Differentiate between digestion in small intestine and digestion in stomach.
Once the food is swallowed, it involuntarily proceeds under the control of the esophagus and brain. The lower esophageal sphincter muscle controls the passage of food and liquid between the esophagus and stomach. As food approaches the closed sphincter, the muscle relaxes and lets food pass through it into the stomach.
The stomach stores the incoming food, mixes it with digestive juices, and slowly empties its contents into the small intestine. The cells lining its wall secrete dilute hydrochloric acid that assists in the breakdown process.
In the small intestine, the food is mixed with digestive juices from the pancreas, liver, and intestine. The walls of the small intestine are specialized to absorb the nutrients from the digested food into the bloodstream. The blood delivers these nutrients to various body parts.
Various enzymes aid the process of digestion and their effectiveness depends on different pH levels. A pH too high (basic) or too low (acidic) might denature a particular enzyme and prevent it from performing its function. Saliva keeps the pH in the mouth between 6.5 and 7, optimum for the enzyme salivary amylase to act on carbohydrates. Pepsin that helps digest proteins in the stomach, works best at a pH around 2, while the enzymes that function in the intestines (including peptidases and maltase), work best at a pH around 7.5.
Once the food is swallowed, it involuntarily proceeds under the control of the esophagus and brain. The lower esophageal sphincter muscle controls the passage of food and liquid between the esophagus and stomach. As food approaches the closed sphincter, the muscle relaxes and lets food pass through it into the stomach.
The stomach stores the incoming food, mixes it with digestive juices, and slowly empties its contents into the small intestine. The cells lining its wall secrete dilute hydrochloric acid that assists in the breakdown process.
In the small intestine, the food is mixed with digestive juices from the pancreas, liver, and intestine. The walls of the small intestine are specialized to absorb the nutrients from the digested food into the bloodstream. The blood delivers these nutrients to various body parts.
Various enzymes aid the process of digestion and their effectiveness depends on different pH levels. A pH too high (basic) or too low (acidic) might denature a particular enzyme and prevent it from performing its function. Saliva keeps the pH in the mouth between 6.5 and 7, optimum for the enzyme salivary amylase to act on carbohydrates. Pepsin that helps digest proteins in the stomach, works best at a pH around 2, while the enzymes that function in the intestines (including peptidases and maltase), work best at a pH around 7.5.
