Primitively, these are groups of dorsal elevator muscles and ventral depressor muscles. 1 Amphibian axial skeleton supports against gravity as well. The hip bone of ilium, ischium, and pubis is clearly evident, and its connection to sacral vertebrae creates a pelvis . Adults tailess, with long, muscular hind legs that end in webbed feet. Gilled, aquatic, larval tadpoles have tails.
Many salamanders use their jaws to catch prey, but frogs also have a tongue for flicking.
The amphibian heart is different than the fish heart, in that there are now a consistent set of lungs and so a two-pass circulation . This deoxygenated blood will drain from the right atrium into a common ventricle . With the moist skin of amphibians, oxygen can be taken up through the skin so cutaneous arteries in addition to pulmonary arteries help to oxygenate blood. The now-oxygenated blood drains back into the left atrium , to be pumped by the ventricle to systemic arteries to the body and carotid arteries to the head. Amphibians in water share the same osmoregulatory concerns as do freshwater fish, and so there excrete a lot of dilute urine.