Quadrants and regions of abdomen | |
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Anatomical terminology |
The human abdomen is divided into quadrants and regions by anatomists and physicians for the purposes of study, diagnosis, and treatment. [1] [2] The division into four quadrants allows the localisation of pain and tenderness, scars, lumps, and other items of interest, narrowing in on which organs and tissues may be involved. The quadrants are referred to as the left lower quadrant, left upper quadrant, right upper quadrant and right lower quadrant. These terms are not used in comparative anatomy, since most other animals do not stand erect.
The left lower quadrant includes the left iliac fossa and half of the flank. The equivalent in other animals is left posterior quadrant. The left upper quadrant extends from the umbilical plane to the left ribcage. This is the left anterior quadrant in other animals. The right upper quadrant extends from umbilical plane to the right ribcage. The equivalent in other animals is right anterior quadrant. The right lower quadrant extends from the umbilical plane to the right inguinal ligament. This in other animals is the right posterior quadrant.
The nine regions offer more detailed anatomy and are delineated by two vertical and two horizontal lines.
The left lower quadrant (LLQ) of the human abdomen is the area left of the midline and below the umbilicus. The LLQ includes the left iliac fossa and half of the left flank region. The equivalent term for animals is left posterior quadrant. Important organs here are:
The left upper quadrant (LUQ) extends from the median plane to the left of the patient, and from the umbilical plane to the left ribcage. The equivalent term for animals is left anterior quadrant. Important organs here are:
The right upper quadrant (RUQ) extends from the median plane to the right of the patient, and from the umbilical plane to the right ribcage. The equivalent term for animals is right anterior quadrant. Important organs here are:
The right lower quadrant (RLQ) extends from the median plane to the right of the patient, and from the umbilical plane to the right inguinal ligament. The equivalent term for animals is right posterior quadrant. Important organs here are:
Nine regions of the abdomen can be marked using two horizontal and two vertical dividing lines. The vertical lines are the mid-clavicular lines taken from the mid-point of each clavicle. The upper horizontal line is the subcostal line taken from the inferior parts of the lowest costal cartilages. The lower horizontal line is the extoturbular line connecting the tubercles of the pelvis. [3] [4]
The three main centrally positioned regions are the epigastric region, the umbilical region, and the hypogastric region also known as the pubic region.
On the sides of the abdomen the other six regions are the left and right hypochondriac regions, on either side of the epigastrium; the left and right lumbar flank regions, on either side of the umbilical region, and the left and right iliac or inguinal regions on either side of the hypogastrium. [3] [4]
("Hypo-" means below; "epi-" means above; "chondron" means cartilage (in this case, the cartilage of the rib) and "gaster" means stomach. The reversal of "left" and "right" is intentional, because the anatomical designations reflect the patient's own right and left.)
If abdominal pain or signs of peritonitis are localised in the LLQ, colitis, diverticulitis, ureteral colic or pain due to ovarian cysts or pelvic inflammatory disease may be suspected. Examples of tumors in the left lower quadrant include colon cancer and ovarian tumor.
The LUQ may be painful or tender in the case of intestinal malrotation. The RUQ may be painful or tender in hepatitis, cholecystitis, and peptic ulcer. The RLQ, in particular the right inguinal region or right iliac fossa may be painful and tender in conditions such as appendicitis.
Articles related to anatomy include:
Rovsing's sign, named after the Danish surgeon Niels Thorkild Rovsing (1862–1927), is a sign of appendicitis. If palpation of the left lower quadrant of a person's abdomen increases the pain felt in the right lower quadrant, the patient is said to have a positive Rovsing's sign and may have appendicitis. The phenomenon was first described by Swedish surgeon Emil Samuel Perman (1856–1945) writing in the journal Hygiea in 1904.
In anatomy, the epigastrium is the upper central region of the abdomen. It is located between the costal margins and the subcostal plane. Pain may be referred to the epigastrium from damage to structures derived from the foregut.
The inguinal ligament, also known as Poupart's ligament or groin ligament, is a band running from the pubic tubercle to the anterior superior iliac spine. It forms the base of the inguinal canal through which an indirect inguinal hernia may develop.
The external iliac arteries are two major arteries which bifurcate off the common iliac arteries anterior to the sacroiliac joint of the pelvis.
The abdominal internal oblique muscle, also internal oblique muscle or interior oblique, is an abdominal muscle in the abdominal wall that lies below the external oblique muscle and just above the transverse abdominal muscle.
The ventral body cavity is a human body cavity that is in the anterior (front) aspect of the human body. It is made up of the thoracic cavity, and the abdominopelvic cavity. The abdominopelvic cavity is further divided into the abdominal cavity and pelvic cavity, but there is no physical barrier between the two. The abdominal cavity contains digestive organs, spleen and the kidneys, the pelvic cavity contains the urinary bladder, internal reproductive organs, and rectum.
The abdominal external oblique muscle is the largest and outermost of the three flat abdominal muscles of the lateral anterior abdomen.
The abdomen is the front part of the torso between the thorax (chest) and pelvis in humans and in other vertebrates. The area occupied by the abdomen is called the abdominal cavity. In arthropods, it is the posterior tagma of the body; it follows the thorax or cephalothorax.
The internal iliac artery is the main artery of the pelvis.
In human anatomy, the inferior epigastric artery is an artery that arises from the external iliac artery. It is accompanied by the inferior epigastric vein; inferiorly, these two inferior epigastric vessels together travel within the lateral umbilical fold The inferior epigastric artery then traverses the arcuate line of rectus sheath to enter the rectus sheath, then anastomoses with the superior epigastric artery within the rectus sheath.
The pelvic cavity is a body cavity that is bounded by the bones of the pelvis. Its oblique roof is the pelvic inlet. Its lower boundary is the pelvic floor.
The wing(ala)of ilium is the large expanded portion of the ilium, the bone which bounds the greater pelvis laterally. It presents for examination two surfaces—an external and an internal—a crest, and two borders—an anterior and a posterior.
The iliac fossa is a large, smooth, concave surface on the internal surface of the ilium.
The testicular artery is a branch of the abdominal aorta that supplies blood to the testicle. It is a paired artery, with one for each of the testicles.
The umbilical region is one of the nine regions of the abdomen. It is the region that surrounds the area around the umbilicus and is placed approximately halfway between the xiphoid process and the pubic symphysis. This region of the abdomen contains part of the stomach, the head of the pancreas, the duodenum, a section of the transverse colon and the lower aspects of the left and right kidney. The upper three regions, from left to right, are the left hypochondriac, epigastric, and right hypochondriac regions. The middle three regions, from left to right, are the left lumbar, umbilical, and right lumbar regions. The bottom three regions, from left to right, are the left inguinal, hypogastric, and right inguinal regions.
The following outline is provided as an overview of and topical guide to human anatomy:
Supracristal plane is an anatomical transverse plane lying at the upper most part of the pelvis, the iliac crest. This is usually at the level of the L4 vertebrae. It passes through the umbilical region and the left and right lumbar regions.
The pelvis is the lower part of an anatomical trunk, between the abdomen and the thighs, together with its embedded skeleton.
Anatomical terminology is a form of scientific terminology used by anatomists, zoologists, and health professionals such as doctors, physicians, and pharmacists.