Secondary neurulation forms which part of the CNS?

Secondary neurulation forms which part of the CNS?

• A. Brain
• B. Caudal spinal cord from caudal cell mass
• C. Cerebellum
• D. Retina

Answer: (B)

Secondary neurulation forms the caudal portion of the spinal cord, arising from the caudal cell mass. After the neural tube is formed by primary neurulation to create most of the brain and spinal cord, a second process occurs in the tail region. The caudal cell mass undergoes canalization to form a secondary neural tube that becomes the distal spinal cord, including the conus medullaris and filum terminale. The brain, cerebellum, and retina come from structures established during primary neurulation and subsequent differentiation, not from secondary neurulation.

Secondary neurulation forms the caudal portion of the spinal cord, arising from the caudal cell mass. After the neural tube is formed by primary neurulation to create most of the brain and spinal cord, a second process occurs in the tail region. The caudal cell mass undergoes canalization to form a secondary neural tube that becomes the distal spinal cord, including the conus medullaris and filum terminale. The brain, cerebellum, and retina come from structures established during primary neurulation and subsequent differentiation, not from secondary neurulation.