Final answer:
Salamanders use gills, lungs, or skin to breathe, with a network of blood vessels facilitating oxygen transport across these respiratory surfaces into the circulatory system.
Step-by-step explanation:
The components inside the boundary of a salamander that pick up oxygen as it comes in and move it to the rest of the organs are the circulatory system and respiratory surfaces. Salamanders can breathe through gills, lungs, or their skin. For those that use their skin, such as lungless salamanders, a dense network of capillaries just below the skin facilitates the gas exchange process. These capillaries pick up oxygen that diffuses across the moist skin and transport it throughout the body.