What is the primary function of the digestive system?
a) To circulate oxygen and nutrients through the body
b) To break down food and absorb nutrients
c) To send electrical signals to the muscles
d) To protect internal organs from injury
The correct answer and explanation is:
The correct answer is b) To break down food and absorb nutrients.
The primary function of the digestive system is to break down food into smaller components, which are then absorbed into the bloodstream or lymphatic system to provide energy, growth, and cell repair. This process involves several organs working together in a coordinated manner.
The digestive process starts in the mouth, where food is mechanically broken down by chewing and chemically processed by saliva. Once the food reaches the stomach, it is further broken down by stomach acids and enzymes. The stomach also acts as a temporary storage site for food.
Next, food moves into the small intestine, which is where the majority of digestion and nutrient absorption occurs. The small intestine contains specialized cells that absorb nutrients such as proteins, carbohydrates, fats, vitamins, and minerals into the bloodstream. This is assisted by enzymes from the pancreas and bile from the liver. The walls of the small intestine are lined with tiny hair-like structures called villi, which increase the surface area for nutrient absorption.
Once the nutrients are absorbed, the remaining undigested food passes into the large intestine, where water and salts are absorbed, and the rest of the material is prepared for elimination. The large intestine also houses beneficial bacteria that help break down some substances that the body cannot digest on its own.
In summary, the digestive system’s primary function is to break down food into its chemical components, absorb essential nutrients, and eliminate waste products, ensuring the body receives the necessary substances to function effectively.