For fast and efficient exchange of gases in your lungs.
Alveoli are just tiny pockets where oxygen goes to so the blood in the capillaries surrounding them can pick the oxygen up and transport it throughout the body. The blood also drops off waste such as CO2. The reason there are so many alveoli is because there needs to be as many as possible to keep up with the constant need for oxygen and to rid of waste.
---------------------------- The exchange of gasses takes place across the Alveoli, which are air spaces surrounded by very small air sacs and have a rich supply of blood, because they are surrounded by capillaries. The lungs are made up of many alveoli which are the respiratory surface. Oxygen diffuses from the alveoli into the blood in the capillaries and carbon dioxide diffuses from the blood in the capillaries into the alveoli.
The alveoli provide large surface area for the exchange of gases between the blood and the air. Each alvoeli is surrounded by many capillaries(tiny blood vessels). The very thin walls and large surface area of the alveoli and numerous capillaries surrounding them enable gases to be exchanged quickly and efficiently. Oxygen in the inhaled air diffuses from the alveoli to the blood in the capillaries. The blook then carries the oxygen to the cells in the other parts of the body. The waste product of respiration, CO2 , diffuses from the blood to the lungs through the capillaries surrounding alveoli. It leaves the body through bronchi and trachea when you exhale( breathe out).
There are many capillaries in the lungs. These small blood vessels are the site of gas exchange in the alveoli.
by suking it
The Alveoli in the lungs have a very good capillary network because this is where gas exchange occurs. There needs to be sufficient area to allow the red blood cells to expel their carbon dioxide and to receive oxygen across the capillary and alveoli walls.
As oxygen enters the body it will travel down the trachea (throat), through the bronchioles (tubes leading to the lungs), and into the lungs. In the lungs there are very tiny grape-like-sacs called alveoli. The membrane on these sacks is very thin, and they are surrounded by many tiny capillaries (blood vessels) whose membrane is also very thin. It is here where oxygen from the alveoli enters the capillaries, and carbon dioxide (waste product) from the capillaries enters the alveoli. The oxygen is now carried through the blood to the heart where it is pumped throughout the body, and the carbon dioxide, now in the alveoli, is expelled as the person exhales. In a situation of altitude it is this process that is hindered. Because of the lower pressure of oxygen the oxygen does not enter the capillaries as easily and the body is deprived of oxygen.
1.They are single cell thick 2.Thin film of moisture covering the alveoli allows the oxygen to dissolve in therefore making the process efficient 3. they have a large surface area 4.they are surrounded by network of blood capillaries maintaining the concentration gradient for the gaseous exchange
Blood carries many things: oxygen, carbon dioxide, electrolytes and various wastes.
There are many capillaries in your lungs, digestive system and muscles because each of these locations require blood to be transfered to individual cells snd capillaries are the smallest vessels that can do this.In your lungs capillaries connect to the alveoli and enable gas exchange within the body.In your digestive system capillaries enables food to be passed through the walls of the intestines.In your muscles capillaries deliver a fresh supply of oxygen to each cell and remove any bi-products enabling you to move sufficiently.
All of them
The exchange of carbon dioxide and oxygen takes place in the lungs, specifically in the alveoli where oxygen is taken in by the blood and carbon dioxide is released from the blood to be exhaled out of the body through the respiratory system.
it has many more capillaries...if you were to wrap all of your capillaries around earth it would wrap around twice