Gas exchange occurrs in all organisms, but judging by the category this question placed in, I am making the assumption that this question is asking about gas exchange in humans.
Humans use lungs for gas exchange. The lungs are two internal "sac-like" organs. The lungs are able to expand and contract becuase of the alveoli. Alveoli are small cavities/air sacs in the lungs.
The lungs are connected to the outside air by way of a system of tubular passageways; the trachea, bronchi and bronchioles. Each lung is divided into a number of lobes, each recieving its own bronchus. Each bronchus divides many times into bronchioles, which then end in many alveole ducts and alveoli. These provide a very large surface area for the exchange of respiratory gases by diffusion betweent he alveoli and the blood in the capillaries.
Gas exchange occurs in two stages of ventillation, called inhilation and exhilation. Inhilation is when the intercostal muscles contract, which causes the ribcage to expand and move up, and the diaphragm then contracts and moves down. This action causes the thoraic voume to increase, which allows the lungs to expand and this decreases the pressure inside them. Air is then pulled in from the atmosphere is response to this pressure gradient. The cardiovascular system then participates by transporting the respiratory gases to and from the cells of the body.
In the second stage of ventilation, exhilation, the intercostal muscles and diaphragm relax. and gravity pulls the ribcage down. The lungs then recoil, which decrease the volume inside and therefore increases the pressure. The air then flows out of the lungs to equalize with the air pressure outside of the lungs, and with it we release carbon dioxide.
So to summarise: We breathe in O2 when the lungs expand, and we release CO2 when the lungs contract.
thru osmosis, the movement of a high concentration to a lower concentration
gaseus exchanged i the body happees in capillaries and alveoli i the lungs
by simple diffusion.
gas exchange occurs between pulmonary capillaries and the alveoli in the lungs.
Respiration is a process of gas exchange. Respiration is necessary to supply cells with oxygen for metabolism and to remove the waste by product carbon dioxide.
Stomata are the openings in leaves that (among other functions) regulate gas exchange.
regulate the rate of gas exchange
capillaries
Gas exchange is a function of respiration not digestion.
Alveoli is where gas exchange occurs.
It lowers the area available for gas exchange, therefore gas exchange doesn't happen as quickly or as much as it should.
Capillary system is where gas exchange occurs
The exchange surfaces are moist.
gaseous exchange
gas exchange occurs between pulmonary capillaries and the alveoli in the lungs.
gas exchange occurs between the thin walls of the alveoli and the thin walls of the capillaries
worms carry out gas exchange by absorbing air through their skin
The actual sites of gas exchange within the lungs are the alvioli.
the organ that is involved in gas exchange is the lung. the specific lung structure that is the site for gas exchange is the alveolus which is part of the alveoli, which is found in the lung.
Respiration is a process of gas exchange. Respiration is necessary to supply cells with oxygen for metabolism and to remove the waste by product carbon dioxide.