Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
11 Cards in this Set
- Front
- Back
Family of Strongyloides stercoralis?
common name? |
Strongylididae
human intestinal threadworm |
|
Strongyloides stercoralis general morphology
(larvae pictured) |
among smallest human nematodes; males even smaller than trichinella spiralis, but only parthenogenic females parasitic
rhabditiform esophagus |
|
Strongyloides stercoralis host, type of cycle and location?
|
cosmopolitan human, primarily warm climates, direct, intestine.
|
|
|
Strongyloides stercoralis male details
parasitic? esophagus type? Spicules, gubernaculum? |
Not parasitic; free-living have short rhabditiform esophagus.
Has long, thick testes opening to a seminal vesicle that narrows into a terminal muscular ejaculatory duct. Pair of short spicule and gubernaculum are present |
|
|
Strongyloides stercoralis life cycle
|
Two kinds of eggs, first and second stage are the homogonic line which has three chromosomes and produces rhabditiform and third stage filariform juveniles which have notched tial.
Filariform juveniles enter the host through the skin and become parthenogenesit females. Eggs producing heterogonic line make one line with one chromosome and produce free living male and two chromosomes are free-living females. The free-living females produce 3N juveniles that are infective like the homogonic line. The filariform juveniles upon contact of skin penetrate epidermis, enter blood vessels, and carried to the lungs (3rd molt), break out of capillaries, into alveoli and make way via trachea, where most twice and reach maturity |
|
|
disease caused by Stronglydoides stercoralis
|
strongyloidiasis, tropical and subtropical climes
adbominal pain, diarrhea. |
|
|
Life cycle terminology relevant to Strongyloides stercoralis
|
homogonic vs heterogonic. heterogonic is free-living life cycle when preceded by parasitic life cycle
|
|
|
Family of Necator americanus
common name? geography? |
Uncinariidae
so-called "new world hookworm" (probably brought in slave trade, disc'd in Brazil) US, tropical/subtropical nations |
|
Necator americanus general morphology
|
similar to duodenale but smaller and the free margin of the cutting plates is smooth and semilunar (crescent) in shape;
pair of single lancets is at the bottom of the buccal capsule (male pictured) |
|
|
Necator americanus male details
|
Bursa wider than long, dorsal lobe having broad median indentation so that the dorsal ray is divided almost to its base to divergent branching...
eternodorsal rays club-shaped and near the laterals. Postero and mediolateral rays originate from a common stalk, ventral rays arising from that same stalk. Spicules long and slender. Distal ends are fused and tipped with a barb |
|
|
Necator americanus female details
how to tell male from female? |
females larger (11mm vs 9mm max)
vulva slightly anterior to middle of body no spine at tip of tail |
