Final answer:
The process of taking up substances and transporting them into the bloodstream is known as absorption, which can occur via mechanisms like active transport, passive diffusion, facilitated diffusion, co-transport, and endocytosis.
Step-by-step explanation:
The process by which substances are taken up and transported to the bloodstream is known as absorption. There are various mechanisms through which absorption can occur, including active transport, where substances move across a cell membrane from an area of lower concentration to one of higher concentration using energy, and passive diffusion, where substances move from an area of higher concentration to one of lower without the use of energy. Additionally, other mechanisms like facilitated diffusion, co-transport, and endocytosis play roles in the process of absorption. Once absorbed, these nutrients and substances can be distributed by the bloodstream to various parts of the body.