DIGESTIVE SYSTEM G8 4th Q

• Digestive System


  Responsible for the breaking down of food into nutrients such as carbohydrates, fats, and proteins that can be used by the cells of the body
• Mouth


  Beginning of the digestive tract and the part in which food is taken
• Types of Digestion


  • Mechanical
  • Chemical
• Mechanical Digestion


  Food is bitten, torn, and crushed by the teeth
• Chemical Digestion


  Amylase breaks down complex carbohydrates into simple sugars
• Teeth


  Bone-like structures in the upper and lower parts of the mouth responsible for mastication or chewing, the crushing and grinding of food
• Salivary Glands


  Structures in the mouth that produce saliva, which keeps the mouth moist and clean
• Tongue


  Movable muscular organ inside the mouth that pushes the food around the mouth during mastication
• Papillae


  Projections on the surface of the tongue, some of which have taste buds
• Taste Buds


  Structures responsible for identifying the taste of food, they stimulate the production of certain enzymes in the mouth that help digest food by partially breaking them down
• Bolus


  Saliva-filled mass of food
• Pharynx


  Thin-walled chamber at the back of the mouth that leads either to the respiratory tract or to the digestive tract
• Esophagus


  Muscular tube that transports food from the pharynx to the stomach, about 25 cm long and extends from the end of the pharynx to the upper part of the stomach
• Peristalsis


  Rhythmic muscle contractions of the esophagus to move the bolus down to the stomach
• Cardioesophageal Sphincter


  Allows the entry of the bolus into the stomach and prevents the stomach contents from going back into the esophagus
• Stomach


  Expandable, J-shaped bag connected to both the esophagus and the small intestine where food is further broken down chemically and stored temporarily
• Gastric Glands


  Produce hydrochloric acid and enzymes. Also pepsin
• Hydrochloric Acid


  Turns the bolus into a soupy substance called chyme
• Pepsin


  Digests the proteins from the chyme and converts these into a chain of several amino acids
• Small Intestine


  Long tube that measures about 4 cm in diameter and is located between the stomach and large intestine
• Villi


  Fingerlike structures on the surface of the small intestine's folds that provide a huge surface area for nutrient absorption
• Large Intestine


  Tube that is shorter and wider than the small intestine, measures about 2 m in length and about 6.5 cm in diameter
• Main Functions of Large Intestine

  Reabsorption of water and formation and movement of feces to the anus
• Rectum


  Where the undigested materials are restored
• Elimination of Undigested Materials

  The undigested materials pass into the anal canal and is removed through the anus by strong muscle contractions in the rectum
• Anal Sphincter


  Muscle ring that regulates the elimination of undigested materials
• Liver


  Largest gland of the body, weighing about 1.4 to 1.6 kg, a reddish brown lobed mass located under the diaphragm that absorbs excess amino acids, stores glycogen and fat-soluble vitamins, produces somatomedins and bile
• Pancreas


  Leaf-like gland that consists of a head, body, and a tail, located behind the stomach and the lower left ribs, composed of the islets of Langerhans which produce insulin, a hormone that decreases blood sugar level, also produces pancreatic juices which goes to the small intestine upon the signal of hormones
• Gall Bladder


  Small sac that lies beneath the liver, concentrates and stores bile
• Life Processes


  • Ingestion
  • Absorption
  • Assimilation
  • Excretion
• Ingestion


  The process of taking food into the body through the mouth
• Absorption


  The smaller molecules that are produced through digestion get absorbed by the system
• Assimilation


  Movement of the absorbed nutrients to the specific cells
• Excretion


  The removal of remaining waste materials after absorption
• Other word for chewing is called Mastication.
• Epiglottis is the door, at which keeps food and liquids out of the respiratory system.
• Digestive tract is the path, as where food is broken down and released.
• Accessory organs are Liver, Pancreas and Gallbladder.
• The Digestive tract organs are Mouth, Pharynx, Esophagus, Stomach, Small intestine, Large Rectum and Anus.
• What are the Digestive Tract organs?

  Mouth, Pharynx Esophagus Stomach Small intestine Large intestine rectum and anus