Kidney Nephron – the filter in the kidney
The electrolytes sodium and potassium are controlled by the kidney. And diseases involving sodium and potassium usually involve the kidney.
The Nephron – selectively decides what to keep, or get rid of if toxic or in excess quantity.
BOWMENS CAPSULE – COFFEE FILTER
The blood vessels interface with bowmen’s capsule and start the filtering. It works like a coffee filter. The holes in the filter are smaller than the larger molecules it wants to filter out. Like potassium, sodium, calcium, urea, and many other things allowed through the filter the rest stays in the blood.
Next the lope of Henley and the tubule will selectively separate out what it want’s to keep and dump back into the blood, or leave them in the urinary tubule so you can urinate it out.
Flowing down the tubules the concept of a concentration gradient is used. Particles of a greater concentration flow to a lesser concentration until they are equal on both sides.
LOOP OF HENLEY
The arterioles are what make up the other side of the concentration gradient. The arterioles have blood in them, and the tubules have the filtrate in them, filtered through the coffee filter. The Loop of Henley is where the concentration gradient is established. The concentration is getting greater because you loose water. The cells in the loop are permeable or open to water, not sodium, potassium, calcium, and everything we don’t want in our body. On the upside of the Loop of Henley there are channels or transporters. These co-transporters use energy to selectively move things in the right direction.
Next is the Convoluted Tubule
In the convoluted tubule there are pumps. Pumps use energy to move substances against concentration gradients. There pumps use Aldosterone. Aldosterone is the sodium saver. Where there is sodium there is going to be water, so it you increase ingestion of sodium you increase the storage of water.
FILTRATION REABSORPTION SECREATION EXCREATION
The above picture shows areas of filtration reabsorption, secretion, reabsorption, and excretion. Secretion takes place where we move a product from the blood back into the tubule. Secretion is shown in the diagram by the blue box with the letter ‘S’.
POTASSIUM AND OTHER AREAS OF ABSORPTION
This diagram show areas for sodium, potassium, and calcium absorption. Therefore any time someone has a kidney disorder their electrolytes will be imbalances. Also if a person takes a diuretic it impacts the permeability of the ascending cells of the loop of Henley so it can’t reabsorb potassium. Therefore you urinate out potassium so there is a higher concentration of potassium in the urine. Different areas are affected with different drugs and these affect reabsorption.
SODIUM REGULATION IN THE BODY
Starting with the pituitary gland. The kidneys and pituitary work together. If we have to much sodium in the body the posterior pituitary is told by the brain. This tells the posterior pituitary to stop releasing anti diuretic hormones. This controls the amount you urinate. ADH, antidiuretic hormone decreases urination. Aldosterone is also inhibited as its the sodium saver. This changes the permeability of the cells in the nephron. When sodium is not reabsorbed water is going to follow that. So there will be an increase in sodium and water in the urine and a decrease in blood volume in the nephron. Remember sodium being inhibited means aldosterone is inhibited.
Calcium is regulated by the thyroid gland. If you have too much calcium the thyroid gland releasers calcitonin. If you have too little calcium in the BLOOD the parathyroid gland releases parathyroid hormone that results in cannibalizing the bones to bring calcium back into the blood. That’s WHY HAIR TISSUEMINERAL ALANYSIS shows these relationships before you start to get osteoporosis.
Dietary phosphorus is readily absorbed in the small intestine, and in healthy individuals, excess phosphorus is excreted by the kidneys under the regulatory action of the endocrine hormones: parathyroid hormone (PTH), vitamin D, and fibroblast growth factor-23. The acute regulation of blood calcium and phosphorus concentrations is controlled through the actions of PTH and the active form of vitamin D. A slight drop in blood calcium levels (e.g., in the case of inadequate calcium intake) is sensed by the parathyroid glands, resulting in their increased secretion of PTH, which rapidly decreases urinary excretion of calcium but increases urinary excretion of phosphorus and stimulates bone resorption. This results in the release of bone mineral (calcium and phosphate) — actions that restore serum calcium concentrations.