Embryonic Gut Development: Regions, Vasculature, Innervation, and Rotation

Foregut

Region from oral cavity to proximal duodenum; includes liver, stomach, pancreas.

Midgut

Region forming most of the small intestine and part of large intestine.

Hindgut

Region forming distal colon, rectum, and anus.

Head fold

Embryonic fold that helps form the foregut.

Tail fold

Embryonic fold that helps form the hindgut.

Celiac artery

Main arterial supply to the foregut.

Superior mesenteric artery

Artery supplying the midgut.

Inferior mesenteric artery

Artery supplying the hindgut.

Splenic vein

Drains foregut structures into portal system.

Superior mesenteric vein

Drains midgut.

Inferior mesenteric vein

Drains hindgut.

Vagus nerve (CN X)

Parasympathetic innervation to foregut and midgut.

Pelvic splanchnic nerves

Parasympathetic innervation to hindgut.

Greater splanchnic nerve

Sympathetic supply to foregut.

Lesser splanchnic nerve

Sympathetic supply to midgut.

Least/lumbar splanchnic nerves

Sympathetic supply to hindgut.

Celiac ganglion

Sympathetic ganglion for foregut.

Mesenteric ganglia

Sympathetic ganglia for midgut and hindgut.

Mesentery

Tissue that suspends gut tube and carries blood vessels.

Ventral mesentery

Connects gut to ventral body wall (only in foregut region).

Dorsal mesentery

Connects gut to dorsal body wall.

Lesser omentum

Connects liver to stomach/duodenum.

Greater omentum

Large fatty structure hanging from stomach.

Falciform ligament

Connects liver to anterior body wall.

Hepatic diverticulum

Outgrowth forming liver and gallbladder.

Pancreatic buds

Dorsal and ventral structures that fuse to form pancreas.

Foregut rotation

Movement causing stomach left shift and liver right shift.

Midgut herniation

Temporary protrusion of midgut outside embryo due to growth.

Midgut rotation

270° counterclockwise rotation around superior mesenteric artery.

Repackaging

Return of midgut into abdominal cavity after herniation.

Cloaca

Common chamber for digestive and urogenital systems.

Cloacal division

Separation into rectum/anus and urinary bladder in mammals.

Rectum

Terminal part of digestive tract storing feces.

Anus

Opening for waste elimination.

Respiratory diverticulum

Outgrowth of foregut forming lungs.

Trachea

Tube derived from foregut connecting to lungs.

Primary bronchi

First branches of the lung bud.

Pleural cavities

Cavities surrounding lungs.

Pericardial cavity

Cavity surrounding heart.

Peritoneal cavity

Abdominal cavity housing digestive organs.

Coelom

Body cavity that becomes subdivided into major organ cavities.