How to Examine the Abdominal Wall
When you examine a patient’s abdomen, being able to associate the surface of the abdominal wall with the organs found inside the abdominal cavity is helpful. Well, good news: You can do this with some imaginary lines that divide the abdomen into different areas. You can draw the lines in two ways, as you find out in the following sections: One way uses two imaginary lines to create four quadrants, and the other method uses four lines to create nine regions.
Using two lines: The four quadrants
The abdomen can be divided into four quadrants by drawing two imaginary lines on the abdomen, one vertical and one horizontal, that meet in the middle. These two planes are the following:
Transumbilical plane: Marked by the horizontal line, this plane runs through the umbilicus (navel) and the intervertebral disc between the 3rd and 4th lumbar vertebrae.
Median (midsagittal) plane: Marked by the vertical line running through the midline of the body, this plane divides it into the right half and the left half.
These lines result in four quadrants: the right upper, left upper, right lower, and left lower.
Using four lines: The nine regions
In addition to the four quadrants in the preceding section, the abdomen can also be divided into nine regions by two vertical lines and two horizontal lines (imagine a tic-tac-toe board), which provides for a little more accuracy when describing the location of pain or a lesion.
Vertical lines: Two vertical lines are formed by the midclavicular planes, which line up with the midpoints of the clavicles.
Horizontal lines: Two horizontal lines are provided by the following planes:
The subcostal plane is at the level of the bottom of the 10th costal cartilages. That’s near the bottom of the rib cage.
The transtubercular plane is at the level of the body of the 5th lumbar vertebra and near the top of the hip bones.
The lines form three rows with three regions each.
Top row: The regions in the superior (top) row consists of the right hypochondriac, epigastric, and left hypochondriac.
Middle row: The regions in the middle row consists of the right lumbar (lateral), umbilical, and left lumbar (lateral).
Bottom row: The regions in the inferior (bottom) row consists of the right inguinal (iliac), hypogastric (pubic), and left inguinal (iliac).