion c...

## Nerve Review 1. **Efferent** - from brain to effectors (muscle), **Afferent** - from body to brain 2. **Neurons** - excitability, conductivity, signal transmission - Nissl body are composed of RER for protein synthesis such as lysosomal enzymes, secreted (neurotransmitters), membrane (ion channels) 3. **Oligodendrocyte (glial cell)** - myelinate axons in CNS 4. **CSF** - provides nutrients to neurons, protects brain, removes waste 5. **Axon hillocks** generate action potentials. Have high conc. ion channels 6. **Chemical vs Electrical Synapse** - **Synaptic cleft** between neurons, that release neurotransmitters across cleft, slower speed due to diffusion of NT - **Electrical** = gap junctions that link to adjacent neuron, fast speed due to electric coupling 7. **Through chemical plasticity, synapses can change strength needed for learning/memory** 8. **Schwann cells** generate myelin in PNS. - Myelin acts as insulator, preventing ion leakage across axan membrane 9. **Glial cells** - **Astrocytes** = blood brain barrier formed by astrocyte endfeet for brain protection, acting as selective barrier, they help in scarring & repair - **Microglia** = act as immune cells, protects brain from pathogens, acts in phagocytosis - **Ependymal** = lines ventricles, produces CSF and helps circulate it 10. **Multipolar** = motor neurons (brain) 11. **Bipolar** = inner ear neuron (sensory) 12. **Unipolar** = olfactory - Soma = nucleus, protein synthesis | dendrites = receive signal & send to body - Axon = transmit signal to other neurons 13. **Microtubules** = structure, maintain shape, facilitate axonal transport 14. **Neurofilaments** = structure & mechanical strength 15. **Removal of NT** = recycling of synaptic vesicle, degrading by enzymes breakdown NT, diffusion from cleft 16. **Schwann cells** can myelinate a single segment of axon, oliogio myelinate many 17. **Schmidt Lanterman cleft** = cytoplasmic channels in myelin sheath 18. **CNS** = brain / sp, **PNS** = nerves, ganglia 19. **Ganglia** = group of neuronal cell bodies in PNS 20. **Glutamate** = excitatory NT 21. **CT** = **Endoneurium** - surround individual axons, **Perineurium** - encloses axon bundles forming fascicle, **Epineurium** - dense CT encase entire nerve **Diagram:** The diagram shows a neuron with the following parts: - Axon - Terminal - Schwann cells - Soma - Dendrite - Fascicle - Endoneurium - Epineurium - Perineurium