ZEB 122 Chpt3 81-92 Parasitic Cestodes Flashcards
- What is the common name for cestodes? a) Flatworms b) Roundworms c) Tapeworms d) Hookworms
Answer: c) Tapeworms Explanation: Cestodes are commonly called tapeworms due to their flat tape-like structure.
2 Where do adult cestodes typically reside in their host? a) Liver b) Lungs c) Intestine d) Brain
Answer: c) Intestine Explanation: Adult cestodes are endoparasitic and live in the intestine of vertebrates.
3 Which of these is NOT a characteristic feature of cestodes? a) Bilaterally symmetrical b) Possess a digestive system c) Hermaphroditic d) Have a scolex for attachment
Answer: b) Possess a digestive system Explanation: Cestodes lack a digestive system and absorb nutrients directly through their cuticle.
4.What is the name of the structure used by cestodes for attachment? a) Proglottid b) Scolex c) Rostellum d) Neck
Answer: b) Scolex Explanation: The scolex or head of the cestode has organs of attachment known as suckers or grooves (bothria).
- How many intermediate hosts are typically involved in the life cycle of most cestodes? a) None b) One c) Two or more d) Always three
Answer: c) Two or more Explanation: The life cycles of most cestodes involve two or more intermediate hosts except for Hymenolepis nana.
- What is the scientific name of the beef tapeworm? a) Taenia solium b) Hymenolepis nana c) Diphyllobothrium latum d) Taenia saginata
Answer: d) Taenia saginata Explanation: The beef tapeworm is scientifically known as Taenia saginata.
7Where is Taenia solium infection known to be more prevalent? a) North America b) Central and South America c) Australia d) Antarctica
Answer: b) Central and South America Explanation: Although cosmopolitan
- What is the approximate maximum length a Taenia saginata can reach? a) 1 meter b) 3 meters c) 5 meters d) 10 meters
Answer: c) 5 meters Explanation: T. saginata can reach a length of 5-8 meters.
- What differentiates the scolex of T. solium from that of T. saginata? a) T. solium has hooks T. saginata does not. b) T. saginata has hooks T. solium does not. c) T. solium has a rostellum T. saginata does not. d) T. saginata has suckers T. solium does not.
Answer: a) T. solium has hooks T. saginata does not. Explanation: Both T. solium and T. saginata have four suckers on a pea-shaped scolex. However T. solium also has a row of 4-6 rostellum (hooks).
- What is the definitive host for Taenia species? a) Cattle b) Pigs c) Humans d) Snails
Answer: c) Humans Explanation: Humans are the definitive host for Taenia species. They become infected by eating undercooked beef (T. saginata) or pork (T. solium
11What stage of the Taenia life cycle is infective to humans? a) Oncosphere b) Cysticercus c) Embryonated egg d) Procercoid larva
Answer: b) Cysticercus Explanation: The cysticercus also known as bladder-worm is the larval stage found in the muscles of the intermediate host (cattle for T. saginata pigs for T. solium).
12.When humans ingest this stage in raw or undercooked meat the larva develops into the adult tapeworm in the human intestine. How long does it typically take for the Taenia larva to mature in the human intestine? a) 24 hours b) 1 week c) 2-3 months d) 6-8 months
Answer: c) 2-3 months Explanation: After ingestion of the cysticercus the larva detaches and migrates to the small intestine where it matures within 2-3 months. 13.What is the primary diagnostic method for Taenia infection? a) Blood test b) X-ray c) Stol examination d) Physical examination
14.What condition can result from the excessive loss of blood due to Taenia solium infection? a) Epilepsy b) Blindness c) Anaemia d) Paralysis
Answer: c) Anaemia Explanation: The worms cause trauma to their hosts using their suckers and hooks leading to anemia from excessive blood loss.
- What is cysticercosis? a) Infection with the adult tapeworm in the intestine b) Presence of tapeworm larvae in tissues outside the intestine c) Allergic reaction to tapeworm antigens d) Auto-infection with tapeworm eggs
Answer: b) Presence of tapeworm larvae in tissues outside the intestine.Explanation: Cysticercosis is a condition where Taenia larvae (cysticerci) develop in tissues like the brain eyes and muscles causing various neurological disorders.
16 Which of the following is the drug of choice for treating Taenia infections? a) Niclosamide b) Praziquantel c) Albendazole d) Mebendazole
Answer: b) Praziquantel Explanation: Praziquantel is the drug of choice for Taenia infections. 17.What temperature is sufficient to kill Taenia cysticerci in meat? a) -10°C b) 0°C c) 10°C d) 50°C
18What does hypobiosis refer to in the context of Taenia infection? a) Rapid growth of the tapeworm b) Arrested development of the larva c) Shedding of gravid proglottids d) Formation of cysts in the host tissues
Answer: b) Arrested development of the larva Explanation: Hypobiosis is the arrested development of the tapeworm larva ensuring that when the process of development to adulthood is impaired the larva can survive for as long as 6-8 months.
- What is the intermediate host for Taenia saginata? a) Pig b) Cattle c) Fish d) Snail
Answer: b) Cattle Explanation: Cattle serve as the intermediate host for Taenia saginata.
20What is the intermediate host for Taenia solium? a) Pig b) Cattle c) Fish d) Snail
Answer: a) Pig Explanation: Pigs serve as the intermediate host for Taenia solium.
- What is the common name for Diphyllobothrium latum a) Dwarf tapeworm b) Beef tapeworm c) Pork tapeworm d) Fish tapeworm
Answer d) Fish tapeworm Explanation Diphyllobothrium latum is commonly known as the fish or broad tapeworm
- Where is the infection with Diphyllobothrium latum a more serious problem a) Tropical regions b) Places where properly cooked fish is consumed c) Places where pickled or insufficiently cooked fresh fish is a delicacy d) Arid regions
Answer c) Places where pickled or insufficiently cooked fresh fish is a delicacy Explanation The infection is a more serious problem in places where pickled or insufficiently cooked fresh fish is a delicacy
- What is the maximum length that Diphyllobothrium latum can grow up to a) 2 meters b) 5 meters c) 8 meters d) 10 meters
Answer d) 10 meters Explanation Diphyllobothrium latum can grow up to a length of 8-10 meters
- What is unique about the proglottids of Diphyllobothrium latum a) They are the longest among all tapeworms b) They are shed in chains c) They contain both male and female reproductive organs d) They have bothria on both ventral and dorsal surfaces
Answer c)
- How do humans typically get infected with Diphyllobothrium latum a) Ingesting undercooked beef b) Ingesting undercooked pork c) Consuming contaminated water d) Consuming raw or improperly cooked fish
Answer d) Consuming raw or improperly cooked fish Explanation Human infection with D. latum occurs through the consumption of raw or improperly cooked fish containing plerocercoid larvae
- How do humans typically get infected with Diphyllobothrium latum? a) Ingesting undercooked beef b) Ingesting undercooked pork c) Consuming contaminated water d) Consuming raw or improperly cooked fish
Answer d) Consuming raw or improperly cooked fish Explanation Human infection with D. latum occurs through the consumption of raw or improperly cooked fish containing plerocercoid larvae
- What is the first larval stage of Diphyllobothrium latum called? a) Cysticercus b) Coracidium c) Procercoid d) Oncosphere
Answer b) CoracidiumExplanation The first larval stage is called a coracidium which hatches from eggs in water and is ingested by a crustacean
- What is the second larval stage of Diphyllobothrium latum called? a) Cysticercus b) Coracidium c) Procercoid d) Oncosphere
Answer c) Procercoid Explanation The second larval stage is called a procercoid which develops in the crustacean and then infects a freshwater fish
- What is the third larval stage of Diphyllobothrium latum called? a) Cysticercus b) Coracidium c) Plerocercoid d) Oncosphere
Answer c) Plerocercoid Explanation The third larval stage is called a plerocercoid which develops in the fish and is infective to humans
- What is the diagnostic stage of Diphyllobothrium latum infection? a) Unembryonated eggs discharged in faeces b) Gravid proglottids c) Plerocercoid larvae d) Adult worms in the small intestine
Answer a) Unembryonated eggs discharged in faeces Explanation Diagnosis of D. latum infection is based on finding unembryonated eggs discharged in faeces
- Which vitamin deficiency can be caused by Diphyllobothrium latum infection? a) Vitamin A b) Vitamin B12 c) Vitamin C d) Vitamin D
Answer b) Vitamin B12 Explanation D. latum can compete with the host for vitamin B12 resulting in anemia31. What is sparganosis? a) Infection with the adult D. latum b) Infection with plerocercoid larvae of various Diphyllobothrium tapeworms c) Allergic reaction to D. latum antigens d) Vitamin B12 deficiency caused by D. latum
- What is the drug of choice for treating sparganosis? a) Niclosamide b) Praziquantel c) Albendazole d) Mebendazole
Answer: b) Praziquantel Explanation: Praziquantel is the drug of choice for treating sparganosis.
- What is a control measure for Diphyllobothrium latum infection? a) Proper cooking of beef b) Proper cooking of pork c) Proper sewage disposal d) Vaccination
Answer: c) Proper sewage disposal Explanation: Proper sewage disposal especially of human faeces is a control measure for D. latum infection.
- What is the common name for Hymenolepis nana? a) Fish tapeworm b) Beef tapeworm c) Dwarf tapeworm d) Pork tapeworm
Answer: c) Dwarf tapeworm Explanation: Hymenolepis nana is commonly called the dwarf tapeworm.
- What is unusual about the life cycle of Hymenolepis nana compared to other tapeworms? a) It requires three intermediate hosts b) It does not require an intermediate host c) It can complete its life cycle in the same host d) It has a free-living larval stage
Answer: c) It can complete its life cycle in the same host Explanation: The adult worm is about 20-30mm in length It is peculiar because it can complete its life cycle in the absence of the intermediate host (usually a beetle) unlike other tapeworms.
- What is the typical intermediate host for Hymenolepis nana? a) Cattle b) Pig c) Fish d) Arthropod
Answer: d) Arthropod Explanation: The intermediate host for H. nana is usually an arthropod such as a beetle or flea.
- How do humans typically get infected with Hymenolepis nana? a) Consuming undercooked meat b) Consuming contaminated water c) Ingesting infected arthropods d) Contact with infected animals
Answer: c) Ingesting infected arthropods Explanation: Humans become infected by ingesting arthropods that are infected with the cysticercoid larva.
- What is the diagnostic stage of Hymenolepis nana infection? a) Adult worms in the small intestine b) Cysticercoid larva in arthropods c) Eggs or proglottids in faeces d) Oncospheres in the environment
Answer: c) Eggs or proglottids in faeces Explanation: Diagnosis of H. nana infection is based on finding the egg or proglottid in feces.
- What is the drug of choice for treating Hymenolepis nana infection? a) Niclosamide b) Praziquantel c) Albendazole d) Mebendazole
Answer: a) Niclosamide Explanation: Niclosamide is the drug of choice for H. nana infection Praziquantel is also effective.
- What is the causative agent of hydatid disease? a) Taenia solium b) Diphyllobothrium latum c) Hymenolepis nana d) Echinococcus granulosus
Answer: d) Echinococcus granulosus Explanation: The larvae of cestodes of the genus Echinococcus (E. granulosus and E. multilocularis) are the causative agents of hydatid disease.
- Where is Echinococcus granulosus infection particularly prevalent a) North America b) South America and Europe c) Australia d) Antarctica
Answer: b) South America and Europe Explanation: E. granulosus is cosmopolitan but more prevalent in South America and Europe
- What is the definitive host for Echinococcus granulosus a) Humans b) Cattle c) Domestic and wild carnivores d) Rodents
Answer: c) Domestic and wild carnivores Explanation: Domestic and wild carnivores are the hosts of the adult worm
- What is the infective stage of Echinococcus granulosus for humans a) Adult worm b) Hydatid cyst c) Gravid proglottid d) Oncosphere
Answer: b) Hydatid cyst Explanation: The infective stage is the hydatid cyst which develops in intermediate hosts like sheep cattle and humans
- How do humans typically get infected with Echinococcus granulosus a) Consuming undercooked meat b) Ingesting contaminated food or drink c) Contact with infected animals d) Insect bites
Answer: b) Ingesting contaminated food or drink Explanation: Humans are infected by ingesting food or drink contaminated with E. granulosus eggs usually from contact with infected carnivores or their faeces
- What organ is most commonly affected by hydatid cysts in humans a) Brain b) Lungs c) Liver d) Kidneys
Answer: c) Liver Explanation: The cysts most commonly affect the liver but can also occur in the lungs brain and other organs
- Describe the morphology of adult cestodes
Answer: Adult cestodes have a flat tape-like body composed of segments called proglottids. They have a scolex or head with specialized structures for attachment such as suckers and hooks. They lack a digestive system and absorb nutrients through their cuticle
- Outline the general life cycle of a tapeworm
Answer: The general life cycle of a tapeworm involves Adult Stage Adult tapeworms reside in the intestine of the definitive host (usually a vertebrate) Egg Release They release eggs that are passed in the host’s feces Intermediate Host Eggs are ingested by an intermediate host (another animal) Larval Development Larvae develop in the intermediate host’s tissues Definitive Host Infection The definitive host becomes infected by consuming the intermediate host containing the infective larval stage
- Explain how Taenia solium infection can lead to neurological complications
Answer: Taenia solium infection can lead to neurological complications through a condition called cysticercosis. When humans ingest T. solium eggs the larvae (cysticerci) can migrate to the brain and other tissues forming cysts. These cysts can cause various neurological disorders including epilepsy blindness and paralysis
- What are the key differences between Taenia saginata and Taenia solium infections
Answer: While both T. saginata and T. solium are intestinal tapeworms with similar life cycles and modes of transmission some key differences exist Intermediate Host The intermediate host for T. saginata is cattle while for T. solium it is pigs Scolex Morphology The scolex of T. solium possesses hooks while T. saginata does not Cysticercosis T. solium poses a greater risk of cysticercosis in humans as humans can act as both the definitive and intermediate host
- Discuss the public health significance of cestode infections and measures to prevent them
Answer: Cestode infections are a significant public health concern especially in regions with poor sanitation and hygiene practices. These infections can cause various health problems ranging from mild gastrointestinal discomfort to severe neurological complications Key preventive measures include Proper meat inspection and cooking Improved sanitation and hygiene Safe disposal of human feces Health education to promote awareness about cestode infections and their prevention.
