Search results
Results from the WOW.Com Content Network
Gas exchange is the physical process by which gases move passively by diffusion across a surface. For example, this surface might be the air/water interface of a water body, the surface of a gas bubble in a liquid, a gas-permeable membrane, or a biological membrane that forms the boundary between an organism and its extracellular environment.
Cutaneous respiration, or cutaneous gas exchange (sometimes called skin breathing), [1] is a form of respiration in which gas exchange occurs across the skin or outer integument of an organism rather than gills or lungs. Cutaneous respiration may be the sole method of gas exchange, or may accompany other forms, such as ventilation.
Gas exchange takes place in the gills which consist of thin or very flat filaments and lammellae which expose a very large surface area of highly vascularized tissue to the water. Other animals, such as insects , have respiratory systems with very simple anatomical features, and in amphibians , even the skin plays a vital role in gas exchange.
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 .
Aquatic arthropods generally possess some form of gills in which gas exchange takes place by diffusing through the exoskeleton. Others may breathe atmospheric air while remaining submerged, via breathing tubes or trapped air bubbles, though some aquatic insects may remain submerged indefinitely and respire using a plastron. A number of insects ...
The placenta can be defined as an organ formed by the sustained apposition or fusion of fetal membranes and parental tissue for physiological exchange. [1] This definition is modified from the original Mossman (1937) [ 2 ] definition, which constrained placentation in animals to only those instances where it occurred in the uterus.
The main reason for exhalation is to rid the body of carbon dioxide, which is the waste product of gas exchange in humans. Air is brought into the lungs through inhalation. Diffusion in the alveoli allows for the exchange of O 2 into the pulmonary capillaries and the removal of CO 2 and other gases from the pulmonary capillaries to be exhaled ...
The concentration of carbon dioxide (CO 2) rises in the blood when the metabolic use of oxygen (O 2), and the production of CO 2 is increased during, for example, exercise. The CO 2 in the blood is transported largely as bicarbonate (HCO 3 − ) ions, by conversion first to carbonic acid (H 2 CO 3 ), by the enzyme carbonic anhydrase , and then ...