neuroanatomy Neuroanatomy is the study of the structure and organization of the nervous system. In contrast to animals with radial symmetry, whose nervous system consists of a distributed network of cells, animals with bilateral symmetry have segregated, defi ...

, the paracentral lobule is on the medial surface of the

cerebral hemisphere The vertebrate cerebrum ( brain) is formed by two cerebral hemispheres that are separated by a groove, the longitudinal fissure. The brain can thus be described as being divided into left and right cerebral hemispheres. Each of these hemisphere ...

and is the continuation of the precentral and postcentral gyri. The paracentral lobule controls

motor An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy. Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power g ...

and sensory innervations of the contralateral lower extremity. It is also responsible for control of

defecation Defecation (or defaecation) follows digestion, and is a necessary process by which organisms eliminate a solid, semisolid, or liquid waste material known as feces from the digestive tract via the anus. The act has a variety of names ranging f ...

and

urination Urination, also known as micturition, is the release of urine from the urinary bladder through the urethra to the outside of the body. It is the urinary system's form of excretion. It is also known medically as micturition, voiding, uresis, ...

. It includes portions of the

frontal Front may refer to: Arts, entertainment, and media Films * ''The Front'' (1943 film), a 1943 Soviet drama film * ''The Front'', 1976 film Music *The Front (band), an American rock band signed to Columbia Records and active in the 1980s and ea ...

and

parietal lobe The parietal lobe is one of the four major lobes of the cerebral cortex in the brain of mammals. The parietal lobe is positioned above the temporal lobe and behind the frontal lobe and central sulcus. The parietal lobe integrates sensory informa ...

s: * The anterior portion of the paracentral lobule is part of the frontal lobe and contains a little portion of Brodmann's area 6 (SMA): this is because the

paracentral sulcus The paracentral sulcus is a sulcus of the brain. It forms the paracentral lobule's anterior border. It is part of the cingulate sulcus. Gallery File:Gray727 cingulate sulcus.svg, Medial surface of left cerebral hemisphere. (Cingulate sulcus ...

(branch of the limbic sulcus) does not correspond to the

precentral sulcus The precentral sulcus is a part of the human brain that lies parallel to, and in front of, the central sulcus. (A ''sulcus'' is one of the prominent grooves on the surface of the human brain.) The precentral sulcus divides the inferior, midd ...

on the medial plane. * The posterior portion is considered part of the parietal lobe and deals with

somatosensory In physiology, the somatosensory system is the network of neural structures in the brain and body that produce the perception of touch (haptic perception), as well as temperature (thermoception), body position ( proprioception), and pain. It ...

of the distal limbs. While the boundary between the lobes, the

central sulcus In neuroanatomy, the central sulcus (also central fissure, fissure of Rolando, or Rolandic fissure, after Luigi Rolando) is a sulcus, or groove, in the cerebral cortex in the brains of vertebrates. It is sometimes confused with the longitudinal ...

, is easy to locate on the lateral surface of the cerebral hemispheres, this boundary is often discerned in a cytoarchetectonic manner in cases where the central sulcus is not visible on the medial surface.

Function

Neurons in paracentral lobule are concerned with: #

Motor An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy. Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power g ...

and sensory innervations of the contralateral lower extremity # Regulation of physiological function such as defecation and micturition

Blood supply

It is supplied by branches of the

anterior cerebral artery The anterior cerebral artery (ACA) is one of a pair of cerebral arteries that supplies oxygenated blood to most midline portions of the frontal lobes and superior medial parietal lobes of the brain. The two anterior cerebral arteries arise from ...

Applied anatomy

Damage of paracentral lobule occurs from occlusion of anterior cerebral artery. Characteristic manifestations include: * Contralateral lower limb muscle weakness * Urinary incontinence

Gallery

File:Paracentral lobule animation small.gif, Animation. Paracentral lobule is shown in red. File:Medial surface of cerebral cortex - gyri.png, Medial view of a human right

. Paracentral lobule is labeled at top center, in green. File:Sobo 1909 632 - Paracentral lobule.png, Medial view of a human right cerebral hemisphere. Paracentral lobule is labeled at top center, in blue. File:Gray727 cingulate sulcus.svg,

Cingulate sulcus The cingulate sulcus is a sulcus (brain fold) on the cingulate cortex in the medial wall of the cerebral cortex. The frontal and parietal lobes are separated from the cingulate gyrus by the cingulate sulcus. It terminates as the marginal sulcus o ...

defines the boundaries of the paracentral lobule. File:Gray727 marginal sulcus.svg, Marginal sulcus. It defines the posterior boundary of the paracentral lobule. File:Gray727 paracentral sulcus.png,

Paracentral sulcus The paracentral sulcus is a sulcus of the brain. It forms the paracentral lobule's anterior border. It is part of the cingulate sulcus. Gallery File:Gray727 cingulate sulcus.svg, Medial surface of left cerebral hemisphere. (Cingulate sulcus ...

. It defines the anterior boundary of the paracentral lobule. File:Gray727 central sulcus.svg,

Central sulcus In neuroanatomy, the central sulcus (also central fissure, fissure of Rolando, or Rolandic fissure, after Luigi Rolando) is a sulcus, or groove, in the cerebral cortex in the brains of vertebrates. It is sometimes confused with the longitudinal ...

on the medial surface. It divides the paracentral lobule into the anterior part and the posterior part. File:Paracentral - DK ATLAS.png, Paracentral lobule, shown in the right cerebral hemisphere.

References

External links

* https://web.archive.org/web/20090405083407/http://psychology.uwo.ca/fmri4newbies/PrimeronCorticalSulci.html#Cingulate%20sulcus {{Authority control Gyri Frontal lobe Parietal lobe Medial surface of cerebral hemisphere