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Anatomy & Physiology II Unit Three . Digestion. The digestive tract is a tubular passage that extends from the lips of the mouth, through the body, and terminates with an anus. This system can be divided into three regions: + oral cavity + pharynx + alimentary canal. Digestion.
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Anatomy & Physiology II Unit Three
Digestion The digestive tract is a tubular passage that extends from the lips of the mouth, through the body, and terminates with an anus This system can be divided into three regions: + oral cavity + pharynx + alimentary canal
Digestion The alimentary canal can be further divided into four segments: + esophagus + stomach + small intestine + large intestine
Digestion Associated with the system are four glands/organs that are located outside the tube, but secrete fluids into the system to aid in digestion: + salivary glands + liver + gall bladder + pancreas
Digestion The function of the digestive system is to mechanically & chemically breakdown food so that nutrients can be obtained through absorption and energy can be released
Digestion Mechanical digestion breaks the food into physically smaller particles, while chemical digestion breaks macromolecules into monomers
Digestion The monomers and other nutrients are now small enough to be absorbed through the wall of the digestive tract and into the bloodstream where they will be distributed to body cells for energy needs and building materials
Oral Digestion Hard palate Uvula Oral structures involved in mechanical digestion: * teeth * tongue * hard palate * cheeks Tonsil Soft palate Tongue Teeth
Oral Digestion Enamel Dentin Canines Incisors Pulp Gingiva Molars Premolars
Oral Digestion Oral structures involved in chemical digestion: * parotid salivary glands * submandibular salivary glands * sublingual salivary glands Parotid salivary gland Submandibular salivary gland Sublingual salivary gland
Oral Digestion Soft palate Uvula Hard palate Structures involved in swallowing: * soft palate & uvula * pharynx * epiglottis * esophagus Pharynx Tonsils Epiglottis Glottis Esophagus
Oral Digestion Deglutition (swallowing)
Alimentary Canal Histology Serosa Mucosa Submucosa Muscularis externa (longitudinal muscle) Muscularis interna (circular muscle)
Alimentary Canal Movements Segmentation Peristalsis
Alimentary Canal Esophagus Diaphragm Stomach
Stomach Diaphragm Esophagus Fundic region Cardiac region Body A aa Lesser curvature Muscle layers Rugae Pyloric antrum Greater curvature Pyloric sphincter
Stomach Wall Rugae Gastric pit Mucosa Gastric gland Submucosa Muscularis layers Serosa
Stomach Wall Cardiac or Pyloric Gland Gastric Gland Mucous cell Parietal cell Chief cell G cell
Stomach Disorders Emesis - the forceful ejection of stomach or duodenal contents Bulimia – eating disorder in which emesis is induced so as to rid the body of the food recently eaten
Stomach Disorders Anorexia – eating disorder in which a person loses their appetite because they believe they are fat Peptic ulcers – erosion of the stomach lining caused by bacteria, aspirin, HCl or pepsin
Accessory Organ Anatomy Liver Common hepatic duct Gall bladder Anterior Posterior
Liver Function The liver carries out a number of functions: > degradation of toxins, drugs, etc. > cleaning bacteria and debris from the blood > produces and secretes plasma proteins
Liver Function The liver carries out a number of functions that concern digestion: > process the monomers of digestion > processes vitamins and iron > produces bile
Liver Function Cirrhosis of the liver is the replacing of liver tissue with connective tissue, reducing the function of the liver
Liver Function Cirrhosis can have several causes: > viral (hepatitis) > drug abuse > trauma
Accessory Organ Anatomy Gall bladder Hepatic ducts Common hepatic duct Common bile duct Cystic duct Hepatopancreatic duct Pancreatic duct Pancreas Hepatopancreatic sphincter Duodenum
Small Intestine Physiology Villus Microvilli (brush border) Capillaries Lacteal
Large Intestine Disorders Diverticulitis Diarrhea Constipation Flatulence