Dorsal
From Free net encyclopedia
The word dorsal can refer to many different things.
- In anatomy, the dorsal is the side in which the backbone is located. This is usually the top of an animal, although in humans it refers to the back. In fishes, it refers to the top, front fin (see Dorsal fin). It is the anatomical opposite of ventral (referring to the front or underside of an animal).
- Dorsum and dorsally are derivatives of this word and refer to anatomical structures that are either toward the back (backbone) or off the back side of an animal. The names of some structures have even had dorsal (or a form of dorsal) incorporated into them. Examples of this include the dorsal fin, dorsal root ganglion, dorsal root, dorsal nerve, dorsum sellae, dorsal arch, dorsalis pedis arteries, dorsal ramus, dorsal respiratory group, dorsal venous arch, and dorsiflexion among others.
- In linguistics, a dorsal consonant refers to hard sounds utilizing the tongue on the back of the mouth, such as palatal, velar, and uvular consonants.
- In neurology, dorsal is an outdated term for the medial longitudinal fasciculus in the neural arch. In 1846 neurologist Benedict Stilling first referred to what is now known as the medial longitudinal fasciculus as acusticus, followed by Theodor Meynert in 1872 calling it posterior. But in 1891, Heinrich Schutz chose the name dorsal to describe the longitudinal bundle, "for brevity's sake". This name stuck despite other authors attempting further renaming (Ramon y Cajal's periependymal in 1904, Theodor Ziehens's nubecula dorsalis in 1913). But finally, it was Wilhelm His, Sr who changed the name to medial for the sake of the Basle nomenclature to end the confusion.
- The word dorsal can also refer to a knife with only one sharp side.
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Etymology
The use of dorsal meaning "the back of an animal or fish" dates from the 18th century, after a Medieval Latin source meaning "back". But in the 16th century, the word dorsal referred only to a type of knife: a knife with only one cutting edge (i.e. a knife with a 'back'). The opposite of dorsal in this sense was ansall, meaning a double-sided knife.
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