Exam 4 Review: Chapter 25: Regulation II: Other Endocrine Systems
aldosterone - The main steroid hormone produced by the outermost layer of the adrenal cortex, whose release is stimulated by increased potassium levels in the plasma; this mineralocorticoid targets the kidney to actively transport sodium ions out of the urine and potassium ions into the urine (chloride ions and water passively follow the sodium ions back to the bloodstream); the net effects of this hormone are to increase blood pressure and blood volume and to adjust sodium and potassium levels in the blood.
adrenal cortex - The outer portion of the adrenal glands which is divided into three zones, each zone produces a different functional class of steroid hormones (derived from cholesterol): the mineralcorticoids (aldosterone), the glucocorticoids (cortisol, cortisone and hydrocortisone), and the gonadocorticoids (estrogens and androgens).
hypothalamus - That portion of the central nervous system found surrounding the lower portion of the third ventricle which receives and integrates many types of sensory information about the internal environment and directs actions to control internal homeostasis by both initiating commands carried by autonomic neurons and by regulating some of the endocrine activity of the pituitary gland.
antidiuretic hormone (ADH) = vasopressin - the neurohypophyseal peptide hormone which stimulates contraction of smooth muscle in blood vessel walls and stimulates the kidney tubules to reabsorb water; both target responses tend to increase blood pressure.
atrial natriuretic peptide = ANP - The peptide hormone released from special endocrine cells in the walls of the upper chambers/atria of the heart in response to the stretching of the chamber walls due to increased blood volume or increased blood pressure; ANP is the antagonist to aldosterone and thus triggers salt (NaCl) and water excretion and potassium ion reabsorption at the kidney tubules.
parathyroid hormone = parathormone = PTH - A protein hormone, produced by the principle or chief cells of the parathyroid gland which increases plasma calcium levels (mechanisms 1, 2, and 3) and decreases plasma phosphate levels (mechanism 3) by (1) targeting oseoclasts to increase dissolution of bone matrix, (2) targeting the intestinal lining to increase calcium ion absorption from the digested meal, and (3) targeting the kidney to reaabsorb calcium ions from and secrete phosphate ions into the urine; PTH is the antagonist to thyrocalcitonine.
calcitonin = thyrocalcitonin - A protein hormone, produced by the parafollicular cells/C cells of the thyroid gland which lowers plasma calcium and phosphate levels by targeting oseoblasts to increase formation of bone matrix; the antagonist to parathyroid hormone.
Explain:
8. how hyponatremia can lead to circulatory shock.
Hyponatremia through loss of NaCL typically follows the tissue "weeping" associated with severe or extensive burns, significant diarrhea or vomiting, from prolonged gastric drainage (gastric intubation), excessive use of certain classes of diuretics, aldosterone deficiency (Addison's disease), in severe renal disease, especially severe glomerulonephritis, nephrotic syndrome, and kidney failure, and in (rare) case of abnormal excessive ADH release. In these circumstances, water follows the sodium by passive osmosis, and, as a result, blood volume is decreased. When severe, the reduced blood volume and accompanying reduced blood pressure reach the stage of circulatory shock.