APK 2100C Lecture Notes - Lecture 9: Node Of Ranvier, Myelin, Ependyma

• School: University of Florida
• Department: Applied Physiology and Kinesiology
• Course: APK 2100C
• Professor: Ahlgren Joslyn Korrin

Document Summary

Functions: increase neurotransmitter reuptake signal increased blood flow to active brain areas control ionic environment around neurons. Functions: line cerebrospinal fluid-filled cavities simple and ciliated epithelium form permeable lining of ventricles. Oligodendrocytes processes form myelin sheaths around long axons in cns. Nodes of ranvier present (gap in myelin sheath) Satellite and schwann cells surround neurons in pns no processes. Schwann cells surround all axons in pns, only some axons have myelin sheath. Myelin sheaths concentric layers of plasma membrane from schwann cells/oligodendrocytes tightly wrap segments of thickest axons with myelin. Myelinated axons in pns axon wrapped with fatty, insulating sheath from schwann cells. 2: schwann cell rotates around axon, wraps plasma membrane around loosely in layers. 3: schwann cell cytoplasm forced from between membranes; tight membrane wrappings surrounding axon form the sheath. Nonmyelinated axons in pns axons not covered with insulating sheath. 2: each axon encircled by schwann cell plasma membrane. 2: macrophages clean out dead axon distal to injury.