Endocrine System

• endocrine glands


  release hormones directly into the blood
• exocrine glands


  release their secretions through ducts
• antidiuretic hormone (ADH)


  produced in the hypothalamus,

  stored in posterior pituitary,

  targets the kidney collecting duct,

  causes cells to insert aquaporins, which forms a pore in the collecting duct where water can move from filtrate back into blood
• oxytocin (OT)


  produced in hypothalamus, stored in posterior pituitary

  causes contraction of the smooth muscle of the uterus,

  causes mammary glands to eject milk
• thyroid stimulating hormone (TSH)


  produced by anterior pituitary,

  interacts with thyroid gland, causes release of T3 and T4
• Adrenocorticoptropic hormone (ACTH)


  produced by anterior pituitary, targets adrenal cortex

  causes release of glucocorticoids (cortisol) and androgens
• tropic hormones


  causes release of other hormones
• human growth hormone (GH)


  produced in anterior pituitary,

  stimulates growth of skeletal muscles and bones
• prolactin (PRL)


  produced in anterior pituitary,

  causes mammary glands to produce milk
• Follicle-stimulating hormone (FSH)


  produced in anterior pituitary,

  required for gamete development in ovaries and testes
• luteinizing hormone (LH)


  produced in anterior pituitary,

  triggers ovulation in females and testosterone production in males
• calcitonin


  produced in thyroid gland,

  makes bone matrix stronger by inhibiting osteoclast activity and stimulates incorporation of calcium into bone matrix
• T3 and T4


  AKA Thyroid Hormone (TH),

  released within thyroid gland and differ in number of iodine atoms.

  T4 is mostly released, and then converted to T3 by target tissues.

  increases basal metabolic rate, helps control body temperature, and is important for growth and development of several organ systems.
• hyperthyroidism


  too much TH
• hypothyroidism


  too little TH
• parathyroid hormone (PTH)


  released by parathyroid glands when blood calcium is too low. causes increase in osteoclast activity, which releases more calcium into blood.

  also increases release of calcitriol from kidneys, and increases reabsorption of calcium in the kidneys from the filtrate back into the blood.
• insulin


  produced in pancreas.

  released when blood glucose levels are too high. causes cells in the liver to convert glucose to glycogen and store it. causes most body cells to insert glucose transporters into their cell membranes.
• diabetes mellitus


  results when you have too little insulin or too few insulin receptors
• diabetes insipidus


  produces high urine content because they have too little ADH or ADH receptors
• glucagon


  produced in pancreas.

  released when blood glucose level is too low. binds to receptors on liver cells, causing the cells to break down glycogen and release glucose.
• Glucocorticoids


  produced in the adrenal cortex. includes: cortisol, cortisone, corticosterone. involved in energy use and are released when we are stressed.
• Mineralocorticoids


  produced in adrenal cortex. mainly aldosterone, which regulates blood sodium and potassium levels, which in return affects fluid levels.

  Causes cells in kidney tubules to reabsorb more sodium from filtrate, which causes water to follow. Also causes the secretion of potassium.
• adrenal androgens


  male sex hormones produced in adrenal cortex
• epinephrine and norepinephrine (NE)


  produced in adrenal medulla
• Erythropoietin (EPO)


  released by the kidney when blood oxygen levels are too low. EPO enters blood and goes to red bone marrow to stimulate erythrocyte production
• Calcitriol (Vitamin D)


  released by kidney when blood calcium levels are too low. reaches cells of small intestine and causes the cells to absorb more calcium from food
• renin


  released by the kidney when blood pressure is too low. renin changes angiotensinogen into angiotensin I, which is converted by angiotensin-converting enzyme (ACE) into angiotensin II.
• angiotensin II


  causes the body's small arteries to vasoconstrict, which shunts blood away from less important places (skin) and towards more important places (brain, heart). It also stimulates adrenal cortex to release aldosterone which regulates blood pressure by causing sodium reabsorption. Also causes the release of ADH from the posterior pituitary.
• atrial natiuretic hormone (ANH)


  produced by the heart. produced when blood pressure is too high. it causes system arterioles (small arteries) to vasodilate, which allows more blood to be delivered to the periphery, which makes blood pressure in the core decrease.

  Limits reabsorption of sodium in the kidneys, and inhibits release of renin, which decreases angiotensin II and aldosterone levels.

  Directly inhibits aldosterone release from the adrenal cortex.