Nervous tissue 4: ganglia

Question 1

Compare between Craniospinal ganglion and autonomic (sympathetic) ganglion

Answer 1

1. Craniospinal has thicker C.T capsule
2. Craniospinal has less BV
3. Craniospinal has cells arranged in groups, Autonmic has cells scattered
4. Craniospinal has many Satallite cells in 1 continous layer, autonomic has few satallite cells interrupted by dendrites
5. Craniospinal has cells of different sizes, Autonomic has cells of uniform size
6. Craniospinal has unipolar cells, Autonomic has multipolar cells
7. Cells of Craniospinal ganglion are larger
8. Craniospinal ganglion has myelinated nerve fibers, autonomic has unmyelinated
9. Craniospinal has no synapse between cells, Autonomic has synapse between cells
10. Nerve cells of craniospinal have glomeruli, but those of Autonmic dont

Question 2

Describe retrograde (traumatic) degenration

Answer 2

Occurs in proximal part of nerve fiber:
* Chromatolysis: disappearance of Nissel bodies (basophilia)
* Disappearance of Golgi apperatus, mitochondria, dendrites
* Increase in lysosomes
* Increase in volume of perikaryon (cell body), becoming globular
* migration of nucleus peripheraly
* Fragmentation of neurofibrils

Question 3

Describe Wallerian degenration

Answer 3

occurs in distal part of Nerve fiber:
* Neurofibrils of axon are beaded, then segmented, then granular, then disappear
* Widening of Nodes of ranvier
* Schwann cells proliferation (giving rise to cellular columns guiding growing axons)

Question 4

Enumerate stains of Nerve tissue degenration, and what they show

Answer 4

• Osmic Acid: changes in myelin sheath
• Silver(Ag): changes in golgi apperatus and neurofibrils
• Basic stains: Nissel body changes

Question 5

Describe regenration of Nerves

Answer 5

Macrophages remove debris and secrete interleukin1 which promotes schwann cells to secrete nerve growth substances

Question 6

problem with extensive gap of degenration

Answer 6

Newly grown nerve fibers may form swelling (neuroma) that can cause spontanious pain

Question 7

Demyelinating disease

Answer 7

Autoimmune disease that causes damage to myelin sheath, causing loss of ability to transmit electrical impulses