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Lesson 12: The Nervous System.

EMBRYOLOGY

“Do what is right, Not what is easy.”



- Roy T. Bennett

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Content

• What Is Development of the Nervous System?
• Clinical Considerations

What Nervous System Structures Does Ectoderm Give Rise to?

The Nervous System

The Nervous System is one of many structures formed from ectoderm

The Nervous System

The Nervous System

The Nervous System

The Nervous System

Neural tube closure begins in the middle of the craniocaudal axis and progresses both caudally and cranially.

The Nervous System

• Neural tube closure begins in the middle of the craniocaudal axis and progresses both caudally and cranially.
• They will ultimately close around day 25 and day 27 (week 4), respectively. In all, the neural tube is created in about 1 month.

Neuropore Closure

The Nervous System

The anterior neuropore closes during week 4 (day 25) and becomes the lamina terminalis.

The Nervous System

The Nervous System

The Nervous System

What Is the Neural Crest?

• The neural crest gives rise to the sensory portions of nerves and sensory ganglia and to autonomic ganglia and postganglionic fibers.