Stomach: In humans, stomach has four parts:
1.The
mucosa within the stomach is also different from the rest of the digestive tract.The extra muscle layer facilitates
the churning, mixing and mechanical digestion of food that occurs within the
stomach, as well as supporting the onward journey of the food by peristalsis.The stomach is
supplied with arterial blood from a branch of the celiac artery, and venous blood
leaves the stomach via the hepatic vein.The vagus nerve innervates the stomach
with parasympathetic fibres that stimulate gastric motility and the secretion of
gastric juice.The
body region occupies the space between the lesser and greater curvature of the
stomach, and the pyloric region narrows into the pyloric canal.Sympathetic fibres from the celiac plexus reduce gastric activity.It has
longitudinal, circular and oblique muscle fibres.