Digestive System

• Digestive system


  A group of organs working together to convert food into energy and basic nutrients to feed the entire body
• Teeth


  • Designed for cutting and grinding food into smaller pieces
• Tongue


  • Contains many rough papillae for gripping food as it is moved by the tongue's muscles
  • Helps to push food toward the posterior part of the mouth for swallowing
• Salivary glands


  • Produce a watery secretion known as saliva
  • The body uses saliva to lubricate food as it passes through the mouth, pharynx, and esophagus
• Pharynx


  • Responsible for the passing of masses of chewed food from the mouth to the esophagus
  • Passageway for both food and air
  • Contains a flap of tissue known as the epiglottis that acts as a switch to route food to the esophagus and air to the larynx
• Esophagus


  • Carries swallowed masses of chewed food along its length
• Stomach


  • Acts as a storage tank for food so that the body has time to digest large meals properly
• Small intestine


  • Inside surface is full of many ridges and folds called villi
  • These folds are used to maximize the digestion of food and absorption of nutrients
  • Final digestion and absorption occur

  
• Liver


  • Main function in digestion is the production of bile and its secretion into the small intestine
• Gallbladder


  • Used to store and recycle excess bile from the small intestine so that it can be reused for the digestion of subsequent meals
• Pancreas


  • Secretes digestive enzymes into the small intestine to complete the chemical digestion of foods
• Large intestine


  • Absorbs water and contains many symbiotic bacteria that aid in the breaking down of wastes to extract some small amounts of nutrients
  • Feces in the large intestine exit the body through the anal canal
• Rectum


  • A straight, 8-inch chamber that connects the colon to the anus
  • Receives stool from the colon, lets you know that there is stool to be evacuated (pooped out) and to hold the stool until evacuation happens
• The large intestine absorbs water and forms feces.
• The small intestine is where most nutrient absorption occurs through villi and microvilli.
• The liver produces bile which helps with fat digestion.
• The gallbladder stores and releases bile as needed.
• The stomach secretes hydrochloric acid and pepsinogen to break down food.
• Stomach churns food into a thick liquid called chyme.
• Pancreas secretes enzymes into the duodenum to break down carbohydrates, proteins, and fats.
• The esophagus moves food into the stomach using peristalsis.
• The mouth has teeth and salivary glands to begin breaking down food mechanically and chemically.
• The pharynx receives food from the mouth and passes it on to the esophagus or trachea depending on whether swallowing or breathing is occurring.
• Gastric juice contains HCl and Pepsinogen, which are secreted by gastric glands.
• The liver produces bile that helps digest fatty foods.
• The stomach is the organ that receives food from the esophagus, mixes it with digestive juices, and stores it until it can be digested.
• The rectum stores feces until they are eliminated during defecation.
• Salivary glands produce saliva containing amylase, which begins the breakdown of starches.