question

What are the 8 main segments of the gastrointestinal tract?

answer

mouth esophagus stomach small intestine large intestine rectum anus

question

What are the 4 accessory organs?

answer

salivary glands liver gallbladder pancreas

question

Defenses against a heavy load of microorganisms:

answer

Heavy load of mucus Secretory IgA Peristalsis (movement of intestines) keeps microbes moving Saliva: lysozyme, lactoferrin Stomach: extremely low pH Bile is antimicrobial GALT (gut-associated lymphoid tissue)

question

Microbial composition _ between individuals. Oral cavity: _ species of bacteria. Esophagus and stomach: _ species of organisms. Large intestine: _ microbes per gram of contents; where most microbes are found. Accessory organs: _ of resident organisms; liver, gallbladder, salivary glands, pancreas.

answer

varies 600 200 10^11 free

question

Functions of normal gut biota: (3)

answer

Protective function Aid digestion and provide nutrients A diverse gut microbiome is associated with health

question

defenses of the oral cavity

answer

saliva secretory IgA lysozyme tonsils adenoids

question

defenses of the rest of the gastrointestinal tract

answer

GALT lymphoid tissue peyer's patches appendix secretory IgA rich normal biota

question

What are the 2 types of diseases of the gastrointestinal tract?

answer

nonhelminthic helminthic

question

Nonhelminthic diseases of the gastrointestinal tract: (7)

answer

Teeth and Gums Salivary Glands Gastric Infections Acute Diarrhea with or without vomiting Acute Diarrhea with vomiting Chronic Diarrhea Hepatitis

question

not lasting longer than 2 weeks

answer

acute

question

lasting longer than 2 weeks

answer

chronic

question

Helminthic disease of the Gastrointestinal tract (8)

answer

Whipworm Pinworm Tapeworm Giant intestinal roundworm Hookworm Liver flukes Trichinosis Schistosomiasis

question

Helminthic infections are caused by _.

answer

worms

question

most common infectious disease of human beings

answer

dental caries

question

Dissolution of the tooth surface due to the metabolic action of bacteria Results in minor to complete disruption of enamel

answer

dental caries

question

What are the main causative agents of dental caries (cavities)?

answer

Streptococcus mutans Streptococcus sobrinus

question

Dental caries incidence varies according to _ consumption, _ hygiene, and _ factors.

answer

carbohydrate oral genetic

question

What is the most common mode of transmission for dental caries?

answer

direct contact

question

What are the virulence factors or dental caries?

answer

adhesion acid production

question

What are 2 prevention techniques against dental caries?

answer

oral hygiene fluoride supplementation

question

What is the treatment for dental caries?

answer

removal of diseased tooth material

question

Epidemiological features of dental caries: _-_% prevalence in school-aged children.

answer

60-90

question

Periodontitis is a _ to dental caries.

answer

sequelae

question

first phase in periodontal disease

answer

gingivitis

question

Swelling, loss of normal contour, patches of redness, and increased bleeding Spaces or pockets develop between the tooth and gingiva Disease extends into the periodontal membrane and cementum Deeper involvement increases the size of pockets, causes bone resorption, and tooth loss

answer

gingivitis (periodontitis)

question

"trench mouth" (WWI poor oral hygiene) severe pain bleeding pseudomembrane formation necrosis

answer

Necrotizing Ulcerative Gingivitis and Periodontitis

question

Gingivitis and periodontitis synergistic infections include: (3)

answer

Treponema vincentii Prevotella intermedia Fusobacterium species

question

Periodontitis causative agents include: (3)

answer

tannerella forsythia aggregatibacter actinomycetemcomitans porphyromonas gingivalis

question

What are the virulence factors of periodontal disease? (2)

answer

induction of inflammation enzymatic destruction of tissues

question

Prevention of periodontal disease:

answer

oral hygiene

question

Treatment of periodontal disease:

answer

removal of plaque/calculus gum restoration possibly anti-inflammatory treatments

question

Epidemiological features of periodontal disease in the U.S.: smokers= _% nonsmokers=_% internationally: _-_% of all adults

answer

11 2 10-15

question

Causative agents of Necrotizing Ulcerative Gingivitis and Periodontitis: (3)

answer

treponema vincentii prevotella intermedia fusobacterium species

question

Virulence factors of Necrotizing Ulcerative Gingivitis and Periodontitis: (2)

answer

inflammation invasiveness

question

Prevention against Necrotizing Ulcerative Gingivitis and Periodontitis:

answer

oral hygiene

question

Treatment of Necrotizing Ulcerative Gingivitis and Periodontitis: (2)

answer

debridement of damaged tissue possibly antibiotics

question

Nasal discharge, muscle pain, malaise Inflammation of the salivary glands producing gopherlike swelling of cheeks Can invade other organs: testes, ovaries, pancreas, meninges, heart, and kidney

answer

mumps

question

20 - 30% of young adult males, Mumps localizes in the epididymis and testes, but does not cause _.

answer

sterility

question

Mumps can be prevented by the _ vaccine.

answer

MMR

question

Causative agent of mumps

answer

mumps virus (genus paramyxovirus)

question

Most common mode of transmission for mumps:

answer

droplet contact

question

Virulence factors of mumps:

answer

spike-induced syncytium formation

question

Culture/Diagnosis for mumps:

answer

clinical fluorescent Ag tests ELISA for Ab

question

Prevention against mumps:

answer

MMR live attenuated vaccine

question

Treatment for mumps:

answer

supportive

question

Epidemiological features of mumps US: fluctuates between a few _ and a few _ a year internationally: epidemic peaks every _-_ years

answer

hundred/thousand 2-5

question

sharp or burning pain emanating from the abdomen

answer

Gastritis

question

lesions on the stomach or uppermost portion of the small intestine

answer

gastric/peptic ulcers

question

Causative agent of Gastritis and Gastric Ulcers:

answer

helicobacter pylori

question

Helicobacter pylori infects _ of world's population.

answer

1/2

question

Virulence factors of Gastritis and Gastric Ulcers:

answer

adehesions urease

question

Culture/Diagnosis of Gastritis and Gastric Ulcers:

answer

endoscopy urea breath test stool antigen test

question

Prevention for Gastritis and Gastric Ulcers:

answer

none

question

Treatment for Gastritis and Gastric Ulcers:

answer

amoxicillin followed by clarithromycin and tinidazole

question

Epidemiological features of Gastritis and Gastric ulcers: US: infection rates at _% of adults internationally: infection rates at _%

answer

35 50

question

Defined as 3 or more loose stools in a 24 hour period

answer

Acute Diarrhea (With or Without Vomiting)

question

Statistics of Diarrhea: US: average of _ - _ cases per person per year. _ transmitted by contaminated food. In tropical countries, children experience _ episodes per year. More than _ children die from diarrhea per year, mostly in developing countries.

answer

1.2-1.9 1/3 10 3 M

question

Enteric fever or gastroenteritis: can range from mild diarrhea to fever and septicemia Typhoid fever: progressive, invasive infection that eventually leads to septicemia characterized by fever, diarrhea, and abdominal pain Ability to cause disease is dependent on its ability to adhere to gut mucosa Has a high ID50

answer

Signs and symptoms of salmonella

question

_ cases and _ deaths a year due to Salmonella.

answer

1.2 M 500

question

Gram-negative straight rods, nonmotile, and non-endospore-forming Frequent, watery stools, and intense abdominal pain, Dysentery

answer

shigella

question

most severe form of shigella

answer

shigella dysenteriae

question

Shigella _ and Shigella _ cause 20,000-25,000 cases per year, half in children.

answer

sonnei flexerni

question

diarrhea containing blood

answer

dysentery

question

Shigella invades the _ cells of the _ _, but does not perforate the intestine or invade the blood.

answer

villus large intestine

question

Shigella invades villus cells of the large intestine as well as release _, causing fever.

answer

endotoxin

question

affects the entire GI tract, damages the mucosa and villi, and gives rise to bleeding and secretion of mucus (shigella)

answer

enterotoxin

question

responsible for more serious damage to the intestine as well as systemic effects (shigella)

answer

shiga toxin

question

Symptoms of Shigella range from mild gastroenteritis to fever with bloody diarrhea with the Shiga-Toxin-Producing E. coli, _.

answer

E. coli O157:H7

question

severe hemolytic anemia that can cause kidney damage and failure

answer

Hemolytic uremic syndrome

question

Toxins identical to shiga toxins produced by Shigella

answer

E. coli O157:H7

question

Transmission through the ingestion of undercooked beef and other contaminated foods and beverages

answer

E. coli O157:H7

question

traveler's diarrhea, watery diarrhea, low-grade fever, nausea, and vomiting

answer

Enterotoxigenic E. coli

question

bacillary dysentery, blood and mucus in the stool, more common in developing countries

answer

Enteroinvasive E. coli

question

profuse, watery diarrhea, with fever and vomiting, produce effacement of gut surfaces

answer

Enteropathogenic E. coli

question

causes diarrhea in young patients and AIDS patients

answer

Enteroaggregative E. coli

question

typically associated with the development of urinary tract infections; may play a role in inflammatory bowel disease

answer

Diffusely adherent E. coli

question

most common cause of bacterial diarrhea in the United States

answer

Campylobacter

question

Frequent watery stools, fever, vomiting, headaches, and severe abdominal pain Symptoms may last longer than 2 weeks

answer

Campylobacter

question

Slender, curved or spiral gram-negative bacteria with polar flagella

answer

Campylobacter

question

Microaerophilic inhabitants of the intestinal tracts of animals and humans

answer

Campylobacter

question

Gram-positive endospore-forming rod found as normal biota of the intestine. Pseudomembranous colitis, antibiotic-associated colitis Precipitated by therapy with broad-spectrum antibiotics Enterotoxins A and B cause necrosis in the wall of the intestine

answer

Clostridium difficile

question

Treatment of Clostridium difficile: (3)

answer

Withdrawal of antibiotics, replacement of fluids Metronidazole Fecal transplant

question

Comma-shaped rod with single polar flagellum

answer

Vibrio cholerae

question

Vomiting, copious watery feces, "rice-water stool" Fluid losses of 1 liter per hour in severe cases Loss of blood volume, acidosis, potassium depletion, muscle cramps, severe thirst, flaccid skin, and sunken eyes, leading to convulsions and coma Hypotension, tachycardia, cyanosis, shock

answer

Vibrio cholerae

question

Vibrio cholerae has a _ - _% mortality rate.

answer

55-70

question

disrupts the normal physiology of intestinal cells, causing them to shed large amounts of electrolytes into the intestine

answer

Cholera toxin

question

Pathogenesis and virulence factor of Vibrio cholerae:

answer

Cholera toxin

question

Transmission and epidemiology of Vibrio cholerae:

answer

Warm, monsoon, alkaline, and saline conditions favor growth of vibrio

question

Treatment of Vibrio cholerae:

answer

Oral rehydration therapy

question

Intestinal apicomplexan protozoan Hardy intestinal oocyst as well as a tissue phase Penetrates intestinal cell walls and lives intracellularly Oocysts are highly infectious and resistant to chlorine treatment

answer

Cryptosporidium

question

Outbreaks of Cryptosporidium are associated with _.

answer

swimming pools

question

Symptoms of crytosporidiosis generally begin _-_ days (average _ days) after becoming infected with the parasite.

answer

2-10 7

question

Symptoms of crytosporidiosis include: (7)

answer

watery diarrhea stomach cramps or pain dehydration nausea vomiting fever weight loss

question

Double-stranded RNA genome with both an inner and outer capsid

answer

Rotavirus

question

primary cause of morbidity and mortality resulting from diarrhea

answer

rotavirus

question

_-_ million cases per year of rotavirus. _ hospitalizations.

answer

2-3 700,000

question

Rotavirus is transmitted by:

answer

fecal-oral route

question

Treatment for rotavirus includes:

answer

oral rehydration therapy fluid replacement

question

_ and _ are vaccines that are available to prevent against rotavirus.

answer

Rotarix RotaTeq

question

a type of fluid replacement used to prevent and treat dehydration, especially that due to diarrhea Therapy should routinely include the use of zinc supplements. Use of oral rehydration therapy decreases the risk of death from diarrhea by about 93%.

answer

Oral rehydration therapy (ORT)

question

involves drinking water with modest amounts of sugar and salts; can be given by a nasogastric tube

answer

Oral rehydration therapy (ORT)

question

Oral rehydration therapy should routinely include the use of _ supplements.

answer

zinc

question

Use of oral rehydration therapy decreases the risk of death from diarrhea by about _%.

answer

93

question

Most common viral cause of food-borne disease in the United States

answer

norovirus

question

Profuse, watery diarrhea for 3 - 5 days, vomiting in the early stages Low infectious dose: 1 - 20 viruses

answer

norovirus

question

Norovirus has many outbreaks associated with _.

answer

cruise ships

question

Transmission for Norovirus:

answer

Fecal-oral transmission or via contamination of food and water

question

Nausea and vomiting accompanied by diarrhea, often companions that shared a meal suffer the same fate Symptoms in the gut caused by a preformed toxin Occasionally comes from nonmicrobial sources such as fish, shellfish, or mushrooms Intoxication rather than infection

answer

food poisoning

question

Associated with custards, sauces, cream pastries, processed meats, chicken salad, or ham

answer

Staphylococcus aureus Exotoxin

question

Staphylococcus aureus thrives due to high _ tolerance.

answer

salt

question

_ is heat stable and induces symptoms of cramping, nausea, vomiting, and diarrhea in food poisoning. Onset within 1 - 6 hours, recovery within 24 hours Self-limiting, antibiotics not warranted

answer

Enterotoxin

question

The onset of Staphylococcus aureus Exotoxin is within _-_ hours, and recovery is within _ hours.

answer

1-6 24

question

Staphylococcus aureus Exotoxin are _-_, antibiotics not warranted.

answer

self limiting

question

Sporulating gram-positive bacterium that lives in the soil

answer

Bacillus cereus Exotoxin

question

Emetic form most frequently tied to fried rice that has been cooked and kept warm for long periods of time

answer

Bacillus cereus Exotoxin

question

Diarrheal form associated with cooked meats or vegetables held at a warm temperature for long periods of time (Profuse, watery diarrhea that lasts about 24 hours)

answer

Bacillus cereus Exotoxin

question

Also the causative agent of gas gangrene

answer

Clostridium perfringens Exotoxin

question

Contaminates meat, fish, and vegetables and beans that have not been cooked properly

answer

Clostridium perfringens Exotoxin

question

Endospores germinate in foods, C. perfringens cells enter the _ and release exotoxin.

answer

small intestine

question

Abdominal pain, diarrhea and nausea lasting 8 - 16 hours Also causes enterocolitis similar to that caused by C. difficile

answer

Clostridium perfringens Exotoxin

question

Diarrhea lasting longer than 14 days Can have an infectious or noninfectious cause Irritable bowel syndrome, ulcerative colitis AIDS patients universally suffer from *THIS*

answer

Chronic Diarrhea

question

Associated with chronic disease, particularly in children and those who are malnourished. Adheres to human cells in aggregates rather than single cells Stimulates large amounts of mucus in the gut Transmission through food and water

answer

Enteroaggregative E. coli

question

Cyclospora cayetanensis is a _.

answer

protozoan

question

Emerging pathogen; numerous outbreaks in the US and Canada in the past years

answer

Cyclospora cayetanensis:

question

Fecal-oral transmission and through the consumption of fresh produce and water contaminated with feces Oocysts are not observable in the feces, but can be visualized when exposed to UV light

answer

Cyclospora cayetanensis

question

Symptoms: watery diarrhea, stomach cramps, bloating, fever, muscle aches

answer

Cyclospora cayetanensis

question

People become infected with Cyclospora by ingesting _, which are the infected form of the parasite. This most commonly occurs when food or water contaminated with feces is consumed. An infected person sheds unsporulated (immature, non-infective) Cyclospora oocysts in the feces.

answer

spoulated oocysts

question

The oocysts are thought to require days to weeks in favorable environmental conditions to _ (become infective). Therefore, direct person-to-person transmission is unlikely, as is transmission via ingestion of newly contaminated food or water.

answer

sporulated

question

Pathogenic flagellated protozoan

answer

Giardia

question

Signs and symptoms: diarrhea of long duration, abdominal pain, flatulence, greasy, malodorous stools

answer

Giardia

question

Complex epidemiological pattern Isolated from beavers, cattle, coyotes, cats, and human carriers

answer

Giardia

question

Giardia cysts survive for up to _ months in the environment Epidemics traced to water from mountain streams as well as chlorinated municipal water.

answer

2

question

_ infection is an intestinal infection marked by abdominal cramps, bloating, nausea and bouts of watery diarrhea. *This* is caused by a microscopic parasite that is found worldwide, especially in areas with poor sanitation and unsafe water.

answer

Giardia

question

Exists in intestinal and extraintestinal form

answer

Entamoeba

question

Targets the cecum, appendix, colon, and rectum Actively penetrates deeper layers of mucosa Dysentery, Abdominal pain, diarrhea, fever, and weight loss Can lead to hemorrhage, perforation, appendicitis, and amoebomas Humans are primary hosts; infection through food and water contaminated with cysts

answer

Entamoeba

question

_ is a disease caused by the parasite Entamoeba histolytica. It can affect anyone, althought it is more common in people who live in tropical areas with poor sanitary conditions.

answer

Amebiasis

question

Diagnosis of _ can be difficult because other parasites can look very similar to E. histolytica when seen under a microscope

answer

Amebiasis

question

Inflammatory disease of the liver

answer

hepatitis

question

Necrosis of hepatocytes

answer

hepatitis

question

Response by mononuclear white blood cells that swells and disrupts the liver architecture

answer

hepatitis

question

Interferes with excretion of bile pigments and causes bilirubin to accumulate in blood and tissues, causing jaundice

answer

hepatitis

question

Non enveloped, single-stranded RNA virus. Signs and symptoms: Subclinical or vague, flulike symptoms Jaundice in only 10% of cases dependent upon patient Transmission and epidemiology: Fecal-oral route, associated with deficient personal hygiene and lack of public health measures Immunizations are available

answer

hepatitis a

question

Enveloped DNA virus. Signs and symptoms: Fever, chills, malaise, anorexia, abdominal discomfort, diarrhea nausea Rashes and arthritis may occur Causes hepatocellular carcinoma Transmitted by minute amounts of blood. An effective vaccine is available. Especially important for healthcare workers

answer

hepatitis b

question

Silent epidemic: 4.1 million Americans infected. Signs and symptoms: Similar to hepatitis B virus 75 - 85% remain infected indefinitely Transmission and epidemiology: Blood transfusions, needle sharing Treatment: No vaccine available Pegylated interferon, ribavirin, protease and polymerase inhibiting drugs "Harvoni"- new and effective chemotherapeutic

answer

hepatitis c

question

Amazing _ among helminths that parasitize humans.

answer

diversity

question

_ (high eosinophil count) is a hallmark of helminthic infection.

answer

Eosinophilia

question

Cause a large burden of disease in the poorest countries in the world Receive the least recognition and research funding

answer

Neglected tropical diseases

question

Specialized parts for attachment, enzymes to penetrate tissues, cuticle for protection from host defenses; definitive host

answer

pathogenesis and virulence factors of gastrointestinal tract diseases caused by helminths

question

host in which the adult worm reproduces sexually

answer

definitive host

question

diagnosis of gastrointestinal tract diseases caused by helminths

answer

Eosinophilia Discovery of eggs, larvae, or adult worms in stool and tissues

question

What are the preventions and treatments of gastrointestinal tract diseases caused by helminths? (7)

answer

No vaccines available Regular treatment with antihelminthic drugs Proper sewage disposal Avoiding using human feces as fertilizer Disinfection of the water supply Thoroughly washing and cooking vegetables and meats Freezing food

question

Whipworm

answer

Trichuris trichuria

question

Life Cycle A Highest incidence in the tropics and subtropics that have poor sanitation

answer

Trichuris trichuria (whipworm)

question

Female whipworms lay _-_ eggs daily in the bowel.

answer

3000 5000

question

Symptoms of whipworm (Trichuris trichuria): (4)

answer

localized hemorrhage of the bowel dysentery loss of muscle tone rectal prolapse

question

Pinworm

answer

Enterobius vermicularis

question

Most common worm disease of children in temperate zones Life Cycle A

answer

Enterobius vermicularis (Pinworm)

question

Hallmark symptom of enterobius vermicularis (pinworm)

answer

pronounced anal itching

question

Pinworm Infection is not fatal and most cases are _.

answer

asymptomatic

question

Tapeworm (pigs)

answer

Taenia solium

question

Adult tapeworms are up to _ meters long.

answer

5

question

Tapeworms (Taenia solium) are distributed worldwide, but concentrated in areas where humans live in close proximity with _ or eat undercooked _.

answer

pigs pork

question

Tapeworms (Taenia solium) go through Life Cycle _.

answer

C

question

Symptoms of tapeworm (tania solium)

answer

Proglottids in stool Vague abdominal pain and nausea

question

tapeworms (fish)

answer

Diphyllobothrium latum

question

Has an intermediate fish host Can be transmitted in sushi and sashimi Also transmitted through undercooked or smoked trout, perch, or pike Common in the Great Lakes, Alaska, and Canada

answer

Tapeworm (Diphyllobothrium latum)

question

Symptoms of tapeworm (diphyllobtherium latum): (2)

answer

abdominal discomfort or nausea anemia

question

Giant intestinal roundworm

answer

Ascaris lumbricoides

question

Larval and adult stages in humans, embryonic eggs expelled in feces Penetrate intestinal wall and enter lymphatic and circulatory systems Swept into the heart and arrive at capillaries in the lungs Migrate up the respiratory tree to the glottis Worms are swallowed and return to the small intestine

answer

Ascaris lumbricoides

question

Hookworm (2)

answer

Necator americanus Ancylostoma duodenale

question

endemic to the New World

answer

Necator americanus

question

endemic to the Old World

answer

Ancylostoma duodenale

question

Hatch outside the body and infect by penetrating the skin

answer

hookworms

question

Hookworms take Life Cycle _.

answer

B

question

localized dermatitis (hookworm)

answer

ground itch

question

result of transit of the worms to the lung (hookworm)

answer

Pneumonia and eosinophilia

question

Heavy worm burden in the intestine can cause _, _, _, _, and _.

answer

nausea vomiting cramps bloody diarrhea anemia

question

Both known as Chinese liver flukes

answer

Opsithorcis sinensis and Clonorchis sinensis

question

Opsithorcis sinensis and Clonorchis sinensis take on Life Cycle _.

answer

D

question

Larvae of Opsithorcis sinensis and Clonorchis sinensis hatch and crawl into the bile duct, shed eggs into the _ tract.

answer

intestinal

question

Symptoms of infection from Opsithorcis sinensis and Clonorchis sinensis: (4)

answer

Slow to develop Thickening of the lining of the bile duct granuloma formation in areas of the liver Bile duct may be blocked

question

Liver fluke common in sheep, cattle, goats, and other animals

answer

Fasciola hepatica

question

Outbreaks associated with eating wild watercress Complex life cycle, mammal is the definitive host

answer

Fasciola hepatica

question

Symptoms of Fasciola hepatica: (4)

answer

vomiting diarrhea hepatomegaly bile obstruction of infected with a large number of flukes

question

Transmitted by eating pork and sometimes other wildlife. Symptoms range from unnoticeable to life threatening 2 phases

answer

Muscle and Neurological Symptoms: Trichinosis

question

What are the 2 phases of Muscle and Neurological Symptoms: Trichinosis?

answer

First phase: diarrhea, nausea, abdominal pains, fever, sweating Second phase: puffiness around the eyes, intense muscle and joint pain, shortness of breath, eosinophilia Prevention through adequate storage and cooking of pork and wild meats

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