Neuron Structure and Function: Dendrites, Axons, Myelination, and Glial Cells - Prof. Doug, Study notes of Biology

Download Neuron Structure and Function: Dendrites, Axons, Myelination, and Glial Cells - Prof. Doug and more Study notes Biology in PDF only on Docsity! 24 January Neuron structure Dendrites on receiving end Information received from many other cells Long axon with terminals Axon collaterals branch off main axon Initial segment/axon hillock most sensitive to starting action potential Varicosities can also release neurotransmitters Anterograde transport – cell body to periphery Retrograde – periphery to cell body Transport via microtubules and kinesins/dyneins Neurofilaments form spirals inside axons – determine width of axon Glial cells Schwann cells Wraps around axon Forms myelin Increases conduction velocity Also produce growth substances In between Schwann cells are nodes of Ranvier In central nervous system – oligodendrocyte Forms myelin sheath around axons Astrocyte Form blood-brain barrier Pick up excess neurotransmitters Produce growth substances Signal to change blood flow Microglia Originate in bone marrow Scavenging Clean up breakdown products Involved in immunologic response Glial cells 90% of volume in brain Due to extensive myelination Ependymal cells Line brain cavities Produce substances, e.g. cerebrospinal fluid Neuron classification Afferent – periphery → CNS Efferent – CNS → periphery Interneurons – connect neurons in the CNS, integrate information, 99% of all neurons Electrogenic pump (Na+/K+) maintains potential across membrane (negative on inside) Negativity also attributable to negatively charged proteins inside cell