Fasciola hepatica is also known as a common liver fluke or sheep liver fluke. It causes hepatic fibrosis in ruminants and humans known as Fascioliasis. History and distribution of Fasciola hepatica Fasciola hepatica was the first fluke or trematode that was discovered more than 600 years ago in 1379 by … Read more
Introduction Giardia duodenalis is also known as Giardia lamblia and Giardia intestinalis. It is a flagellated unicellular eukaryotic microorganism that colonizes and reproduces in the small intestine. It commonly causes a gastrointestinal condition known as Giardiasis. Classification of Giardia duodenalis There are five species of Giardia, out of that, G. … Read more
Hydra reproduces asexually by budding and sexually by the formation of gametes. Asexual reproduction of Hydra by Budding Figure: Hydra Budding. 1. Non-reproducing, 2. Creating a bud, 3. Daughter growing out, 4. Beginning to cleave, 5. Daughter broken off, 6. Daughter clone of the parent. Image Source: A.houghton19 (Wikimedia). Budding is a … Read more
Locomotion in Hydra Hydras are essentially sessile animals. They live attached by their pedal discs to objects in the water. Brown and green hydras can remain fixed at one spot for a considerable time, but green hydras often move about from place to place by several ingenious devices. They twist … Read more
Hydra are inconspicuous freshwater relatives of corals, sea anemones, and jellyfish that are classified under the phylum Cnidaria, Class Hydrozoa, Order Anthomedusae/Anthoathecata, and Family Hydroidea. It is essentially a sedentary organism living attached to stones, pebbles, and water plants, but can get released from the substratum and swim. The name … Read more
What is Visceral leishmaniasis (Kala-azar)? Visceral leishmaniasis is sometimes known as systemic leishmaniasis or kala-azar. Kala-azar also is known as black fever or Dumdum fever in Asia. It usually occurs 3 to 6 months after being bitten by a sandfly. It primarily infects the reticuloendothelial system. It damages internal organs, … Read more
What is Cysticercosis? Cysticercosis refers to the tissue infection caused by the metacestode, or larval stage, of Taenia solium. It is acquired by the accidental ingestion of T. solium eggs. It is endemic to many parts of the developing world, including Latin America, Asia, and sub-Saharan Africa. Cysticercosis is the … Read more
Lab diagnosis of Ascaris lumbricoides a. Detection of Parasite Adult Worm In the case of heavy infection, the adult worm is possible to find in stool or sputum of the patient by the naked eye. Barium meal may reveal the presence of an adult worm in the small intestine. A … Read more
What is Ancylostoma duodenale? Ancylostoma duodenale is the most dangerous parasitic roundworm, causing serious infection in humans. It is commonly known as Old World hookworm. It is common in the tropical, subtropical, and temperate region of Asia, Africa, Europe, the Pacific Islands, and the Southern States of America. Ancylostoma duodenale … Read more
What is Plasmodium vivax? Plasmodium vivax is the most common of the human infecting malaria fever parasites. It is an intracellular parasite in man. It lives in the red blood corpuscles and liver cells in man. While extracellular in mosquitoes, living in its alimentary canal and salivary glands. The life … Read more
Wuchereria bancrofti is a filarial nematode that causes Wuchereriasis or filariasis(commonly called elephantiasis) in human beings. The name of this worm is given Wuchereria bancrofti in honor of the two scientists Wucherer and Bancroft who made a considerable contribution in studying the disease caused by these worms. Image Source: Study … Read more
Image Source: Laboratory Diagnostic Assistance (DPDx), CDC. Life history and Development of Taenia solium 1. Copulation and fertilization The life cycle of Taenia solium is digenetic, involving two hosts. But the life cycle of tapeworm is simple and without a free larval stage. Fertilization is preceded by copulation, inserting cirrus … Read more
Nutrition in Taenia solium Tapeworm completely lacks alimentation in all stages of life-history. It is clear that tapeworms absorb nutrients from their hosts and that such movement of materials from the hosts into parasites is an essential element of host-parasite relationships. The soluble nutrients like glucose, amino acids, glycerol, etc., … Read more
Systematic position Phylum: Protozoa Subphylum: Sacromastigophora Superclass: Mastigophora Class: Zoomastigophora Order: Kinetoplastida Genus: Leishmania Species: donovani Discovery and Distribution The species of Leishmania donovani was reported simultaneously by Leishmania from London and Donovan from Mardas in (1903) hence the name Leishmania donovani. L. donovani causes a malaria-like fever-oriental disease in … Read more
Classification of Taenia solium Phylum Platyhelminthes Class Cestoda Subclass Eucestoda Order Taenioidea Genus Taenia Species solium Habits and Habitat of Taenia solium Taenia solium, also known as pork tapeworm, is found worldwide. Thus, its distribution is cosmopolitan. Its adults dwell in man’s small intestine as an internal parasite, i.e., endoparasitic, … Read more
Reproductive system of earthworm Earthworms do not reproduce asexually. Reproductive organs are somewhat complicated. The pheretima is monoecious or hermaphrodites having both male and female reproductive organs in the same individual. They cannot fertilize their own eggs because they are protandrous. Cross-fertilization occurs as a rule because of the relative … Read more
Life cycle of Ascaris lumbricoides In the life cycle of Ascaris, there is no secondary host. The life cycle of Ascaris is monogenetic as it involves only one host i.e. Man. Figure: Life cycle of Ascaris lumbricoides. Image Source: CDC. 1. Egg in feces The sexually mature female produces as … Read more
Reproductive system of Ascaris lumbricoides Only sexual reproduction occurs in Ascaris. Sexes are separate i.e., dioecious in Ascaris and these roundworms also show distinct sexual dimorphism. Males are smaller than the females and they also have a curved tail with pre and post anal papillae, cloaca, and a pair of … Read more
Digestive System of Ascaris lumbricoides I) Alimentary canal: It is a straight and complete tube that starts with the mouth at the anterior end and ends with the anus at the posterior end. It comprises a short pharynx or esophagus representing foregut, along intestine or mid-gut, and short rectum or … Read more