ENDOCRINE SYSTEM

The endocrine system is an extensive and intricately regulated network of glands and hormone-secreting cells that controls long-term physiological processes in the human body. Through the secretion of hormones into the bloodstream, the endocrine system influences growth, development, metabolism, reproduction, stress responses, and energy balance. Unlike the nervous system, which produces rapid and short-lived effects, endocrine signaling is slower in onset but sustained and widespread. This chapter provides a deeply expanded and detailed account of endocrine structure and function, with extensive discussion of hormone regulation and feedback loops, the anatomy and physiology of the pituitary, thyroid, adrenal, and pancreatic glands, major endocrine disorders including diabetes mellitus and thyroid dysfunction, and the principles of endocrine pharmacology with special emphasis on insulin therapy and management. The chapter integrates anatomical, physiological, pathological, and pharmacological perspectives to provide a comprehensive academic resource.