What happens on day 24 of development?

What happens on day 24 of development?

• A. The neural plate thickens
• B. The cranial neurospore closes
• C. The neural tube closes at the cranial end
• D. Neural crest cells begin migrating

Answer: (B)

Neurulation is the process that forms the neural tube from the neural plate. The cranial neuropore is the anterior opening of that tube. By about day 24 of human development, this opening has closed, sealing the head portion of the neural tube. This closure is crucial because it prevents neural tissue from remaining exposed and sets up proper brain development; if it fails, severe neural tube defects like anencephaly can result. After this, the neural tube will finish closing along its length in the following days, with the caudal end closing a bit later around day 27–28. The neural plate thickens earlier during gastrulation and early neurulation, and neural crest cells begin migrating after the neural tube has formed and closed, so those events don’t occur exactly on day 24.

Neurulation is the process that forms the neural tube from the neural plate. The cranial neuropore is the anterior opening of that tube. By about day 24 of human development, this opening has closed, sealing the head portion of the neural tube. This closure is crucial because it prevents neural tissue from remaining exposed and sets up proper brain development; if it fails, severe neural tube defects like anencephaly can result. After this, the neural tube will finish closing along its length in the following days, with the caudal end closing a bit later around day 27–28. The neural plate thickens earlier during gastrulation and early neurulation, and neural crest cells begin migrating after the neural tube has formed and closed, so those events don’t occur exactly on day 24.