Animal anatomy, histology, pathological anatomy

OPTION TECHNIQUE
Bird corpses are opened in the dorsal position (Fig. 318). Parenchymal organs are removed separately, and the gastrointestinal tract (including the esophagus and pharynx) is removed as a single (one) organ complex.
The age of birds is determined by their plumage.
After the seventh week of life, age is more accurately determined by the change in flight feathers. The wing has ten primary flight feathers. Every two weeks, one flight feather falls out in succession.
Before opening a bird corpse, it is moistened with water or a disinfectant liquid (to prevent feathers and fluff from flying), then the feathers and fluff are plucked and removed from the neck, head, chest, and belly; Make a skin incision along the midline from the mandible to the anus and carefully remove the skin from the neck, chest and abdomen. Having prepared the skin from the chest and abdomen, separate it from the limbs and make incisions in the groin area towards the heads of the femurs. After this, they take the limbs with their hands and, with a strong movement, remove the femurs from the hip joints.
To remove the organs of the abdominal cavity, an incision is made along the midline from the edge of the sternum to the cloaca, then an incision is made from the end of the sternum to the right and left with scissors to the hypochondrium. The chest bone is lifted and the metathoracic air sacs are examined. Next, the ribs are trimmed on both sides of the sternum, the caracoid bone, the collarbone, and the sternum is removed. Then the individual organs are removed.



Fig. 318. Scheme of opening the thoraco-abdominal cavity. The cut lines are shown in dotted lines.

After removing the intestines, the lungs, ovary, testes (in males), kidneys, and adrenal glands are opened for inspection.

Due to its small size, the heart of birds is opened with one incision through the apex to the base in such a way that both ventricles and both atria are cut into two halves at the same time.
To open the oral cavity, the jaws of the scissors are inserted into the oral cavity towards the right corner of the larynx. The incision is made on the left side of the corner of the oral cavity and the bony base of the mandible is cut with scissors. After this, the mandible is bent to the side, and the entire oral cavity with the tongue, larynx, hard palate, airway fissure, and pharynx (entrance to the pharynx) is opened to the researcher.
Depending on the age of the birds, the brain is opened in two ways. In young birds and chicks in which ossification of the skull has not yet occurred, the skull is opened with small pointed scissors.
The incision starts from the foramen magnum on the right side. This incision line should extend behind the orbits to the foramen magnum. After removing the skull, the cerebral hemispheres, cerebellum and medulla oblongata are carefully removed.
The second method of extracting the brain is more applicable to an adult bird in which ossification of the skull has occurred, and the skull is separated into two halves. The beak is not sawed. Halves of the brain on both sides are removed with the end of a knife or scalpel.
If necessary, the spinal cord is examined. The spinal canal is opened as follows: the spinal column is cleared of soft tissue and all bone processes are removed with bone scissors so that the ventral and dorsal surfaces are as smooth as possible. These surfaces are then cut with a thin saw along the center line. The spinal canal can also be opened by cutting through the vertebral arches with bone forceps or scissors, after dividing the spinal canal into three parts: cervical, thoracic, lumbosacral.