Abdominopelvic cavity Part of the ventral cavity that contains the abdominal and pelvic cavities.
Anatomical (anatomic) position (an-uh-TOM-i-kul, an-uh-TOM-ik) The body standing erect with face forward, feet together, arms hanging at the sides, and palms forward.
Anatomy (uh-NAT-uh-mee) Study of the shape and structure of the human body.
Anterior Toward the front.
Appendicular (ap-en-DIK-yoo-ler) Pertaining to the body region that consists of the arms and legs.
Axial (AK-see-ul) Referring to the body region that comprises the head, neck, and trunk.
Connective tissue The major support material of the body.
Cranial (KRAY-nee-ul) cavity Space that houses the brain.
Cytoplasm (SI-toe-plaz-em) Gel-like fluid inside the cell.
Differentiation Term for the specialization function of cells.
Dorsal cavity Cavity located in the back of the body.
Epithelial (ep-i-THEE-lee-ul) tissue Type of tissue that forms the covering of all body surfaces.
National Institute of Dental and Craniofacial Research (NIDCR) The federal government’s lead agency for scientific research on oral, dental, and craniofacial disease.
Nucleus (NOO-klee-us) “Control center” of the cell.
Organelle (or-guh-NEL) Specialized part of a cell that performs a specific function.
Parietal (puh-RYE-e-tul) Pertaining to the walls of a body cavity.
Physiology (fiz-ee-OL-uh-jee) Study of the functions of the human body.
Posterior Toward the back.
Sagittal (SADJ-ih-tal) plane Any vertical plane parallel to the midline that divides the body into unequal left and right portions.
Spinal cavity Space in the body that contains the spinal cord.
Thoracic cavity Contains the heart, lungs, esophagus, and trachea.
Ventral cavity Cavity located at the front of the body.
Visceral (VIS-er-ul) Pertaining to internal organs or the covering of those organs.
It is important for the dental assistant to understand the basic structure and anatomy of the human body. Anatomy is the scientific study of the shape and structure of the human body. Physiology is the scientific study of how the body functions (see Chapter 7). Studies of anatomy and physiology are closely related because one continuously influences the other. Remember that function affects structure, and structure affects function.
To communicate effectively as a health professional, you must begin by learning some basic terms that relate to the anatomy of the body. This chapter discusses terms used to describe directions and regions of the body. You are learning a new vocabulary that will continue to grow as you progress through the book. The basic anatomic reference systems are (1) planes and body directions, (2) structural units, and (3) body cavities.
Planes and Body Directions
The word anatomy comes from the Greek words ana and tome-, which means to “cut up.” In the study of anatomy, the human body is described as if it were dissected. Terms used to describe directions in relation to the whole body are easier to understand if you think of them as pairs of opposite directions, such as up and down, left and right, or front and back (Table 6-1).
|Superior||Above another part, or closer to head||Nose is superior to mouth.|
|Inferior||Below another part, or closer to feet||Heart is inferior to neck.|
|Proximal||Closer to a point of attachment, or closer to trunk of body||Elbow is proximal to wrist.|
|Distal||Farther from a point of attachment, or farther from trunk of body||Fingers are distal to wrist.|
|Lateral||The side, or away from the midline||Ears are lateral to eyes.|
|Medial||Toward, or nearer the midline||Nose is medial to ears.|