Three spinal cord horns are visible in cross-sectional views of the spinal cord

Spinal cord

The spinal cord is a long, thin, tubular bundle of nervous tissue and support cells that extends from the brain . The brain and spinal cord together make up the central nervous system...

: dorsal horn, ventral horn, and the lateral horn

Lateral horn

In the thoracic region, the postero-lateral part of the anterior column projects lateralward as a triangular field, which is named the lateral column .-Nerve Cells in the Lateral Column:...

 (or intermediolateral horn). Each is composed of gray matter

Grey matter

Grey matter is a major component of the central nervous system, consisting of neuronal cell bodies, neuropil , glial cells and capillaries. Grey matter contains neural cell bodies, in contrast to white matter, which does not and mostly contains myelinated axon tracts...

, meaning that the horns comprise mostly 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...

al and glial cell bodies (but also have axon

Axon

An axon is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neuron's cell body or soma....

s and dendrite

Dendrite

Dendrites are the branched projections of a neuron that act to conduct the electrochemical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project...

s). The dorsal horn is generally associated with sensory neuron

Sensory neuron

Sensory neurons are typically classified as the neurons responsible for converting external stimuli from the environment into internal stimuli. They are activated by sensory input , and send projections into the central nervous system that convey sensory information to the brain or spinal cord...

s, while the neurons of the ventral horn are mostly motor neuron

Motor neuron

In vertebrates, the term motor neuron classically applies to neurons located in the central nervous system that project their axons outside the CNS and directly or indirectly control muscles...

s. The lateral horn is only present in certain segments of the spinal cord (cervical and superior lumbar segments), where it contains neurons innervating limb muscles, preganglionic cell bodies of the autonomic nervous system

Autonomic nervous system

The autonomic nervous system is the part of the peripheral nervous system that acts as a control system functioning largely below the level of consciousness, and controls visceral functions. The ANS affects heart rate, digestion, respiration rate, salivation, perspiration, diameter of the pupils,...

, and sensory relay neurons.