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PART 1 Organization of the Human Body

Head

Neck

Frontal (forehead)Orbital (eye)Nasal (nose)Oral (mouth)

Cervical

Otic (ear)Buccal (cheek)Mental (chin)

Clavicular (collarbone)

Thoracic(thorax)

Pectoral (chest)Sternal (breastbone)

Mammary (breast)

Axillary (armpit)

Brachial (arm)

Antecubital (front of elbow)

Trunk

Abdominal (abdomen)Umbilical (navel)

Pelvic (pelvis)Inguinal (groin)Pubic (genital)

Antebrachial (forearm)

Upper limb

Carpal (wrist)

Palmar (palm)

Digital (fingers)

Coxal (hip)

Femoral (thigh)

Patellar (kneecap)

Manual (hand)

(a)

Crural (leg)

Lower limb

FIGURE 1.10 Body Parts and Regions

The anatomical and common ( in parentheses ) namesare indicated for the major parts and regions of thebody. ( a ) Anterior view.

Talus (ankle)Dorsum (top of foot)Digital (toes)

Pedal (foot)

The central region of the body consists of the head, neck, and trunk. The trunk can be divided into the thorax, abdomen, and pelvis. The thorax is the chest cavity where the heart and lungs arelocated. The abdomen contains organs such as the liver, stomach,and intestines. The pelvis contains the bladder and reproductiveorgans. The upper limb is divided into the arm, forearm, wrist,and hand. The arm extends from the shoulder to the elbow, andthe forearm extends from the elbow to the wrist. The lower limbis divided into the thigh, leg, ankle, and foot. The thigh extendsfrom the hip to the knee, and the leg extends from the knee to theankle. Note that, contrary to popular usage, the terms arm and leg refer to only a part of the limb.The abdomen is often subdivided superficially into quad-rants by two imaginary lines—one horizontal and one vertical—that intersect at the navel (figure 1.11 a ). The quadrants formed arethe right-upper, left-upper, right-lower, and left-lower quadrants.In addition to these quadrants, the abdomen is sometimes sub-divided into regions by four imaginary lines: two horizontal andtwo vertical. These four lines create a “virtual” tic-tac-toe gridon the abdomen, resulting in nine regions: epigastric, right andleft hypochondriac, umbilical, right and left lumbar, hypogastric,and right and left iliac (figure 1.11 b ). Health professionals use the

quadrants and regions as reference points for locating underlyingorgans. For example, the appendix is in the right-lower quadrant,and the pain of an acute appendicitis is usually felt there.

Planes

At times, it is useful to describe the body as having imaginary flatsurfaces, called planes, passing through it (figure 1.12). A planedivides, or sections, the body, making it possible to “look inside”and observe the body’s structures. A sagittal (saj′i-t ă l) plane runs vertically through the body, separating it into right andleft portions. The word sagittal literally means “the flight of anarrow” and refers to the way the body would be split by an arrowpassing anteriorly to posteriorly. A median plane is a sagittalplane that passes through the midline of the body, dividing it intoequal right and left halves. A transverse ( horizontal ) plane runsparallel to the ground, dividing the body into superior and infe-rior portions. A frontal ( coronal ) (k ō r′ ŏ -n ă l, k ō -r ō ′n ă l; crown) plane runs vertically to divide the body into anterior (front) andposterior (back) parts.Organs are often sectioned to reveal their internal struc-ture (figure 1.13). A cut through the length of the organ is a