The birds have an efficient circulation, a high rate of metabolism and a high and constant temperature. The birds and mammals are the only vertebrates that have a complete separation of the respiratory and systemic circulations, making possible a high arteriolar pressure, which allows materials to reach the tissues rapidly. The circulatory system of pigeon includes heart, arteries, veins, the [...]
The digestive system of pigeon is well developed and includes an alimentary canal and the digestive glands. Alimentary Canal: The alimentary canal of pigeon (Fig. 26.28) is long, tubular and coiled. It comprises mouth, buccal cavity, pharynx, oesophagus, stomach, small intestine and large intestine which opens to the exterior by cloacal aperture. All the segments of alimentary canal fall into [...]
The coelom of birds (pigeon) is well developed and divided into two cavities, anterior thoracic and posterior abdominal cavities, by a membranous oblique septum or diaphragm. The thoracic cavity has two dorso-lateral pleural cavities, each enclosing a lung. The two pleural cavities are separated from each other by the antero-ventral pericardial cavity enclosing the heart lying in the middle between [...]