The endocrine system consists of glands that secrete substances into the blood stream such as hormones. These hormones are either categorized as proteins or steroids. The organs of the endocrine system are found in various places within the body.
The pineal gland, hypothalamus, and pituitary gland are found in the brain. The pineal gland produces and secretes melatonin which can make you feel sleepy. This gland also regulates your bodies natural sleep cycle called circadian rhythms. The hypothalamus controls hunger, thirst, fluid balance, and regulates the pituitary gland. The anterior pituitary gland or front part, produces thyroid stimulating hormone TSH, growth hormone GH, an adrenal hormone (adrenocorticotropic) ACTH, and two reproductive hormones (follicle-stimulating) FSH and luteinizing hormone LH. The posterior pituitary or the back part, creates oxytocin and antiduiretic hormone (ADH).
The thyroid, parathyroid, and thymus are found in the upper chest. The thyroid receives the TSH from the pituitary and produces triiodothyronine (T3), thyroxine (T4), and calcitonin. These hormones control growth, metabolism, and the amount of calcium in the body. The parathyroid produces its own hormone PTH which increases calcium in the body. The thymus produces thymosin which strenthens the immune system.
The pancreas and adrenal glands are found in the mid abdomen area. The pancreas secretes glucagon and insulin to help with blood sugar. The adrenal galnds produce cortisol, epinephrine, and norephinephrine that aid in the bodies stress response as well as estrogens.
The gonads or male and female reproductive organs are found in the lower abdomen. The ovaries in the female produce estrogen and progesterone. The testes in the male produce testosterone.