Cells Of The Nervous System And Neuromuscular Joint Flashcards
Neuron characteristics
Excitable cells of CNS
Heterogenous morphology (uni/bi/multipolar)
Non dividing
Axon characteristics
1 axon projection per neurone with branches off called ‘collaterals’
Usually covered in myelin
Send communications
Dendrite characteristics
Receive signals from other neurons
Many coming off per neuron
Not covered in myelin
Oligodendrocyte function
Provides myelin for multiple axons
Helps signal speed
Astrocyte function
Supportive
Most abundant cell type
Microglia function
Immune cells
Neuronal macrophages
Ependyma cells
Epithelial cells lining the vessels
Na+/K+ rough levels in/out of cell
High extracellular [Na+]
Low intracellular [Na+]
Vice versa for K+
Membrane depolarisation affects on Voltage Gated Channels (VGCs)
VGNaCs open - Na+ influx
VGKCs open at a slower rate - efflux of K+ - membrane re polarisation
How is Na+ K+ balance restored
Na+-K+-ATPase pump
How does saltatory conduction occur
Myelin has high resistance so prevents AP spreading
AP jumps from node to node (of ranvier)
How is neurotransmitter (NT) released
AP opens voltage gated Ca 2+ channels at presynaptic terminal
Ca2+ influx causes vesicle exocytocis
How is postsynaptic receptor activated
NT binds to receptor in posynaptic cleft
Activates receptor
What happens to NT after activation
NT dissociates from receptor and is;
Metabolised by enzymes
Recycled by transporter proteins
Axosomatic synapse
Axon to cell body
