In anatomy

Anatomy

Anatomy is a branch of biology and medicine that is the consideration of the structure of living things. It is a general term that includes human anatomy, animal anatomy , and plant anatomy...

 and neurology

Neurology

Neurology is a medical specialty dealing with disorders of the nervous system. Specifically, it deals with the diagnosis and treatment of all categories of disease involving the central, peripheral, and autonomic nervous systems, including their coverings, blood vessels, and all effector tissue,...

, the dorsal root (or posterior root) is the afferent

Afferent nerve

In the nervous system, afferent neurons , carry nerve impulses from receptors or sense organs towards the central nervous system. This term can also be used to describe relative connections between structures. Afferent neurons communicate with specialized interneurons...

sensory

Somatosensory system

The somatosensory system is a diverse sensory system composed of the receptors and processing centres to produce the sensory modalities such as touch, temperature, proprioception , and nociception . The sensory receptors cover the skin and epithelia, skeletal muscles, bones and joints, internal...

 root of a spinal nerve

Spinal nerve

The term spinal nerve generally refers to a mixed spinal nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body...

.

At the distal end of the dorsal root is the dorsal root ganglion

Dorsal root ganglion

In anatomy and neuroscience, a dorsal root ganglion is a nodule on a dorsal root that contains cell bodies of neurons in afferent spinal nerves.-Unique unipolar structure:...

, which contains the neuron

Neuron

A neuron is an electrically excitable cell that processes and transmits information by electrical and chemical signaling. Chemical signaling occurs via synapses, specialized connections with other cells. Neurons connect to each other to form networks. Neurons are the core components of the nervous...

 cell bodies of the nerve

Nerve

A peripheral nerve, or simply nerve, is an enclosed, cable-like bundle of peripheral axons . A nerve provides a common pathway for the electrochemical nerve impulses that are transmitted along each of the axons. Nerves are found only in the peripheral nervous system...

 fibres conveyed by the root.

If the dorsal root of a spinal nerve were severed it would lead to numbness in certain areas of the body.

The lateral division of the dorsal root contains lightly myelinated and unmyelinated axons of small diameter. These transmit pain and temperature sensation from the body. These fibers cross through the anterior white commissure

Anterior white commissure

The anterior white commissure, also known as the alba anterior medullae spinalis, is a bundle of nerve fibers which cross the midline of the spinal cord just anterior to the gray commissure...

 to form the Anterior lateral system in the lateral funiculus.

The medial division of the dorsal root contains myelinated axons of larger diameter. These transmit information of discriminative touch, pressure, vibration, and conscious proprioception originating from spinal levels C2 through S5. These fibers are pushed in towards the posterior medial sulcus to form the fasciculus gracilis

Fasciculus gracilis

The fasciculus gracilis is a bundle of axon fibres in the posterior column of the spinal cord and carries information from the middle thoracic and lower limbs of the body...

 and the fasciculus cuneatus

Fasciculus cuneatus

The fasciculus cuneatus is a tract of nerves in the spinal cord which primarily transmits information from the arms...

.

External links

- "Superior view of a section through the spinal cord within the vertebral foramen

Vertebral foramen

In a typical vertebra, the vertebral foramen is the foramen formed by the anterior segment , and the posterior part, the vertebral arch....

." - "Spinal Root Nerve Fibers"

• Dorsal Root - Cell Centered Database