SCIENCE utut

• Digestive system


  A complex system responsible for breaking down food into nutrients that the body can absorb and utilize for energy, growth, and repair
• Digestive system


  • Involves several organs working together to achieve the process of digestion
• Alimentary canal


  Also known as the gastrointestinal (GI) tract or digestive tract, a long, muscular tube that extends from the mouth to the anus and is the primary pathway through which food passes during the process of digestion
• Organs of the alimentary canal

  • Mouth
  • Pharynx or throat
  • Esophagus
  • Stomach
  • Small intestine
  • Large intestine or colon
  • Rectum
  • Anus
• Mouth


  The "entry point" of the alimentary canal where food is mechanically broken down by chewing (mastication) and mixed with saliva containing enzymes that begin the chemical digestion of complex carbohydrates
• Pharynx or throat


  A muscular tube located behind the mouth and nasal cavity that serves as a passageway for food, liquids, and air, and during swallowing directs food into the esophagus and prevents it from entering the trachea (windpipe)
• Esophagus


  A muscular tube that connects the pharynx (throat) to the stomach and transports swallowed food (bolus) from the mouth to the stomach using rhythmic muscular contractions called peristalsis, with esophageal sphincters at both ends preventing backflow
• Stomach


  A J-shaped organ located below the diaphragm in the upper abdomen that serves as a storage organ for food and secretes gastric juices containing hydrochloric acid and digestive enzymes that break down proteins, with the stomach's muscular contractions churning and mixing food with the gastric juices to form a semi-liquid mixture called chyme
• Small intestine

  A long, coiled tube that extends from the stomach to the large intestine and is the primary site of digestion and nutrient absorption, with the inner surface lined with finger-like projections called "villi" and "microvilli" that increase the surface area for nutrient absorption into the bloodstream
• Large intestine or colon


  A wider tube that follows the small intestine and forms the final part of the alimentary canal, absorbing water and electrolytes from undigested food material to form solid feces, and housing a large population of beneficial bacteria that ferment indigestible carbohydrates
• Rectum


  The final portion of the large intestine where feces or poop are stored until they are expelled from the body
• Anus


  The opening at the end of the digestive tract through which feces are eliminated during defecation
• Accessory glands of the digestive system

  • Salivary glands
  • Liver
  • Gallbladder
  • Pancreas
• Salivary glands


  Located in the mouth and secrete saliva, which contains enzymes (such as amylase) that initiate the breakdown of carbohydrates and mucus that lubricates food for easier swallowing
• Liver


  The largest internal organ, located in the upper right abdomen, that produces bile, a digestive fluid that breaks down fats into smaller droplets to help with digestion and absorption, with bile stored and concentrated in the gallbladder before being released into the small intestine
• Gallbladder


  Located beneath or below the liver, stores and concentrates bile produced by the liver and releases it into the small intestine (duodenum) when there are fatty foods to aid in the digestion and absorption of fats
• Pancreas


  Located behind the stomach, functions as both an endocrine gland (producing hormones such as insulin and glucagon) and an exocrine gland (producing digestive enzymes and bicarbonate), secreting digestive enzymes (such as pancreatic amylase, lipase, and proteases) into the small intestine to break down carbohydrates, fats, and proteins, and producing bicarbonate to neutralize the acidic chyme coming from the stomach
• Stages of digestion


  • Ingestion
  • Digestion
  • Absorption
  • Elimination or defecation
• Ingestion


  The process of taking food into the mouth, where it is initially broken down into smaller pieces through chewing and mixed with saliva to form a bolus that can be easily swallowed
• Digestion


  The process of breaking down food into smaller molecules that can be absorbed by the body, occurring through both mechanical (physical breakdown) and chemical (enzymatic breakdown) processes
• Absorption


  The process where nutrients and other molecules are absorbed from the digestive system into the bloodstream or lymphatic system, primarily occurring in the small intestine where the inner surface is lined with specialized structures called villi and microvilli that increase the surface area for absorption
• Elimination or defecation


  The process of removing indigestible materials (such as fiber and waste products) from the body as feces, with remaining waste material passing into the large intestine where water and electrolytes are absorbed, and feces are then stored in the rectum until expelled through the anus
• Digestive enzymes


  • Amylase
  • Maltase
  • Lactase
  • Sucrase
  • Pepsin
  • Trypsin
  • Lipase
• Amylase


  Breaks down complex carbohydrates such as starches into simple sugars (monosaccharides), found in saliva (salivary amylase) and the pancreas (pancreatic amylase)
• Maltase


  Breaks down maltose (a sugar found in grains) into smaller sugars, found in the small intestine
• Lactase


  Breaks down lactose (the sugar in milk) into simpler sugars, found in the small intestine
• Sucrase


  Breaks down sucrose (table sugar) into simpler sugars, found in the small intestine
• Pepsin


  Helps break down proteins in the stomach into smaller peptides and amino acids, found in the stomach
• Trypsin


  Continues breaking down proteins into smaller peptides and amino acids in the small intestine, produced by the pancreas and released into the small intestine
• Lipase


  Breaks down fats (lipids) into fatty acids and glycerol in the small intestine, produced in the pancreas and works in the small intestine
• Diseases and disorders of the digestive system

  • Gastroesophageal reflux disease (GERD)
  • Gallstones
  • Stomach ulcer / Gastric ulcer
  • Appendicitis
  • Indigestion
  • Constipation
  • Colorectal cancer
• Gastroesophageal reflux disease (GERD)


  Acid in the stomach goes to the esophagus, causing a burning sensation, prevented by having small, frequent meals and avoiding trigger foods, treated with over-the-counter medicines like antacids, H2 blockers, or proton pump inhibitors
• Gallstones


  Hard materials or deposits formed in the gallbladder when there is too much cholesterol or bilirubin, prevented by maintaining a balanced diet low in saturated fats and avoiding rapid weight loss, treated with medications to dissolve the stones or surgical removal of the gallbladder if necessary
• Stomach ulcer / Gastric ulcer


  A painful sore in the stomach lining or small intestine caused by a bacterial infection or long-term use of non-steroidal anti-inflammatory drugs, prevented by a healthy diet and lifestyle, treated with antibiotics and proton pump inhibitor medications
• Appendicitis


  Inflammation of the appendix, often caused by a blockage, requiring immediate medical attention and often surgical removal of the appendix to prevent rupture and life-threatening complications
• Indigestion


  Also known as dyspepsia, a discomfort or pain experienced in the upper abdomen, often caused by overeating, eating too quickly, or consuming certain foods, prevented by consuming smaller, well-balanced meals and treated with over-the-counter medicines
• Constipation


  Difficulty moving the bowels regularly, resulting in hard, small, and difficult to excrete stools, prevented and treated by adding more fiber, fruits, and vegetables to the diet, drinking more water, and exercising
• Colorectal cancer


  A type of cancer that starts in the colon or rectum, often developing from polyps in the lining, prevented by a healthy lifestyle and regular screening, treated with surgery, radiation therapy, chemotherapy, and other methods
• Eat foods that are packed with essential nutrients and fiber, and avoid synthetically processed food or high in refined sugar, carbs, trans fats, saturated fats and food additives
• Eat foods that contain healthy fats in moderation, as the only kind of fat that should be taken is the healthy fat because it makes the food more satisfying