Science (Digestive System)_Isaac

• Digestion - the breakdown of organic compound into their simple form. It break down food chemically and physically.
• Process of Digestion

  1. Ingestion
  2. Digestion
  3. Absorption
  4. Assimilation
  5. Excretion
  6. Egestion
• Ingestion - Is the first process, where the food or any substance is taken into the body through the mouth
• Mouth - The journey of food
• Digestion - Is the second process, it involves the break down of large food molecules for easy absorption of cells
• Teeth - While the food is in the mouth, the teeth crush, cut, and break it apart into tiny pieces
• Tongue - Mixes the food with saliva to make it easier to swallow.
• Salivary Glands - Secretes Salivary amylase that helps with digestion
• Bolus - Moist Ball
• Process of Mastication (Chewing)
• Saliva contains salivary amylase
• Esophagus - muscular tube that connects the mouth to the stomach
• Peristalsis - wave-like muscle contraction
• Peristalsis push and transport foods liquid in small section to the stomach
• Stomach - J-shape, bag-like muscular organ that can hold approximately one litter of fluid and food
• Chyme - semifluid material formed from bolus that is acted upon by the gastric juices secreted by the stomach
• The walls of the stomach have special cells that secrete gastric juices like hydrochloric acid and pepsin that begins the chemical breakdown of protein
• Liver, pancreas, gall bladder, helps in secretion of essential substances
• Liver - produces bile, a green fluid the turns large fat droplets into smaller ones and stores them in the gall bladder
• Pancreas - makes three different kinds of enzymes namely amylase, peptidase, and lipase released through a pancreatic duct that aid in the digestion of all three organic compounds such as carbohydrates, proteins, and fats respectively
• The liver is the biggest organ inside the body with a mass of about two kilograms
• Gall Bladder - A small pear-shaped sac that can hold about 50ml of bile
• The pancreas is a small organ found below the stomach
• The process takes about half of a liter of digestive juices each day
• Small Intestine - has three parts: duodenum, jejunum, and ileum
• Duodenum - Is the first and shortest part of the small intestine that starts at the lower end of the stomach and extends for about 20 cm to 25 cm in lenght
• Carbohydrates - are broken down into sugars by enzymes like amylase, maltase, and lactase
• Proteins - are broken down into amino acids by enzymes like trypsin and peptidase
• Fats - are broken down into fatty acids by enzymes like lipase
• Secretion - The production and release of enzymes and acids in the digestive system
• Jejunum - Second part of the small intestine that is 2.5 cm in lenght
• Absorption - Is the third process that happens in the digestive system
• Assimilation - Is the fourth process that occurs in the digestive system
• Microvilli - Microscopic cellular membrane projections that serves to expand the surface area for diffusion and also to lessen any increase in volume

  
• Ileum - Third part of the small intestine which is about 3.5 meters in length. Its main function is the assimilation (absorption) of B12 and the re-assimilation (reabsorption) of conjugated bile salts
• Large Intestine - Divided into caecum, ascending colon, transverse colon, descending colon, and sigmoid colon. Reabsorption of liquid, electrolytes and some vitamins from the indigested food takes place
• Rectum - the last part of the large intestine, where faeces are stored and absorbed
• Anus - the opening of the digestive system that allows feces to leave the body
• Villi - tiny, finger-like projections from the epithelial lining of the intestinal wall

  A) Villi

  
• PARTS

  A) MOUTH

  B) SALIVARY GLANDS

  C) ESOPHAGUS

  D) LIVER

  E) STOMACH

  F) GALL BLADDER

  G) PANCREAS