For humans, anatomical terms are always referenced to an individual standing in what is known as the standard anatomical position. Thus, for such an individual, the sagittal (median) plane divides the body or an organ into left and right sides while a transverse (horizontal) plane divides the body or organ into superior (upper) and inferior (lower) portions, and a frontal (coronal) plane divides the body or organ into anterior and posterior sides.
Other useful anatomical terms include medial (toward the center of the body), lateral (toward the side of the body), proximal (nearer to the reference point) and distal (further from the reference point). Thus, the outside of the leg is the lateral surface while the inside is the medial surface, and the distal end of the humerus (the arm bone) articulates with the radius and ulna of the forearm, while the proximal end fits into a socket in the scapula.
In a human, anterior describes structures nearest the front side of the body, and posterior describes structures toward the rear, or backside, of the body. The terms dorsal (backside) and ventral (“belly”) are used interchangeably with the terms posterior and anterior. The sternum (breast bone) is on the ventral side of the body and anterior to the vertebral column, while the scapula (shoulder blade) is on the dorsal side of the body and posterior to the clavicle (collarbone).
The terms superior and inferior refer to the location of structures along the long axis of the body. Superior structures are above other structures and inferior structures are below other body parts. Thus, in humans the nose is superior to the mouth, and the toes are inferior to the knees.
The terms superficial and deep describe a structures relationship to the body surface and the deepest part of the body. The skin is superficial to the skeletal muscles and the heart is deep to the sternum.
Finally, the terms proximal and distal refer to the