The Rexed laminae (singular: Rexed lamina) comprise a system of ten layers of

grey matter Grey matter, or gray matter in American English, is a major component of the central nervous system, consisting of neuronal cell bodies, neuropil ( dendrites and unmyelinated axons), glial cells ( astrocytes and oligodendrocytes), synapses, ...

(I–X), identified in the early 1950s by

Bror Rexed Bror Anders Rexed (19 June 1914 – 21 August 2002) was a Swedish neuroscientist and professor at Uppsala University. Internationally, he is best known today for his development of the system now known as Rexed laminae, but in Sweden, he is a ...

to label portions of the

grey column The grey columns are three regions of the somewhat ridge-shaped mass of grey matter in the spinal cord. These regions present as three columns: the anterior grey column, the posterior grey column, and the lateral grey column, all of which ...

s of the

spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue that extends from the medulla oblongata in the lower brainstem to the lumbar region of the vertebral column (backbone) of vertebrate animals. The center of the spinal c ...

. Similar to

Brodmann area A Brodmann area is a region of the cerebral cortex, in the human or other primate brain, defined by its cytoarchitecture, or histological structure and organization of cells. The concept was first introduced by the German anatomist Korbinian B ...

s, they are defined by their cellular structure rather than by their location, but the location still remains reasonably consistent.

Laminae

Posterior grey column The grey columns are three regions of the somewhat ridge-shaped mass of grey matter in the spinal cord. These regions present as three columns: the anterior grey column, the posterior grey column, and the lateral grey column, all of which are ...

: I–VI ** Lamina I: marginal nucleus of spinal cord or posteromarginal nucleus ** Lamina II:

substantia gelatinosa of Rolando The apex of the posterior grey column, one of the three grey columns of the spinal cord, is capped by a V-shaped or crescentic mass of translucent, gelatinous neuroglia, termed the substantia gelatinosa of Rolando (or SGR) (or gelatinous substan ...

** Laminae III and IV:

nucleus proprius The nucleus proprius of spinal cord is a layer of the spinal cord adjacent to the substantia gelatinosa. The nucleus proprius can be found in the gray matter in all levels of the spinal cord. It constitutes the first synapse of the posterior gray ...

** Lamina V: Neck of the dorsal horn. Neurons within lamina V are mainly involved in processing sensory afferent stimuli from cutaneous, muscle and joint mechanical nociceptors as well as visceral nociceptors. This layer is home to wide dynamic range tract neurons, interneurons and propriospinal neurons. Viscerosomatic pain signal convergence often occurs in this lamina due to the presence of wide dynamic range tract neurons resulting in pain referral. ** Lamina VI: Base of the dorsal horn. No nociceptive input occurs here, instead this lamina receives input from large-diameter fibres innervating muscles and joints and from muscle spindles which are sensitive to innocuous joint movement and muscle stretch to feed forward this information to the cerebellum where it can modulate muscle tone accordingly. *

Lateral grey column The lateral grey column (lateral column, lateral cornu, lateral horn of spinal cord, intermediolateral column) is one of the three grey columns of the spinal cord (which give the shape of a butterfly); the others being the anterior grey column, ...

: VII and X ** Lamina VII: intermediomedial nucleus, intermediolateral nucleus, posterior thoracic nucleus in the thoracic and upper lumbar region ** Lamina X: an area of grey matter – the grey commissure surrounding the

central canal The central canal (also known as spinal foramen or ependymal canal) is the cerebrospinal fluid-filled space that runs through the spinal cord. The central canal lies below and is connected to the ventricular system of the brain, from which it r ...

. This region also serves to connect the anterior and posterior

grey columns The grey columns are three regions of the somewhat ridge-shaped mass of grey matter in the spinal cord. These regions present as three columns: the anterior grey column, the posterior grey column, and the lateral grey column, all of which ar ...

. Rexed never described this as ''lamina X'' but as ''area X''. *

Anterior grey column The grey columns are three regions of the somewhat ridge-shaped mass of grey matter in the spinal cord. These regions present as three columns: the anterior grey column, the posterior grey column, and the lateral grey column, all of which are ...

: VIII–IX ** Lamina VIII: motor

interneurons Interneurons (also called internuncial neurons, association neurons, connector neurons, or intermediate neurons) are neurons that are not specifically motor neurons or sensory neurons. Interneurons are the central nodes of neural circuits, ena ...

** Lamina IX: hypaxial (body wall muscles), lateral (in limb regions) and medial (back muscles)

motor neurons A motor neuron (or motoneuron), also known as efferent neuron is a neuron whose cell body is located in the motor cortex, brainstem or the spinal cord, and whose axon (fiber) projects to the spinal cord or outside of the spinal cord to directly or ...

, also

phrenic The phrenic nerve is a mixed nerve that originates from the C3–C5 spinal nerves in the neck. The nerve is important for breathing because it provides exclusive motor control of the diaphragm, the primary muscle of respiration. In humans, t ...

and spinal accessory nuclei at cervical levels, and

Onuf's nucleus Onuf's nucleus is a distinct group of neurons located in the ventral part ( lamina IX) of the anterior horn of the sacral region of the human spinal cord involved in the maintenance of micturition and defecatory continence, as well as muscular ...

in the sacral region

References

{{Authority control Spinal cord

Laminae

See also

References