The Notochord

From WikiMD free medical encyclopedia
Jump to: navigation, search

Reference > Anatomy of the Human Body > I. Embryology > 7. The Notochord Henry Gray (1821–1865). Anatomy of the Human Body. 1918.

7. The Notochord

The notochord (Fig. 19) consists of a rod of cells situated on the ventral aspect of the neural tube; it constitutes the foundation of the axial skeleton, since around it the segments of the vertebral column are formed. Its appearance synchronizes with that of the neural tube. On the ventral aspect of the neural groove an axial thickening of the entoderm takes place; this thickening assumes the appearance of a furrow—the chordal furrow—the margins of which come into contact, and so convert it into a solid rod of cells—the notochord—which is then separated from the entoderm. It extends throughout the entire length of the future vertebral column, and reaches as far as the anterior end of the mid-brain, where it ends in a hook-like extremity in the region of the future dorsum sellæ of the sphenoid bone. It lies at first between the neural tube and the entoderm of the yolk-sac, but soon becomes separated from them by the mesoderm, which grows medial-ward and surrounds it. From the mesoderm surrounding the neural tube and notochord, the skull and vertebral column, and the membranes of the brain and medulla spinalis are developed.


image19.gif


FIG. 19– Transverse section of a chick embryo of forty-five hours’ incubation. (Balfour.) (Picture From the Classic Gray's Anatomy)


Grays Anatomy Contents | Grays Anatomy Subject Index

WikiMD Sponsors - W8MD Weight Loss, Sleep and MedSpa Centers

Pronounced weightMD, our state of the art W8MD weight loss, sleep, holistic IV nutrition and aesthetic medicine programs can help you not only to lose weight, and sleep better but also look your best! Since its inception in 2011, W8MD’s insurance physician weight loss program has successfully helped thousands of patients.

W8MD Weight Loss

W8MD’s Physician weight loss is unique in many ways with a comprehensive multidisciplinary approach to weight loss. Weight Loss Success Stories....

W8MD Sleep Services

Sleep medicine program uses state of the art technology to diagnose and treat over 80 different sleep disorders. W8MD Sleep Services…

W8MD Medical Aesthetic Services

Medical aesthetic program offers a wide variety of advanced laser skin treatments including oxygen super facials, photofacials and Affordable Botox. W8MD Aesthetic Services…

IM and IV nutrition therapy includes booster shots for B12, vitamin B complex, Vitamin C, Detox treatments and IV nutrition therapy. W8MD IV Nutrition…

W8MD weight loss | Philadelphia medical weight loss | NYC medical weight loss | NJ medical weight loss

W8MD Weight Loss, Sleep & Medical Aesthetics

Intro to W8MD Weight Loss, Sleep & Medical Aesthetics


Disclaimer: The entire contents of WIKIMD.ORG are for informational purposes only and do not render medical advice or professional services. If you have a medical emergency, you should CALL 911 immediately! Given the nature of the wiki, the information provided may not be accurate and or incorrect. Use the information on this wiki at your own risk! See full Disclaimers.WikiMD is supported by W8MD Weight loss, Poly-Tech Sleep & Medical Aesthetic Centers of America.