Nematoda and Invertebrate Contributions to Medicine

Flashcards about Nematoda and Invertebrate Contributions to Medicine

What are some characteristics of Nematoda?

Ubiquitous in marine, freshwater, and terrestrial environments; free-living & parasitic. They are extremely abundant & dense, small in body size, and lack cilia.

What is unique about the Nematode cuticle?

It is a multilayer, acellular cuticle secreted by the epidermis. It is water permeable, molted periodically, and has 3 crossed layers of collagen fibers. Flexibility is gained by changing the angle between fibers.

What are some characteristics of Nematode internal anatomy?

They lack a circulatory system and any coelom is not lined by mesodermal tissue (pseudocoelom). They have four main neurons: ventral, dorsal, L & R lateral.

How do free-living Nematodes feed?

They have a linear gut with an anus near the posterior end. They have a pharynx with “swallowing” waves to push food into the digestive tract.

Give examples of parasitic nematodes.

Trichinella spiralis, Mermis nigrescens, Meloidogyne sp., Dirofilaria, and Dracunculus

What is unique about Nematode reproduction?

They are Gonochoristic, copulation (internal fertilization) with amoeboid sperm. Also, they experience chromosome diminution and are eutelic.

Name four Ecdysozoa.

Nematoda, Tardigrada, Onychophora, and Arthropoda

What contributions do invertebrates make to medicine?

Medicinal compounds can be isolated from invertebrates and invertebrates serve as models for human disease or development.

What medicinal compounds are derived from sponges?

Azidothymidine (AZT) and sorbilactone A

What medicinal compounds are derived from cnidarians and bryozoans?

Prostaglandins and bryostatins

What medicinal compounds are derived from mollusca?

Conotoxin derivatives and tartrolons

What medicinal compounds are derived from arthropoda?

Canthaxanthins and hunter toxins

Name two invertebrate models and what makes them special

Caenorhabditis elegans has a full cell-line and neuronal map and full genome. Grasshopper Dissosteira carolina uses nitric oxide (NO) to guide neuron development just as in humans (synaptic plasticity)

What are Urochordates used to understand?

Self/non-self recognition in innate immune system and maternal immune tolerance during pregnancy.