Hormone signaling is a process where hormones, which are chemical messengers produced by glands in the endocrine system, travel through the bloodstream to target organs or tissues. These hormones bind to specific receptors on the surface or inside of cells, triggering various biological responses that regulate functions such as growth, metabolism, and mood. This signaling mechanism is crucial for maintaining homeostasis, the body's stable internal environment. Different hormones, like insulin and adrenaline, have unique roles; for example, insulin helps control blood sugar levels, while adrenaline prepares the body for a "fight or flight" response during stressful situations.