Science Buddies: "Ask an Expert"

I have read multiple articles and textbooks on embryonic vertebral development, but they left some questions for me unanswered.

They say that chondrification in the vertebrae begins in the sixth weeks with the appearance of two centers in the centrum and one center in each arch, and the centres in the centrum fuse at the end of the embryonic period. They also say that ossification begins in the 7th week.

Why does it takes so long for the chondrification centres in the centrum to fuse? And do they fuse after each half of the vertebra has fully chondrified or as it is chondrifying(some article online said that the centres in the centrum are initially seperated as they develop)?

Hi Abirr,

These are good questions you have; regarding how long it takes for fusion, this process is dependent on cell migration, differentiation and death, which are in turn orchestrated by gradients of growth factors. So the speed is based on how long these things take, and is very tightly regulated.

Are you working on a specific project? This forum is for specifically for students to get help with science fair projects. If you have a project regarding centrum fusion/chondrification, let us know what your experimental plan is, and we can go from there.