Animal Science Lecture 2 - Parasitology PDF

parasitology DR/ Mona Ibrahim  quiz time you have 10 questions, 2 mins for each  START !! 1 ) Animals are classified into VIVIPAROUS and OVIPAROUS according to : a) structure b) reproduction c) food they eat 2)....... It often acts as a...

parasitology DR/ Mona Ibrahim  quiz time you have 10 questions, 2 mins for each  START !! 1 ) Animals are classified into VIVIPAROUS and OVIPAROUS according to : a) structure b) reproduction c) food they eat 2)....... It often acts as a vector of the parasite. a) final host b) primary host c) intermediate host  START !! 3)They are protozoans whose body is surrounded by a thin protoplasmic membrane with no definite shape. a)Mastigophora b) Trypanosoma sp. c) sarcodina 4) the prev. organism have......... as an organ of locomotion and also help in feeding. a) pseudopodia b) cilia & flagella c) gliding  START !! 5)........... is the main type of reproduction In ciliates such as Paramecium a)Conjugation b) Endopolygeny c) Gamontogamy 6) The infective stage in Trypanosoma is.................. a. Procyclic trypomastigotes b. Epimastigotes c. Metacyclic trypomastigotes.  START !! 7)10)African sleeping sickness is cause by..................... a- Trypanosoma b- Trypanosoma c-Trypanosoma gambiense d- a& b rhodesiense cruzi T or F question 8) subkingdom metazoa is classified into protozoa and Eumetazoa , the first is divided into radiata and bilateria. 9) Gamontogamy is a special form of sexual reproduction where the gametes fuse together 10)The intermediate host in Chagas disease is Tse Tse fly now, lets start our lec.  Subclass Coccidia Plasmodium sp. They are intracellular blood parasites of blood cells and tissues of birds and mammals. They causes to human several diseases, which transmitted by blood sucking arthropods acts as intermediate hosts. There are four species of Plasmodium causing malaria to man: 1. Plasmodium vivax 2. P. malariae 3. P. ovale. 4. P. falciparum vedio time !!! Life cycle of Plasmodium sp. 1-Exerythrocytic cycle (Liver stage) 2- Erythrocytic cycle (Human blood stage) 3- Mosquito stage  Life cycle of Plasmodium sp Female Anopheles mosquito Man (Intermediate host) : (Final host) : 1.Schizogony in liver cells (Exo- 1.Gamogony (Sexual cycle inside erythrocytic cycle): the stomach of mosquitoes). A.Primary tissue phase 2.Sporogony (Asexual cycle in B.Secondary tissue phase or Re-infection haemolymph of mosquitoes) 2.Schizogony in RBCs (Erythrocytic cycle) Life cycle of Plasmodium sp  Kingdom Animalia-Subkingdom Metazoa Branch Parazoa Phylum Porifera (Sponges) (Pore bearers) They are stationary and rooted in their places, and so they were considered as plants for centuries, but eventually their animal nature was discovered. The Porifera (15,000 species) represent Metazoa at the cellular level of organization. Sponges are usually found in relatively shallow water, but some groups live at great depths. Few species live in freshwater.  General characters of Sponges 1. They are radially symmetrical. 2. Body with many pores or ostia through which water flows. 3. The internal cavity is known as spongocoel lined with choanocytes (flagellated cells). 4. They are holozoic with no mouth, no digestive system and digestion is intracellular. 5. They respire and excrete by simple diffusion.  Kingdom Animalia-Subkingdom Metazoa Branch Eumetazoa (Enterozoa) Division Radiata (Diploblastica) Phylum Cnidaria (Coelenterata) Classification of Phylum Cnidaria: - Phylum Cnidaria is classified into 4 classes which are: 1-ClassHydrozoa(Gr., hydro, water + zoon, animal) = Water animals, Examples: Hydra, Obelia. 2-Class Scyphozoa (True jelly-fish), Example: Aurelia. 3-Class Cubozoa (Cube jelly-fish), Examples: Box jellies (Sea wasps). 4-Class Anthozoa (Actinozoa) (Gr., anthos, flower + zoon, animal) = Flower animals  Kingdom Animalia-Subkingdom Metazoa Branch Eumetazoa (Enterozoa) Division Radiata (Diploblastica) Phylum Cnidaria (Coelenterata) Class Anthozoa is subdivided into two subclasses: a- Subclass: Alcyonaria (Soft corals), Examples: Alcyonium, Xenia. b- Subclass: Zoantharia (hard corals), Examples: Sea anemones & stony corals. Xenia Sea anemone stony coral  General characters of Cnidarians 1)They are solitary or colonial, sedentary or free swimming. 2)They are aquatic, mostly marine, some are fresh water. 3)The body is radially symmetrical. 4)Most cnidarians are carnivorous. 5)There is a central gastro-vascular cavity (coelenteron or enteron) which is communicated with the exterior by a single opening, the mouth. 6)The mouth is surrounded by tentacles arranged in one or more whorls. The tentacles help in food capture, ingestion and for defense. 7)Body wall has peculiar stinging cells called cnidocytes which are more abundant on the tentacles than elsewhere. General characters of Cnidarians  Helminthology (Science of studying worms) These are triploblastic, dividing according to the presence or absence of coelom (body cavity) into:  Helminthology (Science of studying worms) 2- 1- Acoelomate Pseudocoelomate 3- Coelomate e.g. e.g. e.g. Anellida & higer Platyhelminthes Nematoda taxa (Flatworms) ( round worms) ( ring worms) * Has no body * Has a body cavity * Has a body cavity; spaces (pseudocoelom) lined cavity (coelom) between organs externally by lined externally are filled by mesoderm and and internally by parenchyma internally by mesoderm endoderm. Kingdom Animalia-Subkingdom Metazoa Branch Eumetazoa (Enterozoa) Division Bilateria (Triploblastica) Section Acoelomata Phylum Platyhelminthes (Flatworms)  General characters 1- Body dorso-ventrally compressed with bilateral symmetry. 2- Triploblastic animals. 3- Epidermis is soft and ciliated as in Turbellaria or covered by tegument and with external suckers or hooks or both for attachment to host as in Monogenea, Digenea and Cestoda. 4- There is no secondary body cavity (acoelomate). 5- The muscular system is well developed. 6- Incomplete digestive system (with mouth, no anus). 7- Excretory system represented by flame cells or solenocytes. 8- It is the first phylum possesses some sense organs and central nervous system. 9- Sexes usually monoecious or hermaphrodite (except Schistosoma) with a complicated reproductive system. 10- No skeletal, circulatory or respiratory systems.  Classification of Phylum Platyhelminthes: - Five classes of Phylum Platyhelminthes are recently recognized: 1- Class: Turbellaria, mostly free living. 2- Class: Monogenea, typically ectoparasitic. 3- Class: Aspidogastrea (Aspidobothrea) 4- Class: Digenea, endoparasitic. E.g. Fasciola, Schistosoma 5- Class: Cestoda (Tape worms), endoparasitic & segmented. E.g. Taenia  Class Digenea General characters 1- All endoparasitic 2- Body is flattened and unsegmented 3- Attach to their hosts by suckers 4- Alimentary canal with mouth and no anus 5- Complex muscle layers 6- Excretory organs and nervous system are present The adult worms are found in different tissues of the primary host (vertebrate). According to their location in the body of the host, digenetic trematodes are grouped as follows: 1- Hepatic or liver flukes, e.g. Fasciola 2- Blood flukes, e.g. Schistosoma 3- Intestinal flukes, e.g. Heterophyes  Liver Flukes (Fasciolaspp.) -The adult worms live in the bile ducts of the liver of cattle, sheep and pigs. -It produces the disease known as Fascioliasis (liver rot). -Fasciolagiganticais the common liver fluke in Egypt, while Fasciola hepatica (human liver fluke) is more common in Europe and Australia. -Mode of infection: When man eats vegetables or animals ingest the aquatic plants which contain the encysted metacercariae (infective stage).  Liver Flukes (Fasciolaspp.)  Blood Flukes (Schistosoma spp. or Bilharzia) - Schistosomes cause serious disease called Schistosomiasis or Bilharziasis. - Mode of infection: Cercariae (infective stage) penetrate the skin of man when drinking, washing, walking or bathing in infected water. Intermediate host Mesenteric vein Venous Final host plexus of bladder  Kingdom Animalia Subkingdom Metazoa Branch Eumetazoa (Enterozoa) Division Bilateria (Triploblastica) Section pseudocoelomata  General characters 1- They are bilaterally symmetrical, unsegmented triploblastic worms. 2- Pseudocoelomate animals with slender cylindrical bodies. 3- Alimentary canal is straight and complete with mouth and anus (or cloacal opening). 4- Respiratory and circulatory systems are absent. 5- Cuticle usually present and cilia are absent. 6- Body wall with longitudinal muscles only. 7- Excretory system of glandular organs or a system of canals or both. 8- Dioecious; male is smaller than female. 9- Fertilization is internal. 10-The nervous system is composed of a nerve ring around the oesophagus from which arise 6 short anterior and 6 long posterior nerve cords. 11- Eggs are shelled covering with a chitinous shell. 12- Development is usually direct and no asexual reproduction or regeneration occurs.  Classification of Phylum Nematoda Phylum Nematoda is classified into 2 main classes: 1. Class: Secernentea (Phasmidea), It includes: a. Order: Ascaridida e.g. Ascaris lumbricoides (Eel worm) b. Order: Strongylida e.g. Ancylostoma duodenale (Hook worm) Ascaris lumbricoides (Eel worm) This is a common intestinal parasite of man (children in particular) & other animals. It causes to the human a disease known as Ascariasis: [a] In mild infections, it causes abdominal disorders [b] In severe cases, it causes general weakness, intestinal obstruction, hepatitis obstruction of biliary passages & further of the trachea, lead to suffocation‫االختناق‬  Ascaris lumbricoides (Eel worm) Mode of infection: When man eats vegetables & food or drinks water contaminated with the second rhabditiform larvae (infective stage  Morphology of Ascaris [A] Anterior end : 1- Head has a terminal mouth, surrounded by three lips 2- Dorsal lip bear two double sensory papillae, and each latero-ventral lip has one double sensory papillae 3- Each latero-ventral lip has amphid which are olfactory chemoreceptors 4- Lips have fine teeth 5- Excretory pore behind lips [B] Cuticle of the body : Smooth with Four longitudinal epidermal lines (one dorsal, one ventral, two lateral) [C] Posterior end: 1- Male has cloacal aperture provided with number of anal papillae with two equal spicules project 2- Female has vulva on the anterior part Morphology of Ascaris life cycle of Ascaris Thank You