OpenStax
Open Stax: Anatomy & Physiology: Body Fluids and Fluid Compartments
Learn about the chemical and physical characteristics of the fluids that make up the human body.
Wikimedia
Wikipedia: Endocytosis
This encyclopedia article from Wikipedia over endocytosis discusses the three forms in which it can take place. Links are provided for additional information on this subject as well as related subjects.
Wikimedia
Wikipedia: Exocytosis
This site from the Wikipedia Encyclopedia describes the process of exocytosis and what is accomplished by the process. Throughout this brief article, links are provided for additional information on the subject.