Embryological Development of the Spine Flashcards
What are the three main structures of embryological development of the spine?
Notochord
Somites
Sclerotomes
What is the purpose of the notochord?
Creates the axial support structure - first body framework to appear in human embryo
What does the notochord transition into once it’s served its purpose?
Nucleus pulposus of the intervertebral discs
On what day does the notochord appear?
18th day of development
From what is the notochord derived?
The mesoderm
Describe the position of the notochord within the embryo
Runs midline between the neural tube and the primitive gut, extending from the skull to the coccyx
What are the three basic embryonic tissues?
Ectoderm
Mesoderm
Endoderm
What does the ectoderm become?
Skin
What does the endoderm become?
Gastrointestinal tract
What are somites made of?
Mesoderm
Where are the somites during development?
Paired on either side of the neural tube
Generally how many pairs of somites are there?
42-44
How many somite pairs for occiput?
4
How many somite pairs for cervical?
8
How many somite pairs for coccyx?
8-10
What is special about the somites for the coccyx?
Most fail to develop - leaving 3-5 segments
Into what three parts do somites differentiate?
Sclerotomes
Myotomes
Dermatomes