BIOD_152_Final_Exam Correct Answers

BIOD_152_Final_Exam Correct Answers A. lumbricoides global burden - ANS-1.2 billion infections worldwide, around 60,000 deaths a year A. lumbricoides Mechanism of Entry - ANS-Fecal oral route, can be obtained from water contaminated by feces or soil. A. lumbricoides Mechanisms of Pathogenesis - ANS-Adults wander into intestine and cause blockage in intestine, bile/pancreatic ducts, perforation of liver, and perforation of intestinal wall. Minor damage caused by juvenilles penetrating intestinal mucosa. Juvenilles can cause damage breaking out of lung capillaries - causing hemorrhaging, heavy infections can lead to edema and clogging of air space. A. lumbricoides Mechanisms of Survival - ANS-Worm burdens are highly variable between people. Crofton's General Principle. A. lumbricoides Niche Selection - ANS-No intermediate host, infects humans specifically A. lumbricoides Reproduction - ANS-Sexual reproduction, female produces up to 200,000 eggs a day. Eggs can persist in garden soil for up to 7 years. A.lumbricoides geography - ANS-Generally below the equator, Africa, Central, East, and Southeast Asia Acaris lumbricoides - ANS-Helminth - nematode, roundworm. Causes vague abdominal pain, able to cause pathology by overcrowding and migration to areas such as bile ducts, intestines, and organs such as the lung, where they cause a variety of symptoms. Detected in stool. Ascaris lumbricoides life cycle - ANS-1. Host swallows embryonated egg (containing L3) 2. Egg hatches in intestines 3. L4 migrate to lungs to aveoli through burrowing of intestinal walls 4. Coughed up larvae are re-swallowed 5. Larvae mature into adults in small intestine where they mate 6. Fertilized eggs (infective) and unfertilized eggs are passed in feces 7. Larvae develop to L3 within embryonated egg D. latum Geography - ANSD. latum Global Burden - ANSD. latum life cycle - ANSD. latum Mechanisms of Entry - ANSD. latum Mechanisms of Pathogenesis - ANSD. latum Mechanisms of Survival - ANSD. latum Niche Selection - ANSD. latum Reproduction - ANSD. medinensis Geography - ANS-Formerly: Asia, India, and parts of Africa Currently: Ethiopia, Ghana, Mali, and South Sudan D. medinensis Global Burden - ANS-as of 2-15, only 22 cases D. medinensis life cycle - ANS-1. Human drinks water containing copepods infected with L3 larvae 2. Copepods die, larvae penetrate host stomach and intestinal walls 3. Mature to adults in cutaneous tissue and reproduce/become gravid in subcutaneous tissue 4. fertilized female migrates to surface to skin to disperse larvae (L1) 5. L1 larvae in water 6. L1 larvae consumed by copepod 7. In copepod, larvae undergoes 2 molts L1 -- L2 -- L3 D. medinensis Mechanisms of Entry - ANS-Drinking water contaminated with infected copepods D. medinensis Mechanisms of Pathogenesis - ANS-Swelling and tenderness occurs when female breaks through skin to lay larvae; this can be so humans soak themselves in water where copepods are present. Broken worms can cause extreme inflammatory response, followed by ulceration and scarring. Damage also occurs when worm dies naturally within host. D. medinensis Mechanisms of Survival - ANS-Secretions protect nematode, upon death secretion halts and that's usually when immune system can detect the dead pathogen and inflammation damage can occur. D. medinensis Niche Selection - ANS-Infection is specific with copepod as intermediate host and human as definitive host D. medinensis Reproduction - ANS-Sexual reproduction occurs in human host. parasite becomes gravid in subcutaneous tissue Digenic Trematodes - ANS-Digenic trematodes are also known as flukes, are among the most common and abundant parasitic worms, second to nematodes. Development occurs in at least 2 hosts. Usually start with mollusk infection. Many species have 2nd or 3rd intermediate host. Diphyllobothrium latum - ANSDracunculus medinensis - ANS-Also called the Guinea worm, nematode. Has been the target of a widespread and effective eradication program - Dracunculus eradication program (DEP) . Female will release larvae usually after a year of infection. Removal involves weeks long process of winding worm out of patient. E. vermicularis Geography - ANS-Worldwide distribution E. vermicularis Global Burden - ANS-infects over 400 million E. vermicularis life cycle - ANS-1. Egg (embryonated) is ingeste