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Endocrine Organs
Major Endocrine Organs
| Gland | Location(s) | Hormone(s) Produced | Normal Physiologic Effects | Effects of Hypersecretion | Effects of Hyposcretion |
|---|---|---|---|---|---|
| Gonads (female) | Pelvic cavity | Estrogens and progesterone | Secondary sex characteristics at puberty, menstrual cycle | - | - |
| Gonads (male) | Suspended in a pouchlike sac, the scrotum, outside the pelvic cavity | Testosterone | Secondary sex characteristics at puberty, libido | - | - |
| Thymus | Superior thorax, posterior to the sternum and anterior to the heart and lungs | Thymosin and thymopoietin | Help direct the maturation and specialization of T lymphocytes, or T cells | - | - |
| Pancreas | Partially behind the stomach in the abdomen | Digestive enzymes as well as insulin and glucagon | Glucagon acts antagonistically to insulin to keep the blood glucose levels balanced Glucose Level balance | Insulin: hypoglycemia | Insulin: diabetes mellitus |
| Anterior Pituitary | Concavity of the sella turcica of the sphenoid bone | Four tropic hormones: -Gonadotropins - follicle-stimulating hormone (FSH) and luteinizing hormone (LH) -Adrenocorticotropic hormone ( ACTH) - Thyroid-stimulating hormone (TSH), or thyrotropin AND -Growth hormone (GH) -Prolactin (PRL) | FSH/LH: Regulate gamete production and hormonal activity of gonads ACTH: Regulate endocrine activity of cortex portion of adrenal gland TSH: Influence growth and activity of thyroid gland GH: Growth of muscle and long bones PRL: Lactation | GH: Causes gigantism in children and acromegaly (overgrowth of bones in hands, feet, and face) in adults | GH: Pituitary dwarfism in children |
| Posterior Pituitary | Concavity of the sella turcica of the sphenoid bone | Oxytocin and antidiuretic hormone (ADH) | Oxytocin: Stimulates powerful uterine contractions during birth and coitus and also causes milk ejection in the lactating mother ADH: Causes the distal and collecting tubules of the kidneys to reabsorb more water from the urinary filtrate | ADH: Edema, headache, and disorientation | ADH: Dehydration from excessive urine output, a condition called diabetes insipidus |
| Pineal | Roof of the third ventricle of the brain | Melatonin | Biological rhythms | - | - |
| Thyroid | Throat, just inferior to the larynx | Thyroid Hormone and Calcitonin | Control the rate of body metabolism and cellular oxidation | Elevated metabolic rate, nervousness, weight loss, sweating, and irregular heartbeat | A condition of mental and physical sluggishness, which is called myxedema |
| Parathyroid | Posterior surface of the thyroid gland | Parathyroid hormone (PTH) | Causes release of calcium from bone matrix and prods the kidney to reabsorb more calcium and less phosphate from the filtrate. Also stimulates the kidneys to activate vitamin D | Loss of calcium from bones, causing deformation, softening, and spontaneous fractures | Increases neural excitability and may lead to tetany, prolonged muscle spasms that can result in respiratory paralysis and death |
| Adrenal Medulla | Atop or close to the kidneys | Epinephrine (80%) or norepinephrine (20%) | Elicit the fight-or-flight response to stressors | - | - |
| Adrenal Cortex | Atop or close to the kidneys | Three major groups of steroid hormones, collectively called corticosteroids: -mineralocorticoids, chiefly aldosterone -glucocorticoids (cortisone, hydrocortisone, and corticosterone) -gonadocorticoids, or sex hormones | Mineralocorticoids: Regulate water and electrolyte balance in the extracellular fluids Glucocorticoids: Enable the body to resist long-term stressors Gonadocorticoids: Chiefly androgens produced, but some estrogens | Hypersecretion of gonadocorticoids produces abnormal hairiness (hirsutism), and masculinization occurs | - |