BIOL 1334 Chapter Notes - Chapter 13: Cranial Nerves, Neural Groove, Neural Crest
23 Jan 2020
School
Department
Course
Professor
Document Summary
The brain is composed of 4 major regions: the cerebrum, diencephalon, brainstem, and the cerebellum. The cerebrum is divided into 2 halves, left & right cerebral hemispheres. Each hemisphere is subdivided into five areas called lobes. Our skull volume limits the size of the brain, so the outer tissue folds on itself so more neurons can fit. Nervous system is derived from ectoderm, of the primary germ layers. Formation of nervous tissue begins during 3rd week of development with a thickening of a portion of the ectoderm. Portion of the ectoderm overlies the notochord, which is a tightly packed group of mesoderm cells positioned on the developing embryo midline. Induced by underlying notochord to form a neural tube, which begins the process called neurulation. Process of neurulation: neural plate develops a central longitudinal indentation called the neural groove. Cells along the lateral margins of the neural plate proliferate, becoming thickened neural folds.
