Question

The ascending and descending tracts of spinal cord:
A. Travel in the horns of the spinal cord
B. Convey sensory and motor information to and from the brain
C. Consist entirely of grey matter
D. Serves as origins for the cranial meninges

Answer 1

Hint: The spinal cord is a long tubelike structure. It begins at the end of the brain stem and ends at the bottom of the spine. It consists of nerves that carry impulses between the brain and different parts of the body.

Complete answer:
To solve this question, we must know about the structure of the spinal cord.

The spinal cord is made up of the nerve fibers. It runs down from the brain through a canal in the centre of the bones of the spine. Spinal cord is protected by the bones of the spine. The spinal cord is covered by the meninges and contains cerebrospinal fluid which acts as a shock absorber. The spinal cord is made up of both grey matter and white matter.

In the ascending pathway, the nerve goes upward from the spinal cord toward the brain. It carries sensory information from the body to the brain. In the descending pathway the nerve goes down and carries motor information below the head.

The Cranial meninges originate from the mesenchyme and the neural crest.

Hence, the correct answer is option (B)

Note: There are 31 pairs of spinal nerves. There are 8 cervical, 12 thoracic, 5 lumber, 5 sacral and 1 coccygeal nerves. It connects the spinal cord with a specific region of the body. These are mixed nerves which carry motor, sensory and autonomic signals.