Digestive System

• Mouth-Food starts its journey from the mouth or the oral cavity
• Teeth-grinding food particles into small pieces and are moistened with saliva before the tongue pushes the food into the pharynx
• Pharynx

  -fibromuscular y-shaped tube attached to the terminal end of the mouth

  -passage of chewed/crushed food from the mouth through the esophagus
• The Pharynx has a major part in the respiratory system, as air travels through the pharynx from the nasal cavity on its way to the lungs.
• Esophagus

  -This is a muscular tube that connects the pharynx, which is a part of an upper section of the gastrointestinal tract.
• Esophagus-Located in your throat near your trachea (windpipe), the esophagus receives food from your mouth when you swallow.
• Epiglottis

  -small flap that folds over your windpipe as you swallow to prevent you from choking (when food goes into your windpipe).
• Peristalsis

  -series of muscular contractions within the esophagus that delivers food to your stomach.
• Lower esophageal sphincter -But first a ring-like muscle at the bottom of your esophagus, has to relax to let the food in.
• Lower esophageal sphincter-The sphincter then contracts and prevents the contents of the stomach from flowing back into the esophagus.
• Stomach

  -muscular bag which is situated towards the left side of the abdominal cavity, beneath the diaphragm.
• Stomach-storage for the food and provides enough time to digest meals.
• Stomach-produces digestive enzymes and hydrochloric acid that maintains the process of digestion.
• • Mucous: It is an aqueous secretion produced by the mucous membranes.

  -It functions by protecting the stomach lining and gastric pits from the acid, which is produced by the glands to destroy the bacteria that entered along with the food particles.
• • Digestive enzymes: They are the group of enzymes which functions by breaking down polymeric macromolecules like biopolymers into their smaller and simpler substances.
• • Hydrochloric acid: It is the digestive fluid formed by the stomach during the process of digestion. It functions by destroying harmful microorganisms present in the food particles.
• Small Intestine

  -Contents of the small intestine start out semi-solid, and end in a liquid form after passing through the organ. 
• • Small Intestine- Water, bile, enzymes and mucus contribute to the change in consistency. Once the nutrients have been absorbed and the leftover-food residue liquid has passed through the small intestine, it then moves on to the large intestine, or colon.
• Small Intestine- 22-foot long muscular tube that breaks down food using enzymes released by the pancreas and bile from the liver.
• 3 segments of the small intestine

  Duodenum

  Jejunum

  Ileum
• • Duodenum-first segment of the small intestine. It’s largely responsible for the continuous breaking-down process.
• Jejunum and ileum lower- absorption of nutrients into the bloodstream.
• Large Intestine/Colon

  -processing waste so that emptying the bowels is easy and convenient.
• • Large Intestine/Colon- 6-foot long muscular tube that connects the small intestine to the rectum.
• Large Intestine -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.
• Rectum 

  -Waste products are passed into the end of the large intestine eliminated out of the body as a solid matter called stool.
• Rectum-It is stored in the rectum as semi-solid feces which later exits from the body through the anal canal through the process of defecation.
• Anus-The anus is the last part of the digestive tract.
• Anus-It is a 2-inch long canal consisting of the pelvic floor muscles and the two anal sphincters (internal and external).
• Anus-When we get an urge to go to the bathroom, we rely on our external sphincter to hold the stool until reaching a toilet, where it then relaxes to release the contents.