Answer: The digestive tract, also known as the gastrointestinal (GI) tract, is a complex system responsible for the breakdown, absorption, and processing of food. It consists of several parts, each with distinct functions. Here are five parts of the digestive tract in order, along with one function each performs:Mouth:Function: The mouth is where the digestive process begins. Its primary function is mechanical and chemical digestion. Teeth break down food into smaller particles, and salivary glands release saliva containing enzymes like amylase that start the chemical breakdown of carbohydrates. The tongue helps mix food with saliva and forms it into a bolus for swallowing.Esophagus:Function: The esophagus is a muscular tube that connects the mouth to the stomach. Its main function is to transport the bolus of food from the mouth to the stomach through a series of coordinated muscle contractions called peristalsis. It has a valve at the bottom (lower esophageal sphincter) to prevent stomach acid from flowing back into the esophagus.Stomach:Function: The stomach serves as a storage organ for food and performs both mechanical and chemical digestion. It secretes gastric juices containing hydrochloric acid and digestive enzymes (e.g., pepsin) to break down proteins. The stomach's muscular contractions churn and mix the food, forming a semi-liquid substance known as chyme.Small Intestine:Function: The small intestine is the primary site of nutrient absorption in the digestive tract. It further digests chyme using enzymes from the pancreas and bile from the liver, breaking down carbohydrates, proteins, and fats into their smallest components. Villi and microvilli in the small intestine's lining increase the surface area for absorption of nutrients into the bloodstream.Large Intestine (Colon):Function: The large intestine primarily functions in the absorption of water and electrolytes, as well as the formation and storage of feces. It also plays a role in the fermentation of certain undigested carbohydrates by gut bacteria, producing gases and some additional nutrients. The colon's muscles help propel waste toward the rectum for elimination.These are the key parts of the digestive tract, and each contributes to the overall process of digestion and nutrient absorption in its own way. The digestive system works as a coordinated system to break down ingested food into nutrients that can be absorbed and used by the body for energy and various physiological functions.