Abdomen

What Is the Abdomen?

The abdomen is part of the trunk of the human body between the thoracic diaphragm (chest muscle) and the bony ridge of the pelvis that serves as a boundary of the false pelvis and the true pelvis (pelvic brim)(1).

Abdominal muscles may play an essential role in the respiration process, postural support, and inner organs’ protection(2)

Vital organs, such as the endocrine, urinary, digestive, circulatory, exocrine, and parts of the reproductive system, are housed in the abdominal cavity(3). Specifically, it contains the following(4):

  • Small intestine (jejunum and ileum) 
  • Large intestine (colon)
  • Stomach 
  • Kidney
  • Spleen
  • Gallbladder
  • Pancreas
  • Ovaries
  • Uterus
  • Fallopian tube
  • Bladder
  • Blood vessels (arteries and veins)

The abdomen or the torso has nine layers, from the skin (outermost part) to the innermost lining of the organs or cavity wall (peritoneum)(5)

This region is divided into four quadrants: left upper quadrant, right upper quadrant, right lower quadrant, and left lower quadrant(6). Medical practitioners use these quadrants to identify which organs in the abdominal area cause discomfort or pain(7).

The left upper quadrant houses the pancreas, the spleen, the left portion of the liver, the left kidney, and the small intestine and stomach parts. Discomfort or pain in this abdominal area may indicate malrotation of the colon or the intestine(8).

Meanwhile, the right upper quadrant contains the right portion of the liver, transverse colon, gallbladder, and small intestine parts. If there is inflammation in the peptic ulcer (in the stomach) or infection in the liver or gallbladder, pain may be experienced in this region(9).

Located in the right lower part of the abdomen is the appendix, the right ureter, half of the female reproductive system, and some parts of the small intestine. Pain in this area is frequently associated with appendicitis(10).

The left ureter, the left half of the female reproductive system, and much of the small intestine are in the abdomen’s lower left quadrant. Inflammation of the large intestine (colitis), ovarian cyst, and pelvic inflammatory disease are related to the pain experienced in this area(11).

The symptoms felt in the abdominal area may imply wide varieties of diseases, including autoimmune, vascular, infectious, congenital, and more(12).

Radiology of the Abdomen

Various methods may be used in examining the abdomen. The best way depends on the symptoms experienced and the part of the abdomen to be examined.

Abdominal X-ray

An X-ray or radiography is a painless method that physicians use to diagnose and treat medical conditions(13). This method uses ionizing radiation to capture and produce an image of the contents of the abdominal cavity(14).

The liver, intestines, spleen, and stomach may be studied using X-ray or radiography. KUB (kidney, ureter, and bladder) X-ray is a term used when radiography is done to examine the kidney, bladder, and ureter(15).

An X-ray exam may help in identifying kidney stones or gallstones, ingestion of foreign objects, fissures in the intestines, and intestinal blockage.

Although X-ray is an easy and convenient way to diagnose a condition, the images produced using this method are not as clear as that of computed tomography (CT) scan and magnetic resonance imaging (MRI) of the pelvis and abdomen(16).

Abdominal CT Scan

CT scans use X-ray technology to capture images of internal organs(17). CT scan examination may use a contrast dye injected through an IV (intravenous therapy) or administered orally. 

The contrast dye may help enhance the image quality by making specific parts of the internal organs, like arteries, more visible in the scan(18).

CT scans may take between 15 to 30 minutes. Results may be available within 48 hours(19).

After the procedure, it is advised to drink six to eight glasses of water to flush out the contrast dye.

Abdominal MRI

Radiowaves and powerful magnets are used in magnetic resonance imaging (MRI) scans(20). This procedure does not risk the exposure of X-ray or ionizing radiation(21).

An abdominal MRI may show disorders and diseases, like renal arterial obstruction (narrowing of two or more arteries that carry blood into the kidney), obstructed vena cava, hydronephrosis (swelling of a kidney due to urine build-up), pancreatic cancer, and more.

MRI scans exhibit images of soft tissues without the bones blocking the picture(22). This procedure is often used to verify results from CT scans or X-ray images(23)

Moreover, MRI scans may show different viewpoints of the abdomen and may evaluate certain organ functions(24). Diagnosing abnormal growths, such as abdominal tumors, may be done through MRI scans.

Abdominal Ultrasound

During an abdominal ultrasound, soundwaves are used to produce images of the abdomen(25). This procedure is used to diagnose an organ enlargement or pain and evaluate the liver, gallbladder, kidney, abdominal aorta (the largest artery in the abdominal cavity), pancreas, and spleen(26).

Ultrasound imaging does not use radiation and is extremely safe(27). It provides real-time imaging that may be beneficial in biopsies(28)

Taking Care of the Abdomen

It is essential to take care of the abdominal parts, particularly the digestive system, to avoid stomach upsets and more severe diseases. 

According to the National Health Service (NHS), the United Kingdom’s government-funded health and medical service, lifestyle change is essential to prevent digestive problems(29).

  1. Eat healthily. It is essential to monitor what goes into the body. Eat slowly and chew well.
    It is not advisable to skip meals. Keep everyday meals in small portions and drink plenty of water.
  2. Avoid binge drinking. Heavy drinking may cause increased acid production in the stomach that may lead to heartburn and other digestive disorders.
    Men should avoid drinking eight or more alcohol units in one sitting. Women should avoid drinking six or more units of alcohol in one sitting.
  3. Quit smoking. Smoking may cause reflux or stomach acid that moves back up to the food pipe. Stomach cancer is also one of the severe repercussions of smoking.
  4. Manage stress. Stomach uneasiness may be felt under intense stress. Worrying or anxiety may cause an imbalance of digestion, resulting in bloating, constipation, ulcers, or irritable bowel syndrome (IBS).
  5. Exercise and maintain a healthy weight. Fats may cause heartburn, and losing weight may help ease this condition.

Before trying any treatments or natural remedies for abdominal disorders and pain, a doctor’s consultation is recommended to avoid adverse repercussions.


  1. Wade CI, Streitz MJ. Anatomy, Abdomen and Pelvis, Abdomen. [Updated 2020 Jul 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK553104/
  2. Ibid.
  3. Ibid.
  4. Medline Plus, (n.d.), Abdominal exploration – series—Normal anatomy, retrieved from https://medlineplus.gov/ency/presentations/100049_1.htm
  5. Ibid.
  6. Medicine Libre Text, (August 2020), Abdominopelvic Regions, retrieved from https://med.libretexts.org/Bookshelves/Anatomy_and_Physiology/Book%3A_Anatomy_and_Physiology_(Boundless)/1%3A_Introduction_to_Anatomy_and_Physiology/1.4%3A_Mapping_the_Body/1.4F%3A_Abdominopelvic_Regions
  7. Ibid.
  8. Ibid.
  9. Ibid. 
  10. Ibid.
  11. Ibid.
  12. Wade CI, Op. Cit.
  13. Radiology Info, (n.d.), X-ray (Radiography) – Abdomen, retrieved from https://www.radiologyinfo.org/en/info.cfm?pg=abdominrad#:~:text=Abdominal%20x%2Dray%20is%20a,called%20a%20KUB%20x%2Dray
  14. Ibid.
  15. Ibid.
  16. Ibid.
  17. Cedars Sinai, (n.d.), CT Scan of the Abdomen, retrieved from https://www.cedars-sinai.org/programs/imaging-center/exams/ct-scans/abdomen.html#:~:text=Your%20doctor%20has%20requested%20a,kidneys%20and%20other%20internal%20organs
  18. Ibid.
  19. Ibid.
  20. UCLA Health, (n.d.) Abdominal MRI Scan, retrieved from https://www.uclahealth.org/endocrine-center/abdominal-mri-scan#:~:text=What%20is%20an%20Abdominal%20MRI,radiation%20(x%2Drays)
  21. Ibid.
  22. Ibid.
  23. Ibid.
  24. Ibid.
  25. Radiology Info, (n.d.), Ultrasound – Abdomen, retrieved from https://www.radiologyinfo.org/en/info.cfm?pg=abdominus
  26. Ibid.
  27. Ibid.
  28. Ibid.
  29. NHS, (n.d.), 5 lifestyle tips for a healthy tummy, retrieved from https://www.nhs.uk/live-well/eat-well/five-lifestyle-tips-for-a-healthy-tummy/

Atlas MRI Abdomen

This photo gallery presents the anatomy of the abdomen by means of MRI. Radiologists routinely use magnetic resonance imaging (MRI) to diagnose many upper abdominal tumors(1). MRI is non-ionizing, making the modality more advantageous over other imaging sequences that involve higher radiation exposure. MRI can provide practical information and better soft tissue resolution than computed …

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Atlas of CT Anatomy of the Abdomen

This photo gallery presents the anatomy of the abdomen by means of CT (axial, coronal, and sagittal reconstructions). Abdominal Computed Tomography Abdominal computed tomography (CT) is a type of medical imaging procedure used to diagnose and monitor internal stomach issues, like cancer, bowel obstruction, and abdominal pain. Radiographers suggest an abdominal CT scan to look …

Atlas of CT Anatomy of the Abdomen Read More »

Abdominal X-ray

This webpage presents the anatomical structures found on abdominal X-ray. The Abdomen The abdomen is the anterior part of the body’s trunk between the diaphragm and the pelvic brim(1). Pelvic brim refers to the pelvic inlet’s bony edges that separate the false (major) pelvis and true (minor) pelvis. Abdominal muscles help regulate respiration, protect the …

Abdominal X-ray Read More »

Abdominal ultrasound

This photo gallery presents the anatomy of the superior abdomen by means of ultrasound.

Abdominal aorta

This photo gallery presents the anatomy of the Abdominal aorta by means of CT-scan (3D reconstructions).

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