8 Parasitic Adaptations In Helminths
This document was uploaded by user and they confirmed that they have the permission to share it. If you are author or own the copyright of this book, please report to us by using this DMCA report form. Report DMCA
Overview
Download & View 8 Parasitic Adaptations In Helminths as PDF for free.
More details
- Words: 1,774
- Pages: 60
“Parasitic adaptations in Helminths” A presentation compiled from various sources by
Dr. PARVISH PANDYA, Zoology Dept. Bhavan’s College, Andheri. Dr. PARVISH PANDYA’s presentation
Sites from which presentations have been downloaded and later editted. I am indeed thankful to them for their kindness and support : http://esg-www.mit.edu:8001/esgbio/cb/org/organelles.html http://faculty.pnc.edu/jcamp/parasit/parasit.html http://www.amnh.org/rose/hope/creatinghope/ http://www.biology.eku.edu/SCHUSTER/bio%20141/POWERPOINT %20NOTES/Intro%20to%20Protozoa_files/fullscreen.htm http://www.biosci.ohio-state.edu/~zoology/eeob405/ http://www.tulane.edu/~wiser/protozoology/pwpt/ http://www.iep.water.ca.gov/suisun/photos/wildlife.html http://www.uta.edu/biology/marshall/2343/ http://www.uta.edu/biology/faculty/faculty.html http://www.okc.cc.ok.us/biologylabs/Documents/Zoology/PowerPoint.htm http://bio.fsu.edu/ http://www.aw-bc.com/ http://www.nhm.org/ http://www.geo.cornell.edu/eas/education/course/descr/EAS302/presentations/ It is very easy to find mistakes in these presentations…..I request you to kindly rectify them and supply me the modifications needed at [email protected] Thanks a lot and have fun in teaching & learning Zoology…. Dr. PARVISH PANDYA’s presentation
Phylum Platyhelminthes & Aschelminthes = Helminth worms flatworms Selected characteristics: Anatomy: thin and flat; digestion - free-living and parasitic forms excretion - protonephridia (flame cells) nervous - 1st CNS;ganglia, 2 ventral nerve cords, eyespots, auricles Dr. PARVISH PANDYA’s presentation
Triploblasts
Acoelomates Platyhelminthes Gastrotricha? Nemertea?
Coelomates
Protostomes Mollusca Onycophora Annelida Nemertea? Arthropoda Bryozoa? Tardigrada Protostome mouth from blastopore
Pseudocoelomates Nematoda Rotifera
Deuterostomes Echinodermata Hemichordata Chordata Deuterostome mouth not from blastopore
Dr. PARVISH PANDYA’s presentation
1. Phylum Platyhelminthes: Flatworms are acoelomates with gastrovascular cavities • There are about 20,000 species of flatworms living in marine, freshwater, and damp terrestrial habitats. – They also include many parasitic species, such as the flukes and tapeworms.
• Flatworms have thin bodies, ranging in size from the nearly microscopic to tapeworms over 20 m long.
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Dr. PARVISH PANDYA’s presentation
Phylum Platyhelminthes • • • • •
Flat worms Triploblastic Acoelomate Bilateral symmetry Hermaphroditic – Monoecious
• One opening for digestive system • Ladder nervous system
Dr. PARVISH PANDYA’s presentation
Flatworms are divided into four classes: Turbellaria Monogenia Trematoda and Cestoidea
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Dr. PARVISH PANDYA’s presentation
1. Class Turbellaria • free-living flatworms planarians (Dugesia) highly branched gastrovascular • cavity pharynx - muscular • opening to gastrovascular cavity
Dr. PARVISH PANDYA’s presentation
Class Turbellaria • Eye spots • Ciliated surface • Regenerate if cut in two
Dr. PARVISH PANDYA’s presentation
Turbellarian Pharynx Dr. PARVISH PANDYA’s presentation
Platyhelminthes • the most primitive bilateral animals? • 80% parasites (derived) • specialization potential • Class Turbellaria
• respiration • many w/symbionts for the O2 • increased respiration rate • some deep (5 cm) sediment hunters w/ hemoglobin and symbionts
Dr. PARVISH PANDYA’s presentation
• Flatworms have an excretory system called protonephridia, consisting of a branching network of dead-end tubules. – These are capped by a flame bulb with a tuft of cilia that draws water and solutes from the interstitial fluid, through the flame bulb, and into the tubule system. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Dr. PARVISH PANDYA’s presentation
• Flatworms and other bilaterians are triploblastic, with a middle embryonic tissue layer, mesoderm, which contributes to more complex organs and organs systems and to true muscle tissue. • While flatworms are structurally more complex than cnidarians or ctenophores, they are simpler than other bilaterans. – Like cnidarians and ctenophores, flatworms have a gastrovascular cavity with only one opening (and tapeworms lack a digestive system entirely and absorb nutrients across their body surface). – Unlike other bilaterians, flatworms lack a coelom. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Dr. PARVISH PANDYA’s presentation
• Planarians and other flatworms lack organs specialized for gas exchange and circulation. – Their flat shape places all cells close to the surrounding water and fine branching of the digestive system distributes food throughout the animal. – Nitrogenous wastes are removed by diffusion and simple ciliated flame cells help maintain osmotic balance.
Fig. 33.10 Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Dr. PARVISH PANDYA’s presentation
Turbellarian GI tracts • increasing complexity microturbellarians Acoela • simple pharynx • no gut cavity macroturbellarians Tricladia (3-branched) • tubular protrusible pharynx Polycladida (multi-branched) - marine • 3-brached protrusible pharynx
pharynx plicatus
Protonephridia • excretory • osmorgulatory • flame cells • filtration • selective absorption
Sensory structures • brain (ganglia) • net-like nervous system • variable number of longitudinal nerve cords • evolutionary trend toward net reduction • bilateral brain • paired longitudinal nerve cords • “pigment cup” ocelli (no. varies) • strong negative phototaxis • sensory pits -> chemoreception • complex behaviors - learning
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Phylum Platyhelminthes: Class Turbellaria
Acoelomate
Dr. PARVISH PANDYA’s presentation
Parenchyma • tissue connecting muscles and gut • large flatworms: mesenchymal cells in an extracellular matrix • small flatworms: matrix minimal or absent • liquid in some some fw forms - hydrostatic skeleton + internal transport • parenchymal cells types • epidermal replacement cells • neoblasts - totipotent, wound healing • fixed parenchymal cells - join cells and tissues • low-resistant pathways for intercellular transport of metabolites
2. Classes Trematoda and Monogenea • • • • • •
flukes parasites many feed with oral suckers and microvilli oral and ventral suckers used to attach to host gastrovascular cavity - not branched hosts: primary-where sexual reproduction of parasite occurs • intermediate-no sexual reproductive stage of parasite • Examples: Schistosoma mansoni - human blood fluke • Clonorchis sinensis - Chinese liver fluke
Dr. PARVISH PANDYA’s presentation
Class Trematoda • Flukes • Parasites • Holdfast devices – Most
• Complex life cycle • Intermediate host – Animal with juvenile stage
• Definitive host – Animal with adult stage
Dr. PARVISH PANDYA’s presentation
• Trematodes parasitize a wide range of hosts, and most species have complex life cycles with alternation of sexual and asexual stages. – Many require an intermediate host in which the larvae develop before infecting the final hosts (usually a vertebrate) where the adult worm lives.
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Dr. PARVISH PANDYA’s presentation
Fascioloa hepatica • Sheep liver fluke • Sheep, cattle and man – Weight loss
• Eat vegetation with metacercaria
Dr. PARVISH PANDYA’s presentation
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Generalized Fluke
Dr. PARVISH PANDYA’s presentation
Phylum: Platyhelminthes Class: Trematoda Fluke
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Dr. PARVISH PANDYA’s presentation
Fig. 46.6
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Life CycleDr. of the Sheep Liver Fluke PARVISH PANDYA’s presentation
Schistosoma • Blood flukes • 200 million people • 1 million deaths/year
Dr. PARVISH PANDYA’s presentation
• The blood fluke Schistosoma infects 200 million people, leading to body pains, anemia, and dysentery.
Dr. PARVISH PANDYA’s presentation
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Life Cycle of a Schistosome Fluke Dr. PARVISH PANDYA’s presentation
Schistosome • Cercaria have forked tail
Dr. PARVISH PANDYA’s presentation
Dr. PARVISH PANDYA’s presentation
Class Cestoidea • Tape worms • No digestive system • 40 feet long
Dr. PARVISH PANDYA’s presentation
3. Class Cestoda • • • • •
tapeworms parasitic no digestive cavity body: head = scolex proglottids = body sections containing male and female sex organs • Examples: human tapeworms; pigs, cows, and fish are intermediate hosts • Sushi - tapeworm infestation has risen with the popularity of this dish • ??Filariasis?
Dr. PARVISH PANDYA’s presentation
• Tapeworms (class Cestoidea) are also parasitic. – The adults live mostly in vertebrates, including humans. • Suckers and hooks on the head or scolex anchor the worm in the digestive tract of the host. • A long series of proglottids, sacs of sex organs, lie posterior to the scolex. • Tapeworms absorb food particles from their hosts. Dr. PARVISH PANDYA’s presentation
• Mature proglottids, loaded with thousands of eggs, are released from the posterior end of the tapeworm and leave with the host’s feces. – In one type of cycle, tapeworm eggs in contaminated food or water are ingested by intermediary hosts, such as pigs or cattle. – The eggs develop into larvae that encyst in the muscles of their host. – Humans acquire the larvae by eating undercooked meat contaminated with cysts. – The larvae develop into mature adults within the human. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Dr. PARVISH PANDYA’s presentation
Platyhelminthes • rhabdoids and rhabdites • some expel rhabdites to ensnare prey and gather detritus • duo-glands (adhesive and releaser glands)
• multi-ciliated cells • pedal waves • muscles • looping
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Pork Tapeworm Dr. PARVISH PANDYA’s presentation
(Taenia solium)
Scolex
Dr. PARVISH PANDYA’s presentation
Proglottid Testes Uterus Vas deferens
Seminal receptacle Ovary Yolk gland Dr. PARVISH PANDYA’s presentation
Life Cycle of the Broad-Fish Tapeworm Diphyllobothrium latum
Dr. PARVISH PANDYA’s presentation
Aschelminthes? Ecdysozoans? • the molting aschelminths • ecdysone-like steroids • 4 molts during development • multi-layered collagen cuticle • epidermis often syncytial • continue to grow between molts • eutely
Dr. PARVISH PANDYA’s presentation
Phylum Nematoda • 12,000 species – 500,000 possible
• Cylindrical body • Only longitudinal muscles • Noncellular cuticle with several layers • Pseuodcoelomate • Mouth and anus
Dr. PARVISH PANDYA’s presentation
Nematodes • Found everywhere – – – –
Soil Oceans Polar ice Hot springs
• Parasites of nearly all plant and animal species!
Dr. PARVISH PANDYA’s presentation
Musculature and Movement • no circular muscles - no peristalsis • dorsal and ventral longitudinal muscles • innervation – muscle processes extend to nerve cords • high internal pressure 10 x greater than most inverts • rigid cuticle, partially contracted muscles • round • sinusoidal waves
Dr. PARVISH PANDYA’s presentation
Feeding • 6 muscular lips (often fused to 3) • muscular pharynx moves food and keeps gut lumen open • pharyngeal glands lubricate + enzymes • digestion mainly extracellular • wastes voided by the minute
Dr. PARVISH PANDYA’s presentation
Respiration and Circulation • diffusion
Dr. PARVISH PANDYA’s presentation
Dr. PARVISH PANDYA’s presentation
females sluggish males active
12 US spp., 2 common
little host specificity Dr. PARVISH PANDYA’s presentation
Internal and External Features of a Nematode
Dr. PARVISH PANDYA’s presentation
Nematode Reproductive Systems Dr. PARVISH PANDYA’s presentation
• Roundworm of man • 1.2 billion people in US • Females lay 200,000 eggs a day • Unsanitary habits contaminate ground • Night soil Dr. PARVISH PANDYA’s presentation
Ascaris lumbricoides
Dioecious
Dr. PARVISH PANDYA’s presentation
Life Cycle of Ascaris lumbricoides
Dr. PARVISH PANDYA’s presentation
Trichinella spiralis • Trichina worm • Pigs, bear, dogs, cats, rats and man • Trichinosis – Encysts in muscles
Dr. PARVISH PANDYA’s presentation
Life Cycle of Trichinella spiralis
Dr. PARVISH PANDYA’s presentation
Wuchereria bancrofti • Lives in lymphatic system • Obstruct lymph to cause swelling – Elephantiasis
Dr. PARVISH PANDYA’s presentation
Elephantiasis
Dr. PARVISH PANDYA’s presentation
Life Cycle of Wucheria spp.
Dr. PARVISH PANDYA’s presentation
The End Dr. PARVISH PANDYA’s presentation
Dr. PARVISH PANDYA, Zoology Dept. Bhavan’s College, Andheri. Dr. PARVISH PANDYA’s presentation
Sites from which presentations have been downloaded and later editted. I am indeed thankful to them for their kindness and support : http://esg-www.mit.edu:8001/esgbio/cb/org/organelles.html http://faculty.pnc.edu/jcamp/parasit/parasit.html http://www.amnh.org/rose/hope/creatinghope/ http://www.biology.eku.edu/SCHUSTER/bio%20141/POWERPOINT %20NOTES/Intro%20to%20Protozoa_files/fullscreen.htm http://www.biosci.ohio-state.edu/~zoology/eeob405/ http://www.tulane.edu/~wiser/protozoology/pwpt/ http://www.iep.water.ca.gov/suisun/photos/wildlife.html http://www.uta.edu/biology/marshall/2343/ http://www.uta.edu/biology/faculty/faculty.html http://www.okc.cc.ok.us/biologylabs/Documents/Zoology/PowerPoint.htm http://bio.fsu.edu/ http://www.aw-bc.com/ http://www.nhm.org/ http://www.geo.cornell.edu/eas/education/course/descr/EAS302/presentations/ It is very easy to find mistakes in these presentations…..I request you to kindly rectify them and supply me the modifications needed at [email protected] Thanks a lot and have fun in teaching & learning Zoology…. Dr. PARVISH PANDYA’s presentation
Phylum Platyhelminthes & Aschelminthes = Helminth worms flatworms Selected characteristics: Anatomy: thin and flat; digestion - free-living and parasitic forms excretion - protonephridia (flame cells) nervous - 1st CNS;ganglia, 2 ventral nerve cords, eyespots, auricles Dr. PARVISH PANDYA’s presentation
Triploblasts
Acoelomates Platyhelminthes Gastrotricha? Nemertea?
Coelomates
Protostomes Mollusca Onycophora Annelida Nemertea? Arthropoda Bryozoa? Tardigrada Protostome mouth from blastopore
Pseudocoelomates Nematoda Rotifera
Deuterostomes Echinodermata Hemichordata Chordata Deuterostome mouth not from blastopore
Dr. PARVISH PANDYA’s presentation
1. Phylum Platyhelminthes: Flatworms are acoelomates with gastrovascular cavities • There are about 20,000 species of flatworms living in marine, freshwater, and damp terrestrial habitats. – They also include many parasitic species, such as the flukes and tapeworms.
• Flatworms have thin bodies, ranging in size from the nearly microscopic to tapeworms over 20 m long.
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Dr. PARVISH PANDYA’s presentation
Phylum Platyhelminthes • • • • •
Flat worms Triploblastic Acoelomate Bilateral symmetry Hermaphroditic – Monoecious
• One opening for digestive system • Ladder nervous system
Dr. PARVISH PANDYA’s presentation
Flatworms are divided into four classes: Turbellaria Monogenia Trematoda and Cestoidea
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Dr. PARVISH PANDYA’s presentation
1. Class Turbellaria • free-living flatworms planarians (Dugesia) highly branched gastrovascular • cavity pharynx - muscular • opening to gastrovascular cavity
Dr. PARVISH PANDYA’s presentation
Class Turbellaria • Eye spots • Ciliated surface • Regenerate if cut in two
Dr. PARVISH PANDYA’s presentation
Turbellarian Pharynx Dr. PARVISH PANDYA’s presentation
Platyhelminthes • the most primitive bilateral animals? • 80% parasites (derived) • specialization potential • Class Turbellaria
• respiration • many w/symbionts for the O2 • increased respiration rate • some deep (5 cm) sediment hunters w/ hemoglobin and symbionts
Dr. PARVISH PANDYA’s presentation
• Flatworms have an excretory system called protonephridia, consisting of a branching network of dead-end tubules. – These are capped by a flame bulb with a tuft of cilia that draws water and solutes from the interstitial fluid, through the flame bulb, and into the tubule system. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Dr. PARVISH PANDYA’s presentation
• Flatworms and other bilaterians are triploblastic, with a middle embryonic tissue layer, mesoderm, which contributes to more complex organs and organs systems and to true muscle tissue. • While flatworms are structurally more complex than cnidarians or ctenophores, they are simpler than other bilaterans. – Like cnidarians and ctenophores, flatworms have a gastrovascular cavity with only one opening (and tapeworms lack a digestive system entirely and absorb nutrients across their body surface). – Unlike other bilaterians, flatworms lack a coelom. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Dr. PARVISH PANDYA’s presentation
• Planarians and other flatworms lack organs specialized for gas exchange and circulation. – Their flat shape places all cells close to the surrounding water and fine branching of the digestive system distributes food throughout the animal. – Nitrogenous wastes are removed by diffusion and simple ciliated flame cells help maintain osmotic balance.
Fig. 33.10 Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Dr. PARVISH PANDYA’s presentation
Turbellarian GI tracts • increasing complexity microturbellarians Acoela • simple pharynx • no gut cavity macroturbellarians Tricladia (3-branched) • tubular protrusible pharynx Polycladida (multi-branched) - marine • 3-brached protrusible pharynx
pharynx plicatus
Protonephridia • excretory • osmorgulatory • flame cells • filtration • selective absorption
Sensory structures • brain (ganglia) • net-like nervous system • variable number of longitudinal nerve cords • evolutionary trend toward net reduction • bilateral brain • paired longitudinal nerve cords • “pigment cup” ocelli (no. varies) • strong negative phototaxis • sensory pits -> chemoreception • complex behaviors - learning
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Phylum Platyhelminthes: Class Turbellaria
Acoelomate
Dr. PARVISH PANDYA’s presentation
Parenchyma • tissue connecting muscles and gut • large flatworms: mesenchymal cells in an extracellular matrix • small flatworms: matrix minimal or absent • liquid in some some fw forms - hydrostatic skeleton + internal transport • parenchymal cells types • epidermal replacement cells • neoblasts - totipotent, wound healing • fixed parenchymal cells - join cells and tissues • low-resistant pathways for intercellular transport of metabolites
2. Classes Trematoda and Monogenea • • • • • •
flukes parasites many feed with oral suckers and microvilli oral and ventral suckers used to attach to host gastrovascular cavity - not branched hosts: primary-where sexual reproduction of parasite occurs • intermediate-no sexual reproductive stage of parasite • Examples: Schistosoma mansoni - human blood fluke • Clonorchis sinensis - Chinese liver fluke
Dr. PARVISH PANDYA’s presentation
Class Trematoda • Flukes • Parasites • Holdfast devices – Most
• Complex life cycle • Intermediate host – Animal with juvenile stage
• Definitive host – Animal with adult stage
Dr. PARVISH PANDYA’s presentation
• Trematodes parasitize a wide range of hosts, and most species have complex life cycles with alternation of sexual and asexual stages. – Many require an intermediate host in which the larvae develop before infecting the final hosts (usually a vertebrate) where the adult worm lives.
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Dr. PARVISH PANDYA’s presentation
Fascioloa hepatica • Sheep liver fluke • Sheep, cattle and man – Weight loss
• Eat vegetation with metacercaria
Dr. PARVISH PANDYA’s presentation
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Generalized Fluke
Dr. PARVISH PANDYA’s presentation
Phylum: Platyhelminthes Class: Trematoda Fluke
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Dr. PARVISH PANDYA’s presentation
Fig. 46.6
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Life CycleDr. of the Sheep Liver Fluke PARVISH PANDYA’s presentation
Schistosoma • Blood flukes • 200 million people • 1 million deaths/year
Dr. PARVISH PANDYA’s presentation
• The blood fluke Schistosoma infects 200 million people, leading to body pains, anemia, and dysentery.
Dr. PARVISH PANDYA’s presentation
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Life Cycle of a Schistosome Fluke Dr. PARVISH PANDYA’s presentation
Schistosome • Cercaria have forked tail
Dr. PARVISH PANDYA’s presentation
Dr. PARVISH PANDYA’s presentation
Class Cestoidea • Tape worms • No digestive system • 40 feet long
Dr. PARVISH PANDYA’s presentation
3. Class Cestoda • • • • •
tapeworms parasitic no digestive cavity body: head = scolex proglottids = body sections containing male and female sex organs • Examples: human tapeworms; pigs, cows, and fish are intermediate hosts • Sushi - tapeworm infestation has risen with the popularity of this dish • ??Filariasis?
Dr. PARVISH PANDYA’s presentation
• Tapeworms (class Cestoidea) are also parasitic. – The adults live mostly in vertebrates, including humans. • Suckers and hooks on the head or scolex anchor the worm in the digestive tract of the host. • A long series of proglottids, sacs of sex organs, lie posterior to the scolex. • Tapeworms absorb food particles from their hosts. Dr. PARVISH PANDYA’s presentation
• Mature proglottids, loaded with thousands of eggs, are released from the posterior end of the tapeworm and leave with the host’s feces. – In one type of cycle, tapeworm eggs in contaminated food or water are ingested by intermediary hosts, such as pigs or cattle. – The eggs develop into larvae that encyst in the muscles of their host. – Humans acquire the larvae by eating undercooked meat contaminated with cysts. – The larvae develop into mature adults within the human. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Dr. PARVISH PANDYA’s presentation
Platyhelminthes • rhabdoids and rhabdites • some expel rhabdites to ensnare prey and gather detritus • duo-glands (adhesive and releaser glands)
• multi-ciliated cells • pedal waves • muscles • looping
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Pork Tapeworm Dr. PARVISH PANDYA’s presentation
(Taenia solium)
Scolex
Dr. PARVISH PANDYA’s presentation
Proglottid Testes Uterus Vas deferens
Seminal receptacle Ovary Yolk gland Dr. PARVISH PANDYA’s presentation
Life Cycle of the Broad-Fish Tapeworm Diphyllobothrium latum
Dr. PARVISH PANDYA’s presentation
Aschelminthes? Ecdysozoans? • the molting aschelminths • ecdysone-like steroids • 4 molts during development • multi-layered collagen cuticle • epidermis often syncytial • continue to grow between molts • eutely
Dr. PARVISH PANDYA’s presentation
Phylum Nematoda • 12,000 species – 500,000 possible
• Cylindrical body • Only longitudinal muscles • Noncellular cuticle with several layers • Pseuodcoelomate • Mouth and anus
Dr. PARVISH PANDYA’s presentation
Nematodes • Found everywhere – – – –
Soil Oceans Polar ice Hot springs
• Parasites of nearly all plant and animal species!
Dr. PARVISH PANDYA’s presentation
Musculature and Movement • no circular muscles - no peristalsis • dorsal and ventral longitudinal muscles • innervation – muscle processes extend to nerve cords • high internal pressure 10 x greater than most inverts • rigid cuticle, partially contracted muscles • round • sinusoidal waves
Dr. PARVISH PANDYA’s presentation
Feeding • 6 muscular lips (often fused to 3) • muscular pharynx moves food and keeps gut lumen open • pharyngeal glands lubricate + enzymes • digestion mainly extracellular • wastes voided by the minute
Dr. PARVISH PANDYA’s presentation
Respiration and Circulation • diffusion
Dr. PARVISH PANDYA’s presentation
Dr. PARVISH PANDYA’s presentation
females sluggish males active
12 US spp., 2 common
little host specificity Dr. PARVISH PANDYA’s presentation
Internal and External Features of a Nematode
Dr. PARVISH PANDYA’s presentation
Nematode Reproductive Systems Dr. PARVISH PANDYA’s presentation
• Roundworm of man • 1.2 billion people in US • Females lay 200,000 eggs a day • Unsanitary habits contaminate ground • Night soil Dr. PARVISH PANDYA’s presentation
Ascaris lumbricoides
Dioecious
Dr. PARVISH PANDYA’s presentation
Life Cycle of Ascaris lumbricoides
Dr. PARVISH PANDYA’s presentation
Trichinella spiralis • Trichina worm • Pigs, bear, dogs, cats, rats and man • Trichinosis – Encysts in muscles
Dr. PARVISH PANDYA’s presentation
Life Cycle of Trichinella spiralis
Dr. PARVISH PANDYA’s presentation
Wuchereria bancrofti • Lives in lymphatic system • Obstruct lymph to cause swelling – Elephantiasis
Dr. PARVISH PANDYA’s presentation
Elephantiasis
Dr. PARVISH PANDYA’s presentation
Life Cycle of Wucheria spp.
Dr. PARVISH PANDYA’s presentation
The End Dr. PARVISH PANDYA’s presentation
Related Documents
8 Parasitic Adaptations In Helminths
October 2019 5
Adaptations
June 2020 13
Parasitic Infections In Surgery
May 2020 8
Cellular Adaptations
July 2020 14
Parasitic Infestations
June 2020 9