helminths and nematodes

• What are the two main phyla that parasitic worms belong to?

  Ecdysozoa and Lophotrochozoa
• What is the distinctive head region of cestodes called?

  Scolex
• What is the function of the rostellar hooks in cestodes?

  • Gripping the intestinal wall
  • Essential for attachment
• What is the body structure of cestodes called?

  Strobila
• What condition can cercariae cause when they infect human skin?

  Dermatitis
• What type of digestive system do nematodes have?

  Open at both ends
• What is the reproductive strategy of nematodes?

  Dioecious
• What are the common features of nematodes' body structure?

  Ornamented with ridges, rings, or bristles
• How many lips do nematodes have around their mouth?

  Either 3 or 6 lips
• What forms around the pharynx in nematodes?

  A ring that acts as a brain
• What are soil-transmitted helminths (STH)?


  Intestinal worms infecting humans
• What temperature can composting kill helminth eggs?


  Above 60°C
• How do hookworm eggs differ from Ascaris or Trichuris eggs?

  Hookworm eggs are not infective
• What are soil-transmitted helminths classified as due to their impact?

  Neglected tropical diseases
• What is the typical size of adult Ascaris lumbricoides?

  20 to 35 cm for females
• How many eggs can female Ascaris produce daily?

  200,000 eggs
• What is the duration for complete development from egg to adult Ascaris?

  1. 3 months
• What can heavy infestations of Ascaris cause in children?

  Stunted growth due to malnutrition
• What is the primary vector for filarial nematodes?

  Blood-feeding insects
• What is the disease caused by filarial nematodes?

  Filariasis
• What is the primary cause of elephantiasis?

  Infection of the lymphatic system
• What is the primary treatment for filariasis?

  Diethylcarbamazine (DEC) and ivermectin
• What is the main challenge in treating filariasis?

  No vaccines currently available
• What is the purpose of mass drug treatment for filariasis?


  To reduce transmission, not cure
• What was the estimated number of new cases of Dracunculus medinensis in 1986?

  1. 2 million new cases
• What is the significance of filter straws in Dracunculus medinensis control?

  They prevent humans from bathing blisters
• What is the primary vector for Dracunculus medinensis?

  Cyclops spp. (copepod crustaceans)
• What is the primary method of treatment for lymphatic filariasis?

  Surgical intervention to restore lymph flow
• What is the primary method of treatment for onchocerciasis?

  Removal of nodules and cataracts
• What do trematode eggs hatch into?

  Miracidia
• What is the role of miracidia in the trematode life cycle?

  They infect mollusks
• What do cercariae do in the trematode life cycle?

  They penetrate bird and human skin
• What type of parasites are monogeneans?

  Ectoparasites
• How do monogeneans differ from trematodes in terms of life cycle?

  Monogeneans have a direct life cycle
• What is the specialized organ used by monogeneans for attachment?

  Haptor
• What is the primary characteristic of nematodes?

  Cylindrical body with a cuticle
• What anatomical structures are visible in nematodes?

  Mouth, esophagus, intestine, anus
• What is the biological term for when a parasite alters its host's behavior?

  Host manipulation
• What type of environments do nematomorphids inhabit?

  Aquatic environments
• In which environment do adult nematomorphids reproduce?

  Aquatic environments