The abdomen is a part of the body located between the thorax (chest) and pelvis. It is a large cavity enclosed by the abdominal muscles and the lower part of the rib cage, housing several vital organs. The primary function of the abdomen is to house and protect organs involved in digestion, reproduction, and other essential processes.
Anatomy
The abdomen is bound superiorly by the diaphragm, separating it from the thoracic cavity, and inferiorly by the pelvic brim. Its walls consist of several layers, including skin, fat, muscles (such as the rectus abdominis, external and internal obliques, and transversus abdominis), and fascia.
Organs in the Abdomen
The abdominal cavity contains several major organs, including:
- Digestive system organs: Stomach, small intestine, large intestine, liver, pancreas, gallbladder, and spleen.
- Urinary system organs: Kidneys and ureters.
- Reproductive organs (in females): Uterus, ovaries, and fallopian tubes.
Regions of the Abdomen
Clinically, the abdomen is divided into nine regions or four quadrants to aid in diagnosis:
- Nine regions: Right hypochondriac, epigastric, left hypochondriac, right lumbar, umbilical, left lumbar, right iliac, hypogastric, and left iliac regions.
- Four quadrants: Right upper, left upper, right lower, and left lower quadrants.
Clinical Significance
The abdomen is a frequent focus in medical evaluation due to the presence of many essential organs. Disorders such as appendicitis, gastritis, hernias, and abdominal trauma are common. Imaging techniques like ultrasound, CT scans, and MRIs are often used to examine abdominal structures.
Etymology
The term “abdomen” is derived from the Latin word abdomen, meaning “belly” or “paunch.”