Snakes are reptiles that have elongated bodies and no legs, no eyelids and external ears. Many species of snakes have skulls with many joints, enabling them to swallow prey much larger than their heads with their highly mobile jaws (can be enlarged).
Snakes can be found on every continent except Antarctica. More than 20 families, consisting of about 500 genera and about 3,400 species.

Snake skin covered in scales, snake has a dry smooth texture. Transparent eyelid closed snake, also known as brille. Their eyes are always open, and for sleeping, the retina can be closed or the face buried among the folds of the body. shedding (moulting) serves a number of functions. First, the old and worn skin is replaced, secondly, it helps get rid of parasites such as fleas and ticks.
shedding occurs periodically throughout a snake's life. Before the moult, the snake stops eating and often hides or moves to a safe place. Just before shedding, the skin becomes dull and the eyes become cloudy or blue. After a few days, the eyes clear and the snake "crawls" out of the old skin aided by rubbing against rough surfaces.
An old snake shedding its skin only once or twice a year. But the young snake, still growing, may molt up to twelve times a year.

The only snake skeleton consists of the skull, hyoid, vertebrae, and bone rusuk.Tengkorak snake consists of a solid braincase and complete, many other bones are only loosely attached, particularly highly mobile jaw bones, which facilitate manipulation and consumption of prey items. Left and right side of the lower jaw are joined only by a flexible ligament at the anterior end, allowing them to separate widely, while the posterior end of the lower jaw bones articulate with a quadrate bone, allowing further mobility. The bone of the jaw, and squares can also pick up ground borne vibrations Because the jaw can move independently of each other.

Snakes have stereo hearing sensitive that it can detect the position of the prey. He was able to detect vibrations in the angstrom scale, despite the absence of the external ear and the mechanisms of the small bones of the impedance matching is used in other vertebrates for receiving vibrations from the air.

The heart of a snake wrapped in a sac, called the pericardium, located at the bifurcation of the bronchi. Heart to move, however, due to the lack of a diaphragm. This adjustment protects the heart from potential damage when large ingested prey that passes through the esophagus. The spleen is attached to the gall bladder and pancreas and filters the blood. The thymus gland is located in fatty tissue above the heart and is responsible for the generation of immune cells in the blood. The cardiovascular system is also unique for the presence of snakes portal system of the kidney where blood from the tail of the snake through the kidneys before returning to the heart.

Lungs only one snake. That vestigial left lung is very small or sometimes even absent, as snakes tubular bodies' require all of their organs to be long and thin. In most species, only one functional lung. This lung contains a vascularized anterior portion and a posterior portion that does not function in gas exchange. Saccular lung is used for hydrostatic purposes to adjust buoyancy in some water snakes and its function remains unknown in terrestrial species. Many organs that are paired, such as kidneys or reproductive organs, are staggered within the body, with one located in front of the other.