DIGESTIVE SYSTEM

• DIGESTIVE SYSTEM

  • Prepare food for intake by body cells. Nutrients must be broken down by mechanical and chemical means into molecules that are small enough to be

  absorbed into the circulation.
• Ingestion- intake of solid or light food into the stomach. (oral cavity)
•  Mastication- process by which the teeth chew food in the mouth
•  Propulsion- the movement of food form one end of digestive trach to the other.
• [Travel time: 24-36hrs]
• Peristalsis- propels material through most of digestive trach [paano gumalaw yung pagkain sa katawan]
• Swallowing/ deglutition- moves liquid or  soft mass of food and liquid (bolus)  oral cavity-> esophagus
• Mass movement-  contractions that move materials in the distal parts large intestine to anus [palabas ng body]
• Mixing-  don't propel food from the end of the digestive trach. Digestive secrete secretions and help break food/ materials into smaller pieces
• Secretion- food move into digestive trach. Added to lubricate, liquify, buffer, and digest the food
• mucus- secreted along the entire tract lubricates the food and living of the tract]
•  Digestion- breakdown of food in large organic molecules into components parts
• • Absorption- movement of molecules out of digestive trach and into blood or in the lymphatic system
• • Elimination- waste product of digestion are removed from the body
• Feces - semi-solid waste products
• Defecation- process of eliminating waste products from digestive trach
•  Mixing-  don't propel food from the end of the digestive trach. Digestive secrete secretions and help break food/ materials into smaller pieces
• Secretion- food move into digestive trach. Added to lubricate, liquify, buffer, and digest the food [mucus- secreted along the entire tract lubricates the food and living of the tract]
•  Digestion- breakdown of food in large organic molecules into components parts
• Absorption- movement of molecules out of digestive trach and into blood or in the lymphatic system
• Elimination- waste product of digestion are removed from the body
• Feces - semi-solid waste products
• Defecation- process of eliminating waste products from digestive trach
• MECHANICAL DIGESTION

  • physical break down of food into smaller particles.
• CHEMICAL DIGECTION

  • series of hydrolysis reaction that break dietary macromolecules into

   monomers.
• Digestive Tract – muscular tube extending from mouth to anus.
• Living person = 5m/ 16 feet
• Cadaver = 9m/19 feet [ we loss of muscle tone at death]
• *Digestive tract - a protective barrier to those indigestible and harmful materials
• 1. Mucosa : intermost layer

  • Consists of a mucous epithelium, a lamina propria, and a muscularis mucosae
  • Epithelium extends into the lamina propria to form intestinal glands
• 1. Submucosa :lies outside the mucosa

  • Connective tissue layer containing the submucosal plexus, blood vessels [plexus], and small glands [nerves/blood vessel]
• 1. Muscularis : plexus

  • Consists of an inner layer containing a layer of circular smooth muscle and an

  outer layer of longitudinal smooth muscle.
• • Myenteric plexusbetween the 2 muscle layers
• Interstitial - pace maker. Located throughout the myenteric plexus
• 1. Serosa:

  •  Forms the outermost layer of the digestive tract
• Mesenteries – a connective tissue sheets that held abdominal cavity organ in place
•  Lesser Ommentum- necessary connection, lesser curvature of stomach and proximal of the duodenum to liver and diaphragm
•  Greater Ommentum- extending as fold from the greater curvature and then to the transverse colon
•  Omental Bursa- hollow space that is formed by the greater and lesser ommentum
• Vestibule – space between lips or cheeks and teeth