The hypochondrium is the uppermost part of the abdomen, just below the chest or thoracic region. It sits behind the floating ribs, which are the lowest set of human ribs, on both sides of the epigastrium. The word hypochondrium is derived from Greek, and it means “under cartilage.”
The body is divided into anatomical areas or regions to simplify identification. Through the center of the body, extending vertically from the center of the neck down to the groin, is the imaginary anterior medial line, which is also called the midsternal line because it crosses through the middle of the chest bone called the sternum. This line divides the body into halves. Crossing horizontally through the body, above the navel and below the ribs, is the imaginary Transpyloric plane, which separates the hypochondrium and epigastrium from the sections below called the lumbar and umbilical regions.
Below the navel is another horizontal line called the Transtubercular plane. This line separates the lumbar and umbilical regions from the iliac and hypogastrium. Extending vertically from the center of the clavicles, which are commonly called the collar bones, are two imaginary lines called the Midclavicular lines. These lines create a central region and two sides. The middle of the central region falls under the anterior medial line.
The upper right abdominal area is called the right hypochondrium. It's located to the right side of the right Midclavicular line above the Transpyloric plane. The liver is found in this region.
The upper left abdominal area is the left hypochondrium, and it's located to the left side of the left Midclavicular line above the Transpyloric plane. The spleen is located in this area. Above the Transpyloric plane and in between the right and left hypochondria and Midclavicular lines is the epigastrium, where the stomach is located.
In between the Transplyoric plane and the Transtubercular plane are the right and left lumbar sections and the centrally located umbilical region. The duodenum and ascending colon are found in the right lumbar region. The cecum is in the left lumbar region, and the small intestine is in the umbilical area.
Below the Transtubercular plane are the right and left liliac regions with the hypogastrium in between them. The cecum, also spelled caecum, is found in the area of the right iliac, and it connects the ileum with the ascending colon. The sigmoid colon is located in the left iliac section, and the rectum and bladder, only when full, are found in the hypogastrium.