BIO 004 - Module 9 Flashcards
Level of complexity: Tissue-organ grade
Free-living forms and parasitic forms
Tripoblastic
Body is flattened dorsoventally
Phylum PLATYHELMINTHES
Types of epidermis
Free-living and Parasitic
Free-living forms have this
Ciliated cellular epidermis
Adult parasitic forms nonciliated body covering
Syncytial tegument/neodermis
Resistant to the immune system ang digestive juices of the host
Syncytial tegument
Have the ciliated covering similar to free-living form and later shed it once they come in contact with host
Larval parasitic form
Found below the epidermis
Muscle fiber
Do not have body cavity
Acoelomate animals
Fills the space between muscles and organs
Parenchymal cells
True or False
Platyhelminthes they have a mouth, a pharynx, and an intestine
TRUE
True or False
Gut is complete: with anus, undigested food is released through the mouth
FALSE
Phagocytic cells that digest food
Gastrodermis
Flatworms are attracted to food by ________________
Chemotaxis
Controls water balance
Osmoregulation
Excretory and osmoregulatory organs & appear as networks of dead-end tubules that lack internal openings
Protonephridia
Specialized excretory cells located at the
ends of the protonephridia. They have cilia that are arranged to give a “flame” appearance.
Flame cells
Collects fluids and mainly has
osmoregulatory function
Collecting ducts
Fluids and wastes from
collecting ducts are excreted out the body
Excretory/Terminal pores
Most primitive nervous system; resembles nerve net of cnidarians, but with a “brain”
Subepidermal nerve plexus
The “primitive brain”; actually a mass of ganglion cells with neurons divided into sensory, motor, and association types
Cerebral Ganglia
Head containing the main nervous
and sense organs is present
Cephalization
Light sensitive eyespots
Ocelli
Tactile cells that form the earlike lobes on the sides of the head of planarians
Auricles
For balance/equilibrium
Statocysts
Sensing the direction water currents
Rheoreceptors
Budding off segments
Proglottids
Asexual reproduction of platyhelminthes
Fission
Requires 2 individuals to exchange sperm and fertilize their eggs
Cross-filterization
Open through a common _________________
Genital pore
Free-living
Mouth on ventral sides and leads into gut cavity via a pharynx
Combine muscular with ciliary movements to achieve locomotion
Larger terrestrial turbellarians crawl in the same manner of a snail
TURBELLARIA
Flukes
Monoecious
Mouth is at the anterior/cephalic end
Leaflike
Endoparasites
Larval form: Cercaria
TREMATODA
Organs for adhesion for them to hold on to host’s tissues
Suckers
2 suckers
Oral sucker and ventral suckers (acetabulum)
Mostly parasites
Formerly part of Trematoda
Cause little damage to their hosts under normal conditions
MONOGENEA
Posterior attachment organ with hooks, suckers, and clamps
OPISTHAPTOR
“Tapeworms”
Parasites in the digestive tract of vertebrates
Lack a digestive system
Excretory and nervous
No special sense organsproglottid is Monoecious; can self or cross-fertilize
Produces shelled embryos
Proglottids can break off from worm and can still expel eggs
CESTODA
The “head”, but not a true head, but just the first
segment
Scolex
The segmented part, onsisting long chain of
proglottids.
Strobila
Area just behind scolex where new
proglottids are formed.
Germinative Zone
Segment of the strobila that are reproductive
units
Proglottids
Younger proglottids; closer/more proximal to the scolex
Immature Proglottids
The middle segments; can start
reproducing
Mature Proglottids
The middle segments; can start
reproducing
Gravid Proglottis
Competition with the host’s nutrients
Taeniasis
Juvenile tapeworm at a stage in which
the scolex is inverted in a sac and only becomes adult tapeworm when in the
intestines of the final host
Cysticercus (Blabber worm)
Encysted in the muscle tissues and other organs of host
Cysticercosis
“flat” and “worm”
platys and helmins
Scientific Name:
“Blood flukes”
Schistosoma spp.
Scientific Name:
“Pork tapeworm”
Taenia solium
Scientific Name:
“Common planarian”
Dugesia spp.
