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The lungs of amphibians typically have a few narrow internal walls of soft tissue around the outer walls, increasing the respiratory surface area and giving the lung a honeycomb appearance. In some salamanders, even these are lacking, and the lung has a smooth wall.
Both the lungs and the skin serve as respiratory organs in amphibians. The ventilation of the lungs in amphibians relies on positive pressure ventilation. Muscles lower the floor of the oral cavity, enlarging it and drawing in air through the nostrils into the oral cavity. With the nostrils and mouth closed, the floor of the oral cavity is then ...
In mammals, physiological respiration involves respiratory cycles of inhaled and exhaled breaths. Inhalation (breathing in) is usually an active movement that brings air into the lungs where the process of gas exchange takes place between the air in the alveoli and the blood in the pulmonary capillaries .
In this spider diagram, the position of the book lungs is labelled 1. Spider book lungs (cross section) Internal anatomy of a female spider, book lungs shown in pink A book lung is a type of respiration organ used for atmospheric gas-exchange that is present in many arachnids, such as scorpions and spiders.
Diagram showing the general layout of air sacs in a bird. Birds have a system of air sacs in their ventilation system. [2] The air sacs work to produce a unidirectional flow where air enters and exits the lung at the same rate, contrasting the lungs of other tetrapods such as mammals where air enters and exits the lung in a tidal ventilation.
In 2004, the International Union for Conservation of Nature (IUCN) reported stating that currently birds, [172] mammals, and amphibians extinction rates were at minimum 48 times greater than natural extinction rates—possibly 1,024 times higher. In 2006, there were believed to be 4,035 species of amphibians that depended on water at some stage ...
The anatomical structure of the lungs is less complex in reptiles than in mammals, with reptiles lacking the very extensive bronchial tree found in mammalian lungs. Gas exchange in reptiles still occurs in alveoli , but reptiles do not possess a diaphragm , therefore ventilation occurs via a change in the volume of the body cavity which is ...
The pulmonates have lost their gills [1] and adapted the mantle cavity into a pallial lung. The lung has a single opening on the right side, called the pneumostome, which either remains permanently open, or opens and closes as the animal breathes. The roof of the lung is highly vascularised, and it is through this surface that gas exchange occurs.