Ch 8 Flashcards
What kind of senses use pseudounipolar neurons? Bipolar?
Somatic senses use pseudounipolar neurons
Special senses use bipolar neurons
What neurons have no apparent axon?
Anaxonic CNS interneurons
Describe multipolar CNS interneurons
Highly branched but lack long extensions
How many dendrites does a typical multipolar neuron have and how much does it branch?
5-7 each branching 4-6 times
How is slow axonal transport done?
Moves material by axoplasmic (cytoplasmic) flow at 0.2-2.5 mm/day
What does fast axonal transport? How fast? In what 2 manners?
Moves organelles and vesicles up to 400 mm/day
Anterograde: from cell body to axon terminal
Retrograde: from axon terminal to body
What are the kinds of glial cells in the PNS?
Schwann cells and satellite cells
What do Schwann cells do?
Form myelin sheaths in PNS
Secrete neurotrophic factors
What do satellite cells do?
Support cell bodies in the PNS
What glial cells are found in the CNS?
Ependymal cells
Astrocytes
Microglia
Oligodendrocytes
What do ependymal cells do?
Create barriers between compartments in the CNS
Act as a source for neural stem cells
What do microglia do?
Act as scavengers in the CNS
What do oligodendrocytes do?
Form myelin sheaths in the CNS
What do astrocytes do?
Acts as source of neural stem cells
Take up K+, water, neurotransmitters
Secrete neurotrophic factors
Help form blood-brain barrier
Provide substrates for ATP production
What happens when a peripheral neuron axon is cut?
Section attached to cell body continues to live
Section distal to cut begins to disintegrate
Under some circumstances, the proximal axon may regrow through the existing sheath of Schwann cells and reform a synapse with the proper target
What does the Nernst equation describe?
Membrane potential that an ion type would produce if the membrane were permeable to only that ion
What ion has the largest difference of concentration between ICF and ECF?
Ca2+
What does the Chord Conductance Equation solve for?
Resting membrane potential
