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Which glands are major parts of the endocrine system?
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The human endocrine system is composed of various secretory organs and tissues that synthesize and release hormones directly into the bloodstream to regulate physiological processes. Major glands and endocrine tissues include:12
- Pituitary gland: Often called the master gland, it regulates other endocrine glands and has direct effects on various body tissues.12
- Adrenal glands: Located near the kidneys, these glands produce hormones like cortisol, aldosterone, epinephrine, and norepinephrine.13
- Thyroid gland: Responsible for secreting hormones that stimulate metabolism and nervous system activation.1
- Pancreas: Contains specialized endocrine tissue known as the islets of Langerhans, which secrete insulin and glucagon to regulate blood sugar.13
- Ovaries and Testes: These reproductive glands produce sex hormones essential for development and reproductive cycles.13
- Pineal gland: Secretes melatonin to regulate circadian rhythms.1
- Parathyroid gland: Regulates serum calcium concentrations.1
- Hypothalamus: While part of the brain, it acts as a critical endocrine regulator by secreting hormones that control the pituitary gland.1
Additionally, other organs such as the kidneys, stomach, and duodenum contain endocrine cells that contribute to systemic regulation.1