Digestive System Functions

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Questions and Answers

What is the primary role of the digestive system?

To mechanically break down food only

To break down food into absorbable molecules and facilitate absorption (correct)

To transport food directly to the bloodstream

To absorb liquids without processing food

Where does the majority of nutrient absorption occur in the digestive system?

In the mouth

In the small intestine (correct)

In the large intestine

In the stomach

What initiates the enzymatic digestion of proteins in the digestive system?

Brush-border enzymes in the small intestine

Salivary enzymes in the oral cavity

Enzymes secreted by the pancreas

Acid secretion in the stomach (correct)

Which enzyme converts trypsinogen to its active form?

Enteropeptidase Signup and view all the answers

What are brush-border enzymes?

Enzymes attached to the surface of epithelial cells in the digestive tract Signup and view all the answers

What happens to carbohydrate digestion when food reaches the stomach?

It stops due to denaturation of the enzyme Signup and view all the answers

Which food molecule is primarily broken down into amino acids?

Proteins Signup and view all the answers

Which of the following statements about pancreatic proenzymes is true?

They remain inactive until released into the digestive tract Signup and view all the answers

What type of enzyme does the pancreas secrete to help in carbohydrate digestion?

Pancreatic amylase Signup and view all the answers

Which monosaccharides result from the digestion of carbohydrates by brush-border enzymes?

Glucose, fructose, galactose Signup and view all the answers

How are triglycerides and long-chain fatty acids processed in the small intestine?

Broken down into monoglycerides and free fatty acids Signup and view all the answers

What is the purpose of brush-border digestive enzymes like sucrase, maltase, and lactase?

To digest carbohydrates into monosaccharides Signup and view all the answers

What happens to the chylomicrons after they are assembled in the epithelial cells?

They are exocytosed into interstitial fluid Signup and view all the answers

How are amino acids absorbed in the small intestine?

They are absorbed in the form of di- and tripeptides Signup and view all the answers

Which of the following is NOT a function of lipids in the body?

Provide fiber Signup and view all the answers

The final absorption of nutrients in the small intestine primarily occurs at which cellular structure?

Epithelial cells Signup and view all the answers

Study Notes

Digestive System Functions

The digestive system breaks down food into absorbable molecules.
It absorbs these molecules for use by the body.
The main food molecules are carbohydrates, proteins, and fats.

Digestion in the Oral Cavity

Digestion begins in the mouth.
Food is chewed, and enzymes in saliva start breaking down carbohydrates and fats.
The food is swallowed, passing to the esophagus.

Stomach Digestion

Stomach acid denatures enzymes that began digesting carbohydrates.
Protein digestion begins in the stomach.
Fat digestion continues.

Digestion in the Small Intestine

Most digestion and absorption of nutrients occur in the small intestine.
Enzymes from the pancreas are crucial for this process.
Many pancreatic enzymes are initially inactive (proenzymes).
Proenzymes are activated in the small intestine.
An example of a pancreatic proenzyme is trypsinogen, which becomes trypsin.
This conversion is catalyzed by enteropeptidase, an enzyme attached to the cell membrane of small intestine epithelial cells.
Brush-border enzymes (on the surface of the epithelial cells) carry out further digestion of carbohydrates, proteins, and fats. Examples are sucrase, maltase, lactase.
Carbohydrate digestion products (monosaccharides) are absorbed into the bloodstream.
Protein digestion products (amino acids) are absorbed into the blood.
The absorbed triglycerides combine with cholesterol and proteins to form chylomicrons.
Chylomicrons are absorbed into lymph vessels (lacteals).
Chylomicrons enter the venous circulation through the thoracic ducts.

Further processing

The absorbed cholesterol is also transported in the intestines and is processed in cells

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Description

Explore the key functions and processes of the digestive system in this quiz. Learn how food is broken down, absorbed, and utilized by the body, with a focus on digestion in the mouth, stomach, and small intestine. Test your knowledge on the role of enzymes and nutrients in digestion.