Answer: These villi increase the surface area for more efficient food absorption. Within these villi, are present numerous blood vessels that absorb the digested food and carry it to the bloodstream. It is hence from the bloodstream, the absorbed food is delivered to each and every cell of the body.
The process of exchanging gases (carbon dioxide for oxygen) occurs at the lung alveoli. Alveoli are coated with a moist film that dissolves air in the lungs. Oxygen diffuses across the thin epithelium of the alveoli sacs into the blood within the surrounding capillaries.
In exocytosis, a cell releases substances into its environment. During exocytosis, vesicles that contain substances are moved to the cell membrane and fuse with it. This cell membrane function has three results: the total surface of the membrane increases, toxins or waste products are eliminated, and proteins become part of the plasma membrane.
Step-by-step explanation:
thats all of the things for openings in villi the alveoli and the cell membrane