Question

В чем отличие цикла развития аскариды от цикла развития печеночного сосальщика????

Answer 1

Ответ:

Аскарида-

1)Паразитируют в тонком кишечнике человека

2)Паразитирует в желчных протоках и печени животных и человека

3)Промежуточного хозяина нет

4)Раздельнополы

Сосальщик-

1) В стадии развития есть промежуточный хозяин

2) Паразитирует в желчных протоках и печени животных и человека

3) Гермафродиты

Answer 2

Difference between the life cycle of Ascaris and the life cycle of liver fluke

The life cycles of Ascaris and liver fluke are different due to the distinct characteristics and adaptations of each parasite.

Ascaris Life Cycle: The life cycle of Ascaris involves two main hosts: humans or animals and soil. Here are the key stages of the Ascaris life cycle:

1. Ingestion of eggs: The life cycle begins when a person or animal ingests the eggs of Ascaris, typically through contaminated food or water. 2. Hatching of larvae: Once inside the host's intestines, the eggs hatch, releasing larvae. 3. Migration through the body: The larvae penetrate the intestinal wall and enter the bloodstream, which carries them to the liver and then to the lungs. 4. Coughing and re-ingestion: In the lungs, the larvae mature into adult worms. They then migrate up the respiratory tract and are coughed up and swallowed. This brings them back to the intestines. 5. Maturation and reproduction: In the intestines, the adult worms mature and reproduce, producing eggs that are excreted in the host's feces. 6. Environmental contamination: The eggs are then released into the environment through the feces, where they can contaminate soil or water. 7. Ingestion of contaminated material: If another host ingests the contaminated soil or water, the life cycle begins again.

Liver Fluke Life Cycle: The life cycle of liver fluke involves two intermediate hosts: snails and various mammals, including humans. Here are the key stages of the liver fluke life cycle:

1. Egg release: Adult liver flukes, residing in the bile ducts of the definitive host (such as humans or animals), release eggs into the environment through the host's feces. 2. Miracidium stage: The eggs hatch in water, releasing miracidia, which are free-swimming larvae. 3. Infection of snails: The miracidia penetrate and infect specific species of freshwater snails. 4. Sporocyst and redia stages: Inside the snail, the miracidia develop into sporocysts and then rediae, which multiply asexually. 5. Cercariae stage: The rediae produce cercariae, which are released from the snail into the water. 6. Infection of second intermediate host: The cercariae penetrate and encyst on aquatic vegetation or other suitable surfaces, becoming metacercariae. 7. Ingestion by definitive host: If a mammal, including humans, ingests the metacercariae by consuming contaminated water or vegetation, the life cycle continues. 8. Migration to the liver: The metacercariae excyst in the small intestine and migrate through the intestinal wall to the liver. 9. Maturation and reproduction: In the liver, the flukes mature and migrate to the bile ducts, where they reproduce and release eggs, completing the life cycle.