How does the body neutralize acidic material leaving stomach?

The body neutralizes acidic material leaving stomach through several mechanisms:

1. Bicarbonate Secretion: The pancreas secretes bicarbonate ions (HCO3-) into the duodenum, which is the first part of the small intestine. These bicarbonate ions help to neutralize the acidic chyme (partially digested food) that enters the duodenum from the stomach.

2. Secretin Hormone: The presence of acidic chyme in the duodenum stimulates the release of a hormone called secretin. Secretin acts on the pancreas and stimulates the secretion of bicarbonate-rich fluid, which helps to further neutralize the acidic material.

3. Enteric Nervous System: The enteric nervous system, which controls the digestive system, also plays a role in neutralizing acidic material. It stimulates the release of hormones and other substances that help to regulate the secretion of bicarbonate and the contraction of the muscles in the digestive tract.

4. Mucous Layer: The lining of the duodenum and the rest of the small intestine is protected by a layer of mucus. This mucus layer helps to protect the intestinal cells from the acidic chyme and provides an alkaline environment that is more favorable for the digestion and absorption of nutrients.

5. Liver and Kidneys: The liver and kidneys also play a role in neutralizing acidic material in the body. They help to regulate the acid-base balance of the blood by excreting excess hydrogen ions (H+) and retaining bicarbonate ions.

These mechanisms work together to neutralize the acidic material leaving the stomach and create a more alkaline environment in the small intestine, which is necessary for the proper digestion and absorption of nutrients.