Round & Segmented Worms
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Transcript of Round & Segmented Worms
ROUND & SEGMENTED WORMS
3 PHYLA OF WORMS
• Nematoda – Round worms (round as a toad)• Annelida – Segmented worms
• What is the phylum for flat worms?
NEMATODA (ROUNDWORMS)
• Slender, unsegmented worms• Range in size from microscopic to a meter• Some are free living, and some are parasitic
NEMATODA (ROUNDWORMS)
• Have 3 germ layers• What are the 3 germ layers?
• Are protostomes• What does protostome mean?
NEMATODA (ROUNDWORMS)
• Have 2 openings in their digestive systems• Means have both a mouth and anus
• Pseudocoelomates • Fluid filled cavity only partially lined with mesoderm
PARASITIC ROUNDWORMS
• Trichinosis-Causing Worms• Filarial Worms• Ascarid Worms• Hookworms
TRICHINOSIS-CAUSING WORMS
• Terrible disease• Adult worms live and mate in the intestines of
their host• Host include: humans, pigs, and other mammals
• Females carrying fertilized eggs burrow into intestinal wall and release larvae
TRICHINOSIS-CAUSING WORMS
• Larvae travel through the bloodstream and burrow into organs and tissues• Larvae forms cysts and become inactive in the
host’s muscle tissue• Life cycle complete when another animal eats
muscle tissue containing these cysts
FILARIAL WORMS
• Found mostly in tropical regions of Asia• Threadlike – live in the blood and lymph vessels
of birds and mammals• Transmitted from one primary host to another
through biting insects• MOSQUITOES
• In severe infections a large number or worms block the passage of fluids within the lymph vessels• Causes elephantiasis
ELEPHANTIASIS
ASCARID WORMS
• Causes malnutrition in more than 1 billion people worldwide• Spread by eating veggies or other foods that are
not washed properly• Matures in the intestines of host• Produce eggs that leave body in feces
ASCARID WORMS
• Gets in new host by eating contaminated food or water• Eggs hatch in small intestine and burrow into
walls and enter bloodstream• Go to lungs – then go into air passages – then to
throat and are swallowed which sends them back to intestines
ANNELIDA
• Segmented worms• Name means “little ring” because the segments
look like rings• The divider between the segments are called
septa (singular septum)
QUESTION
• Why would having body segments be beneficial?
BODY SEGMENTS
• Can have segments that perform specific functions• Some have multiple eyes• Some have antennae• Other sense organs• Specialized for respiration
SETAE
• Bristles attached to body segments• What are some possible uses for setae?
COELOMATES
• Annelids have a true coelom• What is a coelom?
CLASSES WITHIN ANNELIDA
• Oligochaeta• Hirudinea
OLIGOCHAETES
• Typically have streamlined bodies• Relatively few setae compared to other annelids• Live in soil or fresh water
EARTHWORM (OLIGOCHAETEA)• Use setae to keep from being
pulled from the ground• Clitellum – secretes mucus for
eggs• Hermaphrodite – has both
male and female reproductive organs
EXTERNAL STRUCTURE
• Nephridiopore – opening into equivalent of kidney• Seminal Receptacle Pore – sperm comes in
through here• Oviduct Pore – egg
HIRUDINEA
• Leeches• External parasites• What do they eat?• Have suckers on both ends of their body
MEDICINAL USE OF LEECHES
• http://www.5min.com/Video/Medicinal-Use-of-Leeches-416309592• Pros of using leeches medicinally• Reduce swelling post surgery• Help circulation in graft areas/reattachment areas• Secrete an “anti-clotting” fluid – so helps relieve pressure
in healing tissues