The fetus is nourished by the __________ during the first 7 weeks and by the _______ from week 8 through birth ?
1 answer:
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Answer:
As part of the development of the neural tube, by the sixth week of embryonic development, the brain vesicles are already formed.
Explanation:
The encephalic vesicles correspond to a group of dilations that will give rise to the brain and its related structures.
Around the 4th week of embryonic development, the primary encephalic vesicles are formed, and by the 6th week there will also be secondary encephalic vesicles, for a total of five divisions.
The five encephalic vesicles formed in week 6 of embryonic development are the myelencephalon, metencephalon, midbrain, diencephalon and telencephalon.
- <em><u>myelencephalon </u></em>: It is the structure that is organized to form the spinal bulb, in addition to the motor nuclei of the cranial nerves (pairs) IX to XII.
- <u><em>Metencephalon</em></u> : It gives rise to the cerebellum and the protrusion.
- <em><u>Midbrain</u></em> : It forms important structures such as the Edinger-Westphal nucleus, the wing plates, the tegment - together with the nuclei of the cranial nerves III and IV - and the upper cerebellar pedicles.
- <u><em>Diencephalon</em></u>: gives rise to the Thalamus, hypothalamus and pituitary gland.
- <em><u>Telencephalon</u></em>: originates the structure of each cerebral hemisphere, besides the striated body and its respective divisions in caudate and lenticular nuclei.
