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In anatomy, the median plane refers to a plane passing vertically through the midline. It divides the body into left and right halves of equal proportion, i.e. in the case of bilateral symmetry. In the human body, the median plane corresponds to the plane running from the top to the bottom through the midline structures such as navel and spine.
The term median came from the Latin medianus, which pertains to the middle whereas the term plane came from the Latin plānum, meaning “flat surface”. Synonym: midsagittal plane.
Anatomical planes are hypothetical planes used in describing the location of bodily structures or movement directions. There are three major planes used in animal and human anatomy: (1) the sagittal plane, (2) coronal plane (also called frontal plane or Y-X plane), and (3) transverse plane (also called axial plane or X-Z plane). The sagittal plane (also called lateral plane or Y-Z plane) refers to any hypothetical plane that runs parallel to the median plane. There are two types of sagittal plane: median and parasagittal.
Median plane vs. median section
The median section (also called midsagittal section) refers to the cross-section that runs through the median plane. The term can be applied both in actuality and through imaging techniques. The median section may be applied to a whole body or any body part that is sliced across the median plane. In the human body, the components of the left plane are often symmetrical to the components of the right plane. Since actual sectioning the median plane results in a right and a left half, an anatomical median section may be a two-dimensional view of the cut surface on the medial aspect of either half.
Median plane vs. sagittal plane
The sagittal plane is a plane traversing the direction from top to bottom. Thus, similar to the median plane, the sagittal plane results in the formation of left and right portions. However, the left and right sections of a sagittal plane may not be of the same girth as the cut could be done anywhere from top to bottom. In the case of cutting through the midline, it would be referred to as the median plane, which is also referred to, in particular, as the mid-sagittal plane. Thus, a median plane is a type of sagittal plane that runs along the midline.
Median plane vs. parasagittal plane
Another type of sagittal plane is the parasagittal plane. It is the plane situated alongside or parallel to the mid-sagittal plane. Thus, it would refer to any plane traversing the direction from top to bottom but except for the midline as it would then be referred to as the median plane. For example, the midclavicular line crossing through the clavicle is a parasagittal plane.
- 1.4D: Body Planes and Sections. (2018, July 18). Retrieved from Medicine LibreTexts website: https://med.libretexts.org/Bookshelves/Anatomy_and_Physiology/Book%3A_Anatomy_and_Physiology_(Boundless)/1%3A_Introduction_to_Anatomy_and_Physiology/1.4%3A_Mapping_the_Body/1.4D%3A_Body_Planes_and_Sections
- Machine Design. (2015, February 2). What’s the Difference Between the Sagittal, Coronal, and Transverse Planes. Machine Design website: https://www.machinedesign.com/medical/what-s-difference-between-sagittal-coronal-and-transverse-planes
- The Anatomical Regions of the Body – dummies. (2017). Dummies website: https://www.dummies.com/education/science/anatomy/anatomical-regions-body/
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