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22 Cards in this Set
- Front
- Back
what are the two structures of the digestive system?
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-The gastrointestinal tract (GI tract)
The pathway from the mouth to the anus -Accessory digestive organs Organs involved in grinding food or providing digestive secretions -Salivary glands -Liver -Gallbladder -Pancreas |
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what is the function of the GI tract?
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-digest food
-absorb nutrients and water into the blood -and eliminate waste |
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what are Components of the gastrointestinal tract?
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-Mouth-site where food is moistened and chewed
-Esophagus-tube leading to the stomach -Stomach-secretes HCI, enzyme: pepsin -Small intestine-digestion and absorption of nutrients -Large intestine (colon) – completes absorption of nutrients: water, steroids, and minerals -Rectum and anus eliminate waste |
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describe the normal biota of the digestive system? where is it?
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-Tongue, teeth, small intestine, colon, rectum
-Heavily colonized with various bacteria -Oral cavity contains up to 700 different bacterial species -Esophagus, stomach, duodenum -“Almost sterile” –how can that be? -HCI in stomach; peristalsis and the rapid transport of food helps prevent colonization by microbes |
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what is tooth decay? and its dangers?
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Dental Caries (tooth Decay)
-Accumulation of microbes on the surface of the teeth is called dental plaque – biofilm -The plaque is made up of streptococci (Streptococcus mutans) and filamentous bacteria Actinomyces -Bacteria hydrolyze the sucrose into glucose and fructose -Then glucose is used to synthesize dextran (gummy polysaccharide) -Inside the plaque, bacteria ferment the fructose into lactic acid. Lactic acid damages the enamel of the tooth -Bacteria invade the dentin -Bacterial population inside the dentin is composed of Gr+ bacilli and filamentous bacteria (about 300 bacterial species are indentified) -If not treated, the tooth decay advances to pulp and roots (contain blood vessels and nerves) -The infection can spread to the neighboring soft tissue -Prevention of dental caries – reducing the amount of sucrose in the diet and, proper brushing and flossing |
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What is periodontal disease?
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-Initial Stage – gingivitis
-Symptoms: swelling, bleeding of gingival, formation of pockets -Advanced stage – periodontitis -Symptoms: tissue destruction, formation of deep pockets, build up of calculus (deposits of CaCO3) loosening of teeth, bone loss |
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Describe mumps.
-cause -symptoms -effects - treatment |
-Mumps virus – paramyxovirus
-Disease of parotid (salivary) gland (located below the ears) -The virus is acquired by respiratory rout -Symptoms: swelling of parotid gland fever, pains during swelling -Complications: inflammation of testis (possibly sterility), meningitis, inflammation of ovaries -Available vaccine (MMR) |
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what is the virulence factors of mumps.
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Virulence factors:
-The virus induces the infected cell to fuse with the adjacent cell – a large multinucleate cell is formed (syncytia) -The virus particles freely pass from one cell to another – evading the antibodies |
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Describe Gastric ulcer
-cause -symptoms -effects |
-Lesions in the mucus membrane of the stomach
-Caused by Helicobacter pylori -The bacterium can survive in the acidic environment in the stomach by producing urease that neutralizes the acid -H. polyri causes destruction of the protective mucus layer that leads to the period to the wall -Symptoms : Abdominal burning pain |
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How do is Helicobacter diagnosed?
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Visually by endoscopy – a flexible tube is inserted through the mouth into the stomach
-ELISA test – blood is tested for the presence of antibodies against Helicobacter |
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describe Salmonellosis
- cause -effects -treatment - incubation period - source of infection |
-Caused by Salmonella –Gr-, facultative anaerobic rods, there are about 2000 serotyps
-Bacteria invade the intestinal mucous membrane. From there they can enter the lymphatic system. -Incubation time is 12-36h but it depends on the number of cells ingested. -Recovery – after few days, typically self-limited infection -Antibiotics not effective -Source of infection: poultry, eggs, egg products |
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describe . Typhoid fever
- cause -incubation period -symptoms -treatment |
Typhoid fever
-Caused by Salmonella typhi -Bacteria multiply in phagocytic cells. They can be found in blood, urine feces. -Incubation period is up to 3 weeks. -Symptoms: Headache, high fever, and diarrhea (after 2nd week) -Susceptibility: Travel in areas with poor sanitation -Patients can become chronic carriers of the diseases. They shed bacteria from their gall bladder. -Treatment: Antimicrobial drugs |
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Describe Shigellosis (Bacillary Dysentry)
-cause -symptoms -treatment |
Shigellosis (Bacillary Dysentry)
-Caused by Shigella – facultative anaerobic Gr negative rods -Bacteria multiply int eh small intestine in the cells of mucous membrane -Produce the shiga toxin -Symptoms: severe diarrhea with blood in stool, abdominal cramps and fever. -Treatment: Fluid and electrotype replacement and antimicrobial treatment |
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describe Cholera
- cause -symptoms -treatment - mortality rate |
-Causative agent: Vibrio cholera, slightly curved rod with a single polar flagellum
-The bacterium grows on the epithelial cells in the small intestine (does not enter the host cell) -Produces entertoxin. The enterotoxin causes excessive secretion of water and electrolytes. -Symptoms: severe diarrhea with sudden loss of fluids, which results in shock, collapse, and even death. -The blood becomes very vicious. -Treatment: replacing lost fluid and electrolytes, tetracycline -Mortality rate: -Untreated; 50% -Treated: 1% |
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describe Cryptosporidiosis
cause source of infection symptoms treatment |
-Cryptosporidium hominis (infects humans)
-Contracted by ingestion of the oocysts; drinking or recreational water -Water contamination – animal waste -Oocysts develop into sporozoits- embed in the epithelial cells of the intestine -Symptoms: diarrhea -Treatment: usually not required in the case of healthy individuals; antidiarrheal agent |
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Describe Staphylococcal food poisoning
-cause - source of disease -symptoms -treatment |
-Caused by Staphylococcus aureus – lives in nasal cavity
-Food provides favorable environment (if left in room temperature) for multiplication of bacteria -S. aureus can outgrow other competing bacteria (tolerates higher osmotic pressure, higher temperatures, low moisture level). -Foods such as custards, sauces, processed meats – contaminated and left unrefrigerated -Toxins are released. Taste and smell of the food is not altered -Further cooking can eliminate bacteria by not the toxin -The toxin damages the tissues -Symptoms of intoxication: abdominal cramps, vomiting, and diarrhea -The disease is self-limiting, recovery within 24h |
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describe Amoebic dysentery
-cause - symptoms -diagnosis -treatment |
_-Causative agent: Entamoeba histolytica
-Contracted by ingestion of cysts in contaminated water -Trophozoits released from the cysts – multiply in the epithelial cells of large intestine- causing ulcers -Severe dysentery (blood in stool) -Can spread to other organs (liver) -Diagnosis: serological tests, fluorescent antibody tests -Treatment: metronidazoie |
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what is hepatitis?
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-Hepatitis is an inflammation of the liver caused by an infection with viruses
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what viruses cause hepatitis?
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There are five known viruses that can cause hepatitis: Hepatitis A, B, C, D, E)
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What are symptoms of hepatitis?
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-Symptoms include jaundice, abdominal pain, fatigue, nausea, vomiting, appetite loss
Jaundice – yellowing of skin and the whites of eyes |
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Describe hepatitis A. ( what i had..)
-cause -transmission -symptoms -treatment |
-Causative agent: Single stranded RNA virus, no envelope
-Infection is acquired via oral rout (fecal contamination of food, water, and oysters) -In 50% of cases symptoms are subclinical -Symptoms: anorexia, nausea, fever, abdominal discomfort, fever, and chills, and jaundice -Vaccine is available |
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Describe hepatitis B.
-cause -transmission -symptoms -treatment |
-Causative agent: Hepatitis B virus (HBV) , double stranded DNA virus with the envelope.
-Transmission: break in the skin- body fluids (blood, saliva, breast milk, and semen) -Multiples exclusively in the liver -Symptoms; loss of appetite, fever, joint pains, and jaundice -10% of patients become carriers (reservoirs of the disease). They are more likely to get liver cancer. -Vaccination recommended for health care professionals and other high-risk groups. -Vaccine is obtained by genetic engineering. |