ventral root

Examples of ventral root in the following topics:

• Spinal Cord Grey Matter and Spinal Roots

  • Damage to the grey matter (eg, the ventral gray horn) may lead to tingling and muscle weakness.
  • The cord has grooves in the dorsal and ventral sides.
  • The posterior median sulcus is the groove in the dorsal side, and the anterior median fissure is the groove in the ventral side.
  • Ventral roots consist of axons from motor neurons, which bring information to the periphery from cell bodies within the CNS.
  • Dorsal roots and ventral roots come together and exit the intervertebral foramina as they become spinal nerves.

• Overview of the Spinal Nerves

  • Each spinal nerve is formed by the combination of nerve fibers from the dorsal and ventral roots of the spinal cord.
  • The dorsal roots carry afferent sensory axons, while the ventral roots carry efferent motor axons.
  • The ventral ramus contains nerves that serve the remaining ventral parts of the trunk and the upper and lower limbs (hypaxial muscles); they carry visceral motor, somatic motor, and sensory information to and from the ventrolateral body surface, structures in the body wall, and the limbs.
  • Its anterior root helps form the coccygeal plexus.
  • Spinal nerves arise from a combination of nerve fibers from the dorsal and ventral roots of the spinal cord.

• Sensory-Somatic Nervous System

  • The sensory neuron cell bodies are grouped in structures called dorsal root ganglia .
  • Motor neurons have cell bodies in the ventral gray matter of the spinal cord that project to muscle through the ventral root.
  • The cell bodies of sensory neurons are located in dorsal root ganglia.
  • The cell bodies of motor neurons are found in the ventral portion of the gray matter of the spinal cord.

• Somatic Sensory Pathways

  • The somatosensory pathway is composed of three neurons located in the dorsal root ganglion, the spinal cord, and the thalamus.
  • The first always has its cell body in the dorsal root ganglion of the spinal nerve.
  • This is the target for neurons of the dorsal column–medial lemniscal pathway and the ventral spinothalamic pathway.
  • Sensory nerves of a dorsal root ganglion are depicted entering the spinal cord.
  • The formation of the spinal nerve from the dorsal and ventral roots.

• Overview of the Spinal Cord

  • Each spinal nerve is formed from the combination of nerve fibers from its posterior and anterior roots.
  • The posterior root is the sensory (afferent) root that carries sensory information to the brain from other areas of the body.
  • The anterior root is the motor (efferent) root that carries motor information to the body from the brain.
  • The swelling found in the posterior root is the posterior (dorsal) root ganglion, which contains the cell bodies of sensory neurons.
  • The anterior (ventral) root contains axons of motor neurons that conduct nerve impulses from the CNS to other parts of the body such as the muscles.

• Somatic Sensory Pathways to the Cerebellum

  • The ventral and dorsal spinocerebellar tracts convey proprioceptive information from the body to the cerebellum.
  • The ventral spinocerebellar tract conveys proprioceptive information from the body to the cerebellum.
  • Axons first cross midline in the spinal cord and run in the ventral border of the lateral funiculi.
  • It is part of the somatosensory system and runs in parallel with the ventral spinocerebellar tract.
  • Proprioceptive information is taken to the spinal cord via central processes of the dorsal root ganglia (where first order neurons reside).

• Brachial Plexus

  • The brachial plexus is a network of nerve fibers that run from the spine that are formed by the ventral rami of the lower four cervical and first thoracic nerve roots (C5–C8, T1).
  • The brachial plexus is divided into roots, trunks, divisions, cords, and branches.
  • Five roots: The five anterior rami of the spinal nerves, after they have given off their segmental supply to the muscles of the neck.
  • These roots merge to form three trunks: The superior or upper (C5–C6), the middle (C7), and the inferior or lower (C8, T1).

• Cervical Plexus

  • The cervical plexus is the plexus of the ventral rami of the first four cervical spinal nerves.
  • The cervical plexus is a plexus of the ventral rami of the first four cervical spinal nerves located from the C1 to C4 cervical segment in the neck.
  • There are two additional branches that are formed by the posterior roots of the spinal nerves:

• Embryonic Development

  • Five molecularly distinct groups of ventral neurons form from these neuronal progenitor cells in vitro.
  • Shown is the dorsal root ganglion (green ellipsoid regions where cells express neurofilament) and the ventricular zone (red region where cells proliferate) as well as the neural tube with roof and floor plate.
  • Shh secreted from the floor plate creates a gradient along the ventral neural tube.
  • Shh functions in a concentration-dependent manner to specify ventral neuronal fates.
  • V0-V3 represent four different classes of ventral interneurons, and MN indicates motor neurons.

• Dermatomes

  • A dermatome is an area of skin that is supplied by a single spinal nerve, and a myotome is a group of muscles that a single spinal nerve root innervates.
  • Symptoms that follow a dermatome, such as pain or a rash, may indicate a pathology that involves the related nerve root.
  • A myotome is the group of muscles that a single spinal nerve root innervates.
  • Results may indicate lesions to the spinal cord nerve root, or intervertebral disc herniation that presses on the spinal nerve roots.
  • Dermatomes and the associated major cutaneous nerves are shown here in a ventral view.