Term
| Antidiuretic Hormone (ADH) |
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Definition
| A small peptide molecule that is released by the pituitary gland at the base of the brain, after being made close by in the hypothalamus. After being synthetized in the hypothalamus, ADH is then transported to the posterior pituitary. ADH in the bloodstream targets the kidneys and sends signals to them to reabsorb more water and to concentrate the urine, in order for your body to conserve water until you are able to hydrate yourself. ADH is responsible for making the upper sections of the distal tubules as well as the entire collecting duct permeable to water. By doing so, water reabsorption is aided tremendously. If there is too little water in the blood, the hypothalamus detects this change and proceeds to send signals to the pituitary gland, which then produces more ADH. ADH has an effect on the kidney as it is the ADH that makes the kidney reabsorb more water. Blood becomes less concentrated, negative feedback, more ADH produced, blood returns to correct osmotic concentration. |
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Term
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Definition
| A steroid hormone that is produced by the outer section of the adrenal cortex in the adrenal gland (2). Aldosterone targets the kidneys. Aldosterone causes nephrons to reabsorb Na+(aq)from the distal tubule and collecting ducts. As the Na+(aq) ions proceed to cross these membranes, they create a high solute concentration. H2O follows by osmosis because of the increase in the osmotic gradient. It is the job of Aldosterone to help regulate blood pressure and this happens by increasing fluid levels of the body. Blood pressure is then increased effectively due to the increase of water in the blood and by the constriction of blood vessels). |
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Definition
| A hormone produced by the kidneys that is responsible for promoting the formation of red blood cells by the bone marrow (3). The target organ is the kidneys and the red bone marrow. The kidneys monitor the blood that passes through their capillaries. When the blood becomes hypoxic (carrying deficient levels of oxygen), cells begin to produce EPO and release it into the bloodstream. EPO travels through the blood to the red bone marrow, where it then stimulates hematopoietic cells to increase their rate of red blood cell production. Red blood cells contain hemoglobin, which increases the bloods oxygen-carrying capacity and ends hypoxic conditions. |
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Term
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Definition
| A hormone secreted by the medulla of the adrenal glands. It targets most cells in the body, the heart, and blood vessels. Epinephrine is involved in the 'fight or flight' response that takes place when a person is subject to potential danger. A signalling process occurs and this causes the body to react accordingly. This happens by a signal being sent to the brain in which the brain then sends nerve impulses to the adrenal gland located in the kidneys. When this signal reaches the adrenal gland, the cells in the medulla release epinephrine. It then enters the bloodstream and is carried around the body to different cells, where it initiates responses. The purpose of epinephrine's effects are to provide energy so the muscles can respond to any perceived threat. |
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Term
| Atrial Natriuretic Hormone |
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Definition
| A hormone produced by the heart that increases sodium excretion and decreases blood pressure and blood volume. It targets the heart and the kidneys. ANH has the opposite function of aldosterone. ANH works to lower blood pressure by the homeostatic regulation of body water, sodium, potassium, and fat. The physiological effects of ANH include: An increase in glomerular filtration rate by dilating afferent arterioles, inhibiting collecting ducts from reabsorbing sodium, and inhibits release of renin. |
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Term
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Definition
| A peptide hormone with an overall effect of increasing blood pressure, body water and sodium content. As angiotensin 1 passes through the lungs and the kidneys, it is then metabolized to form angiotensin 2 by the angiotensin converting enzyme. Angiotensin 2 affects many parts of the body including blood vessels, nerves, adrenal glands, and the kidneys. Angiotensin affects the kidneys by increasing sodium retention and altering the way the kidney filters blood, which increases water reabsorption in the kidney to increase blood volume and blood pressure. |
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Term
| Parathyroid Hormone (PTH) |
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Definition
| A hormone produced by the parathyroid glands, which are four tiny glands located in the neck. The parathyroid hormone targets the bones, small intestines, and the kidneys. The purpose of this hormone is to increase the reabsorption of calcium and phosphate from the bones to the blood. If the blood calcium level is too low, it is the job of the parathyroid glands to release more PTH. The bones will then release more calcium into the blood and the amount of calcium produced by the kidneys into the urine, is then reduced. If PTH levels are too high or too low, problems can arise with the kidneys and the bones. |
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