professionals divide the abdomen into regions and/or quadrants to assist in analysis and diagnoses. Two separate divisions are commonly noted, one in which the abdomen is divided into nine regions, and another where it is divided into four quadrants.
The nine regions are divided into relatively smaller areas than the four quadrants, and allow for more specific analysis of each individual area.
Figure 1-20 Abdominal regions.
The specific areas included are the:
•right hypochondriac
•right lumbar
•right iliac
•epigastric
•umbilical
•hypogastric
•left hypochondriac
•left lumbar
•left iliac
The right and left hypochondriac regions are the most lateral and superior segments, and sit directly beneath the ribcages on their respective sides.
The epigastric lies between the two hypochondriac regions, directly in the midline and above the umbilical region. The lateral and central sections are the right lumbar and left lumbar regions, with the umbilical region lying between. The most inferior sections are the right and left iliac regions with the hypogastric area in between.
The four abdominopelvic quadrants are used to divide the entire region of the trunk below the diaphragm into four equal sections.
Figure 1-21 Body systems work together.
The quadrants are named simply by their relative locations:
•Left lower quadrant (LLQ)
•Right lower quadrant (RLQ)
•Left upper quadrant (LUQ)
•Right upper quadrant (RUQ)
In the RUQ, a majority of the liver can be found, as well as the gallbladder and right kidney.
The LUQ is host to the left lobe of the liver, the left kidney, spleen, and a major portion of the stomach.
In the RLQ sits the cecum and appendix.
The LLQ contains the parts of the small intestine and the descending colon.
Anatomically organizing the abdomen into these rewgions and/or quadrants offers medical professionals a rapid and efficient way of forming a differential diagnosis, especially critical in the cases of an acute abdomen.
■Types of Movement
The human body must also be appreciated for the many types of movements it is capable of. The body is able to perform an extensive range of movements, subject to the location and more specifically the joint, at which pivotal point movement occurs.
Movement takes place due to the contraction of skeletal muscles over joints in the body.
Depending on the location, mobility, and type of joint at which the contraction occurs, a direct and specific movement will be observed.
Accordingly, these forms of movements have specialized names, and are often described in pairs of opposed actions.
The first pair of opposite movements in our discussion is called flexion and extension.
Flexion occurs when a muscular contraction causes the angle of a joint to decrease. For example, the humerus bone of the upper arm joins with the ulna and radius bones of the lower arm at the elbow joint. During contraction of the biceps muscle, the bones of the lower arm are pulled toward the upper arm, thereby decreasing the angle of the elbow.
The opposite type of movement is called extension, where the angle of a joint increases. Using the above example, when the triceps muscle contracts, it pulls the bones of the lower arm farther away from the upper arm, increasing the angle of the elbow joint. Another example of flexion/extension occurs at the knee joint.
During contraction of the quadriceps muscle in the thigh, the lower leg is pulled away from the thigh, straightening the entire leg, resulting in extension, or an increase in the angle of the knee joint. During contraction of the biceps femoris, semitendinosus, and semimembranosus muscles, (commonly referred to as the hamstrings), the lower leg is brought closer to the thigh resulting in flexion, or a decrease of the angle of the knee joint.
The second pair or opposite movements to be discussed are called abduction and adduction. Abduction is the term given to describe the movement of a limb away from the midline of the body. An easy way to picture this is to imagine someone doing jumping jacks.
The opposite movement, called adduction, is to bring the limbs back toward the midline of the body, just as when you stand still with your feet together and your arms pressed against your sides.
Figure 1-22 Adduction and abduction.
The next pair of opposing movements is called supination and pronation. These movements are unique to the elbow joint in rotating the wrist. Pronation is demonstrated by turning the palm of the hand over from anatomical position to face toward the back of the body. Supination is rotating the palm forward, up, or down and returning it to anatomical position.
Another pair of opposing movements is internal rotation (also called medial rotation) and external rotation (also called lateral rotation). Internal rotation can be demonstrated by contraction of the pectoralis major, commonly referred to as the “pecs” or chest muscle, which causes an internal rotation of the humerus; essentially drawing the arm near the body. External rotation is just the opposite. The infraspinatus and teres minor muscles (small muscles on the posterior aspect of the body) contract to externally rotate the humerus, causing the upper arm to move away from the body.
Elevation and depression is another pair of opposite movements. Elevation is movement in a superior direction. The only prominent example of this is contraction of the upper fibers in the trapezius muscle, which causes an elevation of the shoulder girdle (such as extending the arms outward at shoulder level, as if pretending to be an airplane). The opposite movement occurs when the lower fibers of the trapezius muscle are contracted (arms back to the sides), resulting in depression of the shoulder girdle.
Another pair of opposite movements is dorsiflexion and plantar flexion. Dorsiflexion is a subtype of flexion movement, where contraction of the tibialis anterior, or “shin muscle”, causes a decrease of the angle between the dorsum (top) of the foot and the lower leg. This movement can be demonstrated by observing someone remove their foot from a gas pedal of an automobile. The opposite movement, caused by contraction of the gastrocnemius, or “calf muscle”, is called plantar flexion.
This is actually a misnomer; since the movement actually increases the angle between the dorsum of the foot and the lower leg. Rather, it should be appropriately named plantar
