digestive mucosa
digestive mucosa
The small intestine is the answer your looking for.
An exchange surface is in direct contact with the external environment in the respiratory and digestive systems. In the respiratory system, the alveoli in the lungs act as exchange surfaces for oxygen and carbon dioxide. In the digestive system, the lining of the small intestine serves as an exchange surface for the absorption of nutrients.
Food moves the digestive system through the mouth, pharynx, esophagus, stomach, small intestine, and large intestine. Solid food waste is expelled through the anus, at the end of the digestive tract.
A typhlosole is a fold in the intestine of certain animals, such as earthworms, that increases the surface area available for nutrient absorption. It helps in the digestion process by increasing the contact between food and digestive enzymes, allowing for more efficient absorption of nutrients.
mucosa
Self-digestion of the stomach and small intestine is prevented by the mucus lining that protects these organs from the acidic and enzymatic activity of the digestive juices. Additionally, the cells of the stomach and small intestine have tight junctions that prevent digestive enzymes from leaking out and causing harm. The presence of bicarbonate in the mucus also helps to neutralize any excess acid that may come into contact with the lining.
Cells with the largest surface area are typically found in specialized structures like the small intestine. The cells lining the small intestine have microvilli, which greatly increase the surface area for absorption of nutrients. These cells are specifically adapted to maximize their contact with nutrients in the digestive system.
Enzymes produced in the pancreas are secreted into the small intestine through the pancreatic duct. When food enters the small intestine from the stomach, these enzymes mix with the food as it is digested. This allows the enzymes to break down carbohydrates, proteins, and fats, facilitating nutrient absorption. Thus, even though food doesn't pass through the pancreas, the enzymes reach it effectively in the small intestine.
the brush border of the small intestine
Segmentation in the digestive tract mixes food with digestive juices and increases the rate of absorption by repeatedly moving different parts of the food mass over the intestinal wall.
National Institute of Diabetes and Digestive and Kidney Disease; http://www.niddk.nih.gov