Parasitology Lecture 2 PDF

① Flattened dorsoventrally (leaf like) except Schistosoma → has rounded female. ② Has no body cavity. ③ Unsegmented. ④ Bilaterally symmetrical. ⑤ Organs of fixation: a) Oral sucker: at the anterior end surrounding the mouth. b) Ventral sucker: in the ventral surface c) Spines cover the cutic...

① Flattened dorsoventrally (leaf like) except Schistosoma → has rounded female. ② Has no body cavity. ③ Unsegmented. ④ Bilaterally symmetrical. ⑤ Organs of fixation: a) Oral sucker: at the anterior end surrounding the mouth. b) Ventral sucker: in the ventral surface c) Spines cover the cuticle and help fixation. ⑥ Digestive system: a) Mouth at the anterior end b) Esophagus having a muscular pharynx c) Two intestinal caeca end blindly at the posterior end ⑦ Hermaphrodites (each adult parasite contains both male and female sex organs) except Schistosoma (unisexual, separate sex, male or female parasite). ① Flattened dorso-venterally. ② No body cavity. ③ No digestive canal (gets its food by diffusion) ④ Segmented into scolex, neck and strobila.  Carries special organs in order to fix the parasite in its place called organs of fixation such as: ❶ ① Suckers or grooves (bothria) ② Rostellum which is a terminal protuberance ③ Hooks which is usually arises from the rostellum ❷  Actively dividing part forming strobila (parasite segments).  Chain of segments which is divided into: ① Immature segments: Reproductive organs are not fully developed. ❸ ② Mature segments: Reproductive organs are fully developed and functioning. ③ Gravid segments: uterus is full of eggs. ⑤ Hermaphrodites: each mature segment contains both male and female sex organs.  Cross as well as auto-copulation takes place. ① Cylindrical, rounded in cross section. ② Has a body cavity. ③ Unsegmented. ④ Separate sexes (unisexual), females are longer than males. ⑤ Digestive system:  Mouth that may have lips, papillae, a buccal cavity or provided with teeth.  Esophagus which takes different shapes  Intestine ends in the anus Leaf ,unsegment Elongated, cylindrical. Tape like ,segmented Unsegmentd No sucker no hooklet Suckers present, some Sucker present, no some have devp buccal hooklets hooklets cavity Present incomplete Absent Complete with mouth Absent Absent Present Monecious Except Monoecious Diecious schistosomes EGG → LARVAL STAGE(S) (IN IH)→ ADULT (IN DH).   The most common method of transmission is through oral route by contaminated food, water, soiled fingers.  The infective stages being cysts, embryonated eggs, or larval ❶ forms.  Infection with E.histolyticaand other intestinal protozoa occurs when the infective cysts are swallowed. ❷  Another important mode of transmission.  Many parasitic diseases are transmitted by in sect bite. ❸  Filaria is transmitted by bite of female Culex mosquito  Parasitic infection may be transmitted by person to person ❹ contact in some cases (Entrobious Pin Worm)  Mother to fetus transmission may take place in Toxocara from mother dog to puppies. ❺  DEPENDS ON PARASITE COURSE OF DEVELOPMENT INSIDE THE HOST AND ITS HABITAT. ① Abdominal colic. ② Diarrhea. ❶ ③ Vomiting. ④ Loss of appetite, loss of weight. ⑤ Vitamins deficiencies. ① Prolonged fever ② Right hypochondrium pain ❷ ③ Jaundice ④ Hepatomegaly. ① Chest pain ② Cough ❸ ③ Dyspnea (difficult breathing) ④ Hemoptysis (coughing of blood). ⑤ Respiratory failure. ① Hepatospleenomegally, ② Esophageal varices: ❹  Hematemesis (vomiting of blood)  Melena (black stool due to the presence of blood)  Elephantiasis. ❺ ① Clinical picture (symptoms and signs) ② Laboratory diagnosis ③ Radiological diagnosis: X Ray, US, C T or MRI on affected organs  To detect the characteristic eggs, segments or larvae  In intestinal or hepatobiliary helminths: stool examination helps in diagnosis  Pulmonary helminths: Sputum Stool examination ❶  Serological tests: detect antibodies in serum.  Skin tests. ❷ ① Which one of the following parasites is segmented and has no body cavity? a) Nematoda b) Cestoda c) Trematoda d) Intestinal protozoa ② Which one of the following parasites needs snail as an intermediate host to complete its life cycle? a) Nematoda b) Cestoda c) Trematoda d) Intestinal protozoa