Anatomy: Posterior ABD

Abdominal Aorta

The primary arterial trunk of the abdomen beginning at the aortic hiatus (~T12) and ending at ~L4 where it bifurcates into the right and left common iliac arteries.

Celiac Trunk

An unpaired anterior visceral branch of the abdominal aorta arising at ~T12 that supplies foregut structures via three main divisions.

Left Gastric Artery

An unpaired branch of the celiac trunk that ascends toward the esophageal hiatus to give off esophageal branches before running along the lesser curvature of the stomach.

Esophageal Arteries

Branches arising from the left gastric artery that supply the abdominal portion of the esophagus.

Splenic Artery

A tortuous main branch of the celiac trunk passing superior to the pancreas toward the spleen, giving off pancreatic branches, short gastric arteries, and the left gastroomental artery.

Dorsal Pancreatic Artery

A pancreatic branch arising from the proximal portion of the splenic artery that supplies the body and neck of the pancreas.

Great Pancreatic Artery

A large pancreatic branch arising from the splenic artery that supplies the body and tail of the pancreas.

Short Gastric Arteries

Small arterial branches arising from the splenic artery near the splenic hilum to supply the fundus of the stomach.

Left Gastroomental Artery

A branch of the splenic artery passing along the greater curvature of the stomach within the greater omentum to anastomose with the right gastroomental artery.

Common Hepatic Artery

An unpaired branch of the celiac trunk that courses to the right to divide into the proper hepatic and gastroduodenal arteries.

Proper Hepatic Artery

An ascending branch of the common hepatic artery running within the hepatoduodenal ligament alongside the portal vein and bile duct to supply the liver and gallbladder.

Right Gastric Artery

An arterial branch arising from the proper hepatic or common hepatic artery that courses along the lesser curvature of the stomach to anastomose with the left gastric artery.

Right Hepatic Artery

A terminal branch of the proper hepatic artery supplying the right lobe of the liver and typically giving origin to the cystic artery.

Left Hepatic Artery

A terminal branch of the proper hepatic artery supplying the left lobe of the liver.

Cystic Artery

An arterial branch usually arising from the right hepatic artery that supplies the gallbladder.

Gastroduodenal Artery

A branch of the common hepatic artery descending posterior to the first part of the duodenum, giving off the supraduodenal, right gastroomental, and superior pancreaticoduodenal arteries.

Supraduodenal Artery

A small branch arising from the gastroduodenal artery to supply the superior aspect of the proximal duodenum.

Right Gastroomental Artery

A terminal branch of the gastroduodenal artery running along the greater curvature of the stomach to anastomose with the left gastroomental artery.

Superior Pancreaticoduodenal Artery

A branch of the gastroduodenal artery that divides into anterior and posterior branches to supply the head of the pancreas and proximal duodenum.

Superior Mesenteric Artery (SMA)

An unpaired anterior visceral branch of the abdominal aorta arising at ~L1 posterior to the neck of the pancreas to supply midgut structures.

Inferior Pancreaticoduodenal Artery

The first branch of the SMA, dividing into anterior and posterior branches that anastomose with the superior pancreaticoduodenal artery to supply the duodenum and head of the pancreas.

Intestinal Arteries

A series of 15 to 18 jejunal and ileal branches arising from the left side of the SMA that form arterial arcades within the mesentery.

Arterial Arcades

Anastomotic loops formed by the intestinal arteries within the mesentery, featuring 1–2 arcades in the jejunum and 3–5 arcades in the ileum.

Vasa Recta

Straight arterial vessels arising from the arterial arcades to supply the small intestine wall, characterized as long in the jejunum and short in the ileum.

Ileocolic Artery

A branch of the SMA supplying the terminal ileum, cecum, and appendix via its appendicular branch.

Appendicular Artery

A branch of the ileocolic artery passing within the mesoappendix to supply the vermiform appendix.

Right Colic Artery

A branch of the SMA supplying the ascending colon.

Middle Colic Artery

A branch of the SMA entering the transverse mesocolon to supply the proximal two-thirds of the transverse colon.

Inferior Mesenteric Artery (IMA)

An unpaired anterior visceral branch of the abdominal aorta arising at ~L3 that descends to the left to supply hindgut structures.

Left Colic Artery

The superior branch of the IMA supplying the distal third of the transverse colon and the descending colon.

Sigmoid Arteries

A group of 3 to 5 branches of the IMA supplying the sigmoid colon.

Superior Rectal Artery

The terminal continuation of the IMA entering the pelvic cavity to supply the rectum and upper anal canal.

Marginal Artery

A continuous anastomotic arterial channel running along the inner border of the large intestine that connects branches of the SMA and IMA.

Superior Suprarenal Arteries

Multiple paired parietal branches arising from the inferior phrenic arteries that supply the superior region of the suprarenal glands.

Middle Suprarenal Arteries

Paired lateral visceral branches arising directly from the abdominal aorta near ~L1 to supply the suprarenal glands.

Inferior Suprarenal Arteries

Paired visceral branches arising from the renal arteries to supply the inferior region of the suprarenal glands.

Renal Arteries

Paired lateral visceral branches arising from the abdominal aorta at ~L1 supplying the kidneys and giving off inferior suprarenal branches.

Gonadal Arteries (Testicular or Ovarian Arteries)

Paired lateral visceral branches arising from the abdominal aorta at ~L2, descending retroperitoneally toward the scrotum or pelvic cavity.

Inferior Phrenic Arteries

Paired posterolateral parietal branches arising from the abdominal aorta at ~T12 immediately superior to the celiac trunk to supply the diaphragm and superior suprarenal glands.

Subcostal Arteries

Paired posterolateral parietal branches arising from the aorta at ~L1 inferior to the 12th ribs to course along the posterior abdominal wall.

Lumbar Arteries

Four pairs of posterolateral parietal branches arising from the abdominal aorta (L1–L4) that supply the posterior abdominal wall musculature and spinal cord.

Median Sacral Artery

An unpaired posterior parietal branch arising from the back of the abdominal aorta just superior to its bifurcation (~L4) to descend along the sacrum.

External Iliac Arteries

Branches of the common iliac arteries descending along the psoas major to pass deep to the inguinal ligament and become the femoral arteries.

Internal Iliac Arteries

Branches of the common iliac arteries descending into the pelvic cavity to supply pelvic organs, walls, and perineum.

Inferior Epigastric Artery

A branch of the external iliac artery arising superior to the inguinal ligament to ascend along the anterior abdominal wall within the rectus sheath.

Deep Circumflex Iliac Artery

A branch of the external iliac artery running laterally along the iliac crest to supply the anterolateral abdominal wall musculature

Inferior Vena Cava (IVC)

The large retroperitoneal vein formed by the confluence of the common iliac veins at ~L5, ascending to the right of the aorta to pass through the diaphragmatic caval foramen (~T8) into the right atrium.

Left Renal Vein

The longer renal vein that traverses the acute angle between the abdominal aorta and superior mesenteric artery to reach the inferior vena cava, receiving the left gonadal and left suprarenal veins along its course.

Nutcracker Syndrome (Renal Vein Entrapment)

Clinical compression of the left renal vein between the SMA and abdominal aorta, manifesting as hematuria, left flank pain, and gonadal venous engorgement.

Hepatic Portal Vein

A large vein formed posterior to the neck of the pancreas by the union of the splenic and superior mesenteric veins, transporting nutrient-rich blood into the liver at the porta hepatis.

Portocaval Anastomoses

Natural anatomical communications between portal tributaries and systemic (caval) veins located at esophageal, rectal, paraumbilical, and retroperitoneal regions.

Portal Hypertension

Pathological elevation of portal venous pressure caused by increased hepatic or portal flow resistance, forcing blood into portocaval anastomoses and producing dilated varicosities.

Esophageal Varices

Extremely fragile, enlarged submucosal veins at the gastroesophageal junction resulting from portocaval shunting between the left gastric vein (portal) and esophageal tributaries of the azygos system (caval).

Caput Medusae

Dilation and tortuosity of superficial cutaneous veins surrounding the umbilicus caused by portocaval flow between paraumbilical veins (portal) and epigastric veins (caval).

Psoas Major Muscle

A chief flexor of the thigh and trunk originating from the T12–L5 vertebrae and intervertebral discs and inserting into the lesser trochanter of the femur, innervated by L1–L4 anterior rami.

Iliacus Muscle

A fan-shaped muscle filling the iliac fossa that merges with psoas major to form the iliopsoas, inserting onto the lesser trochanter under femoral nerve innervation (L2–L4).

Quadratus Lumborum Muscle

A quadrate muscle spanning from the 12th rib and lumbar transverse processes down to the iliac crest, innervated by T12–L4 nerves to laterally flex the spine and stabilize the 12th rib during inspiration.

Median Arcuate Ligament

A fibrous arch spanning between the right and left diaphragmatic crura across the aortic hiatus (~T12).

Medial Arcuate Ligament

A thickened fascial arch over the superior part of the psoas major muscle extending from the lumbar vertebral bodies to the transverse process of L1.

Lateral Arcuate Ligament

A thickened fascial band overlying the quadratus lumborum muscle running from the L1 transverse process to the 12th rib.

Diaphragmatic Crura

Musculotendinous bundles attaching the diaphragm to the upper lumbar vertebrae, with the robust right crus curving around the esophageal hiatus (~T10).

Caval Opening (Foramen)

An aperture in the central tendon of the diaphragm located at ~T8 that transmits the inferior vena cava and terminal branches of the right phrenic nerve.

Esophageal Hiatus

A muscular opening within the right crus of the diaphragm at ~T10 transmitting the esophagus and anterior/posterior vagal trunks.

Aortic Hiatus

An osseo-aponeurotic opening posterior to the median arcuate ligament at ~T12 that permits passage of the abdominal aorta, thoracic duct, and azygos vein.

Lumbar Plexus

A somatic nerve network formed within the substance of the psoas major muscle by the anterior rami of spinal nerves L1–L4.

Genitofemoral Nerve

A lumbar plexus branch (L1, L2) that emerges on the anterior surface of psoas major to divide into genital and femoral sensory/motor branches.

Femoral Nerve

The largest nerve of the lumbar plexus (L2–L4), emerging lateral to psoas major and descending deep to the inguinal ligament to supply the anterior thigh muscles.

Obturator Nerve

A nerve of the lumbar plexus (L2–L4) emerging medial to psoas major that passes through the obturator canal to innervate the adductor muscles of the medial thigh.

Renal Fascia (Gerota's Fascia)

A membranous condensation of subserous fascia enclosing the kidney, suprarenal gland, and perinephric fat capsule.

Perinephric (Perirenal) Fat

An inner protective adipose layer immediately surrounding the renal capsule within the renal fascia.

Paranephric (Pararenal) Fat

An outer layer of fat located external and posterior to the renal fascia along the posterior abdominal wall.

Renal Cortex

The outer parenchymal zone of the kidney containing glomeruli and convoluted tubules, extending inward as renal columns between medullary pyramids.

Renal Pyramids

Conical medullary structures containing collecting tubules that drain at the renal papilla into minor calyces.

Renal Pelvis

A funnel-shaped expansion collecting urine from major calyces that narrows as it exits the renal hilum to become the ureter.

Suprarenal (Adrenal) Glands

Endocrine glands capsulated superior to each kidney, featuring a triangular right gland and a semilunar left gland