Final answer:
Intracellular signaling refers to the communication within a cell that often begins with a signal outside of the cell, such as a hormone binding to a receptor, which then prompts a cascade of internal cellular events facilitated by second messengers.
Step-by-step explanation:
The concept referred to as the "inside-out" for intracellular signaling pertains to the communication that occurs within a cell, as opposed to the communication between cells, which is known as intercellular signaling. Intracellular signaling can be initiated by external signals that bind to cell surface receptors, prompting an internal cellular response. These signals are often transmitted by molecules known as second messengers, which propagate the signal throughout the cytoplasm, and sometimes to the nucleus, to elicit specific cellular responses. This is essential for a cell to function and respond effectively to its environment. Key components involved in this process include G-protein-linked receptors, internal receptors, and various intracellular mediators.