Relative Positions

Descriptions of the location of one part of the body in relation to another part of the body utilize terms of relative position. All of these terms assume that the body is in a standard position called the anatomical position. This posture of the body assumes that the body is facing the viewer, arms and legs down, and palms forward (Figure 1.1). Regardless of the actual position of the body and its parts, anatomical terminology is used as if the body were in anatomical position. Note: in anatomical position the body is facing you; therefore, the right side of the body will be on your left.

Anterior and Posterior. In humans the anterior structures are those at the front of the body such as the face and abdomen. The posterior features are those at the rear of the body, for example, the back and buttocks. The terms ventral and dorsal are sometimes used in place of anterior and posterior. Ventral is normally used of four-legged animals to refer to structures underneath, i.e. the belly. The word dorsal refers to the back.

Superior and Inferior. These two terms explain the vertical relationship between body parts. The Latin word super means above. Therefore, a superior part is above an inferior part. For example the head is superior to the neck while the neck is inferior to the head. The hair on top of the head is superior to all other structures. In animals, the terms cephalad (toward the head) and caudal (toward the tail) are used instead of superior and inferior.

Anatomical Terms For Body Parts
Figure 1.1 Anatomical Position Figure 1.2 Posterior Surface

Anterior Distal (X2) Inferior Lateral Medial Posterior Proximal (X2) Superior

Figure 1.3 Frontal section

Sections of the Body Midsagittal section Transverse section

Medial and Lateral. These words describe the location of structures in relationship to an imaginary plane separating the body into right and left halves. Medial structures are closer to the line than are lateral structures. For example the nose is medial to the eyes; whereas, the eyes are lateral to the nose.

Superficial and Deep. Superficial structures lie closer to the surface of the body than deep structures.

Proximal and Distal. The last words describing relative positions are used to describe the location of parts of a limb relative to the point of attachment of the limb to the trunk.

Those parts which are closer to the point of attachment are said to be proximal. The more distant parts are distal. The fingers are distal to the palm; the palm is proximal to the fingers.

Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

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