What is one way the muscular system aids the digestive system?
A. Nutrients are transported throughout the body in the muscles.
B. The brain sends signals to the stomach to absorb the nutrients.
C. Muscles contract to move food down the esophagus to the stomach.
D. Muscles break down the food and absorb the nutrients for the body to use.
The correct answer and explanation is:
The correct answer is C. Muscles contract to move food down the esophagus to the stomach.
The muscular system plays a key role in digestion through the process of peristalsis, which involves the contraction and relaxation of muscles to move food through the digestive tract. After food is chewed and mixed with saliva in the mouth, it forms a bolus, which is swallowed. This bolus then enters the esophagus, where the smooth muscles in the walls of the esophagus begin to contract in a coordinated fashion, pushing the food down toward the stomach.
The contraction of these muscles is essential for propelling the food through the entire digestive system. The process starts at the top of the esophagus and moves down in waves, allowing food to travel despite the force of gravity. This involuntary action is controlled by the autonomic nervous system, which regulates the smooth muscle activity.
Once the food reaches the stomach, more muscle contractions occur, mixing the food with digestive enzymes and stomach acid to break it down further. These muscle contractions in the stomach also help move the food into the small intestine, where the absorption of nutrients begins.
Thus, without the muscular contractions throughout the digestive system, food would not be able to move through the esophagus or stomach properly, hindering the digestion process. The muscular system helps ensure that food is moved efficiently through the digestive tract, allowing for proper digestion and absorption of nutrients.