Q2 LONG ANSWER 10M ★ High-yield

Describe the stomach under parts, relations, blood supply, lymphatic drainage and nerve supply. Add a note on its applied anatomy.

Anatomy · 1st Professional — Pre-Clinical

The stomach is the most dilated part of the alimentary canal, lying in the epigastric, umbilical and left hypochondriac regions.

Part	Description
Cardia	Where the oesophagus enters, at the level of T11
Fundus	Above the level of the cardiac orifice; contains the gas bubble seen on radiographs
Body	The main part
Pyloric antrum	From the incisura angularis to the pylorus
Pylorus	The pyloric sphincter, at the level of the transpyloric plane (L1)

Two curvatures — the lesser on the right, giving attachment to the lesser omentum; the greater on the left, giving attachment to the greater omentum and gastrosplenic ligament
Incisura angularis — a notch on the lesser curvature marking the junction of body and antrum

Direction	Relations
Anterior	Anterior abdominal wall, left costal margin, left lobe of liver, diaphragm
Posterior (the stomach bed)	Diaphragm, left suprarenal, upper part of left kidney, splenic artery, pancreas, transverse mesocolon, spleen — separated by the lesser sac
Left	Spleen
Right	Liver, lesser omentum

Artery	Origin	Supplies
Left gastric	Coeliac trunk directly	Upper lesser curvature; the smallest branch of the coeliac trunk but the chief gastric artery
Right gastric	Hepatic artery	Lower lesser curvature
Left gastroepiploic	Splenic artery	Upper greater curvature
Right gastroepiploic	Gastroduodenal artery	Lower greater curvature
Short gastric (vasa brevia)	Splenic artery	Fundus

All five arteries derive from the coeliac trunk — the artery of the foregut
Veins correspond and drain into the portal system: left and right gastric directly into the portal vein; left gastroepiploic and short gastric into the splenic; right gastroepiploic into the superior mesenteric

Area	Nodes	Onward
Upper two-thirds of the lesser curvature	Left gastric nodes	Coeliac
Lower lesser curvature and pylorus	Right gastric and hepatic nodes	Coeliac
Upper greater curvature and fundus	Pancreaticosplenic nodes	Coeliac
Lower greater curvature	Right gastroepiploic and pyloric nodes	Coeliac

All lymph ultimately reaches the coeliac nodes, then the cisterna chyli and thoracic duct
This is why carcinoma of the stomach metastasises to the left supraclavicular (virchow) node — Troisier's sign

Parasympathetic — vagus: the anterior vagal trunk is derived mainly from the left vagus, the posterior from the right. Secretomotor and motor — increases acid secretion and motility
Sympathetic — T6–T9 through the coeliac plexus; vasomotor, motor to the pyloric sphincter, and carries pain fibres
Nerve of Latarjet — the terminal branch of the anterior vagus along the lesser curvature, preserved in highly selective vagotomy to maintain gastric emptying

Rugae — longitudinal folds of mucosa, most marked along the greater curvature; they flatten as the stomach fills
Gastric canal (magenstrasse) — a furrow along the lesser curvature through which fluids pass rapidly to the pylorus, bypassing the body
Mucosa — simple columnar epithelium with gastric pits leading to gastric glands

Intrinsic factor from parietal cells is essential for vitamin B12 absorption — which is why total gastrectomy or atrophic gastritis causes pernicious anaemia

Gastric pain is referred to the epigastrium, because afferents travel with the sympathetic to T6–T9
Peptic ulcer — a posterior gastric or duodenal ulcer may erode the splenic or gastroduodenal artery and cause severe haemorrhage; an anterior ulcer tends to perforate into the peritoneal cavity
Perforation causes shoulder tip pain from diaphragmatic irritation, and gas under the diaphragm on an erect radiograph
Carcinoma of the stomach spreads to the Virchow node, to the ovaries (Krukenberg tumour), and to the umbilicus (Sister Mary Joseph nodule)
Congenital hypertrophic pyloric stenosis — presents at 3 to 6 weeks with projectile non-bilious vomiting, visible peristalsis and a palpable "olive"; causes hypochloraemic hypokalaemic metabolic alkalosis

All questions in Abdomen