Snakes walk in various ways, either walking in a straight line or moving forward in a meandering manner, which is determined by the structure of the snake. The whole body of the snake is divided into three parts: head, trunk and tail. The neck is between the head and the trunk, and the boundary is not very obvious. The cloacal anal hole is the boundary between the trunk and the tail. Snakes have no limbs and are covered with scales to protect their skin. Snakes are divided into venomous snakes and non-venomous snakes. The head of non-venomous snakes is generally conical, with a thin front end and a thick rear end; venomous snakes are triangular in shape; the snakes trunk is long and tubular; and the snakes tail is the area after the anus.
The internal structure of a snake is divided into : Ten parts including the skin system, skeletal system, muscular system, respiratory system, digestive system, cloacal system, nervous system, sensory organs and chromosomes. Breathing of snakes: The respiratory organs of snakes are lungs.
Snakes have no nictitating membrane, lacrimal glands and movable eyelids; no tympanic membrane, tympanic cavity atrophy, and disappearance of the Eustachian tube; the oval window and the quadrate bone of the inner ear are connected by the otic columella bone; there is no temporal fossa (but It is the descendant of the bitemporal fossae. The snake skull has no trace of the bitemporal fossa due to the degeneration or disappearance of a large number of membranous bones); the belt bone and sternum have degenerated; the vertebral body is concave in front; except for the atlas and coccyx, all other vertebrae are attached There are movable ribs; due to the influence of body shape, the left and right symmetry of the paired internal organs becomes staggered front and back or only one side is retained (pythons have paired lungs); there is no bladder.
