Science_4th Part 1

• Digestive System


  The food you eat takes an incredible journey through your body, from top (your mouth) to bottom (your anus). Along the way the beneficial parts of your food are absorbed, giving you energy and nutrients.
• Gastrointestinal (GI) tract

  • Mouth
  • Esophagus
  • Stomach
  • Small intestine
  • Large intestine
  • Anus
• Gastrointestinal (GI) tract The organs that make up your GI tract, in the order that they are connected, include your mouth, esophagus, stomach, small intestine, large intestine and anus
• Biliary system

  • Liver
  • Gallbladder
  • Pancreas
  • Bile ducts
• The epiglottis is a small flap that folds over your windpipe as you swallow to prevent you from choking 


  A series of muscular contractions within the esophagus called peristalsis delivers food to your stomach.
• The sphincter then contracts and prevents the contents of the stomach from flowing back into the esophagus.


  A ring-like muscle at the bottom of your esophagus called the lower esophageal sphincter has to relax to let the food in
• The stomach is a hollow organ, or "container," that holds food while it is being mixed with stomach enzymes. These enzymes continue the process of breaking down food into a usable form.


  Small intestine

  Made up of three segments — the duodenum, jejunum, and ileum
• The jejunum and ileum lower in the intestine are mainly responsible for the absorption of nutrients into the bloodstream.


  The duodenum is the first segment of the small intestine. It’s largely responsible for the continuous breaking-down process.
• The pancreas secretes digestive enzymes into the duodenum that break down protein, fats and carbohydrates.


  The Liver

  Process the nutrients absorbed from the small intestine. Bile from the liver secreted into the small intestine also plays an important role in digesting fat and some vitamins.
• The colon is responsible for processing waste so that emptying your bowels is easy and convenient


  The gallbladder stores and concentrates bile from the liver, and then releases it into the duodenum in the small intestine to help absorb and digest fats.
• The colon is made up of the cecum, the ascending (right) colon, the transverse (across) colon, the descending (left) colon, and the sigmoid colon, which connects to the rectum.


  Stool is stored in the sigmoid (S-shaped) colon until a "mass movement" empties it into the rectum once or twice a day.
• The rectum's job is to receive stool from the colon, let you know that there is stool to be evacuated (pooped out) and to hold the stool until evacuation happens.  


  The Anus

  is a 2-inch long canal consisting of the pelvic floor muscles and the two anal sphincters (internal and external)
• Intestinal villi are tiny, finger-like projections made up of cells that line the entire length of your small intestine. 


  Salivary gland, any of the organs that secrete saliva, a substance that moistens and softens food, into the oral cavity of vertebrates.
• The parotid glands are salivary glands that sit just in front of the ears.


  The sublingual gland is the smallest of the three major salivary glands
• The sublingual gland is the smallest of the three major salivary glands 


  Submandibular glands:Located below your jaw, your submandibular salivary glands