Science: Organs of the Digestive Tract

• MOUTH

  Receives food through a process called ingestion.
• MOUTH

  Prepares food for digestion.
• MOUTH

  Initiates the breakdown of starch.
• TONGUE

  Protects the oral cavity.
• TONGUE

  Referred to as the organ of taste.
• TONGUE

  Helps shape the food into a ball called bolus
• TEETH

  Used for cutting, smashing and grinding solid food.
• TEETH has different types: Incisors, Canines, Molars and premolars
• Incisors - chisel-shaped teeth that are used for cutting and biting off small pieces of food.
• Canines - used for tearing off longer pieces of food.
• Molars and premolars - used for grinding and sometimes referred to as cheek teeth.
• PHARYNX

  Opening that leads to esophagus and trachea.
• Epiglottis - flap, leaf-shaped cartilage that covers the opening of the larynx to prevent food from entering the respiratory tract.
• ESOPHAGUS

  Muscular tube about 25 cm long.
• ESOPHAGUS

  Conveys chewed food from pharynx to stomach.
• Peristalsis - involuntary contraction and relaxation of muscles throughout the digestive tract.
• STOMACH

  Expanded J-shaped organ located in the upper left region of the abdominal cavity
• Rugae - folds that linings form when the stomach is empty.
• Sphincter - muscular ring that permits the passage of bolus in one direction.
• Both mechanical and chemical digestion take place in the stomach.
• Chyme - Mixture of gastric juices and food.
• Gastric juice - secreted by the special cells in the lining of the stomach
• Hydrochloric acid - softens connective tissue in meat.
• Pepsin - protein-digesting enzyme in an inactive form.
• SMALL INTESTINE

  The longest part of the digestive tract. it is about 3 m in length and 2.5 m in width.
• Duodenal wall - contains glands that secrete large amount of mucus to protect the small intestine from the acidic chyme.
• SMALL INTESTINE

  It is the major organ of chemical digestion and nutrient absorption.
• Villi - fingerlike projections responsible for chemical digestion and nutrient absorption in small intestine.
• LARGE INTESTINE

  Also known as the colon is the last section of the digestive system.
• LARGE INTESTINE

  it is about 6.5 in diameter and about 1.5 in length.
• LARGE INTESTINE

  It is horseshoe-shaped, like an inverted letter U.
• Large Intestine has 3 regions: ascending colon, transverse colon, and descending colon
• ascending colon - extends upward along the right side of the abdomen toward the liver.
• transverse colon - extends across the abdomen.
• descending colon - extends downward on the left side of the abdomen into the pelvis.
• NUTRIENT ABSORPTION

  Food is broken down into smaller, more absorbable parts, including proteins, lipids, carbs, vitamins, and minerals. The body needs certain nutrients for development, maintenance, and proper operation.
• ENERGY PRODUCTION

  The digestive system transforms food into energy that the body uses for a variety of purposes, such as bodily movement, mental processes, and the upkeep of essential organ systems.
• WASTE ELIMINATION

  By means of digestion and excretion, it rids the body of waste and pollutants. By doing this, dangerous compounds that may otherwise accumulate and cause toxicity or disease are avoided.
• WATER BALANCE

  The digestive tract helps the body stay properly hydrated by absorbing water from the food we eat. This is essential for many body processes, such as the transportation of nutrients and the regulation of body temperature.
• Respiration is not a function of the digestive system. True