Fig. 6.—Venous System of Xenopus and Rana.
[In the Frog the abdominal vein is also formed by the union of the two pelvic veins. The pelvic veins, however, lie more superficially than in the Platana. The femoral vein which passes along the front of the thigh divides into two branches, the one branch forming the pelvic vein, the other, joined by the sciatic vein from the muscles and skin of the back of the thigh, forming the renal portal vein extending along the outer side of the kidney. The dorso-lumbar vein from the dorsal wall of the body joins the renal portal vein.]
Make a drawing showing the above parts.
B. Arterial System.
Distend the œsophagus with a piece of cotton wool or paper to show the blood vessels more clearly. Trace out the anterior part of the arterial system, made up of two branches of the truncus arteriosus each of which divides into:—
(a) The carotid arch passing to the head region.
(b) The systemic arch curving round the œsophagus.
(c) The pulmo-cutaneous arch to the lungs and the skin.