#biology

#digestivesystem

#absorption

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Absorption in the digestive system is the process by which nutrients from digested food are taken into the bloodstream. Here's a step-by-step explanation:

1. Mouth (Initial Breakdown)

• Digestion begins in the mouth, where enzymes in saliva start breaking down carbohydrates. However, absorption doesn't occur here.

2. Stomach (Minimal Absorption)

• The stomach breaks down proteins and churns food into a semi-liquid called chyme.

• Minimal absorption happens in the stomach, mostly for alcohol and some medications.

3. Small Intestine (Major Absorption Site)

• Duodenum: Chyme enters the duodenum where bile (from the liver) and pancreatic enzymes further digest fats, proteins, and carbohydrates.

• Jejunum: Nutrients like sugars, amino acids, fatty acids, and vitamins are absorbed here through the intestinal walls into the bloodstream.

• Ileum: Remaining nutrients, particularly bile salts, vitamin B12, and some water, are absorbed here.

4. Villi and Microvilli (Maximizing Absorption)

• The small intestine is lined with tiny finger-like structures called villi and smaller projections called microvilli, which increase the surface area for maximum nutrient absorption.

5. Nutrient Transport

• Absorbed nutrients enter the bloodstream through capillaries in the villi and are transported to the liver for processing.

• Fats are absorbed into the lymphatic system first and later enter the bloodstream.

6. Large Intestine (Water Absorption)

• The large intestine absorbs water, salts, and some vitamins.

• Any undigested material forms stool, which is eventually excreted.

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