METHODICAL INSTRUCTION FOR STUDENTS
ON MEDICAL BIOLOGY
Speciality “Nurse”
(distant form of studies)
LESSON № 5
Theme: Medical Helminthology. Phylum Plathelminthes. Classes Trematoda and Сestoidea. Phylum Nemathelmithes. Class Nematoda.
Number of hours: 6
Aim: to know general characteristics of phylum Plathyhelminthes, morphological peculiarities, life cycles and pathogenic significance of helminthes of class Trematoda and Cestoda; be able to determine their reference to species, to ground the methods of laboratory diagnostics and prophylactics of schistomiasis, paragonimiasis, clonorchiasis, fascioliasis, opisthorchiasis, dicrocoeliasis, teniasis solium, cysticercosis, taeniasis saginata, diphyllobothriasis.
To know morphological peculiarities, life cycles and pathogenic significance of Ascaris lumbricoides, Enterobius vermicularis, Trichuris trichiura, Trichinella spiralis, Ancylostoma duodenale, Necator americanus, Strongyloides stercoralis; be able to determine their reference to species, to ground the methods of laboratory diagnostics and prophylactics of ascariasis, enterobiasis, trichuriasis, trichinosis, ancylostomiasis, strongyloidiasis.
Professional orientation of students: Schistosomiasis,
paragonimiasis, clonorchiasis are tropical diseases. Schisthosoma are affect
about
Methodology of Practical Class:(900 – 1200).
Task 1. Biliary (liver) flukes. Fasciola hepatica
Sketch it in the notebook. Make following designations: Anterior and ventral suckers, uterus, testis.
Fasciola hepatica:
1.
2.
3.
4.
Examine slide of Fasciola hepatica eggs. Draw ovum of this helminth. Mark operculum and membrane.
Fasciola hepatica egg:
1.
2.
Study the life-cycle of Fasciola hepatica. Note stages of parasite development and their habitat.
Development stage |
Habitat |
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A |
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B |
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C |
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D |
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E |
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F |
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G |
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Give the characteristics of Fasciola hepatica.
Invasive stage for a man - _______________________________________________________
Laboratory diagnosis - __________________________________________________________
Prevention - __________________________________________________________________
Task 2. Lanceolate fluke - Dicrocelium lanceatum.
Sketch it in the notebook. Make following designations: Anterior and ventral suckers, testis.
Dicrocelium lanceatum:
1.
2.
3.
Study the life-cycle of Dicrocelium lanceatum. Note stages of parasite development and their habitat.
Development stage |
Habitat |
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1 |
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2 |
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3 |
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4 |
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5 |
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6 |
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Give the characteristics of Dicrocelium lanceatum.
Invasive stage for a man - _______________________________________________________
Laboratory diagnosis - __________________________________________________________
Prevention - __________________________________________________________________
Task 3. Cat fluke - Opisthorchis felineus.
Sketch it in the notebook. Make following designations: anterior and ventral suckers, testis.
Opisthorchis felineus:
1.
2.
3.
Study the life-cycle of Opisthorchis felineus. Note stages of parasite development and their habitat.
Development stage |
Habitat |
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1 |
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2 |
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3 |
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4 |
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5 |
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6 |
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Give the characteristics of Opisthorchis felineus.
Invasive stage for a man - _______________________________________________________
Laboratory diagnosis - __________________________________________________________
Prevention - ___________________________________________________________________
Task 4. Write the differences between pathogenic species of Trematodes in the table.
Characteristics |
Fasciola hepatica |
Dicrocelium lanceatum |
Opisthorchis felineus |
Paragonimus westermani |
Parasites of genus Shistosoma |
Disease |
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Localization inside human body |
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Definitive host |
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Intermediate host |
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Route of transmission |
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Source of invasion |
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Task 5. Study the life-cycle of Taenia solium.(pork tapeworm) Note stages of parasite development.
Life-cycle of Taenia solium:
1.
2.
3.
4.
5.
6.
7.
Give the characteristics of Taenia solium.
Invasive stage for a man - _______________________________________________________
Laboratory diagnosis - __________________________________________________________
Prevention - __________________________________________________________________
Task 6. Study the life-cycle of Taenia saginata (beef tapeworm). Note stages of parasite development.
Life-cycle of Taenia saginata:
1.
2.
3.
4.
5.
6.
Give the characteristics of Taenia saginata.
Invasive stage for a man - _______________________________________________________
Laboratory diagnosis - __________________________________________________________
Prevention - __________________________________________________________________
Task 7. Study the life-cycle of Diphyllobothrium latum, (fish tapeworm). Note stages of parasite development.
Life-cycle of Diphyllobothrium latum:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Give the characteristics of Diphyllobothrium latum.
Invasive stage for a man - _______________________________________________________
Laboratory diagnosis - __________________________________________________________
Prevention - __________________________________________________________________
Task 8. Study the life-cycle of. Echinococcus granulosus (dog tapeworm). Note stages of parasite development.
Life-cycle of. Echinococcus granulosus:
1.
2.
3.
4.
5.
6.
7.
Give the characteristics of Echinococcus granulosus (dog tapeworm).
Invasive stage for a man - _______________________________________________________
Laboratory diagnosis - __________________________________________________________
Prevention - ___________________________________________________________________
Task 12. Enterobius vermicularis (pinworm) – the causative agent of Enterobiasis.
Study the life-cycle of Enterobius vermicularis. Note stages of parasite development.
Enterobius vermicularis:
1.
2.
3.
4.
Examine the slide of Enterobius vermicularis eggs under microscope (7 x 40). They are transparent and colorless, asymmetrical. Their membrane is thin and smooth. Sketch them. Mark membrane and larva.
Enterobius vermicularis egg:
1.
2.
Give the characteristics of Enterobius vermicularis.
Source of invasion _____________________________________________________________
Invasive stage for a man ________________________________________________________
Localization inside human body __________________________________________________
Pathogenicity _________________________________________________________________
_____________________________________________________________________________
Laboratory diagnosis ___________________________________________________________
Prevention ____________________________________________________________________
Task. 13 Ascaris lumbricoides – the causative agent of Ascariasis.
Study the life-cycle of Ascaris lumbricoides. Point out stages of its development.
Ascaris lumbricoides:
1.
2.
3.
4.
5.
The scheme of Ascaris larvae migration in the human body:
Intestine → ______________________ → ___________________________→ _________________________→ _________________________ → ___________________ → ___________________ → _____________________→ ______________________ → intestine.
Examine the slide of Ascaris lumbricoides eggs under a microscope (7 x 40). They are brown, oval or round form, covered by membranes. An external membrane is tuberous. Sketch. Mark membrane and larva.
Ascaris lumbricoides egg:
1.
2.
Give the characteristics of Ascaris lumbricoides.
Source of invasion _____________________________________________________________
Invasive stage for a man ________________________________________________________
Localization inside human body __________________________________________________
Pathogenicity _________________________________________________________________
_____________________________________________________________________________
Laboratory diagnosis ___________________________________________________________
Prevention ____________________________________________________________________
Task. 14. Trichuris trichiura (whipworm) – the causative agent of Trichuriasis.
Study the life-cycle of Trichuris trichiura. Note stage of parasite development.
Trichuris trichiura:
1.
2.
3.
4.
Examine the slide of Trichuris trichiura eggs under a microscope (7 x 40). The typical eggs are brown, barrel-shaped with a plug at each end. Sketch. Mark membrane, plug and larva.
Trichuris trichiura egg:
1.
2.
3.
Give the characteristics of Trichuris trichiura.
Source of invasion _____________________________________________________________
Invasive stage for a man ________________________________________________________
Localization inside human body __________________________________________________
Pathogenicity _________________________________________________________________
_____________________________________________________________________________
Laboratory diagnosis ___________________________________________________________
Prevention ____________________________________________________________________
Task 15. Trichinella spiralis – the causative agent of trichinosis
Examine the slide of encapsulated Trichinella spiralis larvae in cross-striated muscles of the rat under a microscope (7 x 8; 7 x 40). Sketch. Mark: 1-capsules, 2-muscles fibers, 3-Trichinella larvae.
Trichinella spiralis:
1.
2.
3.
Study the life-cycle of Trichinella spiralis. Note stage of parasite development and their location.
The life-cycle of Trichinella spiralis:
A |
B |
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Development in pig organism |
Development in human organism |
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1 |
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2 |
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3 |
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4 |
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Give the characteristics of Trichinella spiralis.
Source of invasion _____________________________________________________________
Invasive stage for a man ________________________________________________________
Localization inside human body __________________________________________________
Laboratory diagnosis ___________________________________________________________
Prevention ____________________________________________________________________
Seminar discussion of theoretical issues: (1230 - 1400).
Individual Students Program
1. Medical Helminthology. Phylum Plathelminthes. Classes Trematoda and Сestoidea.
1. General characteristic of class Trematoda.
2. Blood Flukes: Schistosoma haematobium, Schistosoma mansoni, Schistosoma japonicum.
3. Lung Fluke: Paragonimus westermani.
4. Biliary Flukes: Clonorchis sinensis, Fasciola hepatica, Opisthorchis felineus, Dicrocoelium lanceatum.
5. General characteristics of class Cestoda.
6. Taenia saginata: morphological peculiarities, distribution, life cycle, transmission, pathogenic significance.
7. Taenia solium: morphological peculiarities, distribution, life cycle, transmission, pathogenic significance.
8. Diphyllobotrium latum: morphological peculiarities, distribution, life cycle, transmission, pathogenic significance.
9. Clinical manifestation and laboratory diagnosis of teniasis, cysticercosis, diphyllobothriasis.
10. Prevention of teniasis, cysticercosis, diphyllobothriasis.
2. Phylum Nemathelmithes. Class Nematoda.
1. General characteristics of Nematodes.
2. Ascaris lumbricoides, Enterobius vermicularis, Trichuris trichiura, Trichinella spiralis, hookworms, Strongyloides stercoralis: morphological peculiarities, distribution, life cycle, transmission, pathogenic significance.
3. Laboratory diagnostics of ascariasis, enterobiasis, trichuriasis, trichinosis, ancylostomiasis, strongyloidiasis.
4. Prevention of trichinosis, ancylostomiasis, strongyloidiasis, ascariasis, enterobiasis, trichuriasis.
Test evaluation and situational tasks.
Multiple Choices.
Choose the correct answer / statement:
1. Where do schistosomes lay fertilized eggs:
A bronchial tubes B intestine
C blood vessels D muscles E bile duct
A fascioliasis B paragonimiasis C chlonorchiasis
D shistosomiasis E ascariasis
3. Indicate parasites which exist as separate sexes but live attached to each other (female resides in a groove in the male, where he continuously fertilizes her eggs):
A schistosomes B Fasciola hepatica C Paragonimus westermani
D Opisthorchis felineus E Ascaris lumbricoides
4. The life cycle of Clonorchis involves asexual reproduction in which animal:
A snail B crab C pig D fish E cattle
Real - life situations to be solved:
6. Name organs of human body in blood vessels of which lay eggs
a) S.haematobium; b) S.mansoni; c) S.japonicum.
8. Indicate the system which Cestodes have not:
A digestive system
B excretory system
C nervous system
D respiratory system
E genital system
9. What kind of helminthosis is characterised by the development of anemia?
A Teniasis solium B Cysticercosis C Taeniasis saginata
D Diphyllobothriasis E Fascioliasis
10. Which cestode causes cysticercosis?
A Taenia solium B Taenia saginata C Diphyllobotrium latum
11. What is the characteristic feature of gravid proglottid of Taenia solium?
A 17 –35 uterine branches
B 7 –12 uterine branches
C bilobed ovary
D trilobed ovary
E gravid uterus is in the form of rosette
Correct answers of test evaluations and situational tasks:
1. C. 2. B.
Self-study (1415 - 1500).
Written test students in “MOODLE”, thematic view instructional videos, in-depth study of material fact made in the independent work.
References
Basic:
1. Bihunyak T.V. Medical Biology – Ternopil:TSMU, 2010. – 214 p.
2. Lynn B. Jorde Medical Genetics / Lynn B. Jorde, John C.Carey, Michael J.Bamshad [et al] – 2006. – 363 p.
3. Sylvia S. Mader Biology. / Sylvia S. Mader, Wm. C. Brown Publishers: Dubuque, Lowa – Melbourne, Australia – Oxford, England, IV edition. – 1996. – 850p.
4. Goodman R. Medical cell biology – Philadelphia, Lippincott-Reven, 1998. –
320 p.
5. Lazarev K.V. Medical biology – Simferopol: IAD CSMU, 2002. – 350 p.
6. Stephen L. Wolfe Introduction to Cell and Molecular Biology – Wadsworth Publishing Company, 1995. – 820 p.
7. G. Thomas Strickland Hunter’s Tropical Medicine – W.B. Saunders Company, 1984. – 1057 p.
Additional:
1. Alberts B. Molecular biology of the cell / Alberts B., Bray D., Lewis J. [et al] – Garland Publishing, NY&London, 1997. – 630 p.
2. Jan A. Pechenik Biology of the Invertebrates – Boston, Massachusetts, III-th edition, 1996. – 557 p.
3. Alberts B. Molecular biology of the cell / Alberts B., Bray D., Lewis J. [et al] –- Garland Publishing, NY&London, 1989. – 1218 p.
4. Strachan T. Human molecular genetics / Strachan T., Read A.P. – Bios Scientific Publ., 1996. – 596 p.
5. Sylvia S.Mader Biology. Art notebook / Sylvia S.Mader, Wm. C. Brown Publishers: Dubuque, Lowa – Melbourne, Australia, 1995. – 205 p.
6. USMLE STEP1. Biochemistry. Lecture notes. – 2004. – 351 p.
7. Elmer W. Koneman Color Atlas and Textbook of Dioagnostic Microbiology / Elmer W.Koneman, Stephen D.Allen, William M.Janda – Lippincott, 1997. – 1395p.
Methodical instruction
has been worked out by: Bihunyak Tatyana
Methodical instruction was discussed and adopted
at the Department sitting 27.08.2013.
Minute № 1