Gastric Acid
Production/Kidney
Filtration
Mr. Nichols
PHHS
COTD
COTD
COTD
COTD
Details
• In the nephron, tiny blood vessels intertwine with urinecollecting 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.