The hypothalamus is a small, crucial part of the brain located deep at the base, below the thalamus and just above the pituitary gland.
The hypothalamus produces releasing and inhibiting hormones that control the anterior pituitary, like TRH, CRH, GHRH, GnRH, to trigger hormones for metabolism, stress, growth, and reproduction, plus somatostatin (inhibits GH/TSH) and dopamine (inhibits prolactin), while also making ADH (water balance) and oxytocin (bonding/birth), which are released by the posterior pituitary, linking the nervous and endocrine systems.
The pituitary gland is a small, pea-sized gland located at the base of the brain, nestled in a bony hollow called the sella turcica, right behind the bridge of your nose and below the hypothalamus
The pituitary gland releases several key hormones from its anterior lobe (Growth Hormone, Prolactin, ACTH, TSH, FSH, LH) and stores hormones from the posterior lobe (Oxytocin, Antidiuretic Hormone (ADH)), each controlling vital functions like growth, metabolism, reproduction (sperm/egg production, sex hormones), stress response, water balance, and milk production, all directed by the hypothalamus.
The pineal gland is a tiny, pine cone-shaped endocrine gland located deep in the center of the brain, tucked in a groove between the two cerebral hemispheres, just above the brain stem and behind the thalamus, near the third ventricle.
The pineal gland's primary hormone is melatonin, which regulates the sleep-wake cycle (circadian rhythm) by increasing in darkness and decreasing in light, influencing sleep, body temperature, and seasonal behaviors. It also produces small amounts of estradiol and has potential roles in reproductive development, antioxidant defense, and connecting the nervous and endocrine systems.
The thyroid gland is located at the **front of the neck, below the voice box (larynx) and on top of the windpipe (trachea).
The thyroid gland produces Thyroxine (T4), Triiodothyronine (T3), and Calcitonin, which regulate metabolism, energy, heart rate, body temperature, and growth, with T3 and T4 being the primary hormones for these functions, while calcitonin manages calcium levels. T4 is the main hormone released, but it's converted to the more active T3 in the body, and the pituitary gland controls this process via Thyroid-Stimulating Hormone (TSH).
Parathyroid glands are four small, pea-sized glands located in the neck, typically on the back surface of the thyroid gland, near its upper and lower poles
The parathyroid glands primarily produce Parathyroid Hormone (PTH), which is crucial for regulating blood calcium levels by increasing calcium release from bones, boosting intestinal absorption from food, and enhancing kidney reabsorption, all to raise low calcium levels, while also managing phosphorus and vitamin D levels for nerve, muscle, and bone health.
The thymus gland is located in the upper chest, behind the breastbone (sternum) and in front of the heart, nestled between the lungs in the chest cavity (mediastinum).
The thymus gland produces hormones like thymosin, thymulin, thymopoietin, and thymic humoral factor (THF), primarily to mature and differentiate T-cells (T lymphocytes) for a strong immune response against infections, while also potentially producing small amounts of melatonin and insulin, with its activity peaking in childhood before shrinking with age.
The adrenal glands are small, triangular-shaped endocrine glands located on top of each kidney, one on each side of the body, in the upper abdomen
Adrenal gland hormones, including cortisol, aldosterone, adrenaline (epinephrine), and noradrenaline (norepinephrine), regulate stress response (fight-or-flight), metabolism, blood pressure, and electrolyte balance, with different hormones controlling sugar, salt, and sex hormone precursors, ensuring essential functions like energy, blood flow, and development are managed.
The pancreas is a gland located deep in the upper abdomen, stretching horizontally behind the stomach, nestled in the curve of the duodenum (first part of the small intestine) and in front of the spine.
The pancreas produces key hormones like insulin (lowers blood sugar by promoting cell glucose uptake and storage) and glucagon (raises blood sugar by signaling liver to release stored glucose), working together to maintain glucose balance. Other hormones include somatostatin, which regulates other hormones, and ghrelin, affecting appetite, with these hormones crucial for metabolism and organ function.
Ovaries are two small, almond-sized glands located in the pelvic cavity, one on each side of the uterus (womb).
Ovaries primarily produce estrogen and progesterone, which drive female sexual development, the menstrual cycle, and pregnancy, also influencing bone health and body shape; they also make small amounts of testosterone, relaxin, and inhibin, which support libido, relax ligaments, and regulate other hormones.
Testes (testicles) are located within the scrotum, a skin sac hanging outside the body below the pelvis, serving to keep them cooler than body temperature for sperm production.
The testes produce key hormones, primarily testosterone, an androgen vital for male sexual development, muscle growth, and sperm production, along with other hormones like Inhibin B, which regulates FSH, and Anti-Müllerian Hormone (AMH), crucial for fetal development, plus small amounts of estradiol (a type of estrogen) for spermatogenesis and bone health.