Breathing is the body’s way of exchanging oxygen for carbon dioxide. The lungs get oxygen through alveoli. The air is transported though the trachea and diverted though the bronchi into a lung, the bronchi extends into smaller tubes called bronchioles witch at the end of them are little air sacks (the alveoli).
Oxygen is needed to get into the blood stream to allow oxygen to be supplied throughout the body in order for it to function normally. It does this by gaseous exchange. Gaseous exchange is done as followed:
Carbon dioxide defuses out of the blood stream and into the alveoli to be exhaled. It is then replaced with oxygen which is defused into the blood.
Diffusion of Oxygen into the blood stream allows the oxygen to be transferred into the blood and Diffusion of Carbon Dioxide out of the blood stream to be excreted by the lungs. The alveoli enable the oxygen in the air we breathe to diffuse into are blood stream and carbon dioxide to be defused out of the body. this is Gaseous exchange.
The alveoli consist of a they are rounded structures which gives them a large surface area to perform gaseous exchange, secondly they have a moist lining for dissolving gases, thirdly they have very thin walls. Finally, they also have a very good blood supply for the two to function as they do. …show more content…
Lungs do not contain any type of muscles so they are unable to expand on there own. However, a number of different muscle contractions happen at the same time to allow air in the lungs. The intercostals muscles contract forcing the ribs upwards and outwards then the diaphragm contracts and flattens these two in and out movement, which increases the volume of the thorax. these chain reactions allow the body to draw air into the lungs which is all done though muscle