Digestion of foods includes the mechanical actions of:
A the stomach to gently release foods into the small intestine.
B chewing to allow some nutrients to be absorbed into the body through the tongue.
C the small intestine to absorb water and create the paste that forms feces.
D peristalsis waves to move the foods down through the digestive tract.
The correct answer and explanation is :
The correct answer is D: peristalsis waves to move the foods down through the digestive tract.
Explanation:
Digestion of food involves both mechanical and chemical processes that break down food into nutrients the body can use. Mechanical digestion refers to the physical breakdown of food, and chemical digestion involves enzymatic processes that further break down the food into simpler molecules.
In the context of mechanical digestion, peristalsis waves play a crucial role in moving food through the digestive tract. Peristalsis refers to a series of wave-like muscle contractions that occur along the esophagus, stomach, small intestine, and large intestine. These muscle contractions help propel food and liquids through the digestive system, ensuring they move from one part of the digestive tract to the next. Peristalsis is essential for advancing the food bolus from the mouth to the stomach, then from the stomach to the small intestine, and eventually to the large intestine, where water absorption occurs and feces is formed.
Now, let’s look at why the other options are incorrect:
- A. The stomach gently releases foods into the small intestine: While the stomach does regulate the release of chyme into the small intestine, this is not a mechanical digestion action but rather part of the regulatory function of the stomach. The actual mechanical digestion in the stomach involves churning and mixing the food with gastric juices.
- B. Chewing to allow some nutrients to be absorbed into the body through the tongue: Chewing, or mastication, is indeed an important mechanical process that breaks down food into smaller pieces for easier digestion. However, nutrients are not absorbed through the tongue; absorption occurs in the small intestine, not in the mouth.
- C. The small intestine absorbs water and creates the paste that forms feces: This describes the function of the large intestine, not the small intestine. The small intestine is primarily responsible for nutrient absorption, while the large intestine absorbs water and electrolytes and compacts the waste into feces.
Thus, the correct mechanical action related to digestion is peristalsis, which ensures the movement of food throughout the digestive system.