3 - CNS Organization

Question 1

Cephalization

Answer 1

The addition of nervous tissue layers over reflex pathways

Question 2

Cranial, Spinal Nerves are in which NS?

Answer 2

Peripheral

Question 3

6 CNS Divisions

Answer 3

1. Spinal Cord
2. Myelencephalon
3. Metencephalon
4. Mesencephalon
5. Diencephalon
6. Telencephalon

Question 4

Myelencephalon

Answer 4

Medulla

Question 5

Metencephalon

Answer 5

Pons + cerebellum

Question 6

Mesencephalon

Answer 6

Midbrain

Question 7

Diencephalon

Answer 7

• Thalamus + Hypothalamus
• 3rd ventricle

Question 8

Rostral

Answer 8

Towards the head, synonymour with anterior

Question 9

Caudal

Answer 9

Towards the tail, synonymous with posterior

Question 10

Gray Matter Composition, Location

Answer 10

• Composition:
  
  • 80% glial cells (astrocytes, oligodendrocytes, microglia)
  • Cell bodies, dendrites (so, most synaptic activity is here)
• Exterior in cerebral cortex, cerebellum, diencephalon
• Interior in spinal cord, medulla, pons, midbrain

Question 11

Gray Matter Neural Arranagements

Answer 11

1. Nuclei = high density clusters of neurons that are functionally related
2. Laminae = neural layers (cerebral, cerebellar cortices)
3. Reticular formation = loose, low density arangements without a clear zone

Question 12

White Matter Composition, Locations

Answer 12

• Composition:
  
  • Densely-packed myelinated axons
• Interior in cerebral cortex, cerebellum, dienephalon
• Exterior in spinal cord, medulla, pons, and midbrain

Question 13

White Matter Tract Types

Answer 13

• Fascicles combine to form funiculi which combine to form peduncles
• Lemniscus: ribbon-shaped bundle
• Commissure: connects hemispheres
• Decussation: tract crosses midline

Question 14

The Basic Types of Neuronal Systems

Answer 14

1. Information-rich: real-world info
2. Regulatory: no real world info; helps other systems work better but influencing signal-to-noise ratio
3. Command: pattern generators for complex circuits like walking, chewing, etc.