The skeleton provides support for the body and organs of movement, protects the most important organs.
Due to the work of the muscles, movement is carried out. Muscles of amphibians are well developed (especially on the limbs); in the body of amphibians, there are up to 350 muscles.
The skeleton is divided into 4 sections:
- skeleton of the head (skull);
- skeleton of the torso;
- the skeleton of the girdles of the limbs;
- skeleton of free limbs.
Head skeleton (skull)
The skeleton of the head, or skull, consists of the cranium and the lower jaw.
The skeleton of the body in all vertebrates consists of a spine and ribs (in amphibians, ribs are very small or absent).
The spine of amphibians is divided into sections:
The cervical spine in all amphibians contains only one vertebra, which is movably attached to the occipital skull (provides head mobility), which is why amphibians can lower and raise their heads.
The number of trunk vertebrae is different (from 7 in a frog to 100 or more in representatives of the Legless Order).
Limb Belts Skeleton
Front limb belt:
- paired shoulder blades;
- paired collarbones;
- paired crow bones;
- one sternum.
The hind limb is formed by the bones of the pelvis connected to the sacral vertebra.
Free limbs skeleton
In connection with the access to land, amphibians developed limbs of the terrestrial (lever) type, consisting of parts and having their own muscle mass.
Front limb skeleton:
- two bones of the forearm (ulna and radius),
- bones of the hand (consisting of parts: wrist, metacarpus, phalanges of the fingers).
Hind limb skeleton:
- 2 shin bones (tibia and tibia);
- bones of the foot.