ENDOCRINE SYSTEM

• The endocrine system secretes hormones that control the growth and development of the body.
• Hormones travel through the bloodstream and target specific organs.
• The pituitary gland is located in the brain and is known as the master gland.
• Human growth hormone (HGH) – promotes the release of insulin-like growth factors (IGFs), which are responsible for the production of proteins in the body; maintains muscle and bone mass for growth; also helps in healing injuries and repair of tissues
• Thyroid-stimulating hormone (TSH) – helps in producing and secreting the thyroid hormones by the thyroid gland
• Follicle-stimulating hormone (FSH) – it targets the ovaries by initiating the development of the follicles in the ovary, which happens monthly
• Luteinizing hormone (LH) – initiates ovulation; also controls the secretion of progesterone (female sex hormone)
• Prolactin – affects the mammary glands by initiating and maintaining the production of milk especially during pregnancy
• Adrenocorticotropic hormone (ACTH) – responsible for the production and secretion of glucocorticoids, the hormones released by the adrenal gland
• Oxytocin – activated during and after giving birth; targets the uterus to cause it to contract during giving birth; also controls milk secretion in the breasts after giving birth
• Antidiuretic hormone (ADH) – causes the kidneys to decrease urine production, which helps in conserving more body water; also known as vasopressin
• hypothalamus is the gland that is also located in the brain. It controls the function of the pituitary gland.
• These hormones secreted by the hypothalamus affect the release of some hormones released by the pituitary gland

  .• Thyrotropin-releasing hormone (TRH) –controls the secretion of the TSH

  • Gonadotropin-releasing hormone (GnRH) – stimulates the production of FSH and LH

  • Corticotropin-releasing hormone (CRH) – initiates the secretion of the ACTH
• thyroid gland is located below the larynx (or the voice box). It is described as a butterfly-shaped gland that is composed of the right and the left lobes. It secretes the hormones thyroxine (T4) and triiodothyronine (T3). These hormones are also called thyroid hormones, which are responsible for protein synthesis; regulation of oxygen use, metabolism, and growth; and the development of the body.
• Calcitonin is another hormone secreted by the thyroid gland, which is responsible for maintaining the calcium level in the body.
• parathyroid glands can be found in the posterior surface of the thyroid gland.
• parathyroid hormone is the hormone secreted by the parathyroid glands. It is the major regulator of the calcium, magnesium, and phosphate levels in the blood
• pancreas is located in the duodenum of the small intestine. It secretes the hormones insulin and glucagon, which are responsible in regulating the blood sugar level
• Insulin – helps in lowering the amount of glucose in the blood when it is too high
• Glucagon – helps in increasing the level of glucose in the blood when it is too low
• adrenal glands are located on top of each kidney. Each adrenal gland is divided into the adrenal cortex and the adrenal medulla
• The adrenal cortex secretes the following hormones:

  • Mineralocorticoids –maintain the balance of minerals in the body such as sodium and potassium

  • Glucocorticoids –break down proteins and triglycerides needed by the body; help in the formation of glucose; have anti-inflammatory effects; cause suppression of immune responses

  • Androgens –secreted by both males and females, but it is an important hormone especially for females because these are converted into estrogen
• Adrenal medulla –secretes epinephrine (adrenaline) and norepinephrine (noradrenaline), which are released during strenuous activities, such as exercise. These hormones control the heart rate, blood pressure, blood level, and breathing rate
• gonads produce sex cells or gametes. ese gonads are the ovaries for females and the testes for the males
• THe ovaries are located in the pelvic cavity. They secrete the hormones estrogen and progesterone. Estrogen is responsible for the female secondary sex characteristics and maintaining the female body shape. Progesterone, with the help from other hormones, helps in pregnancy, lactation, and menstrual cycle
• The testes can be found in the scrotum, and they release the hormone testosterone, which helps in the production of sperm and the development of male secondary sex characteristics.