The syringe.It is the vocal organ of birds. It sits at the base of the trachea, and produces complex sounds without the vocal cords that mammals have. The sounds are produced by vibrations in the walls of the syrinx or by the vibration of the air passing through the syrinx. Only birds and crocodiles have this specialized organ and it allows many species (such as parrots, starlings , crows, jays, magpies, etc.) to imitate the human voice.
location of the syrinx
Since the syrinx is located where the trachea branches off to form the bronchi, deeper than the mammalian larynx, many songbirds can produce two or more sounds simultaneously. The respiratory system has mainly differences between mammals and birds. Those that are only found in birds are the infraorbital sinuses, syrinx and air sacs. The nasal cavity is delimited by different bones and in different shapes. Most birds have an opening that connects the nasal and oral cavities (choana) . They do not have a soft palate and have different swallowing and breathing mechanisms.
The infraorbital sinus is the cavity cranial and ventral to the eye, which is empty and has communicating air sacs and the nasal cavity. It participates in smell and is a relatively accessible cavity subcutaneously through the skin and, in upper respiratory tract infections, it is easy to obtain samples or exudates by puncture. The larynx has a very different morphology from that of a mammal, made up of different cartilages. has no cartilageepiglottic . He has no vocal cords.
The phonation is produced by the syrinx. In the trachea it has totally closed rings and they are arranged in the form of tiles forming a complete tube. In the final portion of the trachea before the bifurcation is the syrinx, which is much like the vocal cords of mammals. It consists of a fusion of cartilage to eardrum. This eardrum is continuous with the outer and inner tympaniform membrane, which has no cartilage and, when forced through, produces a vibration. Birds that can speak, the sound comes from the coelomic cavity.
In some species of ducks
It has a different morphology, but the mechanism is the same. They have a kind of very large cartilaginous snail with the same sound production mechanism. Bird lungs are different because they do not have lobulations. They are unique and are smaller than in mammals of the same size. In mammals, the air ends in the alveolus. In birds, air enters the lungs, exchanges gases, and ends up in the blind sacs (air sacs), which store air and draw air in and out. They have separate function of exchange and air intake. In birds, airsacculitis is more common than pneumonia because it is easier for them to proliferate. Since the air passes through the lung very quickly and it is easier in the air sac because it stays longer. They do not have lung lobes.
types of bronchi
1-The first bronchi have an extrapulmonary and an intrapulmonary portion. They run craniocaudal throughout the lung and end in the air sac. 2-Loa secondary bronchi that run through the lung parenchyma. From the secondary ones come the parabronchi or tertiary bronchi, which are different from mammals because they do not end in the alveolus. 3-The parabronchi do a gas exchange. It is bounded by connective tissue. In light, there are cells (called atrium) that are separated from each other by septa. In the most apical portion they have the muscle of the alveolus of the mammal. They open or close the wall of the atrium.
Developing
The air sacs compensate for the small size of the lung. More than half of the respiratory system is not lung. There are odd (the most cranial: cervical (1), clavicular (1)) and pairs (cranial thoracic (2), caudal thoracic (2) and abdominal (2)). They participate in respiratory mechanics. They also pneumatize the animal and decrease the density of the animal to be able to fly. The animal is balloon-like and infiltrates bony structures and pneumatizes them. The cervical air sac reaches the occipital: it encompasses the cervical vertebrae. The abdominal air sacs penetrate between the arches of the vertebrae and emit diverticula towards the femur.
They only pneumatizelong bones. Respiratory mechanics, as there is no diaphragm, has only a coelomic cavity. The sacs are very important in inspiration and expiration. On inspiration there is dilation of the coelomic cavityby the widening of the ribs and the abdominal cavity and within the air sacs. The cranial air sacs are unpaired: clavicular and cervical. The rest are caudal air sacs. The caudal air sacs have more negative pressure.
In inspiration, all the air goes to the caudal air sacs and the lung air from the previous cycle is collected by the cranial air sac. In expiration there is a closure of the ribs and abdominal pressure and the air is expelled from the air sacs. The cranial air sacs expel collected air from the lung parenchyma. Part of the caudal air sac goes to the outside without being used and part goes to the lung parenchyma for exchanges.
