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peristalsis

Primary Information
Secondary Information

Definition

Peristalsis is a series of rhythmic muscle contractions that move food through the digestive tract. The muscles in the digestive tract contract and relax in a wave-like motion, pushing food forward. Peristalsis is involuntary, which means it happens without us having to think about it. It is essential for digestion, as it helps move food through the digestive tract and into the small intestine where it can be broken down and absorbed.

Peristalsis is controlled by the nervous system. The brain sends signals to the muscles in the digestive tract, telling them to contract and relax.

The speed of peristalsis varies depending on the type of food being eaten. Solid food moves through the digestive tract more slowly than liquid food.

Peristalsis can be affected by certain medical conditions, such as gastroparesis and irritable bowel syndrome.

Peristalsis is an important part of digestion, and without it, we would not be able to eat or digest food properly.

How can the word be used?

Peristalsis can be stimulated by certain foods, such as fiber and fluids.

peristalsis

Different forms of the word

Noun:

  • peristalsis (the involuntary wave-like movement of muscles that propels food through the digestive tract).
  • peristaltic (of or relating to peristalsis).

Adjective:

  • peristaltic (of or relating to peristalsis).

Etymology

The word "peristalsis" is derived from the Greek words "peri" (around) and "stalsis" (contraction). The first recorded use of the word "peristalsis" in English was in the 18th century.

Question

What is peristalsis?

AQA Science Exam Question and Answer

Question:

Describe the process of peristalsis in the digestive system. Explain its role in moving food through the gastrointestinal tract and how it contributes to effective digestion. Provide real-world examples to illustrate the importance of peristalsis.

Answer:

Peristalsis is a rhythmic, involuntary muscular contraction and relaxation process that propels food through the digestive system. When food enters the oesophagus, for example, muscles contract behind the food bolus, pushing it forward. Simultaneously, the muscles ahead of the bolus relax, allowing it to move smoothly. This coordinated action creates a wave-like motion that propels food from the mouth to the stomach and through the rest of the gastrointestinal tract.

Peristalsis is crucial for effective digestion. In the stomach, it mixes food with digestive enzymes and gastric juices, facilitating the breakdown of complex molecules. In the intestines, it further breaks down food particles, allowing for efficient nutrient absorption.

Real-world examples of peristalsis's importance include cases of swallowing large pieces of food. In such instances, peristalsis ensures that the food is gradually broken down and moved through the digestive tract. Additionally, disruptions in peristalsis can lead to digestive issues like constipation, where the movement of faeces is slowed due to ineffective muscular contractions.