Avian digestive system

The Oiseau X lay out of a digestive Système original which has common characteristics although the food modes and the lifestyles are very different. This device at the same time makes it possible to support a high Métabolisme and to be very powerful (the bearded Gypaète is able to digest and assimilate bones).

The food modes

The birds, because of their raised metabolism, must nourish rich foods. For certain birds like the hummingbirds, the reserves of energies are only of a few hours beyond of which they die if they are not fed. The birds are for example granivores, piscivorous, carnivorous, necrophagous, frugivorous, nectarivores but truths Sténophage S are rare. This food specialization results in important variations on the functions of the various bodies. Thus certain species have languages very developed like the hummingbirds and that others have only one very reduced language like the language of 1 cm of the Pélican S. Some, as the granivores developed a jabot, others not. Certain species as the trip hammers have salivary glands very developed, however this is rare, the nozzle not being used for mastiquer food, as in the mammals.

The Goose S, of the Psittacidae , the Columbiformes, of the Cracidae , of the Passeriformes, the Calao S and the Casoar S voluntarily consume ground one speaks about Géophagie. The absorption of ground, like clay, is supposed to reduce the effect of Alcaloïde S poisons contained in certain plants.

The transport of glucose

The transport system of the Glucose of the birds is different from that of the mammals, the Amphibians and fish. It does not vary according to the hydrocarbonate concentrations, including when the season changes. Absorption is mainly passive and does not depend on the variations of the food mode. This system allows a fast assimilation but it is particularly sensitive to the Toxine S. This thus reduces to the food niche birds and when the concentration in glucose is weaker inside the cell than in the Plasma, glucose can diffuse in the bad direction.

Transit of food

The digestive system of the birds is thus composed of a specialized Bec, without teeth. In all the cases, the food is possibly broken but not to chew. The food passes by the esophagus then cross the jabot when there exists. They pass then by the glandular stomach where they undergo the attack of Acide S and Once impregnated Enzyme S., the food is expelled towards the Gésier which is a muscular stomach. Certain species avalent of the stones called Gastrolithe S to increase the effectiveness of this one. On this level, the food is crushed. They are finally assimilated by the intestines. Then eliminated, as well as renal waste by the cesspool. The urine is white and is far from liquid. The dejections, Urine and deposit, semi-solid, forward by the cesspool and are eliminated by the anus.

Certain birds like the Raptor S and the birds of sea expel by the mouth of the balls of rejection whereas the remainder of their preys are in the gizzard. This enables them to prevent that certain gobés bodies not digestes, do not make a complete transit.

Excretions

As much of Reptile S, the birds are mainly Uricotélique S, excreting of the Uric acid and urates and not amino-ureoletic (excretion of a combination of Ammoniaque and Urée). However certain species, like the Trochilidae , are it partially. Among the excrements, one finds Créatine whereas the Mammifère S eliminate from the Créatinine.

The balls of rejection contain when with it primarily hairs, bones.

Bodies

The roles of the Liver and the Pancréas are similar to those of the mammals.

The language

The skeleton of the Langue is formed by the entoglosse and the bone basibranchial crânial. The form of the language, as that of the Bec depends on the food Régime. In the hummingbirds, it very long, is fourchée at its end and is provided with small silks and veins. The language of the peaks-verst resembles a succession of isosceles triangles encased according to their height. That of the Galliformes to the shape of an iron of arrow and is covered crânialement with a horn case. It is particularly muscular at the Psittacidés. The Anatidae have a language which resembles more that of human, punt, broad, soft and round at its end.

The cesspool

The cesspool is divided into three part. The coprodaeum which receives the evacuated contents of the intestines, the Urodaeum which them renal waste.

The birds have two Rein S and Uretère S laid out symmetrically, located in pits known as renal which are depressions of the ventral surface of the Synsacrum and ilia . The kidneys are flat and composed of three parts connected it by parenchymatous bridges enters. These overall rectangular lobes are described as crânial, means and caudal according to their position. The uretères emerge in the urodaeum except for the Struthionidae which have a Vessie.

The pancreas

The pancreas is rather bulky in comparison with that of the mammals, to surely produce sufficient pancreatic juice, which must compensate for the absence of chewing and the limited action of saliva. Juices are released in the duodenum.

The liver

All the birds have a Foie bulky what can be included/understood by their important energy requirement at exact moments. Generally, the liver is large and fatty if the bird is large and fatty. It is also very bulky at oisillons. All the species do not have such an important liver: it is smaller at the Galliformes, the Strigiformes, the raptors night and large the Psittacidés that at the Columbiformes or the migrating species subjected to the Zugunruhe.

The liver of the birds is bilobate and the right lobe is often more developed than it left. The human liver is him composed of four lobes. Their form depends on the species. It secret their bile, acid and not basic as in the mammals, directly in the small intestine via the blister when it exists.

Certain species of Anatidae are high to produce foie gras.

The gall bladder

Certain species do not have a Gall bladder like unquestionable Columbiformes and psittacidés. If it is present, it is placed in a hollow within the right lobe of the liver. It has a tubular form in the water birds and is not present at certain species of Psittacidae .

Intestines

As at the other vertebrate ones, the length of the intestines depends on the food mode. The rejection of gas is less important in the birds than for the mammals. The intestine is consisted of the Small intestine formed of the Duodénum, Jéjunum, Iléon then formed large intestine of very short the Côlon and Cæcum or at certain species, of the bacteria dissolve the Cellulose. Many species, like the Psittacidae , do not have cæcum .

The Large intestine is mainly used to absorb water and the electrolytes. The food remaining is metabolized by Bactérie S. the vitamins K and some vitamins B are synthesized there. It is developed more at certain water birds, Galliformes or Ratite S to facilitate digestion the vegetable matters. One supposes that for most of the species, it is short in order to be lighter, in order to support the flight.

The musculature of the duodenum iléon and colon is more important. The large intestine is relatively runs in the birds.

Diseases

The domestic birds suffer from many disturbance of the digestive system. The food deficits are one of the first causes of disease for these species. A deficit in Calcium causes for example fractures, shells of egg or nozzles soft, Scoliose S. a deficit in Vitamine has or a Obésité can cause Pododermatite, skin diseases or problems of feather. The birds can also develop Goiter S following a deficit in Iode or with an evil operation that the Thyroid gland.

The birds are sensitive to the stress what little to cause a Anorexie. Of other cause can also caused like a disease or a parasitosis. The youthful ones can suffer from a damning up of the jabot and lead to an anorexia.

The Diarrhea S or the Néphrite S are often the consequence of other diseases. The Diarrhée S for example can be the consequence of a intoxication related to a wound by lead. A Tumeur of the kidneys can be the cause of a nephritis.

Good number of food problem also causes problems in a way indirect and have as a consequence a Rétention of egg, losses of feather or Diarrhée S. a constipation, strange in the bird since the droppings are liquid and that they do not have a bladder, is certainly the sign of an egg retention.

See too

Anatomy of the birds

External bonds

, nozzles and languages
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