Helminths PDF

HELMINTHS NEMATODA - Eukaryota Phylum Nematoda (The Roundworms) - Helminths (parasitic worms) are - Unsegmented worms that have full animals that are often included digestive system within...

HELMINTHS NEMATODA - Eukaryota Phylum Nematoda (The Roundworms) - Helminths (parasitic worms) are - Unsegmented worms that have full animals that are often included digestive system within the study of microbiology - Eggs (ova) can sometimes be because many species of these identified in feces or around the worms are identified by their anus of infected individuals microscopic eggs and larvae. - Diverse group containing more than - Multicellular Have limited organ 15,000 species of which several are systems important human parasites - These unsegmented worms have a full digestive system even when parasitic - Some are common intestinal parasites and their eggs can be sometimes be identified in feces or in the anus of infected individual Have complex reproductive cycles with several different life stages (some in more than one type of host) - Monoecious worms – have both male and female reproductive Ascaris lumbricoides organs in single individual - Common roundworm - Also known as hermaphrodite - This is the largest nematode - Dioecious worms – have individual intestinal parasite found in humans worms each having either male or - Females may reach lengths greater female reproductive organs than 1 meter - very widespread even in developed nations. - It may cause symptoms ranging from relatively mild to severe - Mild – cough and mild abdominal pain - Severe – intestinal blockage and impaired growth Enterobius vermicularis - Pinworm - Most common in the united states  - Causes sleeplessness and itching Hookworms around the anus where the female worms lay their eggs during night Necator americanus - New-World hookworm - North American hookworm Ancylostoma duodenale - Old-World hookworm The symptoms of this 2 hookworm infections can be include : Abdominal pain, diarrhea, loss of appetite, weight loss, fatigue, and anemia How the Hookworms enter the body? Trichinosis / trichinellosis - First is through your skin, which is - Cause by Trichinella spiralis the route of entry - It is contracted by consuming the - After entering the skin, next is uncooked meat which releases the through your blood stream larvae and allows them to insist in - And then through your alveoli mucles - Then the worms will go to your small - Infection can cause fever, muscle intestine and feces which is the pain, and digestive system route of his exit. problems. - Severe infection can lead to lack of Dracunculus medinensis coordination, breathing, heart - The best way to get rid of it is to tie it problems and even death. in a match (then pinupulupot tas iniikot) Ascaris lumbricoides PLATYHELMINTHES Phylum Platyhelminthes (The Flatworms) - Includes the flukes, tapeworms, and the turbellarians, which include planarians -  - The flukes and tapeworms are 2nd in the scale of its impact on medically important parasites human populations only to malaria The Flukes (Trematodes) - This parasites like Schistosoma are - Non-segmented flatworms that have found in freash water snails and are an oral sucker and attach to the responsible for the schistosomiasis. inner walls of intestines, lungs, large - The immature form of this blood vessels, or the liver schistosoma burrow through the - Have complex life cycles, often with skin, into the blood, and then they multiple hosts migrate into the lungs, then to liver and later, to the other organs. - Symptoms are: Anemia, malnutrition, fever, abdominal pain, fluid buildup and sometimes death. The Tapeworms (Cestodes) - Segmented flatworms that may have suckers or hooks at the scolex - They use these suckers or hooks to attach to the wall of the small intestine PLATYHELMINTHES Examples: - The body of the worm is made up of - Liver flukes (Clonorchis and segments called proglottids that Opisthorchis) contain reproductive structures - Intestinal fluke (Fasciolopsis buski) - Proglottids (containing eggs) detach - Oriental lung fluke (Paragonimus when the gametes are fertilized, westermani) releasing gravid proglottids with - Blood flukes (Schistosoma mansoni, eggs. S. haematobium, S. japonicum) - Egg à oncosphere (within - Schistosomiasis – is a serious intermediate host) à cysticerci à parasitic disease that is considered adult tapeworms (definitive host) - Tapeworms often have an intermediate host that consumes the  eggs and which then hatch into a larval form called oncosphere - Then the oncosphere migrates to a particular tissue or organ in the intermediate host where it forms cysticerci. - After being eaten by the definitive host, the cysticerci developed into adult tapeworms in the host’s digestive system. Examples: Taenia saginata (beef tapeworm) - Relatively benign although it can cause digestive problems and occasionally allergic reactions. Taenia solium (pork tapeworm) - Can cause more serious problems when the larvae leaves the intestine and colonized other tissues including those of the central nervous system Diphylobotrium latum - The largest human tapeworm and can be ingested in undercooked fish. - It can grow to a length of 15 meters. Echinococcus granulosus (dog tapeworm) - Can parasitize humans and uses dogs as an important host SIDENOTES: - Taenia saginata and Taenia solium enters the human through ingestion of the undercooked contaminated meat. - The adult worms develop and reside in the intestine but the larval stage may migrate and be found in other body locations such as skeletal and smooth muscle Good luck! - Zia