1. Neurohistology Flashcards
Axon Hilocks
Cell body meets axon as it exits
Axon hillocks distance relation to firing speed
Closer to axon hillocks = More likely for neuron to fire
Node of ranvier
Saltitory conduction
Na+ in, K+ out –> depolarization
Schwan cell
PNS
Glial Cell
Only myelinates on neuron
Oligodendrocyte
CNS
Glial Cell
Myelinates many neurons
Involved in alzheimer’s and MS
Parts of a neuron
Dendrite Cell body Axon hillocks Axons Presynaptic terminal
Purkinje Cell
Cerebellum
Sensory integration for coordination
Many dendrites > one axon
Interneurons
Bipolar
One dendrite and one axon off either side of cell body
Sensory neurons
Unipolar
One process off cell body that splits into dendrites and axons in either direction
Motor Neuron
Multipolar
Multiple axons and dendrites
Four main functions of glial cells
Provides structure for the neurons
Forms the (lipid) myelin sheath
Supplies nutrients and oxygen to neurons
Destroys pathogens and removes dead neurons
Myelinated vs unmyelinated
myelinated are larger and conduct approx 100 m/s
Unmyelinated (c-pain) are smaller and conduct about 1 m/s
Astrocytes
CNS - Most common Glial cell Removal of neurotransmitter and scavenging Insulation Blood brain barrier
Microglia
CNS Glial cell Phagocytosis important during brain development Mobilized after injury or infection Destructive in alzheimers, aging, and aids
microglia benefits
Activated and mobilized after injury, infection or disease
Important during brain development
Function as phagocytes (ingest and destroy bacteria, cells and other materials)
