The caudal part of the spinal cord is formed through which one of the following processes?

The caudal part of the spinal cord is formed through a process known as secondary neurulation. Here are the steps:

1. Secondary neurulation begins with the formation of a cord of mesenchymal cells, known as the medullary cord, in the caudal eminence.

2. This medullary cord then undergoes a process called canalization, where a central canal forms within it.

3. Following canalization, the cells in the medullary cord differentiate into neural tissue, forming the caudal part of the spinal cord.

4. The newly formed neural tissue then merges with the neural tissue formed by primary neurulation, completing the formation of the spinal cord.

5. The central canal of the spinal cord then connects with the ventricular system of the brain, allowing for the flow of cerebrospinal fluid.

This process of secondary neurulation allows for the formation of the lower part of the spinal cord, including the sacral and coccygeal spinal cord segments.