The right side of the body holds the liver, the gallbladder, the right kidney, the ascending colon, the cecum and the appendix. The left side holds the stomach, the spleen, the left kidney, the descending colon and the sigmoid colon. The lungs, kidneys, adrenal glands, ureters and ovaries come in pairs, one on each side. The heart, pancreas, small intestine and bladder sit close to the midline.
Right and left always mean the person's own right and left, not the view of someone facing them. The 3D organ finder shows most of these organs on a 3D body, by side and by level. Its model has no lung surfaces and no separate cecum or sigmoid colon.
Organs on the right side of the body
The liver takes up almost all of the space under the right ribs (Gray's Anatomy). The SEER training modules place it just beneath the diaphragm. The gallbladder, 7 to 10 cm long (Gray's), rests against the underside of the liver's right lobe.
| Level | Organs on the right | Landmark |
|---|---|---|
| Chest | Right lung | Three lobes; shorter and wider than the left lung |
| Under the ribs | Liver, gallbladder, right bend of the colon | The gallbladder's tip lies behind the ninth rib cartilage |
| Mid abdomen | Ascending colon, loops of ileum | The colon climbs the right side to the liver |
| Lower abdomen | Cecum, appendix, right ureter; right ovary and uterine tube in females | The cecum lies in the hollow of the right hip bone |
| Back | Right kidney, right adrenal gland, back of the liver | The kidney rests on the twelfth rib |
What organ is under the right ribs?
The organ under the right ribs is the liver. The 1918 edition of Gray's Anatomy traces where the liver is located rib by rib: its upper edge reaches the fifth rib cartilage and its lower edge follows the right rib margin. The gallbladder hangs from its underside, and the colon makes its right bend there, the hepatic flexure. Toward the back, the right kidney rests on the twelfth rib (Gray's).
What organs are on the lower right side?
The lower right holds the cecum, the pouch that starts the large intestine, with the appendix attached to it. The Dartmouth medical textbook Basic Human Anatomy places the cecum in the right iliac fossa, the hollow of the right hip bone.
References differ on the length of the appendix. Gray's gives an average of 8.3 cm, with a range of 2 to 20 cm. In Basic Human Anatomy it is often 9 or 10 cm.
The last loops of the small intestine and the right ureter share this corner. So do the right ovary and uterine tube in females.
Organs on the left side of the body
The stomach and the spleen fill the space under the left ribs. The SEER training modules of the US National Cancer Institute place the stomach in the upper left quadrant of the abdomen. They place the spleen behind it, just under the diaphragm. The spleen is usually about 12 cm long (Gray's) and lies against ribs 9 to 11.
| Level | Organs on the left | Landmark |
|---|---|---|
| Chest | Left lung, tip of the heart | Two lobes; a notch in the lung makes room for the heart |
| Under the ribs | Stomach, spleen, tail of the pancreas, left bend of the colon, tip of the liver's left lobe | The spleen lies against ribs 9 to 11 |
| Mid abdomen | Descending colon, loops of jejunum | The colon runs down the left side |
| Lower abdomen | End of the descending colon, sigmoid colon, left ureter; left ovary and uterine tube in females | The colon crosses the hollow of the left hip bone |
| Back | Left kidney, left adrenal gland, spleen, descending colon | The kidney rests on ribs 11 and 12 |
What organ is on the lower left side?
The lower left belongs mostly to the large intestine. Gray's follows the descending colon to the crest of the hip bone and across the left iliac fossa. In the pelvis it becomes the S-shaped sigmoid colon.
Open RN's Medical Terminology 2e lists the left ureter, the left ovary and the uterine tube in the left lower quadrant. That list follows the four abdominal quadrants, which meet at the navel.
What organ is on the left side of the back?
The left kidney is the main organ on the left side of the back. Gray's maps each kidney inside a box drawn on the back. The box starts 2.5 cm from the midline of the spine and ends 9.5 cm from it. Its top is level with the spinous process, the bony point, of the eleventh thoracic vertebra. Its bottom is level with that of the third lumbar vertebra. Gray's gives a kidney as about 11.25 cm long. The left one usually rests on the eleventh and twelfth ribs, the right one on the twelfth.
References place the kidneys at slightly different heights. SEER and Gray's put them between the twelfth thoracic and third lumbar vertebrae. Basic Human Anatomy puts them opposite the first four lumbar vertebrae in a standing person, and one level higher in a person lying down. The right kidney is a little lower than the left because of the liver. Gray's puts the gap at about 1 cm.
Higher on the left, the spleen lies under ribs 9 to 11. The descending colon runs along the outer edge of the left kidney.
Organs in the middle and organs in pairs
| Organ | Where it sits |
|---|---|
| Heart | Between the lungs, with its tip left of the breastbone |
| Esophagus | Straight down the chest, behind the windpipe |
| Pancreas | Behind the stomach; head on the right, tail at the spleen on the left |
| Small intestine | Center of the abdomen, framed by the large intestine |
| Transverse colon | Crosses from the right bend of the colon to the left bend |
| Bladder | Behind the pubic bone, in front of the rectum |
| Uterus or prostate | Uterus behind the bladder; prostate under the bladder |
| Lungs, kidneys, adrenal glands, ureters, ovaries | One on each side |
The heart sits in the middle of the chest, between the lungs, and projects farther into the left half than the right (Gray's). Its tip points left. Gray's places the tip behind the fifth left intercostal space, 8 to 9 cm from the midline, and marks it 9 cm left of the midline on the chest wall.
The pancreas crosses the midline. Its head sits in the curve of the duodenum, on the right. The gland is 12.5 to 15 cm long, and its tail reaches the spleen on the left (Gray's).
How the two sides differ
The right lung is shorter by 2.5 cm and broader than the left and has three lobes. The left lung has two lobes and a notch, the cardiac notch, on its front edge where the heart lies (Gray's). In the abdomen the liver has no twin on the left, where the stomach and the spleen sit instead.
Basic Human Anatomy calls the usual layout, with the liver on the right, situs solitus. A complete mirror image, with every organ on the opposite side, is called situs inversus.
Several organs share each area at different depths, so the place of a pain does not identify the organ. Sorting that out takes an examination and tests by a doctor or nurse. The 3D human anatomy explorer shows the same organs in place on a whole body.