The spelling of the word "pigmentary commissura" can be confusing due to its complex structure. The word is made up of two parts: pigmentary, which refers to something related to pigment, and commissura, which means a bundle of nerve fibers. The pronunciation of this word is /pɪɡˈmɛntəri kəˈmɪʃərə/, with emphasis on the second and fourth syllables. To properly spell this word, one must remember to include the correct number of letters in each syllable and use the correct phonetic sounds for each letter.
Pigmentary commissura refers to a structure found in the human brain, specifically in the basal ganglia. It is located in the substantia nigra, a region responsible for the production of dopamine, a neurotransmitter involved in regulating movement. The pigmentary commissura consists of a band of nerve fibers, or commissural fibers, that connect the substantia nigra on both sides of the brain.
The main function of the pigmentary commissura is to facilitate communication and coordination between the two halves, or hemispheres, of the substantia nigra. It plays a crucial role in the regulation and modulation of motor activities and control of voluntary movements. The commissura enables the exchange of information and signals between the left and right substantia nigra, allowing for smooth and coordinated movement.
The name "pigmentary commissura" arises from the fact that this structure contains a high concentration of melanin, a pigment that gives it a distinct dark color. The presence of melanin is a characteristic feature of the substantia nigra, which contributes to its appearance and gives rise to its name, meaning "black substance" in Latin.
In summary, the pigmentary commissura is a band of nerve fibers connecting the substantia nigra on both sides of the brain. It allows for communication and coordination between the hemispheres, facilitating the regulation of voluntary movements and motor activities.
Posterior cerebral commissure, a thin band of white matter, crossing from side to side beneath the habenula of the pineal body and overlying the aditus ad aquaeductum cerebri.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.