Algonquin College Health Program Assessment (AC-HPAT) Practice Exam

Which of the following systems is primarily responsible for nutrient absorption in the human body?

1. Respiratory system

2. Digestive system

3. Circulatory system

4. Nervous system

The correct answer is: Digestive system

The digestive system is primarily responsible for nutrient absorption in the human body. This system includes several organs such as the mouth, esophagus, stomach, small intestine, and large intestine, which work together to break down food and extract essential nutrients. The process begins with ingestion and mechanical breakdown of food and continues with enzymatic actions that facilitate the digestion of proteins, fats, and carbohydrates. Once these macronutrients are broken down into smaller molecules, such as amino acids, fatty acids, and glucose, they are absorbed through the walls of the small intestine into the bloodstream. This absorption process is crucial for providing energy, supporting cell growth, and maintaining overall metabolic functions. The other systems listed play different roles: the respiratory system is involved in gas exchange, the circulatory system is responsible for transporting nutrients and oxygen throughout the body, and the nervous system regulates bodily functions but does not directly facilitate nutrient absorption. Therefore, the digestive system's role in processing and absorbing nutrients makes it the correct choice.