Hormones a

Notes

•Hormones and Endocrine System Hormones and other signaling molecules bind to target receptors, triggering specific response pathways. Feedback regulation and coordination with the nervous system are common in endocrine systems. Endocrine glands respond to diverse stimuli to regulate homeostasis, development, and behavior. •Overview: The Body’s Long-Distance Regulators Animal hormones are chemical signals secreted into the circulatory system, communicating regulatory messages throughout the body. Although hormones reach all parts, only target cells with specific receptors respond. •The Body’s Long-Distance Regulators Two systems coordinate body communication: the endocrine system, which secretes hormones for slower, longer-lasting responses—such as reproduction, development, energy metabolism, growth, and behavior—and the nervous system, which transmits high-speed electrical signals via neurons to regulate cells like neurons, muscle, and endocrine cells. •Intercellular Communication Signals between animal cells are classified by the secreting cell type and the route taken to reach the target. Endocrine signaling involves hormones secreted into extracellular fluids and tr...