The intestinal juice does not function in the stomach. Intestinal juice is produced in the small intestine, not the stomach, and plays no role in the stomach's digestive processes. The stomach produces gastric juice, which is responsible for initial food digestion.
Since the premise of the question is incorrect, we can reframe it to ask: "What is the function of intestinal juice in the small intestine?" The answer is:
Functions of Intestinal Juice in the Small Intestine
Intestinal juice, also known as succus entericus, is a watery fluid secreted by the glands in the lining of the small intestine. It plays a crucial role in the final stages of digestion and absorption. Its primary functions include:
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Neutralizing Chyme: Intestinal juice helps neutralize the acidic chyme (partially digested food from the stomach) entering the duodenum (the first part of the small intestine). This neutralization is essential because the enzymes in the small intestine function optimally at a neutral or slightly alkaline pH. The neutralization is aided by bicarbonate secreted by the pancreas.
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Hormone Release: The intestinal mucosa (lining) contains endocrine cells that release various gastrointestinal hormones into the bloodstream in response to the presence of chyme. These hormones regulate digestive processes, such as stimulating the release of bile from the gallbladder and pancreatic enzymes from the pancreas.
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Digestive Enzymes: Intestinal juice contains various enzymes that further break down carbohydrates, proteins, and fats into smaller, absorbable molecules. Some key enzymes present include:
- Peptidases: Break down small peptides into amino acids.
- Sucrase, Maltase, Lactase: Break down disaccharides (sucrose, maltose, lactose) into monosaccharides (glucose, fructose, galactose).
- Lipase: Further digest fats that were initially emulsified by bile.
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Facilitating Absorption: By breaking down complex molecules into simpler ones, intestinal juice facilitates the absorption of nutrients across the intestinal wall into the bloodstream. This is the ultimate goal of digestion: to provide the body with the building blocks and energy it needs.
In summary, intestinal juice is essential for neutralizing the acidity of chyme, releasing digestive hormones, providing digestive enzymes, and ultimately facilitating the absorption of nutrients in the small intestine. It has no function in the stomach.
