About the kidneys , you have any doubts, please click on this sentence, I'll give you the answer
The blood pressure in your body depends upon the following conditions:
The force of contraction of the heart -- related to how much the heart muscle gets stretched by the incoming blood.
The degree to which the arteries and arterioles constrict -- increases the resistance to blood flow, thus requiring a higher blood pressure.
The circulating blood volume -- the higher the circulating blood volume, the more the heart muscle gets stretched by the incoming blood.
The kidney influences blood pressure by:
Causing the arteries and veins to constrict
Increasing the circulating blood volume
About the kidneys , you have any doubts, please click on this sentence, I'll give you the answer
The kidney can correct any imbalances by:
Removing excess acid (hydrogen ion) or bases (bicarbonate) in the urine and
Restoring the bicarbonate concentration in the blood to normal
The kidney cells produce a constant amount of hydrogen ion and bicarbonate because of their own cellular metabolism (production of carbon dioxide). Through a carbonic anhydrase reaction similar to the red blood cells, hydrogen ions get produced and secreted into the lumen of the nephron. Also, bicarbonate ions get produced and secreted into the blood. In the lumen of the nephron, filtered bicarbonate combines with secreted hydrogen ions to form carbon dioxide and water (carbonic anhydrase is also present on the luminal surface of the kidney cells). Whether the kidney removes hydrogen ions or bicarbonate ions in the urine depends upon the amount of bicarbonate filtered in the glomerulus from the blood relative to the amount of hydrogen ions secreted by the kidney cells. If the amount of filtered bicarbonate is greater than the amount of secreted hydrogen ions, then bicarbonate will be lost in the urine. Likewise, If the amount of secreted hydrogen ion is greater than the amount of filtered bicarbonate, then hydrogen ions will be lost in the urine (i.e. acidic urine).
About the kidneys , you have any doubts, please click on this sentence, I'll give you the answer
When you drink a large glass of water, the water gets absorbed into the blood and the following happens:
The absorbed water increases the amount of water filtered in the glomerulus.
The absorbed water in the blood reduces the Na concentration a little.
The reduced Na concentration lowers the amount of Na filtered in the glomerulus.
The nephron reabsorbs all of the reduced Na load and some of the accompanying water, leaving excess water in the filtrate.
The reduced Na concentration is sensed by the osmoreceptors.
The osmoreceptors do not secrete as much ADH.
About the kidneys , you have any doubts, please click on this sentence, I'll give you the answer
Your kidneys have the ability to conserve or waste water. For example, if you drink a large glass of water, you'll find that you will have the urge to urinate within an hour or so. In contrast, if you don't drink for a while, such as overnight, you will not produce much urine and it will usually be very concentrated (i.e. darker). How does your kidney know the difference? The answer to this question involves two mechanisms:
The structure and transport properties of the loop of Henle in the nephron.
The anti-diuretic hormone (ADH), also called vasopressin, secreted by the pituitary gland.
The loop of Henle has a descending limb and an ascending limb. As filtrate moves down the loop of Henle, water is reabsorbed, but ions (Na,Cl) aren't.
About the kidneys , you have any doubts, please click on this sentence, I'll give you the answer
Some substances are secreted from the plasma into the lumen by the cells of the nephron. Examples of such substances are ammonia (NH3). As in reabsorption, there are transporters on the cells that can move these specific substances into the lumen.
Now let's put all of these processes -- filtration, reabsorption and secretion -- together to understand how the kidneys maintain a constant composition of the blood. Let's say that you decide to eat several bags of salty (NaCl) potato chips at one sitting. The Na will be absorbed into your blood by your intestines, increasing the concentration of Na in your blood.
