Clinical Anatomy Glossary: M
mandible: The jawbone.
manubrium: The superior part of the sternum.
matrix: A structural component made of water, collagen fibers, and crystallized calcium salts.
medial: Closer to the midline of the body. The big toe is medial to the little toe.
medial epicondyle: A bony prominence proximal to the medial condyle.
medial rotation: To turn a body part around its long axis, with the anterior surface moving toward the midline, like when you turn your whole lower extremity so that your foot points inward.
median: At the midline of the body. For example, the nose is a median structure.
mediastinum : The compartment that takes up the middle portion of the thoracic cavity.
medullary cavity: Open space inside the bone.
meninges: Coverings of the brain. They protect the brain by housing a fluid-filled space, and they function as a framework for blood vessels.
metabolism: The chemical reactions that convert food into energy.
midsagittal plane: An imaginary vertical plane that clinical anatomy uses to divide the body into left and right halves.
multinucleated: Containing more than one nucleus.
myoblasts: Embryonic muscle cells.
myocardium: Muscle of the heart.