BIO - The Digestive System

baejuhyeoned's version from 2018-01-09 10:21


Question Answer
(1) Ingest food, (2) Break down food, (3) Absorb molecules, (4) Get rid of wastesFunctions of the Digestive System
Alimentary Canal & Accessory Digestive OrgansMain Divisions of the Digestive System
Alimentary CanalContinuous, muscular digestive tube winding throughout the body
Alimentary CanalDigests and absorbs food particles
Alimentary CanalContains Mouth, Pharynx, Esophagus, Stomach, Small and Large Intestines
Accessory Digestive OrgansContains Teeth, Tongue, Gallbladder, Salivary Glands, Liver, and Pancreas
(1) Ingestion, (2) Propulsion, (3) Mechanical digestion, (4) Chemical digestion, (5) Absorption, (6) DefecationDigestive Processes
Peristalsis alternate waves of muscular contraction and relaxation in the primary digestive organs. The end result is to squeeze food from one part of the system to the next.
Mechanical Digestionphysical preparation of food for digestion.
Segmentationmixing of food in the intestines with digestive juices.
Chemical Digestion- Carbohydrates, Fat, and Proteins are broken down by enzymes.
Absorptiontransfer of the digested portion of food into the blood from the digestive canal.
Defecationremoval/elimination of the waste products from the body.
Buccal/oral cavityFunction of the Mouth
Mouth Contains stratified squamous epithelium
Vestibulearea bounded by lips and cheeks
Lipsposses no sweat or oil glands
Palateforms roof of the mouth, soft and hard palate, uvula
TongueHelps grind food into a bolus which contains partially digested food and saliva
Tongue Helps form words and is a sensory organ for taste
(1) Filiform papillae, (2) Fungiform papillae, (3) Circumvallate papillaeThree surface features of tongue
Filiform papillae roughness and grip
Fungiform papillaecontains taste buds
Circumvallate papillaecontains taste buds
Salivary GlandsProduces and secretes saliva
Salivary GlandsCleanses the mouth
Salivary GlandsDissolves food chemicals so they can be tasted
Salivary GlandsMoistens food, compacting it into a bolus
Salivary GlandsBegins the chemical breakdown of food
Salivary amylaseStarch
(1) Submandibular Glands, (2) Sublingual Glands, (3) Parotid GlandsTypes of Salivary Glands
Submandibular Glands Found underneath the mandible
Sublingual GlandsFound underneath the tongue
Parotid GlandsFound anterior to the ear between masseter and skin
TeethBreak food into smaller parts, increasing surface area for digestion
Deciduous Teeth & Permanent TeethTypes of Teeth
Deciduous Teeth Also called as baby teeth
Incisorscutting and shredding (type of teeth)
Caninespiercing and tearing (type of teeth)
Molarsgrinding (type of teeth)
Premolarsgrinding and crushing (type of teeth)
Crown & RootTooth Structure
Crownexposed portion of tooth covered by enamel which covers dentin
Root internal portion that is beneath the gums (gingiva) and is anchored by periodontal ligaments
Deglutition swallowing
Oropharynx and Laryngopharynx are common passageways for food and air
Pharynxcontains stratified squamous epithelium (friction-resistant)
EsophagusMuscular tube that propels food to stomach
Esophageal glands produce mucus to lubricate bolus
Esophageal sphincter prevents backflow into oral cavity
Cardiac sphincter prevents backflow into esophagus
StomachTemporary storage area for food and allows it to mix with gastric juice to produce chyme
cardiac, fundus, body, and pyloricRegions of stomach
Greater and Lesser Curvatures connected to greater and lesser omentums
Rugae foldsongitudinal folds in stomach wall - mucous b/w folds
Simple columnar epitheliumcontains gastric pits that secrete gastric juices
Goblet cellssecrete mucus that coats stomach and prevents it from being digested itself
Parietal cellssecrete hydrochloric acid and intrinsic factor
Chief cellssecrete pepsinogen which is converted to pepsin to aid in protein digestion
Enteroendocrine cellsrelease hormones such as: Histamine, Serotonin, Gastrin, Endorphins, and Somatostatin
Cephalic Phase, Gastric Phase, & Intestinal PhaseDigestive Processes in the Stomach
Cephalic PhaseStimulated by the thought, sight, taste, or aroma or food
Cephalic PhaseInputs from olfactory receptors and taste buds travel to parasympathetic enteric ganglia which then stimulate stomach glands
Gastric PhaseStomach distension activates stretch receptors
Gastric PhaseFood chemicals (e.g. peptides, rising pH) activate chemoreceptors which activate G cells which secrete gastrin
Intestinal PhasePresence of low pH and partially digested foods in duodenum stimulates intestinal gastrin secretion
Small IntestineReceives chyme from stomach; performs majority of digestion and absorption of nutrients
Duodenum, Jejunum/Ileum, Plicae circulares3 Regions of Small Intestine
Duodenumupper region receiving chyme from stomach and digestive enzymes from pancreas and bile from liver and gallbladder
Jejunum/Ileumlower regions where absorption occurs
Plicae circularespermanent folds in mucosa and submucosa that slow movement of chyme
Villifingerlike projections that increase the surface area of the SI
Microvillitiny projections on the plasma membranes of columnar cells that appear fuzzy
Crypts of Lieberkuhnsecrete intestinal juice and special lysozymes that protect against bacteria
Peyer’s Patchesaggregated lymphoid tissues containing lymphocytes
LiverLargest internal organ
LiverFilters and processes nutrient-rich blood of carbohydrates, proteins, and lipids from intestine
LiverProduction and regulation of cholesterol
LiverProduction of bile which emulsifies fats
LiverRemoves drugs and hormones from circulation
LiverStorage of vitamins and minerals
Liver Lobulesstructural unit of liver
Hepatocytesliver cells contained within the lobules
Liver Lobulesstructural unit of liver
Hepatocytesliver cells contained within the lobules
Hepatic portal vein & Hepatic Arterythe circulation of the liver, they bring blood into the liver where it is filtered through the liver sinusoidal capillaries
Kupffer cellsremove debris
Blood supplyreceives fresh O2 blood from hepatic artery
Blood supplyreceives deoxygenated blood with nutrients (from small intestine)
Bile ducts are present at every portal triad
Bilirubinthe chief bile pigment, a waste product of the heme of hemoglobin formed during the breakdown of worn-out erythrocytes
Large IntestineReabsorption of remaining water and electrolytes
Large IntestineProduction and absorption of Vitamins B and K
Teniae Colibands of smooth muscle that create pocket-like sacs (haustra)
Cecumsac-like connection between the small and large intestines
Appendixsmall structure containing lymphoid tissue; small immune function
Rectumstorage area
Anusregulates defecation with two sphincter muscles; internal and external
Goblet cellsproduce mucus for lubrication of feces
Bacterial florasynthesize vitamin B and most of the vitamin K needed for blood clotting
Peptic ulcersgastric and duodenal, caused by Helicobacter pylori, NSAIDS, Hcl hypersecretion
Cirrohsisscarred liver due to chronic inflammation
Borborygmusrumbling noise caused by gas through intestines
Cholecystitisinflammation of gall bladder
Colitisinflammation of colon
Dysphagiadifficulty in swallowing
Enteritisinflammation of the intestines (Flatuation/erucation)

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