Cells and Tissues of the Nervous System

Question 1

neurons in the nervous system

Answer 1

are the main functional cells of the nervous system, specialising in electrical communication.

Question 2

CNS tissue organisation

Answer 2

highly organised with neuronal cells with neuronal cell bodies clustered in some areas and neuronal axons in others

Question 3

where neuronal cell bodies predominate, the tissue is gray and is called gray matter. and occurs in three forms:

Answer 3

1) as the surface layer (cortex) of the cerebrum and cerebellum
2)As central core of gray matter in the spinal cord
3) as small nodules deep with in the brain called nuclei

Question 4

CNS axon structure

Answer 4

nearly all axons are sheathed by myelin, a fatty, white-colored substance. where axons are bundled together, the tissue appears white and is called white matter. Axons in white matter are organised into special bundles that, as they travel from one region to another, are tracts

Question 5

PNS tissue organisation

Answer 5

The nervous tissue of PNS is organized in a similar fashion, but the descriptive terms differ. small nodules of cell bodies of axons are called ganglia. in the PNS, bundles of axons are called nerves.

Question 6

Neuroglia/ glial cells

Answer 6

supporting cels that play a subordinate role to neurons. they maintain the integrity of the brain and spinal cord by gluing neurons together & they sustain neurons by maintaining homeostasis of the extracellular fluid that bathes them. much more numerous than neurons and are not directly involved in electrical signaling

Question 7

CNS glial cells

Answer 7

astrocytes, microglia, oligodendrocytes, epedymal cells

Question 8

astrocytes

Answer 8

tether in place & control composition of extracellular fluid

Question 9

microglia

Answer 9

clean up debris from dead cells & destroy invading organisms

Question 10

oligodendrocytes

Answer 10

Synthesise the myelin sheath of CNS axons

Question 11

ependymal cells

Answer 11

-line the cavities of the brain
-produce cerebrospinal fluid, which cushions and protects brain tissue
-may also act as a neuronal stem cells