Worms by yaofenji

VIEWS: 0 PAGES: 24

									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

								
To top