Gastric Acid Production/Kidney Filtration Mr. Nichols PHHS

COTD

Details In the nephron, tiny blood vessels intertwine with urine- collecting tubes. Each kidney contains about 1 million nephrons. At first, the tubules receive a combination of waste materials and chemicals the body can still use. The kidneys measure out chemicals like sodium, phosphorus, and potassium and release them back to the blood to return to the body. In this way, the kidneys regulate the body's level of these substances. The right balance is necessary for life. In addition to removing wastes, the kidneys release three important hormones: Erythropoietin, or EPO, which stimulates the bone marrow to make red blood cells Renin, which regulates blood pressure Calcitriol, the active form of vitamin D, which helps maintain calcium for bones and for normal chemical balance in the body

Why do kidney’s fail? Most kidney diseases attack the nephrons, causing them to lose their filtering capacity. Damage to the nephrons can happen quickly, often as the result of injury or poisoning. But most kidney diseases destroy the nephrons slowly and silently. High blood pressure can damage the small blood vessels in the kidneys. The damaged vessels cannot filter wastes from the blood as they are supposed to.

Overview of Gastric Acid Creation The serosa - the outer layer that acts as a covering for the other layers. Two muscle layers - the middle layers that propel food from the stomach into the small intestine. The mucosa - the inner layer made up of specialized cells, including parietal cells, g-cells and epithelial cells.

Overview of Gastric Acid Creation Parietal cells (also called oxyntic cells) are the stomach epithelium cells which secrete gastric acid. Parietal cells produce gastric acid (hydrochloric acid) in response to histamine, acetylcholine, and gastrin (made by g-cells). Parietal cells contain an extensive secretory network of hallow filaments from which the HCl is secreted by active transport into the stomach.

How does your stomach not digest itself? The stomach is protected by the epithelial cells, which produce and secrete a bicarbonate-rich solution that coats the mucosa. Bicarbonate is alkaline, a base, and neutralizes the acid secreted by the parietal cells, producing water in the process. This continuous supply of bicarbonate is the main way that your stomach protects itself from autodigestion (the stomach digesting itself) and the overall acidic environment.