The Digestive System Section 38-2 Organs and their functions The action of insulin and glucagon

Can you name some parts of the digestive system?

Label the diagram… Common bile duct Esophagus Duodenum Liver Salivary gland Tongue Trachea Appendix Gall bladder Esophagus Liver Stomach Pancreas Colon Rectum Anus Pancreatic duct

Parts Mouth Esophagus Stomach Small Intestine Large Intestine Rectum tongue teeth salivary glands Esophagus Peristalsis Stomach Small Intestine Liver (bile) Pancreas Gall Bladder Large Intestine Rectum

Mouth Mechanical Teeth (28-32) Tongue (taste) Chemical incisors (cutting) cuspids bicuspids molars (grind) Tongue (taste) Chemical Salivary Glands (3) starch digestion (amylases) lubricates food allows speech lysozyme (antibacterial)

Pharynx Common chamber for the ….. Digestive system (food into the esophagus) Respiratory system (air into the trachea) Epiglottis (LT side Two - Chapter 11)

Esophagus Peristalsis Peristalsis continues further down…. the contraction of smooth muscles: this forces food (a bolus) forward involuntary muscles Peristalsis continues further down….

Stomach Mechanical churns mixes stores food! Chyme is what results (partially digested food in the stomach) Chemical only protein(pepsin) Gastric Glands(3) pepsinogen acid(HCl, antibacterial) mucus

Sphincters - valves Cardiac sphincter pyloric sphincter

Diagram Back to diagram… valves Gall bladder liver pancreas Does food pass through the liver, gall bladder, pancreas, duodenum? Duodenum

Small Intestine Role of liver Role of gall bladder Role of pancreas Does food actually pass through these organs? 3 sections: 1st called duodenum

Liver Makes Bile emulsifies fat not digestion not an enzyme it is the breaking of fat into droplets

Gall Bladder Stores bile

Pancreas Two roles: hormones and digestive enzymes Digestive enzymes act on all food groups... fat protein carbohydrate nucleic acids Hormones will be discussed later.

Small Intestine (cont.) Cells in the walls secrete more enzymes villi and microvilli increased surface area with capillaries (sugars, amino acids) with lymph vessels (lacteals) (fatty acids) What is the relationship between the cell and microvilli? Microvilli are on the membrane of the cells of the small intestine.

Large Intestine Reabsorption of water Bacteria produce B-vitamins

Rectum Storage and elimination of solid waste THE END…….

Credits Mary Wang ‘03 - typist, stomach diagram Mr. Nelson - editing, content