INTRODUCTION ABOUT ARTHROPOD

• major characteristics of Arthropoda


  chitinous exoskeleton, segmented, bilaterally symmetrical, haemocoel (open vascular system), ventral nerve cord, jointed appendages, sexual reproduction.
• the exoskeleton of arthropods are covered by?

  chitinous cuticle
• Crustacea and millipede's cuticle are hardened by this

  calcium
• insects' cuticle is chemically bonded by this

  protein
• A dorsal vessel directs blood (haemolymph) forward toward the brain, an open system (hemocoel) allows the blood to circulate back through the body
• located above the digestive system

  brain ganglia
• True or false. Ventral nerve cord is present at each segment

  True
• True or false. Female arthropods cannot produce offspring without mating

  False
• The parthenogenic ability of a female to produce female offspring without mating
• If the egg is not fertilized, the haploid egg containing a single set of chromosomes will develop into a male. This means the males are haploid, and the females are diploid—a condition called haplodiploidy
• Class Crustacea

  • lobster, crabs
  • at least 5 pairs of locomotory appendages
  • aquatic
  • respiration-blood gills/body wall
  • exoskeleton is hard
• what is the species under class Crustacea that is important in public health?

  Cyclops sp. - intermediate host for tapeworm and guinea worm
• what is the scientific name of guinea worm?

  Drancunculus medinensis
• Class Onychophora

  • annelid-like arthropods
  • ancestors of arthropods
  • moderately-sized, soft bodied
  • caterpillar-liked
  • no known medical importance
• Class Insecta

  • terrestrial, air-breathing, hard exoskeleton, jointed appendages
• True or false. Species under class Insecta have 1 pair of maxilla

  False. 2
• Class Myriapoda

  • air-breathing, terrestrial
  • cylindrical body
  • distinct head
  • head, thorax (each 1 par of legs)
  • other segments - each 2 pairs of legs
  • total of 80-400 legs
• Class Chilopoda (centipedes)

  • terrestrial
  • body flattened dorsoventrally
  • head distinct
  • each segment except last 2 bears 1 pair of legs
  • appendages of first segment modified into poison claws
• Class Arachnida

  • air-breathing
  • head and thorax fused into cephalothorax
  • 4 pairs of walking legs
  • lack antennae
  • abdomen may or may not be segmented
• how arthropods affect host?

  • transmitting agents of diseases (mechanical or biological: propagative, cyclopropagative, cyclo-developmental, transoovarian
  • invading tissues
  • inoculating venon/poisons
• the pathogen has no developmental changes

  propagative
• cyclo-propagative


  pathogens undergo development and multiplication
• pathogen undergoes developmental stages without multiplication


  cyclo-development
• pathogens transmitted to offspring of the vector


  transovarian
• what are example/s of arthropods that are cyclo-propagative transmitting agents?

  malaria parasites
• what are example/s of arthropods that are cyclo-development transmitting agents?

  filariasis
• what are example/s of arthropods that are transovarian transmitting agents?

  scrub typhus, dengue virus in mosquitoes
• parasitic infection caused by flies

  myiasis
• parasitic infection caused by moth and butterfly

  scoleciasis
• parasitic infection caused by beetles

  canthariasis
• medicinal use of arthropods


  maggot debridement therapy (MDT)
• what are the other uses of arthropods?

  medicinal use, forensic indicators, food