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58 Cards in this Set
- Front
- Back
Four tunics of the intestinal tract and predominant tissue type of each |
1. Mucosa - simple columnar epithelium 2. Submucosa - areolar connective tissue 3. Muscularis externa - smooth muscle 4. Serosa - areolar connective tissue covered by simple squamous epithelium |
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5 essential activities of digestive system |
1. Ingestion 2. Chemical Digestion 3. Mechanical digestion 4. Absorption 5. Defacation |
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6 parts of alimentary canal |
1. Mouth 2. Pharynx 3. Esophagus 4. Stomach 5. Small intestine 6. Large intestine |
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6 accessory digestive organs |
1. Teeth 2. Tongue 3. Gallbladder 4. Salivary glands 5. Liver 6. Pancreas |
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Three functions of the mucosa |
1. Secretion of mucous 2. Absorption of the end products of digestion 3. Protection against infectious disease |
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Three layers of mucosa and functions |
1. Epithelium - secretes mucous for protection and to ease movement, stomach and small intestine mucosa contain enzyme secreting cells and hormone secreting cells. 2. Lamina propria - nourishes epithelium and collects nutrients, contains lymph nodes (part of MALT) 3. Muscularis mucosae - smooth muscle that produces ridges to increase surface area. |
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Composition and function of submucosa |
Dense connective tissue containing elastic fibers, blood and lymphatic vessels, lymph nodes, and nerves |
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Function of muscularis externa |
Responsible for peristalsis and segmentation |
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Function of serosa |
Protective visceral peritoneum |
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Where does digestion begin for carbs, proteins, and lipids? |
Carbs: mouth (amylase) Protein: stomach (pepsin) Lipid: small intestine (lipase) |
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How many deciduous teeth? How many permanent? |
Deciduous: 20 Permanent: 32 |
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Structure of a tooth |
Crown is part above gumline, root is part below, neck is where they meet. Enamel covers crown, it's the hardest substance in the body. Dentin is the bone like living material, makes up majority of tooth (made by odontoblasts). Pulp cavity contains blood vessels and nerves. Cementing - calcified connective tissue covering root and anchoring it to periodontal ligament. Periodontal ligament anchors tooth to jaw. |
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Purpose of salivary glands |
1. Cleanse the mouth 2. Dissolve food chemicals for taste 3. Moisten food and help form it into bolus 4. Contains amylase to begin digestion of carbs. |
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Three pairs of extrinsic salivary glands |
1. Parotid (anterior to ear) 2. Submandibular (medial aspect of madibular body) 3. Sublingual (under tongue) |
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Two major components of saliva |
1. Water 2. Amylase |
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Mastication |
Chewing |
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Deglutition |
Swallowing |
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Anatomy of the stomach |
Muscularis - layer of oblique muscle that physically churns and mixes food, breaking it down Epithelial lining - Includes goblet cells that produce a coat of alkaline mucous. Mucous layer traps bicarb rich fluid beneath it. Gastric pits - contain gastric glands that secrete gastric juice, mucus and gastrin
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Gastric glands and their secretions |
1. Mucous neck cells - secrete acid mucous 2. Parietal cells - secrete HCl and intrinsic factor (absorption of B12) 3. Chief cells - produce pepsinogen which is activated to pepsin by HCl in the stomach and pepsin itself via a positive feedback mechanism |
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Functions of stomach |
1. Change bolus into chyme 2. Chemical breakdown of proteins |
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Small intestine |
7 feet long, running from pyloric sphincter to ileocecal valve. Three subdivisions: duodenum (12 inches), jejunum (2 1/2 ft.), and ilium (3 1/2 ft.). Bile duct and main pancreatic duct join duodenum at hepatopancreatic ampulla and are controlled by sphincter of Oddi. Modifications of intestinal wall (plicae circularis, villi, and microvilli) increase surface area. Function is mainly absorption. |
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Peyer's patches |
Found in submucosa of small intestine and protect against bacteria. |
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Brunner's glands |
Located in duodenum, secrete alkaline mucous to neutralize acidic chyme. |
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Three major phases of gastric secretion |
1. Cephalic phase - experiencing food through smell, sight, or sound. 2. Gastric phase - the food hits your stomach. This part takes 4 to 6 hours. Fats slow down the process. 3. Intestinal phase - chyme enters duodenum 3 mL at a time and encourages gastric gland activity. |
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Pancreatic secretions |
Amylase, protease, lipase, nuclease, tripsin |
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Gallbladder function |
Storage tank for bile |
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Liver function |
Detoxification of chemicals coming from the stomach and small intestine |
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Anatomy of liver |
Hexagonal shaped liver lobules. Portal triads at corners of each liver mobile. Contain bile duct, hepatic artery, and hepatic portal vein. Liver sinusoids are enlarged capillaries between hepatic plates. Hepatocytes produce bile, process bloodborne nutrients, store fat soluble vitamins, and detoxification. |
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CCK function |
Relaxes the hepatopancreatic sphincter so it releases secretions into duodenum and causes gallbladder to contract and secrete bile. |
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Secretin function |
Produces increased amount of bicarb from pancreas to neutralize acidic chyme |
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Large intestine |
Not essential for life, just for comfort. Subdivided into cecum, appendix, colon, rectum, and anal canal. |
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Sphincters of rectum and anus |
Teniae coli are bands of smooth muscle that fold colon into pouches called haustra, epiploic appendages are fat filled pouches of mesentary. |
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Mesentary |
Double sheet of serous membrane that hold parts of GI tract in place. |
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Types of nutrients |
1. Carbohydrates 2. Proteins 3. Lipids 4. Vitamins 5. Minerals 6. Water |
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Calories per gram |
4 calories per gram for carbs and proteins, 9 calories per gram for fats |
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Water soluble vitamins |
B and C |
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Fat soluble vitamins |
A, D, E, and K |
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Why are vitamins important? |
They work as coenzymes |
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Monosaccharide glucose |
Most important source of bodily fuel |
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Most important polysaccharide |
Glycogen |
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Complete vs. Incomplete proteins |
Animal sources are complete, plant sources are missing one or more essential amino acids and must be combined to form complete proteins. |
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Proteins |
Not an effective way to generate ATP or create glucose. Protein requirement .8 grams per kg of body weight per day. |
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Heat promotion mechanism |
Shivering |
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Absorptive state |
• Insulin is major hormone • Anabolism - putting things together • Glycogenesis - glucose converted to glycogen • Lipogenesis - glycerol and fatty acids are converted to fat • protein synthesis |
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Post absorptive state |
• Glucagon • Metabolism • Glycogenolysis - glycogen is converted to glucose • Gluconeogenesis (Fat is converted to glycerol and fatty acids. Deamination proteins - not a good way to produce ATP or generate glucose) |
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After a meal is digested: |
1. ATP stores are filled first 2. Glycogen stores are filled 3. Fat |
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Metabolism |
The sum total of all chemical reactions that occur in the body. |
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Gluconeogenesis |
Creation of glucose from non carbohydrate sources (using fats and proteins) - ineffective |
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Glycolysis |
Breaking down fats |
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Beta oxidation |
Breaking down fatty acid chains two by two by two. Occurs in mitochondria. |
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Lipogenesis |
Putting glycerol and fatty acids together to make fat |
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Glycogenolysis |
Breaking down glycogen |
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Glycogenesis |
Making glycogen |
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Deamination |
Take the amine group off and convert it to urea |
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Lipoproteins |
1. vLDLs - transport triglycerides from the liver to peripheral tissue cells 2. LDLs - transport cholesterol from the liver to peripheral tissues 3. HDLs - mostly proteins. Leave empty and sop up excess triglycerides and cholesterol and return them to the liver. |
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What is cholesterol good for? |
Stabilizes cell membrane, precursor to steroid hormones |
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Hydrolysis |
Enzymatic breakdown of food |
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Bile |
Made of cholesterol, bile salts, bilirubin, etc. Stored in gallbladder. |