Echinoderms

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Echinoderms

• Echinoderms have a hard endoskeleton covered by
  bumpy or spiny epidermis
• They have radial symmetry, a mouth, stomach, and
  intestines.
• They have no head or brain, but they do have a
  nerve ring around the mouth.
• They have a water-vascular system connected to
  thousands of tube feet.
• EX.sea stars, brittle stars, sea urchins, sand
  dollars, sea cucumbers

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IN- What advantage does being able to reproduce
sexually asexually have for animals like
sponges, cnidarians, mollusks Echinoderms?
Monday November 4th

• OUT- How do tapeworms get energy?

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Flatworms

• Invertebrates w/soft bodies and bilateral
  symmetry. They have three tissue layers organized
  into organs and organ systems.
• Ex.Planarians, Flukes, and Tapeworms
• Free-living vs. Parasitic- a parasite depends on
  another organism for food or a place to live.

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Planarians

• Free-living flatworm
• One body opening-a mouth
• Most hermaphrodites
• Ability of regenerate

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IN- Explain the difference between free-living
and a parasitic flatworm.

• OUT- Why do parasitic worms often cause weight
  loss in their host organism?

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Flukes

• Parasites w/complex life cycle (snails, animals
  and humans are hosts)
• Infect more than 200 million people, estimated 1
  million people die each year, can infect the
  lungs, liver, eyes and other organs
• Some do infect plants and some are free-living in
  the soil.

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Tapeworms

• Parasites found in dogs, cats, humans and other
  animals are hosts for tapeworms.
• Doesnt have a mouth or digestive system, absorb
  food that is digested by the host from its hosts
  intestine.

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OUT- Explain what a host is in terms of a
parasitic relationship and give an example.
IN-Fill in the levels of complexity
diagram below.
S_____
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IN- List and give an example of the 3 classes of
flatworms1.2.3.

• OUT- fill out the Venn diagram

Flatworm
Roundworm
Segmented Bodies Bilateral 3 tissue layers
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Is it lunch time yet? Nope just time for a little
roundworm
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Roundworms-

• Ascariasis Ascariasis is an infection caused by
  the roundworm Ascaris lumbricoides . Infection
  occurs when an individual consumes food or drink
  contaminated with fecal matter that contains
  mature worm eggs. Adult worms can reside in the
  small intestine and produce eggs for a year or
  more.

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Roundworms-cont

• Hookworm (ancylostomiasis) A hookworm infection
  occurs when larvae of the roundworms Ancylostoma
  duodenale or Necator americanus penetrate human
  skin, making their way through the lungs to the
  small intestine, where they attach and mature
  into adults, laying more eggs. Children are
  particularly susceptible to this kind of
  infection. Once infected, children become weak
  and experience stunted growth patterns. These
  roundworms infect about 25 of the world's
  population

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More bugaboos

• Pinworm (enterobiasis) A pinworm infection
  occurs when an individual consumes food or drink
  contaminated with fecal matter containing the
  roundworm Enterobius vermicularis . After being
  ingested, eggs hatch in the small intestine, and
  adult worms ultimately inhabit the large
  intestine. The pregnant female worms migrate to
  the anus and deposit large numbers of eggs in the
  skin around that area. Pinworm, which is commonly
  spread in day care centers, schools, and camps,
  affects as many as 1/3 of all American children

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They keep coming

• Trichinosis (trichiniasis) Trichinosis is an
  infection caused by the roundworm Trichinella
  spiralis . These larvae live in pigs and other
  wild carnivores, such as bears, but humans can
  become infected with Trichinella spiralis when
  they eat such meat (particularly pork) that is
  undercooked. The larvae mature in small
  intestines and migrate to muscle cells where they
  can live for months or years.

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River blindness (onchocerciasis)

• River blindness (onchocerciasis) River
  blindness is an infection caused by the roundworm
  Onchocerca volvulus . Onchocerciasis, which is
  spread by day-biting flies, is the leading cause
  of blindness worldwide, affecting about 20
  million people, mostly in Africa

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IN- List several examples of Roundworms

1. ______
2. ______
3. ______

• OUT- How can humans preVent infection from many
  roundworms?

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So what is the bottom line?

• Probably the best solution to the problem of
  roundworms rests in preventing these infections
  rather than in curing them. The steps to
  preventing roundworm infection include
• Practice good personal hygiene (such as washing
  hands and avoiding contact with fecal matter).
• Avoid uncooked or unwashed fruits and vegetables
  in areas where sanitation is poor.
• Avoid mosquito or fly-infested areas, unfiltered
  water, and direct skin contact with soil in areas
  where roundworm infections are prevalent.

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Preventive Care

• Wear protective clothing, and use insect
  repellant.
• Cook or freeze meat thoroughly.
• Keep children away from pet feces.
• Consult a veterinarian about deworming pets.
• Public health measures in areas where roundworm
  infections are prevalent include improving
  general sanitation, especially sewage disposal,
  and reducing mosquito and fly populations.