Flashcards in Cells of the Brain and their Function Deck (18):
What does myelin do?
- decreases metabolic energy requirements
- decreases capacitance load of axon
- increases conduction speed of APs (saltatory conduction)
What are the thee neuron types? (shape)
bipolar, pseudounipolar, multipolar
Describe a bipolar neuron
single axon and single dendrite emerging form opposite ends of the soma; ex: retinal ganglion cell
Describe a pseudo-unipolar neuron
dendrite and axon emerging from the same process; ex: DRG
describe a multipolar neuron
more than two dendrites;
Golgi I - neurons with long axons
Golgi II (granule neurons) - neurons with short, locally projecting axons; spinal motor neuron, pyramidal neuron, purkinje cell
What are four functional components that all neurons have in common?
1. input component
2. integrative component
3. conductive component (axon))
4. output component (secretory function)
Some functions of dendrites and soma?
receive and integrate synaptic inputs, propogate these inputs to inital segment (of axons where AP is initiated)
Axons vs Dendrites (number)
neurons have single axon, can have multiple dendrites
Axons vs Dendrites (ribosomes)
axons have none, dendrites have both rough ER and cytoplasmic polysomes
Where are the branches of axons and dendrites located with respect to cell body?
Axonal branches are distal teo cell body and dendrites branch extensively near the cell body
Oligodendrocytes vs Schwann cells
both make myelin, but oligo is in CNS and schwann in PNS
Function of microglia
scavengers and remove debris after injury, disease or neuronal death. Act as resident macrophages
Function of radial glia
guide migrating neurons and direct outgrowht of axons, modulate synaptic properties
Function of astrocytes
participate in formation of maintenance of blood-brain-barrier (BBB), also have signals that act both presynaptically and postsynaptically to regulate synaptic transmission, also function to buffer K concentrations in the CNS
4 types of microglia
amoeboid - present during development and phagocytose debris
ramified- common morphology of resting micoglia
activated - phagocytic AND ANTIGEN PRESENTING
gitter cells - micoglia that are full of debris (unable to phagocytose any more material)
Which type of glial cell can strip synapses off?
Which glial cell can release cytotoxic substances?