A typical circulatory system of the class Amphibia. Note the three chambered heart (most visible in 4) where oxygenated blood (from capillaries in gills, lungs and/or skin) and de-oxygenated blood from systemic tissues mix in the ventricle before returning to both sets of tissues via a fork in the aorta. The heart is shown in two views looking both at the ventral (2) and dorsal (3) surfaces.
The central nervous system of a stereotypical amphibian. An entire dorsal dissection of a brain (1) shows the cerebral hemispheres (Hem), the optic lobes (C. big), the cerebellum (Crbl) and the medulla oblangata (M. obl) amongst other strutctures. The other views represented are a horizontal longitudinal section (2), a vertical longitudinal section (3), an entire ventral dissection with circulatory and digestive systems pulled to the right side (4), partial ventral dissection of M. obl and C. big with hypothalamus removed (5), a cross section of the spinal cord with associated nerves and ganglia (6) and a representation of a mechanosensory hair cell receptor (7) showing neurons associated with “hairs” contained within a flexible gell cap.