The abdomen is frequently divided by healthcare professionals using anatomical mapping systems to accurately describe symptoms or pinpoint the source of a problem. Focusing on the umbilical region, the central zone surrounding the navel, allows for a detailed examination of the organs situated there. This area is a complex anatomical space, housing large loops of the digestive tract and several underlying major circulatory structures.
Defining the Abdominal Regions
Anatomists and clinicians use mapping systems to divide the abdominal area. The simpler four-quadrant system uses intersecting lines at the navel, creating four large areas. For more precise localization, the nine-region system is employed, using two horizontal and two vertical lines to create a grid of nine compartments. The umbilical region is the central square in this grid, encompassing the area immediately surrounding the navel. It is bordered above by the epigastric region, below by the hypogastric region, and laterally by the left and right lumbar regions.
Primary Organ Contents of the Umbilical Area
The majority of the physical space in the umbilical region is occupied by the lengthy, coiled mass of the small intestine. Specifically, the jejunum and the ileum form numerous loops that fill the central abdominal cavity. The jejunum is the middle segment, responsible for nutrient absorption, while the ileum is the final segment. The large intestine also crosses through this region in the form of the transverse colon, which runs horizontally across the upper part of the area. These organs are suspended by a membrane, allowing them mobility within the abdominal space.
Major Vessels and Related Structures
The umbilical region is a pathway for several deeper, non-digestive structures located behind the digestive organs. The abdominal aorta, the body’s largest artery, and the inferior vena cava, the body’s largest vein, run vertically through this area, with the aorta typically splitting into the common iliac arteries near the bottom of the region. The third part of the duodenum crosses horizontally over the inferior vena cava and aorta. Additionally, the head and neck of the pancreas are positioned deep within this central area. The superior mesenteric artery, a major branch off the aorta, originates here and supplies blood to the small intestine.
Clinical Significance of Umbilical Pain
Pain in this area, known as periumbilical pain, can indicate several common health issues, often related to the small intestine which is the main occupant. Discomfort may stem from conditions like gastroenteritis or a small bowel obstruction. Gastroenteritis causes inflammation and cramping pain that frequently centers around the navel. In the early stages of appendicitis, pain classically begins in the periumbilical area before moving to the lower right abdomen. An umbilical hernia, where intestine pushes through a weak spot in the abdominal wall, also causes localized pain and pressure. Due to the central location of major vessels, pain from an abdominal aortic aneurysm can also manifest as deep umbilical discomfort.