Arteries
of the stomach and colon
The
celiac artery
is a short thick trunk, about 1.25 cm. in length, which arises from the front of
the aorta, just below the aortic hiatus of the diaphragm, and, passing nearly
horizontally forward, divides into three large branches, the left gastric, the
hepatic, and the splenic; it occasionally gives off one of the inferior phrenic
arteries.
The celiac artery and its branches; the liver has been raised, and the lesser omentum and anterior layer of the greater omentum removed
Relations.
The
Left Gastric Artery (a. gastrica sinistra; gastric or coronary artery), the
smallest of the three branches of the celiac artery, passes upward and to the
left, posterior to the omental bursa, to the cardiac orifice of the stomach.
Here it distributes branches to the esophagus, which anastomose with the aortic
esophageal arteries; others supply the cardiac part of the stomach, anastomosing
with branches of the lienal artery. It then runs from left to right, along the
lesser curvature of the stomach to the pylorus, between the layers of the lesser
omentum; it gives branches to both surfaces of the stomach and anastomoses with
the right gastric artery.
The
Hepatic Artery (a. hepatica) in the adult is intermediate in size between
the left gastric and lienal; in the fetus, it is the largest of the three
branches of the celiac artery. It is first directed forward and to the right, to
the upper margin of the superior part of the duodenum, forming the lower
boundary of the epiploic foramen (foramen of Winslow). It then crosses the
portal vein anteriorly and ascends between the layers of the lesser omentum, and
in front of the epiploic foramen, to the porta hepatis, where it divides into
two branches, right and left, which supply the corresponding lobes of the liver,
accompanying the ramifications of the portal vein and hepatic ducts. The hepatic
artery, in its course along the right border of the lesser omentum, is in
relation with the common bile-duct and portal vein, the duct lying to the right
of the artery, and the vein behind.
Its
branches are:
Right
Gastric,
Cystic,
and
Gastroduodenal
(which divides into Right Gastroepiploic and Superior Pancreaticoduodenal.
The
right gastric artery (a. gastrica dextra; pyloric artery) arises from the
hepatic, above the pylorus, descends to the pyloric end of the stomach, and
passes from right to left along its lesser curvature, supplying it with
branches, and anastomosing with the left gastric artery.
The celiac artery and its branches; the stomach has been raised and the peritoneum removed
The
gastroduodenal artery (a. gastroduodenalis) is a short but large branch,
which descends, near the pylorus, between the superior part of the duodenum and
the neck of the pancreas, and divides at the lower border of the duodenum into
two branches, the right gastroepiploic and the superior pancreaticoduodenal.
Previous to its division it gives off two or three small branches to the pyloric
end of the stomach and to the pancreas.
The
right gastroepiploic artery (a. gastroepiploica dextra) runs from right to
left along the greater curvature of the stomach, between the layers of the
greater omentum, anastomosing with the left gastroepiploic branch of the lienal
artery. Except at the pylorus where it is in contact with the stomach, it lies
about a finger's breadth from the greater curvature. This vessel gives off
numerous branches, some of which ascend to supply both surfaces of the stomach,
while others descend to supply the greater omentum and anastomose with branches
of the middle colic.
The
superior pancreaticoduodenal artery (a. pancreaticoduodenalis superior)
descends between the contiguous margins of the duodenum and pancreas. It
supplies both these organs, and anastomoses with the inferior
pancreaticoduodenal branch of the superior mesenteric artery, and with the
pancreatic branches of the lienal artery.
The
cystic artery (a. cystica) usually a branch of the right hepatic, passes
downward and forward along the neck of the gall-bladder, and divides into two
branches, one of which ramifies on the free surface, the other on the attached
surface of the gall-bladder.
The
Lienal or Splenic Artery (a. lienalis), the largest branch of the celiac
artery, is remarkable for the tortuosity of its course. It passes horizontally
to the left side, behind the stomach and the omental bursa of the peritoneum,
and along the upper border of the pancreas, accompanied by the lienal vein,
which lies below it; it crosses in front of the upper part of the left kidney,
and, on arriving near the spleen, divides into branches, some of which enter the
hilus of that organ between the two layers of the phrenicolienal ligament to be
distributed to the tissues of the spleen; some are given to the pancreas, while
others pass to the greater curvature of the stomach between the layers of the
gastrolienal ligament.
Its
branches are:
Pancreatic,
Short
Gastric, and
Left
Gastroepiploic
The
pancreatic branches (rami pancreatici) are numerous small vessels derived
from the lienal as it runs behind the upper border of the pancreas, supplying
its body and tail. One of these, larger than the rest, is sometimes given off
near the tail of the pancreas; it runs from left to right near the posterior
surface of the gland, following the course of the pancreatic duct, and is called
the arteria pancreatica magna. These vessels anastomose with the pancreatic
branches of the pancreaticoduodenal and superior mesenteric arteries.
The
short gastric arteries (aa. gastricæ breves; vasa brevia) consist of from
five to seven small branches, which arise from the end of the lienal artery, and
from its terminal divisions. They pass from left to right, between the layers of
the gastrolienal ligament, and are distributed to the greater curvature of the
stomach, anastomosing with branches of the left gastric and left gastroepiploic
arteries.
The
left gastroepiploic artery (a. gastroepiploica sinistra) the largest branch
of the lienal, runs from left to right about a finger’s breadth or more from
the greater curvature of the stomach, between the layers of the greater omentum,
and anastomoses with the right gastroepiploic. In its course it distributes
several ascending branches to both surfaces of the stomach; others descend to
supply the greater omentum and anastomose with branches of the middle colic.
The superior mesenteric artery and its branches
The
superior mesenteric artery (a. mesenterica superior) is a large vessel which
supplies the whole length of the small intestine, except the superior part of
the duodenum; it also supplies the cecum and the ascending part of the colon and
about one-half of the transverse part of the colon. It arises from the front of
the aorta, about 1.25 cm. below the celiac artery, and is crossed at its origin
by the lienal vein and the neck of the pancreas. It passes downward and forward,
anterior to the processus uncinatus of the head of the pancreas and inferior
part of the duodenum, and descends between the layers of the mesentery to the
right iliac fossa, where, considerably diminished in size, it anastomoses with
one of its own branches, viz., the ileocolic. In its course it crosses in front
of the inferior vena cava, the right ureter and Psoas major, and forms an arch,
the convexity of which is directed foward and downward to the left side, the
concavity backward and upward to the right. It is accompanied by the superior
mesenteric vein, which lies to its right side, and it is surrounded by the
superior mesenteric plexus of nerves.
Its
branches are:
Inferior
Pancreaticoduodenal,
Ileocolic,
Intestinal,
Right
Colic, and
Middle
Colic.
The
Inferior Pancreaticoduodenal Artery (a. pancreaticoduodenalis inferior) is
given off from the superior mesenteric or from its first intestinal branch,
opposite the upper border of the inferior part of the duodenum. It courses to
the right between the head of the pancreas and duodenum, and then ascends to
anastomose with the superior pancreaticoduodenal artery. It distributes branches
to the head of the pancreas and to the descending and inferior parts of the
duodenum.
The
Intestinal Arteries (aa. intestinales; vasa intestini tenuis) arise from the
convex side of the superior mesenteric artery. They are usually from twelve to
fifteen in number, and are distributed to the jejunum and ileum. They run nearly
parallel with one another between the layers of the mesentery, each vessel
dividing into two branches, which unite with adjacent branches, forming a series
of arches, the convexities of which are directed toward the intestine From this
first set of arches branches arise, which unite with similar branches from above
and below and thus a second series of arches is formed; from the lower branches
of the artery, a third, a fourth, or even a fifth series of arches may be
formed, diminishing in size the nearer they approach the intestine. In the
short, upper part of the mesentery only one set of arches exists, but as the
depth of the mesentery increases, second, third, fourth, or even fifth groups
are developed. From the terminal arches numerous small straight vessels arise
which encircle the intestine, upon which they are distributed, ramifying between
its coats. From the intestinal arteries small branches are given off to the
lymph glands and other structures between the layers of the mesentery.
The
Ileocolic Artery (a. ileocolica) is the lowest branch arising from the
concavity of the superior mesenteric artery. It passes downward and to the right
behind the peritoneum toward the right iliac fossa, where it divides into a
superior and an inferior branch; the inferior anastomoses with the end of the
superior mesenteric artery, the superior with the right colic artery.
The
inferior branch of the ileocolic runs toward the upper border of the ileocolic
junction and supplies the following branches
(a)
colic,
which pass upward on the ascending colon;
(b)
anterior
and posterior cecal, which are distributed to the front and back of the cecum;
(c) an appendicular artery, which descends behind the termination of the ileum and enters the mesenteriole of the vermiform process; it runs near the free margin of this mesenteriole and ends in branches which supply the vermiform process; and
(d) ileal, which run upward and to the left on the lower part of the ileum, and anastomose with the termination of the superior mesenteric.
The
Right Colic Artery (a. colica dextra) arises from about the middle of the
concavity of the superior mesenteric artery, or from a stem common to it and the
ileocolic. It passes to the right behind the peritoneum, and in front of the
right internal spermatic or ovarian vessels, the right ureter and the Psoas
major, toward the middle of the ascending colon; sometimes the vessel lies at a
higher level, and crosses the descending part of the duodenum and the lower end
of the right kidney. At the colon it divides into a descending branch, which
anastomoses with the ileocolic, and an ascending branch, which anastomoses with
the middle colic. These branches form arches, from the convexity of which
vessels are distributed to the ascending colon.
The
Middle Colic Artery (a. colica media) arises from the superior mesenteric
just below the pancreas and, passing downward and forward between the layers of
the transverse mesocolon, divides into two branches, right and left; the former
anastomoses with the right colic; the latter with the left colic, a branch of
the inferior mesenteric. The arches thus formed are placed about two fingers’
breadth from the transverse colon, to which they distribute branches.
The inferior mesenteric artery and its branches
The
inferior mesenteric artery (a. mesenterica inferior) supplies the left half
of the transverse part of the colon, the whole of the descending and iliac parts
of the colon, the sigmoid colon, and the greater part of the rectum. It is
smaller than the superior mesenteric, and arises from the aorta, about 3 or 4
cm. above its division into the common iliacs and close to the lower border of
the inferior part of the duodenum. It passes downward posterior to the
peritoneum, lying at first anterior to and then on the left side of the aorta.
It crosses the left common iliac artery and is continued into the lesser pelvis
under the name of the superior hemorrhoidal artery, which descends between the
two layers of the sigmoid mesocolon and ends on the upper part of the rectum.
Its
branches are:
Left
Colic,
Sigmoid
and
Superior
Hemorrhoidal.
The
Left Colic Artery (a. colica sinistra) runs to the left behind the
peritoneum and in front of the Psoas major, and after a short, but variable,
course divides into an ascending and a descending branch; the stem of the artery
or its branches cross the left ureter and left internal spermatic vessels. The
ascending branch crosses in front of the left kidney and ends, between the two
layers of the transverse mesocolon, by anastomosing with the middle colic
artery; the descending branch anastomoses with the highest sigmoid artery. From
the arches formed by these anastomoses branches are distributed to the
descending colon and the left part of the transverse colon.
The
Sigmoid Arteries (aa. sigmoideæ) two or three in number, run obliquely
downward and to the left behind the peritoneum and in front of the Psoas major,
ureter, and internal spermatic vessels. Their branches supply the lower part of
the descending colon, the iliac colon, and the sigmoid or pelvic colon;
anastomosing above with the left colic, and below with the superior hemorrhoidal
artery.
Sigmoid colon and rectum, showing distribution of branches of inferior mesenteric artery and their anastomoses
The
Superior Hemorrhoidal Artery (a. hæmorrhoidalis superior) the continuation
of the inferior mesenteric, descends into the pelvis between the layers of the
mesentery of the sigmoid colon, crossing, in its course, the left common iliac
vessels. It divides, opposite the third sacral vertebra, into two branches,
which descend one on either side of the rectum, and about 10 or 12 cm. from the
anus break up into several small branches. These pierce the muscular coat of the
bowel and run downward, as straight vessels, placed at regular intervals from
each other in the wall of the gut between its muscular and mucous coats, to the
level of the Sphincter ani internus; here they form a series of loops around the
lower end of the rectum, and communicate with the middle hemorrhoidal branches
of the hypogastric, and with the inferior hemorrhoidal branches of the internal
pudendal.