Phylum Nematoda: Form, Function, and Classification

This set of flashcards covers key vocabulary related to the form, function, and classification of phylum Nematoda, based on the provided lecture notes.

Nematoda

A phylum of roundworms, many of which are abundant and non-parasitic, with some causing diseases.

Cuticle

An external non-living coating that lines the body and cavities of nematodes.

Sensilla

Sensory structures in nematodes, including papillae (tactile organs), amphids (chemoreceptors), and phasmids (sensory receptors).

Papillae

Tactile organs located at the anterior and posterior ends of nematodes.

Amphids

Chemoreceptors located at the anterior end of nematodes.

Phasmids

Sensory receptors located at the posterior end of nematodes.

Buccal modifications

Special adaptations such as teeth found in parasitic nematodes that assist with feeding.

Muscular pharynx

A pumping mechanism that sucks food and forces it into the intestine, necessary for high pressure in the pseudocoel.

Cloaca

A shared opening in females of nematodes where the rectum connects to the anus and also receives sperm.

Secretory-Excretory System

A tubular system in nematodes with canals for excretion, opening via an excretory pore.

Osmoregulation

The process by which nematodes manage water balance, differing by habitat.

Dioecious

Having distinct male and female organisms, which is common in nematodes.

Copulatory spicules

Structures that males use to open the female vulva during mating.

Gubernaculum

A structure that guides the spicules into the female vulva.

Spermatotheca

A site in female nematodes for sperm storage, fertilization, and completion of meiosis.

Chemotactic

Movement in response to chemical signals, such as pheromones used for locating mates.

Thigmotactic

Movement in response to touch; in nematodes, the male caudal papillae detect the female vulva.

Egg shell layers

Layers including a lipid layer for protection from desiccation and a chitin layer for physical defense.

Embryogenesis

The timing and process of embryo development after leaving the female.

Hatching mechanisms

Processes such as enzyme production by the larva or using a stylet to penetrate operculum for hatching.

Ecdysis

The process of shedding the cuticle during growth stages, occurring between the 4 larval stages (L1-L4, J1-J4).

Hypobiosis

A state of arrested development in nematodes triggered by adverse environmental conditions.