The human
abdomen
The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the to ...
is divided into quadrants and regions by
anatomists and
physician
A physician (American English), medical practitioner (Commonwealth English), medical doctor, or simply doctor, is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through th ...
s for the purposes of study,
diagnosis
Diagnosis is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in many different disciplines, with variations in the use of logic, analytics, and experience, to determine " cause and effect". In systems engin ...
, and
treatment.
The division into four quadrants allows the localisation of
pain and
tenderness,
scar
A scar (or scar tissue) is an area of fibrous tissue that replaces normal skin after an injury. Scars result from the biological process of wound repair in the skin, as well as in other organs, and tissues of the body. Thus, scarring is a n ...
s, lumps, and other items of interest, narrowing in on which
organs
In biology, an organ is a collection of tissues joined in a structural unit to serve a common function. In the hierarchy of life, an organ lies between tissue and an organ system. Tissues are formed from same type cells to act together in a f ...
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
The iliac fossa is a large, smooth, concave surface on the internal surface of the ilium (part of the three fused bones making the hip bone).
Structure
The iliac fossa is bounded above by the iliac crest, and below by the arcuate line. It is b ...
and half of the
flank
Flank may refer to:
* Flank (anatomy), part of the abdomen
** Flank steak, a cut of beef
** Part of the external anatomy of a horse
* Flank speed, a nautical term
* Flank opening, a chess opening
* A term in Australian rules football
* Th ...
. The equivalent in other animals is ''left posterior quadrant''. The left upper quadrant extends from the
umbilical plane to the left
ribcage
The rib cage, as an enclosure that comprises the ribs, vertebral column and sternum in the thorax of most vertebrates, protects vital organs such as the heart, lungs and great vessels.
The sternum, together known as the thoracic cage, is a sem ...
. 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.
Quadrants
![LLQlabled](https://upload.wikimedia.org/wikipedia/commons/5/57/LLQlabled.PNG)
The left lower quadrant (LLQ) of the
human abdomen
The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso. ...
is the area left of the midline and below the
umbilicus. The LLQ includes the left
iliac fossa
The iliac fossa is a large, smooth, concave surface on the internal surface of the ilium (part of the three fused bones making the hip bone).
Structure
The iliac fossa is bounded above by the iliac crest, and below by the arcuate line. It is b ...
and half of the left
flank
Flank may refer to:
* Flank (anatomy), part of the abdomen
** Flank steak, a cut of beef
** Part of the external anatomy of a horse
* Flank speed, a nautical term
* Flank opening, a chess opening
* A term in Australian rules football
* Th ...
region. The equivalent term for animals is ''left posterior quadrant''.
Important organs here are:
*the
descending colon and
sigmoid colon
*the left
ovary and
fallopian tube
*the left
ureter
The ureters are tubes made of smooth muscle that propel urine from the kidneys to the urinary bladder. In a human adult, the ureters are usually long and around in diameter. The ureter is lined by urothelial cells, a type of transitional epit ...
The left upper quadrant (LUQ) extends from the
median plane
The median plane also called a mid-sagittal plane is used to describe the sagittal plane as it bisects the body vertically through the midline marked by the navel, dividing the body exactly in left and right side.
The term parasagittal plane is u ...
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:
*
Stomach
The stomach is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach i ...
*
Spleen
The spleen is an organ found in almost all vertebrates. Similar in structure to a large lymph node, it acts primarily as a blood filter. The word spleen comes .
*
Left lobe of liver
In human anatomy, the liver is divided grossly into four parts or lobes: the right lobe, the left lobe, the caudate lobe, and the quadrate lobe. Seen from the front – the diaphragmatic surface - the liver is divided into two lobes: the right ...
*
Body of pancreas
The pancreas is an organ of the digestive system and endocrine system of vertebrates. In humans, it is located in the abdomen behind the stomach and functions as a gland. The pancreas is a mixed or heterocrine gland, i.e. it has both an endoc ...
*Left
kidney
The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blo ...
and
adrenal gland
The adrenal glands (also known as suprarenal glands) are endocrine glands that produce a variety of hormones including adrenaline and the steroids aldosterone and cortisol. They are found above the kidneys. Each gland has an outer cortex whic ...
*
Splenic flexure
In the anatomy of the human digestive tract, there are two colic flexures, or curvatures in the transverse colon. The right colic flexure is also known as the hepatic flexure, and the left colic flexure is also known as the splenic flexure. Note ...
of
colon
*
Parts of transverse and
descending colon
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:
*
Liver
The liver is a major organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it ...
*
Gall bladder
In vertebrates, the gallbladder, also known as the cholecyst, is a small hollow organ where bile is stored and concentrated before it is released into the small intestine. In humans, the pear-shaped gallbladder lies beneath the liver, although ...
with
biliary tree
The biliary tract, (biliary tree or biliary system) refers to the liver, gallbladder and bile ducts, and how they work together to make, store and secrete bile. Bile consists of water, electrolytes, bile acids, cholesterol, phospholipids and co ...
*
Duodenum
*Head of
pancreas
The pancreas is an organ of the digestive system and endocrine system of vertebrates. In humans, it is located in the abdomen behind the stomach and functions as a gland. The pancreas is a mixed or heterocrine gland, i.e. it has both an en ...
*Right
kidney
The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blo ...
and
adrenal gland
The adrenal glands (also known as suprarenal glands) are endocrine glands that produce a variety of hormones including adrenaline and the steroids aldosterone and cortisol. They are found above the kidneys. Each gland has an outer cortex whic ...
*
Hepatic flexure
In the anatomy of the human digestive tract, there are two colic flexures, or curvatures in the transverse colon. The right colic flexure is also known as the hepatic flexure, and the left colic flexure is also known as the splenic flexure. Note ...
of
colon
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:
*
Cecum
The cecum or caecum is a pouch within the peritoneum that is considered to be the beginning of the large intestine. It is typically located on the right side of the body (the same side of the body as the appendix, to which it is joined). The wo ...
*
Appendix
*
Ascending colon
*Right
ovary and
Fallopian tube
*Right
ureter
The ureters are tubes made of smooth muscle that propel urine from the kidneys to the urinary bladder. In a human adult, the ureters are usually long and around in diameter. The ureter is lined by urothelial cells, a type of transitional epit ...
Regions
![Abdominal Quadrant Regions](https://upload.wikimedia.org/wikipedia/commons/c/c9/Abdominal_Quadrant_Regions.jpg)
Nine regions of the abdomen can be marked using two horizontal and two vertical dividing lines. The vertical lines are the
mid-clavicular line {{short description, None
Anatomical "lines", or "reference lines," are theoretical lines drawn through anatomical structures and are used to describe anatomical location. The following reference lines are identified in '' Terminologia Anatomica' ...
s taken from the mid-point of each
clavicle
The clavicle, or collarbone, is a slender, S-shaped long bone approximately 6 inches (15 cm) long that serves as a strut between the shoulder blade and the sternum (breastbone). There are two clavicles, one on the left and one on the r ...
. The upper horizontal line is the
subcostal line taken from the inferior parts of the lowest costal cartilages. The lower horizontal line is the
intertubercular line
A lower transverse plane midway between the upper transverse and the upper border of the pubic symphysis; this is termed the intertubercular plane (or transtubercular), since it practically corresponds to that passing through the iliac tubercles; ...
connecting the
tubercles of the pelvis.
The three main centrally positioned regions are the
epigastric region
In anatomy, the epigastrium (or epigastric region) 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 fo ...
, the
umbilical region
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 half way between the xiphoid process and the pubic symphysis. This region of the abdomen c ...
, and the
hypogastric region also known as the
pubic
In vertebrates, the pubic region ( la, pubis) is the most forward-facing (ventral and anterior) of the three main regions making up the coxal bone. The left and right pubic regions are each made up of three sections, a superior ramus, inferior r ...
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.
[
("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.)
]
Clinical significance
If abdominal pain
Abdominal pain, also known as a stomach ache, is a symptom associated with both non-serious and serious medical issues.
Common causes of pain in the abdomen include gastroenteritis and irritable bowel syndrome. About 15% of people have a m ...
or signs of peritonitis
Peritonitis is inflammation of the localized or generalized peritoneum, the lining of the inner wall of the abdomen and cover of the abdominal organs. Symptoms may include severe pain, swelling of the abdomen, fever, or weight loss. One part o ...
are localised in the LLQ, colitis
Colitis is swelling or inflammation of the large intestine ( colon). Colitis may be acute and self-limited or long-term. It broadly fits into the category of digestive diseases.
In a medical context, the label ''colitis'' (without qualification ...
, diverticulitis, ureteral colic or pain due to ovarian cyst
An ovarian cyst is a fluid-filled sac within the ovary. Often they cause no symptoms. Occasionally they may produce bloating, lower abdominal pain, or lower back pain. The majority of cysts are harmless. If the cyst either breaks open or causes ...
s or pelvic inflammatory disease may be suspected. Examples of tumors in the left lower quadrant include colon cancer and ovarian tumor
Ovarian tumors, or ovarian neoplasms, are tumors arising from the ovary. They can be benign or malignant (ovarian cancer). They consist of mainly solid tissue, while ovarian cysts contain fluid.
Histopathologic classification
Ovarian tumors are ...
.
The LUQ may be painful or tender in the case of intestinal malrotation
Intestinal malrotation is a congenital anomaly of rotation of the midgut. It occurs during the first trimester as the fetal gut undergoes a complex series of growth and development. Malrotation can lead to a dangerous complication called volvulus ...
. The RUQ may be painful or tender in hepatitis
Hepatitis is inflammation of the liver tissue. Some people or animals with hepatitis have no symptoms, whereas others develop yellow discoloration of the skin and whites of the eyes ( jaundice), poor appetite, vomiting, tiredness, abdominal ...
, cholecystitis
Cholecystitis is inflammation of the gallbladder. Symptoms include right upper abdominal pain, pain in the right shoulder, nausea, vomiting, and occasionally fever. Often gallbladder attacks (biliary colic) precede acute cholecystitis. The pai ...
, and peptic ulcer
Peptic ulcer disease (PUD) is a break in the inner lining of the stomach, the first part of the small intestine, or sometimes the lower esophagus. An ulcer in the stomach is called a gastric ulcer, while one in the first part of the intestines ...
. The RLQ, in particular the right inguinal region or right iliac fossa
The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso. ...
may be painful and tender in conditions such as appendicitis
Appendicitis is inflammation of the appendix. Symptoms commonly include right lower abdominal pain, nausea, vomiting, and decreased appetite. However, approximately 40% of people do not have these typical symptoms. Severe complications of a ru ...
.
Differential diagnosis
Children
* gastroenteritis, mesenteric adenitis
Adenitis is a general term for an inflammation of a gland. Often it is used to refer to lymphadenitis which is the inflammation of a lymph node.
Classification
Lymph node adenitis
''Lymph adenitis'' or ''lymph node adenitis'' is caused by infec ...
, Meckel's diverticulitis, intussusception, Henoch–Schönlein purpura
Henoch–Schönlein purpura (HSP), also known as IgA vasculitis, is a disease of the skin, mucous membranes, and sometimes other organs that most commonly affects children. In the skin, the disease causes palpable purpura (small, raised areas of ...
, lobar pneumonia
Lobar pneumonia is a form of pneumonia characterized by inflammatory exudate within the intra-alveolar space resulting in consolidation that affects a large and continuous area of the lobe of a lung.
It is one of three anatomic classifications ...
Adults
*regional enteritis, renal colic
Renal colic is a type of abdominal pain commonly caused by obstruction of ureter from dislodged kidney stones. The most frequent site of obstruction is the vesico-ureteric junction (VUJ), the narrowest point of the upper urinary tract. Acute ob ...
, perforated peptic ulcer
Peptic ulcer disease (PUD) is a break in the inner lining of the stomach, the first part of the small intestine, or sometimes the lower esophagus. An ulcer in the stomach is called a gastric ulcer, while one in the first part of the intestines ...
, testicular torsion
Testicular torsion occurs when the spermatic cord (from which the testicle is suspended) twists, cutting off the blood supply to the testicle. The most common symptom in children is sudden, severe testicular pain. The testicle may be higher than ...
, rectus sheath hematoma
A rectus sheath hematoma is an accumulation of blood in the sheath of the rectus abdominis muscle. It causes abdominal pain with or without a mass.
The hematoma may be caused by either rupture of the epigastric artery or by a muscular tear. Cau ...
, pelvic inflammatory disease, ectopic pregnancy, endometriosis, torsion/rupture of ovarian cyst
An ovarian cyst is a fluid-filled sac within the ovary. Often they cause no symptoms. Occasionally they may produce bloating, lower abdominal pain, or lower back pain. The majority of cysts are harmless. If the cyst either breaks open or causes ...
, appendicitis
Elderly
* diverticulitis, intestinal obstruction, colonic carcinoma
Colorectal cancer (CRC), also known as bowel cancer, colon cancer, or rectal cancer, is the development of cancer from the colon or rectum (parts of the large intestine). Signs and symptoms may include blood in the stool, a change in bowel m ...
, mesenteric ischemia
Intestinal ischemia is a medical condition in which injury to the large or small intestine occurs due to not enough blood supply. It can come on suddenly, known as acute intestinal ischemia, or gradually, known as chronic intestinal ischemia. The ...
, leaking aortic aneurysm
See also
*Murphy's sign
In medicine, Murphy's sign (also known as Sweeney’s sign) is a maneuver during a physical examination as part of the abdominal examination. It is useful for differentiating pain in the right upper quadrant. Typically, it is positive in chole ...
*McBurney's point
McBurney's point is the name given to the point over the right side of the abdomen that is one-third of the distance from the anterior superior iliac spine to the umbilicus (navel). This is near the most common location of the appendix.
Locatio ...
* Superficial anatomy
References
{{Superficial abdominopelvic anatomy
Abdomen