Abdomen anatomy

Crura of the diaphragm

Lumbar anchors of the posterior diaphragm

External oblique

Superficial sheet linking the ribs to the abdominal wall

Internal oblique

Abdominal layer with regionally changing fiber direction

Quadratus lumborum

A muscular connection between pelvis, lumbar spine and rib 12

Rectus abdominis

Paired vertical muscles inside the rectus sheath

Transversus abdominis

Deep abdominal muscle supporting pressure and stability

Nerves

Anterior vagal trunk

Vagal fibers reaching the front of the abdominal esophagus

Celiac ganglion

Prevertebral sympathetic relay beside the celiac artery

Celiac plexus

Autonomic network around the upper abdominal aorta

Enteric nervous system

Local sensory and motor circuits within the digestive tract

Genitofemoral nerve

Lumbar-plexus nerve with genital and upper-thigh branches

Iliohypogastric nerve

L1 pathway to the suprapubic wall and lateral buttock

Ilioinguinal nerve

Groin sensory nerve accompanying part of the inguinal canal

Lumbar plexus

A nerve network embedded in the posterior part of psoas

Posterior vagal trunk

Right-predominant vagal pathway behind the abdominal esophagus

Vessels

Abdominal aorta

Main arterial trunk between the diaphragm and iliac bifurcation

Afferent arteriole

The regulated vascular inlet to a renal corpuscle

Celiac trunk

Short aortic branch feeding the upper digestive arterial network

Cisterna chyli

Variable abdominal confluence of major lymph trunks

Common hepatic artery

Celiac branch connecting hepatic and gastroduodenal circulations

Common iliac artery

Paired arterial links from the aorta to pelvis and lower limb

Cystic artery

Variable arterial supply to the gallbladder

Efferent arteriole

The glomerular outlet that feeds another capillary bed

Gastro-omental arteries

Arterial routes along the greater curvature

Gastroduodenal artery

Artery behind the proximal duodenum

Gonadal arteries

Long aortic vessels retained as the gonads descend

Hepatic portal vein

Venous inflow connecting digestive organs to liver sinusoids

Hepatic veins

Liver outflow entering the inferior vena cava

Ileocolic artery

Superior mesenteric branch serving the ileocecal region

Inferior mesenteric artery

Aortic supply to the distal colon and upper rectum

Inferior mesenteric vein

Hindgut venous channel with a variable portal-system junction

Inferior phrenic arteries

Paired diaphragmatic arteries with variable origins

Inferior suprarenal artery

The usual renal-arterial contribution to the adrenal

Inferior vena cava

Main venous return from below the diaphragm

Interlobar and arcuate arteries

Arteries traveling between the renal pyramids

Jejunal and ileal arteries

Mesenteric branches forming small-bowel arterial loops

Left colic artery

Inferior mesenteric branch reaching the descending colon

Left gastric artery

Celiac route to the cardia and lesser curvature

Left suprarenal vein

The principal adrenal tributary of the left renal vein

Lumbar arteries

Segmental aortic supply around the lumbar vertebrae

Marginal artery of Drummond

Peripheral arterial connections along the colonic mesentery

Middle colic artery

Mesocolic artery serving much of the transverse colon

Middle suprarenal artery

An aortic contribution to the adrenal vascular network

Ovarian artery

An aortic supply carried in the ovarian suspensory ligament

Ovarian vein

Ovarian drainage joins different veins on each side

Pancreaticoduodenal arteries

Shared arterial arcades around pancreatic head and duodenum

Paraumbilical veins

Portal connections reaching the umbilical abdominal wall

Portosystemic anastomoses

Communications between portal tributaries and systemic veins

Proper hepatic artery

Hepatic inflow artery within the hepatoduodenal ligament

Renal artery

Aortic inflow to the kidney's segmental territories

Renal segmental arteries

Branches defining relatively independent renal territories

Renal vein

Asymmetric venous outflow from the two kidneys

Renal veins

Short right and longer left routes from kidneys to cava

Right colic artery

Variable arterial route to the ascending colon

Right gastric artery

Small artery approaching the pyloric lesser curvature

Right suprarenal vein

A short adrenal connection usually entering the cava

Sigmoid arteries

Inferior mesenteric branches spreading through the sigmoid mesocolon

Splenic artery

Usually tortuous artery following the upper pancreatic border

Splenic vein

Posterior pancreatic vein joining the portal confluence

Superior mesenteric artery

Anterior aortic branch supplying the midgut territory

Superior mesenteric vein

Principal small-bowel and right-colonic venous collector

Superior suprarenal arteries

Small branches approaching the adrenal from above

Testicular artery

A long gonadal vessel from aorta to spermatic cord

Testicular vein

The abdominal continuation of the pampiniform plexus

Vasa recta

Medullary microvessels for exchange and oxygen delivery

Organs

Abdominal part of the ureter

A muscular conduit descending over psoas major

Accessory pancreatic duct

A variable dorsal duct outlet at the minor papilla

Ascending (fourth) part of the duodenum

Duodenal ascent toward the mobile jejunum

Ascending colon

Right-sided colonic ascent toward the liver

Body and pyloric antrum

Secretory reservoir and distal gastric mixer

Cardia of the stomach

Mucosal entry region around the gastroesophageal junction

Caudate and quadrate lobes

Surface lobes that map differently onto functional segments

Cecum

Blind colonic pouch below the ileal opening

Collecting duct system

The final regulated route through cortex and medulla

Common bile duct

Final extrahepatic route from the liver and gallbladder

Common hepatic duct

Hepatic outflow above the cystic duct junction

Couinaud segments

A portal-territory map of the liver

Cystic duct

Bidirectional connection to the gallbladder

Descending (second) part of the duodenum

Duodenal segment beside the pancreatic head

Descending colon

Fixed left colonic segment approaching the sigmoid

Distal convoluted tubule

A cortical segment for controlled electrolyte recovery

Duodenum

Fixed proximal bowel receiving digestive secretions

Fundus of the stomach

Proximal gastric reservoir beneath the left diaphragm

Gallbladder

Bile storage organ against the inferior liver

Greater curvature

Long convex gastric margin carrying omental attachments

Hepatic lobule and acinus

Microscopic maps organized around blood and bile flow

Hepatopancreatic ampulla

Variable common outlet of bile and pancreatic ducts

Horizontal (third) part of the duodenum

Duodenal crossing beneath the mesenteric vessels

Ileocecal junction

Small-to-large bowel transition with variable valve geometry

Ileum

Distal mobile bowel with specialized absorptive and immune roles

Jejunum

Proximal mobile bowel with prominent absorptive folds

Jejunum versus ileum

A gradual change in bowel and mesenteric architecture

Kidney

A retroperitoneal organ for filtration and homeostasis

Left colic (splenic) flexure

Colonic bend near the spleen and an arterial border zone

Left lobe of the liver

Surface left lobe versus the larger functional left liver

Lesser curvature

Concave gastric border facing the liver

Liver

Metabolic organ receiving portal and arterial inflow

Loop of Henle

Tubular limbs with contrasting transport properties

Lower esophageal sphincter

Intrinsic smooth-muscle barrier supported by the crura

Main pancreatic duct

Longitudinal collecting route through the pancreas

Major duodenal papilla

Luminal landmark of the main biliopancreatic outlet

Meckel's diverticulum

True ileal diverticulum from an embryonic gut connection

Mesenteric lymph nodes

Immune surveillance along intestinal vessels

Nephron

A filtering corpuscle connected to a selective tubule

Para-aortic (lumbar) lymph nodes

Lumbar lymph nodes around the great abdominal vessels

Positions of the appendix

A stable cecal origin with a variable tip

Pre-aortic lymph nodes

Central nodes associated with the three gut arteries

Proximal convoluted tubule

A brush-bordered epithelium for bulk recovery

Pyloric sphincter

Muscular regulator at the gastric outlet

Renal calyces

Branching urine-collecting cups in the renal sinus

Renal corpuscle

The glomerular filter and its surrounding capsule

Renal cortex

The glomerulus-containing outer renal tissue

Renal medulla and pyramids

The tubular and vascular core of the concentrating system

Renal papilla

The pyramid tip opening into a minor calyx

Renal pelvis

The upper urinary funnel between calyces and ureter

Right colic (hepatic) flexure

Colonic turn below the right liver

Right lobe of the liver

Large surface lobe distinct from functional right liver

Sigmoid colon

A mobile pelvic loop before the rectum

Sphincter of Oddi

A muscular valve system at the duct outlets

Spleen

Blood filtration and immune defence beneath the left ribs

Stomach

A muscular reservoir that begins protein digestion

Superior (first) part of the duodenum

The proximal duodenum beside the gastric outlet

Teniae coli

Longitudinal muscle concentrated into three bands

Transverse colon

A mobile colonic bridge across the abdomen

Ureter

A peristaltic connection from kidney to bladder

Ureteropelvic junction

The transition from renal funnel to ureter

Vermiform appendix

A lymphoid-rich blind extension of the cecum

Glands

Adrenal (suprarenal) gland

Two endocrine tissues beside the upper kidney

Adrenal cortex

Steroid-producing layers outside the adrenal medulla

Adrenal medulla

Chromaffin cells linking sympathetic nerves to blood

Head and uncinate process of the pancreas

Pancreatic tissue on both sides of mesenteric vessels

Juxtaglomerular apparatus

A local sensor linking tubular salt to vascular control

Pancreas

Digestive gland with endocrine islands behind the stomach

Pancreatic alpha cell

An islet cell that signals hepatic glucose release

Pancreatic beta cell

The endocrine cell that releases insulin with C-peptide

Pancreatic delta cell

A local somatostatin regulator within the islet

Pancreatic islets (of Langerhans)

Vascular endocrine clusters within the pancreas

Zona fasciculata

The broad cortisol-producing cortical layer

Zona glomerulosa

The outer cortex that adjusts mineralocorticoid output

Zona reticularis

The inner cortical network supplying androgen precursors

Ligaments

Coronary and triangular ligaments

Liver–diaphragm peritoneal attachments

Falciform ligament

Anterior hepatic peritoneal fold with an umbilical remnant

Gastrosplenic ligament

A vascular fold between the fundus and splenic hilum

Greater omentum

Mobile vascular and immune tissue over the bowel

Hepatoduodenal ligament

Portal pedicle in the free lesser-omental margin

Lesser omentum

Peritoneal connection from liver to stomach and duodenum

Ligamentum teres hepatis

Round ligament tracing the fetal umbilical venous route

Ligamentum venosum

Fibrous trace of the fetal hepatic shunt

Mesentery of the small intestine

Mobile small bowel suspended from an oblique attachment

Sigmoid mesocolon

The vascular attachment of the sigmoid loop

Splenorenal ligament

The peritoneal route into the splenic hilum

Suspensory muscle of the duodenum

A variable support at the duodenojejunal junction

Transverse mesocolon

The mesentery beneath the stomach and pancreas

Spaces

Bare area of the liver

An extraperitoneal interface with the diaphragm

Calot's triangle

Gallbladder-neck landmarks with two historical definitions

Epiploic foramen

Peritoneal connection behind the portal pedicle

Hepatorenal recess

Dependent right subhepatic peritoneal pocket

Lesser sac (omental bursa)

Sliding peritoneal compartment behind the stomach

Paracolic gutters

Lateral peritoneal routes beside the colon

Perinephric space and renal coverings

The renal fascial compartment and its internal planes

Peritoneum

Continuous serous surface lining walls and covering viscera

Porta hepatis

Hepatic hilum for portal inflow and bile outflow

Renal hilum

The medial entrance into the renal sinus

Retroperitoneum

Posterior extraperitoneal region with communicating tissue planes

Subphrenic recesses

Peritoneal spaces beneath the diaphragm