Mechanical Digestion

Mechanical Digestion

Mechanical digestion is the physical breakdown of food into smaller pieces, which increases surface area and aids in chemical digestion.

Mouth

• The process of mechanical digestion starts in the mouth, where food is chewed and broken into smaller pieces.
• This action, known as mastication, is facilitated by the movement of the jaw and strong contractions of the tongue.
• The process of mastication increases the surface area of the food, aiding in the efficient breakdown by enzymes in the later stages of digestion.

Stomach

• The stomach is another organ that contributes significantly to mechanical digestion.
• Food reaches the stomach from the oesophagus, through a muscular ring called the cardiac sphincter.
• Muscle contractions in the stomach mix the food with gastric juices, breaking it down into a semi-fluid substance known as chyme.

Small Intestine

• The small intestine plays a minor role in mechanical digestion.
• Peristalsis, which are rhythmic muscle contractions in the intestinal walls, helps move the chyme along the small intestine and mixes it with digestive enzymes.

Importance of Mechanical Digestion

• Mechanical digestion is a crucial initial part of the digestive system.
• It increases the surface area of food which makes the chemical digestion by enzymes more efficient.
• This is essential as it allows nutrients to be absorbed more effectively in later stages of the digestive process, ensuring the body receives essential nutrients needed for growth, repair and function.

Remember, understanding the role of different parts of the digestive system in breaking down food is fundamental to understanding the overall process of human nutrition.