Spinal Cord Features Overview

12 Questions

What is the function of the gray matter in the spinal cord?

Contains nerve cell bodies

Where is the Motoneuron Pool located in the spinal cord?

Ventral Horn

Which part of the spinal cord is responsible for carrying sensory information from the body to the brain?

Ascending Tracts

Which part of the spinal cord is responsible for transmitting motor commands from the brain to the muscles?

Descending Pathways

What is the function of the white matter in the spinal cord?

Contains cells coated with myelin for quicker nerve conduction

Which part of the spinal cord branches off the back of the spinal column?

Posterior Root

What are the two enlarged regions of the spinal cord?

Cervical and Lumbosacral

Which layer provides the outermost protection to the spinal cord?

Dura mater

How are the cells in the white matter of the spinal cord coated for faster nerve transmission?

Coated with myelin

How many pairs of sacral nerves emerge from different segments of the spinal cord?

Which region of the spinal cord is responsible for lower limb functions?

Lumbar

Where are the gray matter and white matter located in the spinal cord?

Gray inside, white outside

Study Notes

Spinal Cord Features

The spinal cord is a critical component of the human nervous system, responsible for transmitting signals between the central nervous system (brain) and the periphery. Its unique features allow it to serve this vital function effectively. Let's explore the external, internal, nucleus, and tract features of the spinal cord.

External Features of Spinal Cord

Length: The human spinal cord is approximately 42 cm in males and 38.9 cm in females.
Enlargements: The spinal cord has two enlarged regions, one at the cervical level (upper limbs) and another at the lumbosacral region (lower limbs).
Protective Covering: The spinal cord is protected by three layers of tissue called meninges: dura mater (outermost), arachnoid mater (middle layer), and pia mater (innermost). These coverings provide additional protection to the spinal cord.

Internal Features of Spinal Cord

Structure: The spinal cord consists of an outer layer of white matter and centrally located gray matter. White matter surrounds the gray matter in the spinal cord and contains cells coated with myelin for faster nerve transmission.
Spinal Nerves: There are 31 pairs of spinal nerves that emerge from different segments of the spinal cord. These include 8 pairs of cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal pair.
Posterior Root and Anterior Root: Each segment of the spinal cord has a posterior root, which branches off the back of the spinal column, and an anterior root, which branches off the front of the spinal column.
Gray Matter and White Matter: The gray matter is a dark butterfly-shaped region made up of nerve cell bodies, while the white matter is surrounding the gray matter and contains cells coated with myelin for quicker nerve conduction.

Nucleus of Spinal Cord

Motoneuron Pool: This pool is located within the ventral horn of the spinal cord and contains motor neurons responsible for controlling voluntary muscle movements.

Tracts of Spinal Cord

Ascending Tracts: These tracts carry sensory information from the body to the brain, such as touch, pressure, and pain signals.
Descending Pathways: These pathways transmit motor commands from the brain to the spinal cord and then to the muscles, enabling movement control.

In summary, the spinal cord's features, including its protective coverings, segmentation, internal structure, nucleus, and tracts, enable it to effectively serve its role in the human nervous system by transmitting signals between the brain and the rest of the body.