The transpyloric plane, also known as Addison's plane, is an imaginary

horizontal plane Horizontal may refer to: *Horizontal plane, in astronomy, geography, geometry and other sciences and contexts *Horizontal coordinate system, in astronomy *Horizontalism, in monetary circuit theory *Horizontalidad, Horizontalism, in sociology *Hor ...

, 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 ) 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 ''pyloric canal'' ends a ...

of the stomach, the tips of the ninth costal cartilages and the lower border of the first lumbar vertebra.

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 lower border of first lumbar vertebra lies at the level of the transpyloric plane, according to

Gray's Anatomy ''Gray's Anatomy'' is a reference book of human anatomy written by Henry Gray, illustrated by Henry Vandyke Carter and first published in London in 1858. It has had multiple revised editions, and the current edition, the 42nd (October 2020 ...

. Despite the conus medullaris, the end of the spinal cord, being understood to typically terminate at the level of the transpyloric plane, there is significant variability. Conversely, in the young child the cord is relatively longer and ends at the upper border of the third lumbar vertebra ( subcostal plane). Due to biological variation, some adult people have spinal cords ending either above or 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 Greater may refer to: *Greatness, the state of being great *Greater than, in inequality * ''Greater'' (film), a 2016 American film *Greater (flamingo), the oldest flamingo on record * "Greater" (song), by MercyMe, 2014 * Greater Bank, an Australi ...

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 The duodenum is the first section of the small intestine in most vertebrates, including mammals, reptiles, and birds. In mammals, it may be the principal site for iron absorption. The duodenum precedes the jejunum and ileum and is the shortest p ...

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 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 arises from the

aorta The aorta ( ; : aortas or aortae) is the main and largest artery in the human body, originating from the Ventricle (heart), left ventricle of the heart, branching upwards immediately after, and extending down to the abdomen, where it splits at ...

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 The portal vein or hepatic portal vein (HPV) is a blood vessel that carries blood from the gastrointestinal tract, gallbladder, pancreas and spleen to the liver. This blood contains nutrients and toxins extracted from digested contents. Approxima ...

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 * the root of the transverse mesocolon. * cisterna chyli (which drains into the

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

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 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. At the meridian's midpoint, he then drew a perpendicular line corresponding to the

Equator The equator is the circle of latitude that divides Earth into the Northern Hemisphere, Northern and Southern Hemisphere, Southern Hemispheres of Earth, hemispheres. It is an imaginary line located at 0 degrees latitude, about in circumferen ...

. 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 Anatomical planes