732
UNIT 4
Maintenance of the Body
19
(c) Major branches of the abdominal aorta.
Hiatus (opening)
for inferior vena cava
Diaphragm
Inferior phrenic artery
Middle suprarenal artery
Renal artery
Superior mesenteric artery
Inferior mesenteric artery
Median sacral
artery
Common iliac artery
Ureter
Gonadal (testicular
or ovarian) artery
Hiatus (opening)
for esophagus
Celiac trunk
Adrenal (suprarenal)
gland
Kidney
Abdominal aorta
Lumbar arteries
Superior mesenteric artery
(mes-en-ter
9
ik).
Tis large, unpaired
artery arises from the abdominal aorta at the L
1
level immediately
below the celiac trunk (Figure 19.24d). It runs deep to the pan-
creas and then enters the mesentery (a drapelike membrane that
supports the small intestine), where its numerous anastomosing
branches serve virtually all of the small intestine via the
intestinal
arteries
, and most of the large intestine—the appendix, cecum, as-
cending colon (via the
ileocolic
and
right colic arteries
), and part
of the transverse colon (via the
middle colic artery
).
Suprarenal arteries
(soo
0
prah-re
9
nal).
Te
middle suprare-
nal arteries
flank the origin of the superior mesenteric artery
as they emerge from the abdominal aorta (Figure 19.24c). Tey
supply blood to the adrenal (suprarenal) glands overlying the
kidneys. Te adrenal glands also receive two sets of branches
not illustrated:
superior suprarenal
branches from the nearby
inferior phrenic arteries, and
inferior suprarenal
branches from
the nearby renal arteries.
Renal arteries.
Te short but wide renal arteries, right and
le±, issue from the lateral surfaces of the aorta slightly below
the superior mesenteric artery (between L
1
and L
2
). Each serves
the kidney on its side.
Gonadal arteries
(go-nă
9
dul).
Te paired gonadal arteries
are called the
ovarian arteries
in females and the
testicular
arteries
in males. Te ovarian arteries extend into the pelvis
to serve the ovaries and part of the uterine tubes. Te much
longer testicular arteries descend through the pelvis and in-
guinal canals to enter the scrotum, where they serve the testes.
Inferior mesenteric artery.
Tis final major branch of the
abdominal aorta is unpaired and arises from the anterior aor-
tic surface at the L
3
level. It serves the distal part of the large
intestine—from the midpart of the transverse colon to the
midrectum—via its
lef colic
,
sigmoidal
, and
superior rec-
tal branches
(Figure 19.24d). Looping anastomoses between
the superior and inferior mesenteric arteries help ensure that
blood will continue to reach the digestive viscera in cases of
trauma to one of these abdominal arteries.
Lumbar arteries.
Four pairs of lumbar arteries arise from the
posterolateral surface of the aorta in the lumbar region. Tese
segmental arteries supply the posterior abdominal wall.
Median sacral artery.
Te unpaired median sacral artery is-
sues from the posterior surface of the abdominal aorta at its
terminus. Tis tiny artery supplies the sacrum and coccyx.
Common iliac arteries.
At the L
4
level, the aorta splits into
the right and le± common iliac arteries, which supply blood
to the lower abdominal wall, pelvic organs, and lower limbs
(Figure 19.24c).
Arteries of the Abdomen
(continued)
Table 19.7
Figure 19.24
(continued)
Arteries of the abdomen.
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