Question

In a cross section of the spinal cord, A, B, C, D and E represents which of the following parts?

• A. A - white matter, B - gray matter, C - dorsal root, D - ventral root, E - spinal nerve
• B. A - white matter, B - gray matter, C - ventral root, D - dorsal root, E - spinal nerve
• C. A - gray matter, B - white matter, C - ventral root, D - dorsal root, E - spinal nerve
• D. A - gray matter, B - white matter, C - dorsal root, D - ventral root, E - spinal nerve
• E. A - white matter, B - gray matter, C - spinal nerve, D - ventral root, E - dorsal root

Answer 1

The correct option is A A - white matter, B - gray matter, C - dorsal root, D - ventral root, E - spinal nerve

A - white matter, B - grey matter, C - dorsal root, D - ventral root, E - spinal nerve.

The spinal cord is the main pathway for information connecting the brain and peripheral nervous system. The spinal cord, about 45 cm in length, extends from the foramen magnum, where it is continuous with the medulla oblongata, to the level of the first or second lumbar vertebra. Below that level, the vertebral canal is occupied by spinal nerve roots and meninges.

The spinal cord is located in the vertebral foramen and is made up of 31 segments: 8 cervical, 12 thoracics, 5 lumbar, 5 sacral and 1 coccygeal. A pair of spinal nerves leaves each segment of the spinal cord.

The cross section of the spinal cord shows two grooves, dorsal fissure and ventral fissure that divides the spinal cord into two symmetrical halves.

The spinal cord has grey matter inside and appears H- shaped in cross section.

The part of the grey matter that penetrate the white matter is called as horn, ie, dorsal, ventral and lateral horns.

The white matter in each half of the spinal cord is into four columns, the funicle.

Each funicle is formed of nerve tracts. They contain ascending and descending nerve tracts.

So, the correct answer is option A.