Final answer:
The endocrine system consists of ductless glands that secrete hormones directly into the bloodstream, which then carry these hormones to their target tissues. Major glands include the pituitary, thyroid, and adrenal glands, as well as the pancreas.
Step-by-step explanation:
The endocrine system is the body system of ductless glands that secrete hormones and release them directly into the bloodstream. Unlike exocrine glands that release substances through ducts onto body surfaces, endocrine glands release chemical messenger molecules, called hormones, into the interstitial fluid. From there, hormones diffuse into the blood circulation and are delivered to various organs and tissues within the body that possess the necessary receptors to bind these hormones.
The endocrine system includes key glands such as the pituitary gland, which is often referred to as the master gland because it produces hormones that control other endocrine glands. Other major glands include the thyroid gland, the adrenal glands, and the pancreas, each secreting distinct hormones that regulate crucial body functions such as metabolism, growth, and sexual development.
The endocrine system, a vital regulatory network in the human body, comprises ductless glands that release hormones directly into the bloodstream. Differing from exocrine glands that use ducts to release substances onto body surfaces, endocrine glands disseminate hormones into the interstitial fluid. These chemical messengers then diffuse into the bloodstream, reaching target organs and tissues possessing specific receptors. Key glands within the endocrine system include the master gland, the pituitary gland, orchestrating hormonal control over other endocrine glands. Additional significant players like the thyroid, adrenal glands, and pancreas contribute hormones crucial for the regulation of essential bodily functions, encompassing metabolism, growth, and sexual development.