Sunday, April 1, 2007

Internal Transport

  • have well-developed heart
  • open circulatory system: blood not always within vessels
  • In spiders and some insects...
    --->heart is long and narrow which stretches along abdomen
  • In lobsters and crayfish...
    --->blood pumps through arteries and go into smaller vessels
    --->enters tissues and then leaves vessels into sinuses (spaces in tissue)
    --->the blood is found in a cavity around heart where it re-enters heart through openings

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