It is possible to have multiple independent variables and/or multiple dependent variables. For instance, in multivariable calculus, one often encounters functions of the form, where z is a dependent variable and x and y are independent variables.
Gas exchange between the air within the alveoli and the pulmonary capillaries occurs by diffusion. The oxygen must first dissolve before passing through the respiratory epithelium. Gas moves from a region of high partial pressure to a region of low partial pressure, down a partial pressure gradient.
alveoli tiny air sacs at the end of the bronchioles tiny branches of air tubes in the lungs the alveoli are where the lungs and the bloodstream exchange carbon dioxide and oxygen carbon dioxide in the blood passes into the lungs through the alveolioxygen in the lungs passes through the alveoli into the bloodnih national cancer institutehe alveoli are where the lungs and the bloodstream exchange carbon dioxide and oxygen carbon dioxide in the blood passes into the lungs through the alveoli oxygen in the lungs passes through the alveoli into the blood nih national cancer institute