The transpyloric plane, also known as Addison's plane, is an imaginary horizontal plane, located halfway between the suprasternal notch of the manubrium and the upper border of the symphysis pubis at the level of the first lumbar vertebrae, L1. It lies roughly a hand's breadth beneath the xiphisternum or midway between the xiphisternum and the umbilicus. The plane in most cases cuts through the

pylorus The pylorus ( or ), or pyloric part, connects the stomach to the duodenum. The pylorus is considered as having two parts, the ''pyloric antrum'' (opening to the body of the stomach) and the ''pyloric canal'' (opening to the duodenum). The ''pylori ...

of the stomach, the tips of the ninth

costal cartilages The costal cartilages are bars of hyaline cartilage that serve to prolong the ribs forward and contribute to the elasticity of the walls of the thorax. Costal cartilage is only found at the anterior ends of the ribs, providing medial extension. ...

and the lower border of the

first lumbar vertebra The lumbar vertebrae are, in human anatomy, the five vertebrae between the rib cage and the pelvis. They are the largest segments of the vertebral column and are characterized by the absence of the foramen transversarium within the transverse ...

Structures crossed

The transpyloric plane is clinically notable because it passes through several important abdominal structures. It also divides the supracolic and infracolic compartments, with the liver, spleen and gastric fundus above it and the small intestine and colon below it.

Lumbar vertebra and spinal cord

The first

lumbar vertebra The lumbar vertebrae are, in human anatomy, the five vertebrae between the rib cage and the pelvis. They are the largest segments of the vertebral column and are characterized by the absence of the foramen transversarium within the transverse ...

lies at the level of the transpyloric plane. Despite the

conus medullaris ''Conus'' is a genus of predatory sea snails, or cone snails, marine gastropod mollusks in the family Conidae.Bouchet, P.; Gofas, S. (2015). Conus Linnaeus, 1758. In: MolluscaBase (2015). Accessed through: World Register of Marine Species ...

, the end of the spinal cord, being understood to terminate at the level of the transpyloric plane, there is significant variability. Up to 40% of people have spinal cords ending below the transpyloric plane.

Stomach

The transpyloric plane passes through the pylorus of the stomach, despite it being suspended by the lesser and

greater omentum The greater omentum (also the great omentum, omentum majus, gastrocolic omentum, epiploon, or, especially in animals, caul) is a large apron-like fold of visceral peritoneum that hangs down from the stomach. It extends from the greater curvature ...

and being relatively mobile.Drake, Richard L.; Wayne, Vogl A.; Mitchell, Adam W.M. (2015).
Gray's Anatomy for Students
' (3rd ed.) Philadelphia: Churchill Livingstone Elsevier. p. 311.

Duodenum

The horizontal part of the duodenum slopes upwards to the left of the vertical midline, following which the vertical ascending part of the duodenum reaches the transpyloric plane. It ends in the duodenojejunal junction, which lies approximately 2.5 cm to the left of the midline and just below the transpyloric plane.

Pancreas

The neck of pancreas lies on the transpyloric plane, whilst the body and tail are to the left and above it.

Gallbladder

The

fundus of the gallbladder 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 ...

projects from the liver’s inferior border at the intersection of the transpyloric plane and the right lateral midline.

Kidneys

Despite the right kidney lying 1 cm lower than the left (right just below and the left just above the plane), to be practical, the surface markings are taken the same way. The hilum of the kidney on the left and right is taken as 5 cm from the vertical midline and is on the transpyloric plane.

Vasculature

The

superior mesenteric artery In human anatomy, the superior mesenteric artery (SMA) is an artery which arises from the anterior surface of the abdominal aorta, just inferior to the origin of the celiac trunk, and supplies blood to the intestine from the lower part of the du ...

arises from the

aorta The aorta ( ) is the main and largest artery in the human body, originating from the left ventricle of the heart and extending down to the abdomen, where it splits into two smaller arteries (the common iliac arteries). The aorta distributes o ...

at the level of the transpyloric plane and emerges between the head and neck of the pancreas. The superior mesenteric vein is joined by the splenic vein to form the portal vein at the level of the transpyloric plane.

Spleen

The lower border of the spleen lies near the transpyloric plane.

Other structures

* the left and right

colic 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 ...

* the root of the

transverse mesocolon The mesentery is an organ that attaches the intestines to the posterior abdominal wall in humans and is formed by the double fold of peritoneum. It helps in storing fat and allowing blood vessels, lymphatics, and nerves to supply the intestine ...

. *

cisterna chyli The cisterna chyli (or cysterna chyli, and etymologically more correct, receptaculum chyli) is a dilated sac at the lower end of the thoracic duct in most mammals into which lymph from the intestinal trunk and two lumbar lymphatic trunks flow. It ...

(which drains into the

thoracic duct In human anatomy, the thoracic duct is the larger of the two lymph ducts of the lymphatic system. It is also known as the ''left lymphatic duct'', ''alimentary duct'', ''chyliferous duct'', and ''Van Hoorne's canal''. The other duct is the righ ...

History

The transpyloric plane relates to the three-dimensional mapping of the abdomen founded on more than 10,000 measurements completed on 40 bodies, that surgeon

Viscount Addison Viscount Addison, of Stallingborough in the County of Lincoln, is a title in the Peerage of the United Kingdom. It was created on 6 July 1945 for the physician and politician Christopher Addison, 1st Baron Addison. He had already been created Ba ...

took at the turn of the 20th century.Addison, Sir Christopher, Viscount Addison of Stallingborough (1869 - 1951).
Royal College of Surgeons: Plarr's Lives of the Fellows Online. Retrieved 16 March 2018. Addison reported his findings in a paper titled, "On the anatomical topography of the abdominal viscera in man, especially the gastro-intestinal canal" in which he established a baseline for the anatomy of the abdomen based on the arrangement of the map of the Earth. Using the suprasternal notch as the North Pole of the trunk, and the upper border of the pubic symphysis as the South Pole, he drew a vertical line joining these two points as his

meridian Meridian or a meridian line (from Latin ''meridies'' via Old French ''meridiane'', meaning “midday”) may refer to Science * Meridian (astronomy), imaginary circle in a plane perpendicular to the planes of the celestial equator and horizon * ...

. At the meridian's midpoint, he then drew a perpendicular line corresponding to the Equator. As this transverse plane crossed the pylorus, he called it the transpyloric plane.

Images

File:Surface projections of the organs of the trunk.png, Surface projections of the organs of the trunk, with transpyloric plane labeled at L1 File:Gray1034.png, Front view of the thoracic and abdominal viscera.
a. Median plane.
b. Lateral planes.
c. Trans tubercular plane.
d. Subcostal plane.
e. Transpyloric plane. File:Gray1227.png, Front of abdomen, showing surface markings for arteries and inguinal canal.

References

External links

Planes of the trunk
{{Authority control Anatomy