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| CATEGORIES ABOUT ANATOMICAL TERMS OF LOCATION | |
| anatomy | |
| animal anatomy | |
| SHOPPER'S DELIGHT | |
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In some cases, the terminology in Human Anatomy may differ from that in general anatomy, which also applies to other species (where some very different organs occur). The Anatomical Position holds more relevant information on relations and terms of location for human anatomy. DIRECTIONS General usage Animals typically have one end with a head and mouth, with the opposite end often having the anus and tail. The head end is the cranial end; the tail end is the '''caudal''' end. Within the head itself, '''rostral''' refers to the direction toward the end of the nose, and caudal is still used to refer to the tail direction. The surface or side of the body normally oriented upwards, away from the pull of gravity, is the dorsal side; the opposite side, typically the one closest to the ground when walking on all legs, swimming or flying, is the '''ventral''' side. For example: in Vertebrate s, the Spine or nerve chord is located on the ''dorsal'' side of the organism. A dolphin's dorsal fin is, unsurprisingly, on the ''dorsal'' side. A cow's udder is on the ''ventral'' side. On the limbs or other appendages, a point closer to the main body is "proximal"; a point farther away is "'''distal'''". The right and left side (sometimes in Latin : dexter - right, and '''sinister''' - left) are always given as viewed from the animal that is described. Usage in human anatomy In human anatomy, the body and its parts are always described using the assumption that the body is in Anatomical Position (''main article''), i.e. standing upright. Portions of the body which are closer to the head end are "superior" (Latin "upper"); those which are farther away are "'''inferior'''" ("lower") -- superior corresponds to cranial (at the skull'), and inferior to caudal ('at the tail'). Objects near the front are "'''anterior'''"; those near the rear are "'''posterior'''" -- these correspond respectively to "ventral" and "dorsal". The terms "anterior" and "posterior" should not be used when referring to most animals however, and are particularly incorrect for Quadruped s. In this case, rostral/cranial and caudal are more appropriate. :However the word posterior is commonly used (not in anatomical jargon) as a substantive meaning the buttocks or an adjective referring to them, as in 'posterior discipline' (such as Spanking ) ''Consult the Anatomical Position page for more detailed terminology for human anatomy.'' RELATIVE DIRECTIONS Structures near the midline are called medial and those near the sides of animals are called '''lateral'''. Therefore, medial structures are closer to the midsagittal plane, lateral structures are further from the midsagittal plane. Structures in the midline of the body are '''median'''. For example, your cheeks are lateral to your nose and the tip of the nose is in the median line. '''Ipsilateral''' means on the same side, '''contralateral''' means on the other side and '''bilateral''' means on both sides. Structures that are close to the center of the body are proximal or '''central''', while ones more distant are '''distal''' or '''peripheral'''. For example, the hands are at the distal end of the arms, while the shoulders are at the proximal ends. These terms can also be used relatively to organs, for example the proximal end of the Urethra is attached to the Bladder . Structures on or closer to the body's surface are superficial (or '''external''') and those further inside are '''profound''' or '''deep''' (or '''internal'''). When speaking of inner organs, visceral means close to or attached to the organ, while '''parietal''' is more distant. For example, the visceral Pleura is attached to the lung and the parietal pleura is attached to the chest wall. Relative directions in the limbs In the limbs of most animals, the terms cranial and '''caudal''' are used in the regions proximal to the carpus (the Wrist , in the forelimb) and the tarsus (the Ankle in the hindlimb). Objects and surfaces closer to or facing towards the head are ''cranial''; those facing away or further from the head are ''caudal''. This usage is not common in human anatomy, however. Distal to the carpal joint, the term dorsal replaces '''cranial''' and '''palmar''' replaces '''caudal'''. Similarly, distal to the tarsal joint the term dorsal replaces '''cranial''' and '''plantar''' replaces '''caudal'''. For example, the top of a Dog 's Paw is its ''dorsal'' surface; the underside, either the ''palmar'' (on the forelimb) or the ''plantar'' (on the hindlimb) surface. The sides of the forearm are named after its bones: Structures closer to the Radius are radial, structures closer to the Ulna are '''ulnar''', and structures relating to both bones are referred to as '''radioulnar'''. Similarly, in the lower leg, structures near the Tibia (shinbone) are '''tibial''' and structures near the Fibula are '''fibular''' (or '''peroneal'''). Volar, a term which refers to both the palm and the sole, is sometimes used as a synonym for "palmar". PLANES General usage Three basic reference planes are used in zoological anatomy. A sagittal plane divides the body into left and right portions. The '''midsagittal''' plane is in the midline, i.e. it would pass through midline structures such as the Navel or Spine , and all other sagittal planes are parallel to it. A '''coronal''' plane divides the body into dorsal and ventral portions. A '''transverse''' plane divides the body into cranial and caudal portions. Usage in human anatomy Sometimes the orientation of certain planes need to be distinguished, for instance in Medical Imaging techniques such as CT Scans , MRI Scans or PET Scans . One imagines a human in Anatomical Position (standing, arms hanging down with palms to the front) and an X-Y-Z Coordinate System with the X-Y plane parallel to the ground, the X-axis going front and back, the Y-axis passing left and right, and the Z-axis going up and down.
RELATIVE MOTIONS See Also: Anatomical terms of motion SEE ALSO EXTERNAL LINKS |