some questions related to the human heart and the cirulatory system?? some1 plz help, these are for school hw?

the questions are:

1) What are the similarities and the differences between an open circulatory system and a closed circulatory system?

2) What is the function of the lymphatic system and what physical characteristics does it have?

3) What nutrients are transported through the vessels and where are each of them 'absorbed'?

stuck on these questions...

3 Answers

  • 1 decade ago

    Took these from Biology sites :)

    Closed Circulatory System

    Vertebrates, and a few invertebrates, have a closed circulatory system. Closed circulatory systems have the blood closed at all times within vessels of different size and wall thickness. In this type of system, blood is pumped by a heart through vessels, and does not normally fill body cavities.

    Open Circulatory System

    The open circulatory system is common to molluscs and arthropods. Open circulatory systems (evolved in crustaceans, insects, mollusks and other invertebrates) pump blood into a hemocoel with the blood diffusing back to the circulatory system between cells. Blood is pumped by a heart into the body cavities, where tissues are surrounded by the blood.

    The Lymphatic System has 3 primary functions:

    1.) It returns excess interstitial fluid to the blood.

    2.) Absorbs fats and fat-soluble vitamins from the digestive system and the subsequent transport of these substances to the venous circulation.

    3.) Defends invading microorganisms and disease.

    The lymphatic system consists of organs, ducts, and nodes.

    The nutrients that are transported through the lymphatic vessels are lipids (fats) and lipid-soluble vitamins (A, D, E and K) and are absorbed in the gastrointestinal tract throughout the body. :)

  • 5 years ago

    First thing LEXY even in Portugal you have to prove Guilt not Innocence. So shall we take that if somebody else other than the McCanns is found guilty there is two things I would consider. 1) does the person found guilty look like a scapegoat patsy, i.e some poor begger who just about knows what planet he is on let alone bneing able to defend himself against the charges (see a history of the police miscarriages of justice in high profile cases ie the dumbest looking guy on the block ends up in prison while the real culprit is still at large) 2) I would be extremely surprised and have ask WHY the McCanns acted like they did since Madeleine went missing which seems bizarre. 3) I have always said I will leave YA once charges are brought and leave justice to take its course, so therefore wont be around for either my or somebody elses 'I told you so's EDIT: ha ha how many said I'm not Pro or Anti McCann I just think that they are definately innocent... ha ha... love it.

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