Coeliac at T12, superior mesenteric at L1, renals at L2, inferior mesenteric at L3, bifurcation at L4
Mnemonic
Group them as three unpaired midline, three paired lateral, and the parietal branches:
Unpaired midline (gut), following the embryonic divisions:
- Coeliac trunk, T12, foregut
- Superior mesenteric, L1, midgut
- Inferior mesenteric, L3, hindgut
Paired lateral (visceral):
- Suprarenal, L1
- Renal, L1 to L2
- Gonadal, L2
Paired parietal: inferior phrenic (T12), four lumbar arteries, and the median sacral, before it bifurcates at L4 into the common iliac arteries.
“Gut in the midline, glands at the sides.” The aorta ends at L4, at the level of the iliac crests, which is why an aneurysm is palpated above that line.
Expansion
The abdominal aorta begins at the aortic hiatus (T12) and ends by bifurcating at L4, at the level of the iliac crests.
Unpaired (visceral, midline)
- Coeliac trunk - T12
- Superior mesenteric artery - L1
- Inferior mesenteric artery - L3
Paired (visceral, lateral)
- Middle suprarenal - L1
- Renal - L2
- Gonadal - L2
Paired (parietal)
- Inferior phrenic - T12
- Four pairs of lumbar arteries
- Median sacral, from the bifurcation
The single most useful anchor is the bifurcation at L4, at the transtubercular plane, which is why an abdominal aortic aneurysm is palpated above the umbilicus.