Phylum Nematoda Lecture Notes

Comprehensive vocabulary flashcards covering the general characteristics, classification, and specific species of Phylum Nematoda as discussed in clinical parasitology.

Phylum Nematoda

The most abundant animal on earth; non-segmented, cylindrical worms with a body covering called a cuticle and longitudinal muscles.

Dioecious

A characteristic of nematodes referring to having separate male and female worms, where the female is typically larger.

Pseudocoel

The body cavity of a nematode, which contains a complete digestive tract with both oral and anal openings.

Amphids

Sensory organs located at the anterior end of a nematode that act as chemoreceptors.

Phasmids

Sensory nerve endings located at the posterior (caudal) end of a nematode that act as chemoreceptors.

Aphasmidea

A class of nematodes that includes Trichinella spiralis, Trichuris trichiura, and Capillaria philippinensis.

Phasmidea

A class of nematodes that includes Ascaris lumbricoides, Strongyloides stercoralis, Hookworms, Enterobius vermicularis, and Filarial worms.

Trichinella spiralis

The smallest nematode parasite of humans; known as the 'Trichina worm,' it is minute and threadlike and commonly found in carnivorous mammals, rats, and swine.

Trichuris trichiura

Known as the 'Whipworm,' its anterior $3/5$ is very thin and houses the esophagus, while the posterior $2/5$ is thick and stout, housing the intestine and reproductive organs.

Capillaria philippinensis

Known as the 'Pudoc Worm,' first recognized in the Philippines at PGH in 1963; infection occurs when various fresh water fish are eaten raw.

Ascaris lumbricoides

Known as the 'Giant Intestinal round worm' or 'Pink worm,' it affects more of the world's population than any other parasitic disease (1.3 billion people).

Strongyloides stercoralis

Known as the 'Threadworm,' it has a free-living generation (male and female) and a parasitic generation (parthenogenetic females).

Enterobius vermicularis

Known as 'Pinworm,' 'Seatworm,' or 'Oxyuris,' it is the most common helminth parasite in tropical and subtropical regions.

Hookworms (Ancylostomidae)

A group of parasites named for their hook-like appearance; they live in the host's intestine, attaching to the mucosa to feed on blood and tissue fluids.

Necator americanus

Known as the 'New world Hookworm,' introduced from Africa with the slave trade and found in North/South America, India, China, and SE Asia.

Ancylostoma duodenale

Known as the 'Old world Hookworm,' it is the only hookworm found in Europe and areas bordering the Mediterranean.

Ancylostoma braziliense

A hookworm found in domestic (cats and dogs) and wild carnivores in the tropics; causes human infection in countries including Brazil, the Philippines, and India.

Ancylostoma caninum

The most common hookworm of domestic dogs in the Northern Hemisphere; a common cause of creeping eruptions and eosinophilic enteritis.

Buccal capsule

A large structure at the anterior end of hookworms, hardened by fibrous tissue and armed with cutting plates, teeth, lancets, or a dorsal cone.

Copulatory bursa

A structure found in male hookworms consisting of 2 broad lateral lobes and a smaller dorsal lobe supported by fleshy rays, used as an important taxonomic characteristic.

Chitinized spicules

Structures found in male nematodes used specifically for copulation.

Autoinfection

A process through which Strongyloides stercoralis infections may persist in the host body.

C. hepatica

A species of Capillaria responsible for hepatic capillariasis.

C. aerophila

A species of Capillaria responsible for pulmonary capillariasis.