Clinical Helminthology

Metazoans

They are multicellular invertebrates characterized by elongated, flat or round bodies.
They contain internal organ systems

Parthenogenetic

It can produce an offspring from the ovum without prior fertilization

Oviparous

Produces offspring by means of egg or ovum

Larviparous

produces offspring by means of larva

Hermaphroditic

possesses the reproductive organs of both sexes

unsegmented
have mouth, esophagus, anus
have separate sexes (male / Female)
some are parthenogenetic
oviparous or larviparous

Nematodes

segmented (proglutin)
have scolex, neck, proglottids hermaphroditic
oviparous or larviparous

Cestodes

unsegmented.
leaf-like or cylindrical
generally, hermaphroditic
digenetic, oviparous or larviparous

Trematodes

roundworms

Nematodes are also known as

Nematodes

They are unsegmented, elongated, cylindrical worms with bilateral symmetry

digestive tract and a muscular pharynx that is triradiate

Nematodes possess a well-developed ___

circulatory system

Nematodes do not have ____

diffusion

Nematodes distributes food and nutrients by ____

Adult males

They are generally smaller than the adult females and have a curved posterior end

Copulatory spicules
Copulatory bursa

Reproductive system of adult male nematodes

Copulatory spicules

needle-like mating structures

Copulatory bursa

used for grasping the female during mating (hand)

Amphids
Phasmids

Sensory organs of nematodes

Amphids

sensory organ at the anterior end (upper / head)

Phasmids

sensory organ at the posterior end (lower / tail)

Phasmid
Aphasmid

Calssification of phasmid

Class Secernentea

Phasmid

Class Adenophorea

Aphasmid

Capillaria
Ascaris
Strongyloides
Hookworms

Small intestine

Trichuris
Enterobius

Large intestines

Wuchereria (lymph nodes or vessels)
Brugia (lymph nodes or vessels)
Angiostrongylus (eyes and meninges)
Trichinella (muscle)

Extraintestinal

Ascaris
Trichuris
Enterobius

Ingestion of embryonated eggs

Hookworms
Strongyloides

Skin penetration of filariform larvae

Wuchereria
Brugia

Mosquito bite

Capillaria (fish)
Trichinella (pork)
Angiostrongylus (snails)

Ingestion of infective larvae

Enterobius
Ascaris

Inhalation

Capillaria
Enterobius
Strongyloides

Autoinfection

Hookworms
Ascaris lumbricoides
Trichuris trichiura

Unholy Three

Hookworms
Ascaris lumbricoides
Strongyloides stercoralis

Heart-Lung Migration

Retro infection

Goes back from its original plate

concomitants

Infected with one, infected with others