From Mantropedia
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provides a definition of what is at the front (anterior), behind (posterior) and so on. As part of defining and describing terms, the body is described through the use of anatomical planes and anatomical axes.
The meaning of terms that are used can change depending on whether an organism is bipedal or quadrupedal. Additionally, for some animals such as invertebrates, some terms may not have any meaning at all; for example, an animal that is radially symmetrical will have no anterior surface, but can still have a description that a part is close to the middle (proximal) or further from the middle (distal).
International organisations have determined vocabularies that are often used as standard vocabularies for subdisciplines of anatomy, for example, Terminologia Anatomica for humans, and Nomina Anatomica Veterinaria for animals. These allow parties that use anatomical terms, such as anatomists, veterinarians, and medical doctors to have a standard set of terms to communicate clearly the position of a structure.
Organisms where the ends of the long axis are distinct. (Paramecium caudatum, above, and Stentor roeselii, below.) The axes of the body are lines drawn about which an organism is roughly symmetrical.[8] To do this, distinct ends of an organism are chosen, and the axis is named according to those directions. An organism that is symmetrical on both sides has three main axes that intersect at right angles.[3] An organism that is round or not symmetrical may have different axes.Example axes are:
superior | inferior | medial | lateral / marginal | internal | external | dorsal / posterior | ventral / anterior | |
Anterior | anterosuperior | anteroinferior | anteromedial | anterolateral / anteromarginal | anterointernal | Sagittal plane | anteroventral | |
Posterior | posterosuperior | posteroinferior | posteromedial | posterolateral / posteromarginal | ||||
Ventral | ventromedial | ventrolateral | ||||||
Dorsal | dorsomedial | dorsolateral | dorso-posterior | dorso-anterior | ||||
Centro | centromedian | |||||||
Intermedio | intermediomedial | intermediolateral | ||||||
Ipsi | Ipsimedial | Ipsilateral | ||||||
Contra | Contramedial | Contralateral | ||||||
Co | Collateral | |||||||
Superficial | Superficial posterior | superficial anterior | ||||||
Deep | Deep posterior | Deep anterior | ||||||
dexter | ||||||||
sinister |