Parasitology: Chapter 3 Nematodes

Morphological features

Multicellular, unsegmented and elongated, round on both ends, bilaterally symmetrical, the largest nematode know is the Dictophyma renale

External morphological features

Covered by a cuticle, the hypothermia produces the cuticle, somatic muscular layer; beneath the hypodermis that allows the nematode to move

Internal morphological features

Most important organ systems are the digestive and reproductive systems; the digestive tract extends from the mouth to the anus; females have a rectum and males have cloaca; they are dioecious

Types of eggs

Ascarid/roundworm type, Spirurid type, trichostrongyle/hookworm type

Types of larva

Microfilarae (pre-larval stage), Lungworm larvae (kinked tail larvae), Dracunculoid larvae (long-tailed larvae)

Direct life cycle

Where there is no intermediate host in the life cycle

Indirect life cycle

Where there is an intermediate host in the life cycle