Caption: Endocytosis is a form of active transport in which a cell envelopes extracellular materials using its cell membrane. (a) In phagocytosis, which is relatively nonselective, the cell takes in a large particle. (b) In pinocytosis, the cell takes in small particles in fluid. (c) In contrast, receptor-mediated endocytosis is quite selective. When external receptors bind a specific ligand, the cell responds by endocytosing the ligand.
URL:https://cnx.org/contents/FPtK1zmh@8.108:q2X995E3@12/The-Cell-Membrane
Version 8.25 from the Textbook
OpenStax Anatomy and Physiology