The digestive system of reptiles has its own characteristics, which make it much more complex compared to the same structure in amphibians.
General characteristics of reptiles
Reptiles got their name due to the nature of movement on the earth's surface. They are either devoid of or have short limbs that are located in a horizontal plane. Therefore, they seem to "creep" on the ground. All of them are cold-blooded animals that have mastered both aquatic and terrestrial habitats. But the development of their embryos, which are surrounded by protective egg shells, occurs exclusively on land. The body of reptiles is covered with dry, keratinized scales.
The main features of the internal structure are the appearance of a real chest, exclusively pulmonary respiration, internal fertilization and the excretory system of reptiles, represented by the kidneys, bladder and cloaca.
Digestive system: main divisions
Digestive systemreptiles is represented by a tract and specialized glands. Unlike amphibians, these animals have salivary glands that produce enzymes. These substances are natural biological catalysts. They break down complex organic substances into simple ones. It is in this form that they are able to be absorbed and stored in reserve. The structure of the digestive system of reptiles is also characterized by the presence of undifferentiated teeth and the caecum. These are the main features of the complication compared to amphibians.
The digestive tract of reptiles is represented by the oral cavity, pharynx, narrow esophagus, stomach and intestines. The latter is differentiated and consists of a thin and thick sections, passing into the caecum. The digestive tube ends with a cloaca. This is a hole through which not only undigested food residues are excreted, but also products of the excretory and reproductive systems of reptiles.
Digestive glands
The digestive system of reptiles is quite complex. Digestion of both vegetable and animal food, which they consume, would not be possible without the presence of glands. In addition to salivary substances and enzymes which break down, moisturize and facilitate the ingestion of food, reptiles have a liver and pancreas. Each organ performs its own function. The liver secretes bile, which disinfects and breaks down food particles. And the pancreas secretes enzymes that complete the breakdown of proteins, fats and carbohydrates.
Enzymesdigestive glands of reptiles are chemically active substances. So, everyone knows the fact that snakes do not chew food, but capture their prey entirely. The process of its digestion begins only in the stomach. Sometimes its duration reaches several weeks.
Features of Complication
As already mentioned, the excretory system of reptiles is characterized by certain features of complication. Despite the fact that all teeth in the oropharyngeal cavity are the same and serve only to capture and hold prey, there are also specialized ones. For example, poisonous snakes. Many believe that they paralyze their prey with their tongue. But that's not the case at all. In their oral cavity is a poisonous tooth, in which there is a channel with a toxic substance. And from the mouths of predators, such as crocodiles, it is completely impossible to escape, since their teeth are especially powerful and sharp. For example, the incisors of this animal "work" so often that they change up to several dozen times a year. By the way, unlike amphibians, in many of which the tongue is a food capture organ, this organ of crocodiles practically fuses with the base of their oral cavity, so it seems that it does not exist at all.
Functions of the digestive system of reptiles
The digestive system is designed to break down and absorb nutrients. When they are split, a certain amount of energy is released, which is used by living organisms to carry out all life processes. Whereinsplitting occurs with the help of enzymes of specialized glands, and the movement of food particles from the oral cavity to the cloaca is carried out by the muscular walls of the tract.
So, the digestive system of reptiles has both typical features of the structure of chordates, and some distinctive ones. Obviously, compared to amphibians, it is much more complex. This is manifested in the presence of digestive enzymes, which are secreted by specialized glands, the caecum and the differentiated intestine.
