Endocrine Glands and Hormones
Endocrine Glands, Hormones, and Their Functions
Endocrine Gland | Hormone Released | Chemical Class | Target Tissue/Organ | Major Function of Hormone |
|---|---|---|---|---|
Hypothalamus | Hypothalamic releasing and inhibiting hormones | Peptide | Anterior pituitary | Regulate anterior pituitary hormone secretion, influencing various bodily functions including stress, growth, and metabolism. |
Posterior Pituitary | Antidiuretic Hormone (ADH) | Peptide | Kidneys | Stimulates water reabsorption by kidneys, helping to maintain blood pressure and fluid balance. |
Oxytocin | Peptide | Uterus, Mammary glands | Stimulates uterine muscle contraction during labor and the release of milk during breastfeeding. | |
Anterior Pituitary | Thyroid stimulating hormone (TSH) | Glycoprotein | Thyroid | Stimulates thyroid gland activity, influencing metabolism and energy levels. |
Adrenocorticotropic hormone (ACTH) | Peptide | Adrenal cortex | Stimulates adrenal cortex to release cortisol, involved in the stress response. | |
Gonadotropic hormones (FSH, LH) | Glycoprotein | Gonads | Regulate egg and sperm production and influence sex hormone production. | |
Prolactin (PRL) | Protein | Mammary glands | Promotes milk production in lactating females. | |
Growth hormone (GH) | Protein | Soft tissue, bones | Stimulates cell division, protein synthesis, and promotes growth in muscles and bones. | |
Thyroid | Thyroxine (T4) and Triiodothyronine (T3) | Iodinated amino acid | All tissues | Increases metabolic rate, regulates growth and development, influencing energy use in cells. |
Calcitonin | Peptide | Bones, kidneys, and intestine | Lowers blood calcium level by inhibiting its release from bones and promoting excretion in the kidneys. | |
Parathyroids | Parathyroid hormone (PTH) | Peptide | Bones, kidneys, and intestine | Raises blood calcium levels by promoting release from bones, enhancing absorption in the intestine, and reducing excretion in the kidneys. |
Adrenal Cortex | Glucocorticoids (cortisol) | Steroid | All tissues | Raises blood glucose levels, stimulates breakdown of protein, and is important for the body's stress response. |
Mineralocorticoids (aldosterone) | Steroid | Kidneys | Reabsorbs sodium and excretes potassium, plays a key role in regulating blood pressure and electrolyte balance. | |
Sex Hormones | Steroid | Gonads, skin, muscles, and bones | Involved in stimulating reproductive organs, influencing sex characteristics and reproductive function. | |
Adrenal Medulla | Epinephrine and norepinephrine | Modified amino acid | Cardiac and other muscles | Released during emergency situations; increases heart rate, raises blood glucose levels, and prepares the body for ‘fight or flight’ response. |
Pancreas | Insulin | Protein | Liver, muscles, adipose tissue | Lowers blood glucose levels by facilitating cellular glucose uptake and promoting glycogen formation. |
Glucagon | Protein | Liver, muscles, adipose tissue | Raises blood glucose levels by promoting the conversion of glycogen to glucose in the liver. | |
Testes | Androgens (testosterone) | Steroid | Gonads, skin, muscles, and bones | Stimulates male sex characteristics, including facial hair growth, deepening voice, and muscle development. |
Ovaries | Estrogen and progesterone | Steroid | Gonads, skin, muscles, and bones | Regulates female sex characteristics, menstrual cycle, and plays roles in pregnancy. |
Thymus | Thymosins | Peptide | T lymphocytes | Stimulates production and maturation of T lymphocytes, which are crucial for adaptive immunity. |
Pineal Gland | Melatonin | Modified amino acid | Brain | Controls circadian and circannual rhythms, regulates sleep patterns, and possibly contributes to the maturation of sexual organs during puberty. |