The stomach is roughly J-shaped and can be divided into the cardiac
orifice, fundus, body, pyloric antrum and pylorus. There is a wellmarked
anatomical pyloric sphincter and a functionally competent, but
not anatomically defined sphincter mechanism at the cardiac orifice.
There is a rich arterial supply from all three branches of the coeliac axis
and the accompanying venous drainage is to the portal system. There
is a clinically important porto-systemic anastomosis at the oesophagogastric
junction. The vagus provides the motor and secretomotor nerve
supply while sensory fibres are transmitted by sympathetic fibres passing
via the coeliac ganglion to spinal segments T5 to 12.