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190 Cards in this Set
- Front
- Back
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What makes up the alimentary canal?
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oral cavity, pharynx, esophagus, stomach , small intestine and large intestine.
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What are "accessory organs?
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organs that aid in digestion but are not part of the alimentary canal
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what are the accessory organs?
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pancreas, gallbladder, liver, salivary glands, teeth and tongue
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what chemical begins digestion in the mouth?
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amylase
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what does amylase break down?
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starch
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what good does saliva do?
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cleanses the teeth, aids in swallowing, andinitiating digestion.
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how much saliva is produced daily?
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800 to 1500 ml
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what is the pH of saliva? what controls it?
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between 6 and 7
under parasympathetic control |
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what are the three paired glands in the mouth?
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the parotid, submandibular, and sublingual gland
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where is the parotid gland?
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in front of the ear bwetween the skin and masseter muscle
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what is the percent of secretion and what does the parotid gland secrete?
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20% of secretion
serous fluid-enzyme |
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Where is the submandibular gland?
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midway along the inner side of the jaw
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what does the submandibular gland produce and how much of secretion?
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produces serous and mucous, and produces 60% of secretion
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where is the sublingual gland?
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under the mucosa in the floor of the mouth
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what and how much does the sublingual gland produce?
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serous and mucous 20%
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What is the mumps?
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A viral disease of the parotid salivary gland
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What is parotitis?
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inflammation of parotid gland
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what is Ptyalocele?
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cystic tumor of a salivary gland
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How many taste buds do humans have and how many taste cells does each contain?
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4000 taste buds
30 to 100 taste cells |
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How long is the esophagus and where is located?
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it is 10 to 12 inches long and is located behind the trachea
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What is at the lower end of the esophagus and what is its purpose?
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a sphincter which prevents stomach acid from entering the esophagus
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What is heartburn?
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the regurgitation of gastric contents into the esophagus
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what happens with Achalasia?
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the lower esophageal sphincter (cardiac sphincter)fails to relax
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What are the symptoms of achalasia?
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Dysphagia (difficulty swallowing)
substernal pain food may remain in esophagus for hours |
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what causes achalasia?
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abnormal parasympathetic stimulation
drinking cold liquids emotional stress excess gastrin secretion |
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what is an esophageal tumor?
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carcinoma is a common condition causing obstruction of the esophagus and accounting for about 2% of all carner deaths in the US
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What is an Hiatal hernia?
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it is the protrusion of the upper part of the stomach through the diaphragm and into the thorax
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what are symptoms of an hiatal hernia?
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gastroesophageal reflux, dysphagia, heartburn, and epigastic pain
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What functin, other than storage does the stomach have?
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it prepares the bolus by mechanically mising the food, saliva, and gastric juices to form chyme.
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what is absorbed from the stomach? why?
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because of tight juncions, very little absorption takes places except a small amount of water and some drugs (aspirin and alcohol)
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WHat do mucus cells in the stomach do?
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secrete mucus
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what is the purpose of mucus in the stomach?
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protects the stomach lining
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what do zymogenic cells secrete?
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pepsinogen
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what does pepsinogen do?
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in the acidic condition of the stomach pepsinogen becomes pepsin, which digests proteins
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what do pareital cells secrete?
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HCL and INtrinsic factor
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what is hte normal pH in the stomach?
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2
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What does HCl do in the stomach?
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kills bacteria in food and converts pepsinogen to pepsin
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what does intrinsic factor do?
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allows the ileum of the small intestine to absorn vitamin B12 which is required for erythopoises
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what does the pyloric sphincter do?
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permits passage of chyme and prevents backflow of chyme
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what is pyloric stenosis?
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narrowing of the pyloric sphincter caused by enlargement of circular muscle filbers
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what is the major symptom of pyloric stenosis?
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projectile vomiting.
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What cuases a peptic ulcer?
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lining of the stomach, esophagus or duodenum is attached and digested by HCl and pepsin.
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Where does a gastric ulcer occur?
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in the stomach
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where does a duodenal ulcer occur?
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in the first part of the small intestine (duodenum)
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where does an esophageal ulcer occur?
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in the lower part of the esophagus
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what is the significance of Helicobacter pylori (H. Pylori)?
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according to david Bjorkman this bacteria causes ulcers and is hard to kill with antibiotics
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what causes vommiting?
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relaxation of the cardiac sphincter and strong contraction of the diaphragm and abdominal muscles
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how long is the small intestine?
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20 feet long
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what is the description and pH of the intestinal juice?
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clear fluid with a pH of about 7.6
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What takes place in the small intestines?
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90% of all absorption
produces enzymes to digest all three major food materials |
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where are Brunner's glands located and what do they do?
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they are in the first part of the duodenum and secrete mucus so protect the SI from the gastric juice.
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WHat are the three divisions of the small intestine?
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Duodenum, Jejunum, and Ileum
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what enzyme does the SI produce to digest proteins?
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Peptidase
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what enzyme does the SI produce to digest carbohydrates?
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carbohydrase
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what enzyme does the SI produce to digest fats or lipids?
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Lipase
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Does the small intestine recieve secretions from any other organs?
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yes, the pancreas and the gall bladder send enzymes to help in digestion
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what is the surface area of the small intestine?
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it is about the size of a tennes court
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Where is the large intestine?
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it extends from the ileum of the small intestine to the anus divided structurally into the cecum, colon, and anal canal
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What are the functions of the large intestine?
(2) |
absorption of water and elctrolytes from food materials, storage and expulsion of feces from digestive
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what are the major causes of diahrea?
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infection of the lower GI tract and nervous stimulation
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what causes constipation?
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a diet that lacks roughage and water and fiber
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What happens in an apendicitis?
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the apendix becomes infected and causes severe pain in right abdominal region, swelling
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What is another name for irritable bowel syndrome?
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spastic colitis
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WHat are the symptoms of IBT?
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abdominal discomfort, irregular bowel function, and loud gurgling sounds
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what is believed to cause IBT?
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emotional stress
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what is a colostomy?
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a surgical procedure in which an abdominal exit is made for the colon
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what is dysentery?
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inflammation of intestinal mucosa with bleeding and mucus discharge with the stools.
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What is the largest gland of the body?
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the liver, it weighs about 3 pounds
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what do the lobules in the liver contain?
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cells called hepatocytes that produce bile
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what do hepatocytes produce?
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bile
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why is bile necessary?
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it emulsifies and digests fat
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what stores iron and copper from the breakdown of erythrocytes?
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the liver
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what is produced when erythrocytes break down?
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iron and copper
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what does the liver do with glucose?
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stores it as glycogen and converts it back to glucose when it is needed
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what does the liver do with vitamins?
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synthesises them, stores, and releases them
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what does liver have to do with blood clotting?
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it makes fibrinogen and prothrombin
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what process is used in the liver with foreign material in blood?
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phagocytosis
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what organ is repsonsible for blood detox?
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liver
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where are plasma proteins synthesized? what are examples of these?
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liver. examples are albumin, fibrinogen, angiotensinogen
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what it cirrhosis?
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a condition in which normal liver epithelium is replaced by connective tissue causing blockage of sunusoids.
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what may cause cirrhosis?
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alcohol and malnutrition
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what is hepatitis?
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inflammation of the liver caused by viruses, protozoa, and bacteria, or by the absorption of toxic materials
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what are two types of hepatitis?
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serum and infectious
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what is jaundice?
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yellowish coloration of the skin and mucous membranes due to excessive accumulation of free or conjugated bilirubin
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What are the 3 primary responsibilities of the gall bladder?
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stores, concentrates, and releases bile
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how much bile does the liver secrete a day?
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600-1000 ml
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how much bile can the gall bladder store?
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30-70 ml
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How does the gall bladder store all of the bile secreted by the liver?
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it concentrates the bile solution byt absorption of water, sodium, chloride, and other electorlytes
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what does the gall bladder use to concentrate bile?
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water, sodium, chloride, and other electrolytes
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why is bile essential?
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bile acts as an emulsifier that breaks globulets in fats into smaller particles, these small particles increase the surface area making the fat more digestible by lipase
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where and when is bile released by the gall bladder?
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it is released into the duodenum as the gallbladder contracts forcibly and the sphincter of ampulla relaxes.
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what does the intestinal mucosa release when fat or partially digested proteins are present in the SI?
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cholecystokinin
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what does cholecystokinin do?
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it passes via the blood to the gallbladder and stimulates contration of the gallbladder muscles which then releases bile
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what kind of contraction regulates bile release in the gall bladder?
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rhythmical contraction
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what helps to relax the sphincter of ampulla in regulating the release of bile from the gall bladder?
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peristaltic waves of the duodenum
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where and when is bile released by the gall bladder?
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it is released into the duodenum as the gallbladder contracts forcibly and the sphincter of ampulla relaxes.
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what does the intestinal mucosa release when fat or partially digested proteins are present in the SI?
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cholecystokinin
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what does cholecystokinin do?
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it passes via the blood to the gallbladder and stimulates contration of the gallbladder muscles which then releases bile
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what kind of contraction regulates bile release in the gall bladder?
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rhythmical contraction
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what helps to relax the sphincter of ampulla in regulating the release of bile from the gall bladder?
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peristaltic waves of the duodenum
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what are gallstones
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the percipitation of substances contained in bile, mainly cholesterol and bilirubin
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what in regards to cholesterol contributes to formation of gallstones?
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cholesterol becomes hyperconcentrated in the bile
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what are the 3 factors leading to hyperconcentrated cholesterol in the bile?
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stasis of bile
high levles of cholesterol in the blood inflammation of the gall bladder |
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who is more likely to have gallstones?
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obese, middle-aged, have diabetes, or are female
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what is the endocrine function of the pancrease?
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secretion of insulin and glucagon into the blood
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what is the exocrine function of the pancreas?
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secretion of digestive enzymes into the small intestine
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what is the pH of the fluid released by the pancreas?
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7.1 to 8.2
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how much fluid is released by the pancreas?
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1200-1500 ml each day
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what does bicarbonate do?
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neutralizes acid that enters the intestines from the stomach and provides and environment in which the pancreatic enzymes can function
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when do peptidases or proteolytic enzymes become active?
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after entering the intestinal tract
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Why do peptidases or proteolytic enzymes take so long to become active?
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so they do not digest the pancreas
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what is Acute Pancreatitis?
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a damaged pancreas build a pool of secretions in damaged areas. the trypsin inhibitor becomes overwhelmed and the secretions digest the entire pancreas in a few hours
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What increases nervous regulation of gastric secretion?
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parasympathetic activity (vagus nerve)
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what does nervous regulation of gastric secretion do? 3 things
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increase gastric juice secretion
increase contraction-peristalsis and segmentation increase release of gastrin |
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How do hormones regulate gastric secretion?
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gastrin is released which increases gastric juice secretion and peristalsis
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what will stimulate the secretion of gastrin?
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food entering the stomach
partially digested proteins alcohol, caffeine histamine, calcium |
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what two hormones secreted by the small intestine regulate pancreatic secretion?
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Secretin and cholecystokinin
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where and why is secretin secreted?
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it is secreted from "s" cells in the SI when there is a drop i the pH in the duodenum because of acid from the stomach
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what does secretin do?
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it travels in the blood to the pancreas where it causes the secretion of pancreatic juice rich in bicarbonate
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why is cholecystokinin released?
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it is released when proteins, fats, and fatty acids enter the small intestine.
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What does cholecystokinin do?
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it stimulates the secretion of pancreatic juice rich in enzymes to aid in digestion
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from where is acetycholine (ACH) released?
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it is released from the parasympathetic system
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what does acetycholine (ACH) do?
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stimutlates pancreatic secretion
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where is amylase made?
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in the salivary glands and pancreas
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where does amylase funcion?
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in the mouth and small intestine
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what does amylase do?
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hydrolyzes starch to maltose
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where is maltase made?
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intestinal glands
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where does maltase function?
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small intestine
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what does maltase do?
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breaks down maltose into 2 glcoses
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where is sucrase made?
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intestinal glands
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what does sucrase do?
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hydrolyzes sucrose to glucose and fructose
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where does sucrase function?
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small intestine
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where is lactase made?
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intestinal glands
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what does lactase do?
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hydrolyzes lactose to glucose and galactose
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where does lactase function?
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small intestine
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where is pepsin made?
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gastric glands
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where does pepsin function?
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stomach
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what does pepsin do?
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hydrolyzes specific peptide bonds
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where is trypsin made?
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pancreas
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where does trypsin function?
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small intestine
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what does trypsin do?
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hydrolyzes specific peptide bonds and converts chymotrypsinogen to chymotrypsin
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where is chymotrypsin made?
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pancreas
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where is chymotrypsin effective?
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small intestine
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what does chymotrypsin do?
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hydrolyzes specific peptide bonds
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where is carboxypeptidease made?
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pancrease
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where does carboxypeptidase function?
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small intestine
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what does carboxypeptidase do?
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hydrolyzes terminal peptide bond at carbosyl end
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where is aminopeptidase made?
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intestinal glands
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where is aminopeptidase function?
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small intestine
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what does aminopeptidase do?
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hydrolyzes terminal peptide bond at amino end
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where is dipeptidase made?
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intestinal gland
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where does dipeptidase function?
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small intestine
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what does dipeptidase do?
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hydrolyzes pairs of amino acids
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where is enterokinase made?
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intestinal glands
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where does enterokinase funcition?
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small intestine
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what does enterokinase do?
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converts trypsinogen to trypin
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where is bile made
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liver
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where does bile function?
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small intestine
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what does bile do?
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emlusifies fat
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where is lipase made?
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pancreas and small intestine
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where does lipase what is anabolism?function?
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small intestine
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what does lipase do?
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hydrolyzes lipids
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what is anabolism?
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construction of complex molecules from simple buiding blocks
ex. biosynthesis of proteins |
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what is catabolism?
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the breakind down process
ex. glycolysis |
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what is digestion?
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the act of breaking down food small enough so it can be absorbed into blood stream
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what do proteins break down to?
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amino acids
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what do fats break down to?
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fatty acids and glycerol
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what do carbohydrates break down to?
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monosaccharides
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what three major sources of carbohydrates exist in the normal diet?
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sucrose, lactose, and starches
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what is the process of breaking down fat?
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bile emulsifies fat into fat globules and then lipase breaks those down into glycerol and fatty acids
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what is the process of breaking down proteins:
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proteins are broken into polypeptides and then get broken into small polypeptides and amino acids
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how is food material absorbed from the gut into the body?
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active transport and diffusion
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what increases the rate of transport of glucose into most cells in the body?
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insulin
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what is glycogen?
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many glucose molecules stuck together end to end
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what is the process of making glycogen from glucose?
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glycogenesis
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what is the process of making glucose out of glycogen?
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glycogenolysis
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what is glucose catabolism?
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the act of breaking down one molecule of glucose to get ATP
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what are the different parts of glucose catabolism?
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glycolysis, cell respiration, pyruvate decarboxylation, krebs cycle, electron transport chain.
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what is glycolysis?
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the splitting of glucose into two molecules of pyruvic acid with a net gain of only 2 ATP
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Under anaerobic conditions how many ATP are gained?
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2 because oxygen is needed for cell respiration so it must stop at glycolysis
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what is pyruvate decarboxylation?
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the process of two pyruvic acid molecules being converted into two molecules of acteyl coenzyme A (acetyl CoA)
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what happens in the krebs or citric acid cycle?
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acetyl protion of acetyl CoA is degraded to carobon dioxide and hydrogen atoms
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where do the krebs cycle reaction occur?
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mitochondria
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what happens to to the hydrogen atoms produced by the krebs cycle?
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they are oxiized by the electron transport chain to release much more ATP
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what is the net result of the krebs cycle?
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16 hydrogen atoms and 2 ATP for each molecule of glucose
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what happens in the electron transport chain?
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oxidation of the hydrogens take place
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how much ATP is produced by the end of glucose catablism?
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36
2 in glycolysis 2 in krebs cycle 32 in ETC |
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how many calories in our diet are derived from fats?
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40-45%
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what is acetoacetic acid? t
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it is when large quantities of fatty acids are broken down into acteyl CoA which condense to form it
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when is acetoacetic acid formed
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usually dluring periods of starvation
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