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Two portions of digestive system
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Terms in this set (78)
Two portions of digestive system
Alimentary canal and accessory organs
What does alimentary canal consist of?
mouth, pharynx, esophagus, stomach, small intestine, large intestine, anal canal
what are the accessory organs of the digestive system?
salivary glands, liver, gallbladder, pancreas
4 layers of alimentary canal
mucosa, submucosa, muscularis externa, serosa
which layer does food have direct contact with
mucosa
layer that has blood vessels, lymphatics and glands
submucosa
layer that contains circular and longitudinal layers & moves tubes (motility) and food materials
muscularis externa
visceral peritoneum layer, right on top of organs within abdominal cavity; most superficial layer
serosa
type of movement that moves materials in one direction; propels food particles down the tract in wavelike motion
peristalsis
first part of alimentary canal
mouth/oral cavity
mechanical breakdown of solid particles, mixes them with salivamastication/chewingfunctions as an organ of speech and sensory receptionmouth/oral cavityforms the lateral walls of the mouth; contains muscles for facial expression and chewing; inner lining of stratified squamous epithelium (moist)cheekssurrounds the mouth opening; forms a seal to keep food in and unwanted things out; helps form words; associated with sphincter#1 (oral sphincter/orbicularis oris)lipshelps move food within the mouth and to the next organ (pharynx) when swallowing; involved with sense of tastetonguevisible bumps on the tongue where the taste buds are containedlingual papillaemoistens food particles and makes it possible for food to be swallowedsalivary glandswhat enzyme begins chemical digestion of carbohydratessalivary amylasewhat enzyme begins chemical digestion of lipidssalivary lipasekeeps pH favorable for enzyme activity and protects teeth from acidic foodsbicarbonate ions3 pairs of major salivary glandsparotid, submandibular, sublingualmuscular food passageway from the pharynx to the stomachesophagussphincter #2upper esophageal sphinctersphincter #3lower esophageal/cardiac sphincterfunction of sphincter #3regulates food passage into stomach, and closes to prevent regurgitation of foodfolds of mucosa and submucosa that allow for distention as the stomach fills with foodrugae/gastric foldorgan that initiates chemical digestion of proteinsstomachdoes mechanical digestion that the oral cavity did not finish , moves food into small intestine after it becomes chymestomachlayers of smooth muscle in the stomachinner circular layer, outer longitudinal layer, some portions have a third layer of oblique layersportions of the stomachcardia, fundus, body, pylorusportion of stomach that contains lower esophageal sphinctercardiatemporary food storage, which sometimes contain swallowed airfundussphincter #4pyloric sphincterfunction of pyloric sphinctercontrols gastric emptyinginactive form of pepsin; secreted by chief cellspepsinogenbreaks down proteins into polypeptides, forms in presence of hydrochloric acidpepsinfat splitting enzymegastric lipaseproduced by parietal cells; converts pepsinogen into pepsinhydrochloric acidsecreted by mucus cells; provides lubrication and protects stomach liningmucusproduced by parietal cells; required for absorption of vitamin B12intrinsic factorneural regulation that decreases gastric activitysympathetic impulsesneural regulation that increases gastric activity; promotes release of histamine, which stimulates gastric & intestinal secretion and motilityparasympathetic impulseshormone that comes from stomach and stimulates stomach to increase gastric juice secretion and gastric motilitygastrinHormone release by small intestine cells that decreases gastric motility and stimulates gallbladder to contract and release bile & stimulates pancreas to release enzymes to the small intestinecholecystokinin (CCK)Hormone released by small intestine in response to acid, stimulates pancreas to release bicarbonate to the small intestine which allows for optimum pH for enzymes that work in the small intestinesecretinwhat controls the vomiting centermedulla oblongatacontains enzymes that digest carbohydrates, fats, lipids, proteins, and nucleic acidspancreatic juicecomponents of pancreatic juicepancreatic amylase, pancreatic lipase, trypsin, chymotrypsin, carboxypeptidase, bicarbonate ionslargest internal organliverfunctions of livermakes bile process recently absorbed nutrients detoxify certain substances screening station for pathogensReceives chyme from stomach, liver, and pancreatic secretionsThesmall intestinethe site of MOST of our nutrient absorptionsmall intestineenzymes in the membranes of the microvillipeptidases, sucrase/maltase/lactase, lipasebreak down peptides into amino acidspeptidasesbreak down disaccharides into monosaccharidessucrase, maltase, lactasebreaks down fats into fatty acids and glycerollipaseabsorbs some water and electrolytes; MUCUS FACTORY; forms and stores feceslarge intestineparts of the large intestinececum, colon, rectum, anal canalsphincter #5ileocecal sphincter/ileocecal valveportions of colonascending, transverse, descending, and sigmoidsphincters that guard anusinternal and external anal sphincters75% of feces composed of -waterfunction of the digestive systembreakdown food into smaller substances excrete wastesmajor function of lipstemperature sensor help keep food in mouth as you chewbegins mechanical digestion of foodmouthbegins chemical digestion of foodmouthbegins chemical digestion of proteinsstomachenzyme that begins the chemical digestion of proteinspepsinsite of most nutrient absorptionsmall intestinestimulates the gallbladder to contractCCKfunction of tonguesensory for taste move food within oral cavityfunction of gallbladderstore bileteeth shaped mainly for cutting and slicing foodincisorsfinger-like projections from the wall of the small intestine to enhance surface areavillimajor function of the large intestinereabsorb watersphincter between stomach and small intestinepyloric sphincterlayer of the GI wall that covers the outer surface of each organserosamajor function of salivanecessary for sense of taste necessary to promote swallowing