The language of anatomy will probably be unfamiliar to you at first. But once you have understood the basic word roots, combining word forms, prefixes, and suffixes you will find that anatomical terminologies are not as difficult as you first imagined.
When anatomists or doctors refer to specific areas of the human body, the picture they keep in mind is a universally accepted standard position called the anatomical position. It is essential to understand this position because much of the body terminology used in this book refers to this body positioning, regardless of the position the body happens to be in. In the anatomical position, the human body is erect, with the feet only slightly apart, head and toes pointed forward, and arms hanging at the sides with palms facing forward
Surface Anatomy Anatomical Terminologies
Body surfaces provide a wealth of visible landmarks for the study of the body.
Axial: Relating to the head, neck, and trunk, the axis of the body
Appendicular: Relating to limbs and their attachments to the axis
Anterior Body Landmarks
Abdominal: Anterior body trunk region inferior to the ribs
Acromial: Point of the shoulderAntebrachial: Forearm
Antecubital: Anterior surface of the elbow
Axillary: Armpit Anatomical Terminologies
Cervical: Neck region
Digital: Fingers or toes
Fibular (peroneal): Side of the leg
Hallux: Great toe Anatomical Terminologies
Inguinal: Groin area
Mammary: Breast region
Mental: Chin Nasal: Nose
Orbital: Bony eye socket (orbit)
Palmar: Palm of the hand
Patellar: Anterior knee (kneecap) region
Pelvic: Pelvis region
Pubic: Genital region
Sternal: Region of the breastbone
Posterior Body Landmarks
Acromial: Point of the shoulder
Calcaneal: Heel of the foot
Dorsal: Back Anatomical Terminologies
Gluteal: Buttocks or rump
Lumbar: Area of the back between the ribs and hips; the loin
Occipital: Posterior aspect of the head or base of the skull
Olecranal: Posterior aspect of the elbow Otic: Ear
Perineal: Region between the anus and external genitalia
Plantar: Sole of the foot
Popliteal: Back of the knee
Sacral: Region between the hips (overlying the sacrum)
Scapular: Scapula or shoulder blade area
Sural: Calf or posterior surface of the leg
Vertebral: Area of the spinal column
Relative Directional Terms Anatomical Terminologies
Superior (cranial): Toward the head. The leg is supper to the foot.
Inferior (caudal): Toward the feet. The foot is inferior to the leg.
Anterior (ventral): Toward the front part of the body. The nose is anterior to the ears.
Posterior (dorsal): Towards the back of the body. The ears are posterior to the nose.
Medial: Towards the midline of the body. The nose is medial to the eyes.
Lateral: Away from the midline of the body. The eyes are lateral to the nose.
Proximal: Toward (nearer) the trunk of the body or the attached end of a limb. The shoulder is proximal to the wrist.
Distal: Away (farther) from the trunk of the body or the attached end of a limb. The wrist is distal to the forearm.
Superficial: Nearer the surface of the body. The ribs are superficial to the heart.
Deep: Farther from the surface of the body. The heart is deeper into the ribs.
Peripheral: Away from the central axis of the body. Peripheral nerves radiate away from the brain and spinal cord.
Body Parts Regions
Body Planes and Sections
The body is three-dimensional, and to observe its internal structures, it is often helpful and necessary to make use of a section, or cut. When the section is made through the body wall or through an organ, it is made along an imaginary surface or line called a plane. Anatomists commonly refer to three planes, or sections, that lie at right angles to one another.
Sagittal plane: A plane that runs longitudinally and divides the body into right and left parts is referred to as a sagittal plane. If it divides the body into equal parts, right down the midline of the body, it is called a median, or midsagittal, plane.
Frontal plane: Sometimes called a coronal plane, the frontal plane is a longitudinal plane that divides the body (or an organ) into anterior and posterior parts.
Transverse plane: A transverse plane runs horizontally, dividing the body into superior and inferior parts. When organs are sectioned along the transverse plane, the sections are commonly called cross sections. On microscope slides, the abbreviation for a longitudinal
section (sagittal or frontal) is l.s. Cross sections are abbreviated x.s. or c.s. A sagittal or frontal plane section of any nonspherical object, be it a banana or a body organ, provides quite a different view from a transverse section.
The axial portion of the body has two large cavities that provide different degrees of protection to the organs within them.
Dorsal Body Cavities: Anatomical Terminologies
The dorsal body cavity can be subdivided into two cavities. The cranial cavity, within the rigid skull, contains the brain.The vertebral (or spinal) cavity, which is within the bony vertebral column, protects the delicate spinal cord. Because the spinal cord is a continuation of the brain, these cavities are continuous with each other.
Ventral Body Cavity:
Like the dorsal cavity, the ventral body cavity is subdivided. The superior thoracic cavity is separated from the rest of the ventral cavity by the dome-shaped diaphragm. The heart and lungs, located in the thoracic cavity, are protected by the bony rib cage. The cavity inferior to the diaphragm is often referred to as the abdominopelvic cavity. Although there is no further physical separation of the ventral cavity, some describe the abdominopelvic cavity as two areas, a superior abdominal cavity (the area that houses the stomach, intestines, liver, and other organs) and an inferior pelvic cavity (the region that is partially enclosed by the bony pelvis and contains the reproductive organs, bladder, and rectum). The abdominal and pelvic cavities are not continuous with each other in a straight plane; the pelvic cavity is tipped forward.
Serous Membranes of the Ventral Body Cavity
The walls of the ventral body cavity and the outer surfaces of the organs it contains are covered with an exceedingly thin, double-layered membrane called the serosa, or serous membrane. The part of the membrane lining the cavity walls is referred to as the parietal serosa, and it is continuous with a similar membrane, the visceral serosa, covering the external surface of the organs within the cavity. These membranes produce a thin lubricating fluid that allows the visceral organs to slide over one another or to rub against the body wall without friction. Serous membranes also compartmentalize the various organs. This helps prevent infection in one organ from spreading to others.
The specific names of the serous membranes depend on the structures they surround. The serosa lining the abdominal cavity and covering its organs is the peritoneum, that enclosing the lungs is the pleura, and that around the heart is the pericardium.
Abdominopelvic Quadrants and Regions
Because the abdominopelvic cavity is quite large and contains many organs, it is helpful to divide it up into smaller areas for discussion or study. Most physicians and nurses use a scheme that divides the abdominal surface and the abdominopelvic cavity into four approximately equal regions called quadrants. These quadrants are named according to their relative position—that is, right upper quadrant, right lower quadrant, left upper quadrant, and left lower quadrant. (Note that the terms left and right refer to the left and right side of the body in following figure, not the left and right side of the art on the page). The left and right of the body viewed are referred to as anatomical left and right.
Body Orientation and Direction
Study the terms that follow (refer to Figure 1.5). Notice that certain terms have a different meaning for a four-legged animal (quadruped) than they do for a human (biped).
Superior/inferior (above/below): These terms refer to the placement of a structure along the long axis of the body. Superior structures always appear above other structures, and inferior structures are always below other structures. For example, the nose is superior to the mouth, and the abdomen is inferior to the chest.
Anterior/posterior (front/back): In humans, the most anterior structures are those that are most forward—the face, chest, and abdomen. Posterior structures are those toward the backside of the body. For instance, the spine is posterior to the heart.
Medial/lateral (toward the midline/away from the midline or median plane): The sternum (breastbone) is medial to the ribs; the ear is lateral to the nose.
These terms of position assume the person is in the anatomical position. The next four term pairs are more absolute. They apply in any body position, and they consistently have the same meaning in all vertebrate animals.
Cephalad (cranial)/caudal (toward the head/toward the tail): In humans, these terms are used interchangeably with superior and inferior, but in four-legged animals, they are the same as anterior and posterior, respectively.
Dorsal/ventral (backside/belly side): These terms are used chiefly in discussing the comparative anatomy of animals, assuming the animal is standing. The dorsum is a Latin word meaning “back.” Thus, dorsal refers to the animal’s back or the backside of any other structures; for example, the posterior surface of the human leg is its dorsal surface. The term ventral derives from the Latin term venter, meaning “belly,” and always refers to the belly side of animals. In humans, the terms ventral and dorsal are used interchangeably with the terms anterior and posterior, but in four-legged animals, ventral and dorsal are the same as inferior
and superior, respectively.
Proximal/distal (nearer the trunk or attached end/farther from the trunk or point of attachment): These terms are used primarily to locate various areas of the body limbs. For example, the fingers are distal to the elbow; the knee is proximal to the toes. However, these terms may also be used to indicate regions (closer to or farther from the head) of internal tubular
Superficial (external)/deep (internal) (toward or at the body surface/away from the body surface): These terms locate body organs according to their relative closeness to the body surface. For example, the skin is superficial to the skeletal muscles, and the lungs are deep to the rib cage.