(M) Nematoda: Adenophorea (lecture-based) Flashcards
Phylum
Nemathelminthes
Class
Nematoda
Either parasitic or free-living are worms classified under Metazoa
HELMINTHES
Phyla
nematodes or roundworms
Nematoda
Phyla
hair-snakes or gorgiid worms
Nematomorpha
Phyla
trematodes (flukes), cestodes
(tapeworms), turbellaria
Platyhelminthes
Phyla
thorny-headed worms
Acanthocephala
Most of the medically important helminths are under the phylum?
Nematoda and Platyhelminthes
TOF. They are provided with structures serving digestive, excretory, nervous, integumentary, and
reproductive functions.
T
TOF. Species of phylum Platyhelminthes have separate sexes while Nematoda are mostly hermaphroditic.
F (opposite)
Cup like structures, which enable them to attach and
maintain their position in the host’s body
Suckers or acetabula
Among flukes and tapeworms, what glands secrete substances for the egg shell?
ootype and vitelline glands
How many eggs per day can Ascaris lumbricoides lay>
200,000
This are considered true roundworms
Nematodes
basis for the severity of the infection
number of parasites present
some infection, size of worm determines the extent
Majority of parasitic nematodes inhabits where?
intestinal tract of man
TOF. Worms that develop first in other sites before
reaching the final habitat are likely to produce more
pathologic damage.
T
the pattern of development
Egg - larva - adult
This can also occur with some nematodes like
Strongyloides stercoralis, and Enterobius vermiculari
response of the body
Autoinfection
Movement
body flexion
Body cavity is called
no mesothelial lining cells
pseudocele
This consists of a mouth, pharyngeal cavity, esophagus, intestine (foregut, midgut and hindgut), and rectum, which opens into the cloaca. Sperm cells are discharged through the cloaca.
digestive tract
Esophagus
long, slender, simple, and muscular, seen among Strongyloidea.
Filariform
Esophagus
muscular with three parts: proximal bulb, narrow isthmus, and distal body or corpus, as seen among free-living rhabditoids, parasitic oxyuroids, and free-living and non-infective strongyloids.
Rhabditiform
Esophagus
with muscular anterior and glandular posterior, seen in most of the spiruroidea and filaroidea
Spiruroid
Esophagus
long, slender embedded in a row of emboidal esophageal glandular cells (stichocytes), seen among trichinelloidea
Stichosoma
present in females
Esophagus
with short, muscular buccal structure
with a waist, seen among ancylostomatidae
Strongyliform
excretory system consists of
excretory gland cells, lateral canals, and excretory pore
situated at the mid-ventral portion
of the cephalic or cervical region
excretory pore
composed of fibers with dorsal, ventral, and lateral longitudinal trunks with transverse commissures
nervous system
nervous system is composed of fibers with dorsal, ventral, and lateral longitudinal trunks with transverse
commissures, whereby the most important is the???
MODIFIED
NERVE CENTER MO SIYA BEH
circumesophageal ring (around the esophagues)
TOF. Most part of nematodes’ existence is under aerobic condition thus, they have a respiratory- or circulatory structures.
F (anaerobic environment, no respi and circulatory)
Males of most species have curved tail end and are, usually, provided with special structures such
copulatory spicule or bursa
Male or Female repro
amoeboid instead of flagella type
Male
Male or Female repro
consist of testis, vas deferens, seminal vesicle, and ejaculatory duct, which open into the cloaca
Male
Male or Female repro
It may be single or double
female
Male or Female repro
They discharge eggs in the intestinal tract
and are evacuated with the feces to be deposited in the environment
Female (oviparous worms)
Male or Female repro
Embryonation may take place in the intestine and therefore, the feces of the human host may contain larval forms and/or embryonated eggs
Female
Among bursate nematodes, the perianal or caudal cuticle is extended into an umbrella-like structure called
bursa (male)
Species with a single female reproductive system
Trichinella spiralis, trichuris trichiura
Species with a double female reproductive system
Ascaris, enterobius and hookworms
Embryonated eggs of Ascaris lumbricoides or Trichuris
trichiura enter the body of man?
What MOT
oral route
Portal of Entry
Eggs of Enterobius vermicularis are usually
inahaled (nasal route) or to a lesser extent, may also be ingested (oral route).
Portal of Entry
The infective larval stages of hookworms or Strongyloides stercoralis enter the body through?
skin penetration
Portal of Entry
The infective stages of filaria worms enter the human body through?
percutaneous (skin) route via bites of insect vectors.
Portal of Entry
What INFECTIVE larval forms can pass through the placenta or mammary glands resulting to infection of the unborn baby
state the genus or species
Strongyloides stercoralis, Ancylostoma species, and Toxocara species,
basically, the order strongyloida, rhabditida and ascaridoidea
Transmission
non-essential, but advantageous
intermediate host
PARATHENESIS
Host
transport host (non-essential
intermediate host) is called
PARATHENIC HOST
All nematodes are provided with a pair of lateral, tiny, receptors called?
amphids or lateral organs
Nematodes without caudal glands have a pair of lateral post-anal glands called
caudal chemoreceptors
species with caudal chemoreceptors
SECERNENTEA (PHASMIDS)
species without caudal chemoreceptors
ADENOPHOREA (APHASMIDS)
Non-parasitic and free-living subclass
adenophorea