1. Nervous System: Cells & Tissues
Department of Biology, WCU

2. Nervous tissue 1. Neurons 2. Supporting cells Embryonic origin
surround and wrap
Embryonic origin i.
ii.

3. Neurons single axon axon hillock
axon length (up to 3 feet), nerve fiber
axon collaterals
telodendria
terminal boutons
lack Nissl bodies

4. Neuron classification
Multipolar: 3 or more processes
mostly in CNS

5. Neuron classification
Bipolar: 2 processes (axon & dendrite)
e.g. eye

6. Neuron classification
Unipolar: single process
mostly in PNS

7. Neurons Functional areas Conducting component (axon)
Secretory component (synapse)

8. Chemical synapse

9. Chemical synapse Events infiltration of Ca++ synaptic vesicles
crossing the synapse
binding to postsynaptic membrane

10. Anaesthetics Modes of action
block synaptic transmission (bind to postsynaptic membrane)
raise threshold (membrane potential lecture)

11. Supporting cells Neuron scaffolding Types: 4 CNS, 2 PNS
Common function: insulation

12. CNS supporting cells Neuroglia (9:1) Types 1. Astrocytes abundant
link neuron to nutrients
“mop up” leaky K+ and neurotransmitter

13. CNS supporting cells
2. Microglia
protection (microbes, dead tissue)

14. CNS supporting cells 3. Ependymal cells ciliated permeable barrier
circulation and protection

15. CNS supporting cells 4. Oligodendrocytes myelin sheath
insulate electrical impulse

16. PNS supporting cells 1. Satellite cells 2. Schwann cells
surround cell body
function like Astrocytes
2. Schwann cells
myelin sheath
insulate, phagocytosis

17. Myelin nerve fibers (myelin vs unmylenated) lipo-protein
saltatory conduction (1 to 150 m/sec)

18. Myelin
Schwann cells
Neurilemma
Collateral branches

19. Nerve structure Collection of neurons Endoneurium Fascicles
Perineurium
Epineurium