Respiratory System
Amphibians- Amphibians have 3 ways of breathing. They can breath through their lungs, gills, or their skin! Their gills allow them to breath underwater. In frogs, the gills are only present in their tadpole stage. As they age, their gills are absorbed by the body, and the lungs take over. As an adult, the amphibian will breath through its skin until it returns to the surface. The frogs ventilate their lungs with a unique mechanism that pumps air into the lungs, this process is called positive pressure breathing.
Reptiles- all reptiles have a set of lungs, and none of the reptiles go through an aquatic larva stage. Although most reptiles only have lungs, some species are able to use their skin as a way to absorb oxygen and exhale carbon dioxide. In aquatic turtles, the mucus membrane is able to extract oxygen from the water. Reptiles have relatively large lungs and these lungs are divided into several chambers. In snakes, only the right lung functions properly, while the left is either non-functional or entirely absent.
Mammals- The Respiratory system in mammals equiliberates air to the body, protects against foreign materials, and allows gas exchange through the lungs. Enviormental air moves into the body and must pass through the nasal cavities, where it is warmed and surveyed for particles. As air moves out of the nasal cavities, it moves into the pharnyx, larynx, trachea, primary bronchi, secondary and tertiary bronchi, bronchioles, alveolar ducts then alveolar sacs where gas exchange occurs with capillaries.
Mollusks- In mollusks, repiratory organs are found in the visceral mass. Aquatic mollusks, suchas snails, clams and octopi breath using gills in their mantle cavity tubes that are known as siphans help by bringing water in and out of the body. terrestrial mollusks such as snails and slugs respire using a mantle cavity that has a large surface area lined with blood vessels. diffusion occurs through moist skin of mollsuks.
Arthropods- Aquatic arthropods such as crabs possess gills for respiration. Although the gills are different in stucture and location they are always out growths of the skin and are covered by the exoskeleton, which is thin in this and not a barrier of the exchange of gasses. terrestrial arthropods possess trachea and book lungs as respiration organs. Trachea are a system of small tubes that allow passage of gases into the inside of the body. In some tracheal tubes are bathed in blood. tracheae are unique to arthropods. tracheal systems are good for thr small land arthropods. spiracles reduce water loss. Chitnous lining prevent collapse. Most spiders have book lungs and trachea, but big trantulas and scorpions have only book lungs.
Annelids- Some aquatic annelids have small thin-walled gills through which gases are exhangedbetween the blood and enviroment. most annelids don't have special organs for exchanging gases. Annelids breathe directly through the body wall.
Echinoderms- Echinoderms such as starfish have terrible and poorly developed respiration systems. they breathe through simple gills. Another way they breathe is through their tube feet. Their tube feet take in oxygen and pass out carbon dioxide.
