The digestive system is responsible for breaking down food and absorbing nutrients needed for energy and growth. Other functions, such as pumping blood or temperature regulation, are performed by other body systems.

The small intestine is where the majority of nutrient absorption occurs due to its highly folded surface and villi. Other organs like the stomach and large intestine have roles in digestion and water absorption respectively, but not in nutrient absorption.

Mechanical digestion starts in the mouth, where chewing breaks food into smaller pieces. This initial process makes it easier for enzymes to chemically digest the food later in the system.

The liver produces bile, which is then stored in the gallbladder until it is needed for emulsifying fats. The pancreas produces digestive enzymes, while the stomach mainly secretes acid and enzymes for protein digestion.

Amylase is present in saliva and begins the breakdown of carbohydrates into simpler sugars. The other enzymes are involved in the digestion of fats and proteins at later stages in the digestive process.

Peristalsis refers to the wave-like muscle contractions that move food through the digestive tract. It plays no role in secreting enzymes or directly absorbing nutrients.

The stomach is the primary site of chemical digestion due to its production of acid and enzymes like pepsin. Although the mouth initiates digestion, the stomach continues with a more intensive chemical breakdown.

The pancreas secretes pancreatic enzymes which help break down carbohydrates, proteins, and fats in the small intestine. Bile is produced by the liver, and insulin is a hormone involved in blood sugar regulation.

The small intestine is lined with tiny finger-like projections called villi, and even smaller microvilli, which greatly increase the surface area available for nutrient absorption. This design is vital for efficiently absorbing the digested nutrients.

The liver is not only involved in digestion by producing bile but also plays a critical role in detoxifying chemicals and metabolizing various substances. Its multifaceted functions make it essential for overall body health.

The large intestine's primary role is to absorb water from indigestible food matter and to form and move waste toward elimination. It is not mainly involved in breaking down proteins or producing enzymes.

Pepsin is the enzyme secreted by the stomach that begins the breakdown of proteins into peptides. The other enzymes target carbohydrates or fats.

The epiglottis is a flap of tissue that closes over the trachea during swallowing, preventing food from entering the airway. Its role is specific to coordinating breathing and swallowing safely.

Bile is critical for emulsifying fats, breaking them into smaller droplets to increase the surface area for pancreatic enzymes to act upon. It does not digest proteins or carbohydrates directly, nor does it neutralize acid.

Digestive enzymes and acids in the stomach work by chemically breaking down complex food molecules into simpler forms. This chemical digestion is essential for further digestion and nutrient absorption in the small intestine.

The stomach's thick muscular walls enable it to churn and mix food, combining it with acidic gastric juices and enzymes for chemical digestion. This dual mechanism ensures that food is broken down efficiently before it moves to the small intestine.

The liver produces bile which is stored in the gallbladder and released into the small intestine when fats are present. The bile helps emulsify the fats, breaking them into smaller droplets that can be more efficiently digested by enzymes, demonstrating impressive organ coordination.

Hormones such as cholecystokinin (CCK) are released in response to food entering the small intestine, signaling the pancreas to release digestive enzymes and the gallbladder to contract and release bile. This hormonal regulation is essential for synchronizing the digestive process.

A high-fiber diet adds bulk to the diet and helps regulate digestion by increasing water retention in the intestines, easing stool formation and movement. This supports overall digestive health and prevents issues like constipation.

When enzyme production is reduced, the breakdown of food is compromised, leading to poor absorption of essential nutrients and potential health issues such as malnutrition, weight loss, and digestive discomfort. This scenario underscores the critical role enzymes play in maintaining digestive efficiency and overall health.