I am studying the portal system of rat and frog. It is not clear in scientific literature whether a frog has, besides a left gastric vein (vena gastrica sinistra) also a right gastric vein. Do you...

Hepatic portal system: Found in all chordates. In mammals, there is a single vein called hepatic
portal vein, formed by the union of six main veins, which drain venous blood from different parts
of alimentary canal (digestive system) into the liver. These veins are :
(i) Posterior or Inferior mesenteric vein: Collect blood from rectal wall and anal region. This
vein possesses maximum diluted blood. Posterior mesenteric made up of by joining of 4 small
veins that is rectal vein, sigmoid...