The Purpose of a circulatory (Transport) System in multicellular organisms


The Purpose of a Circulatory (Transport) System



  1. To transport nutrients and oxygen to all cells in the body so they can function properly.
  2. To remove the waste that are produced by cells to a point where they can be removed from the body.e.g urea-to the skin and kidneys, carbon dioxide –to the lungs etc
  3. To move other chemicals such as hormones, antibodies and blood proteins around the body

     

    Transport in Unicellular organisms

    ·        Single celled (unicellular eg, amoeba) organisms get their nutrients, oxygen and remove their waste by diffusion.

    • ·        These substances (food, oxygen, waste etc) diffuse into and out of the bodies of unicellular organisms through their cell membranes.
    • ·        This is because no part of the body of these single cellular organisms is too far away from their surrounding or environment (which is usually water or moist areas). 
    • ·        Therefore, one-celled organisms have a large surface area to volume ratio. The smaller the size of a single-celled organism, the more surface area it has relative to its volume.
    • ·        Simple diffusion is efficient in unicellular organism because substances have a short distance to travel to reach their destination.

     

     Transport in multicellular organisms

     

    ·        The larger (more complex) the organism is, the more cells it is made up of. This means that substances will have more difficulty reaching and being removed from individual cells.

    ·        As the organism increases in body mass or cells, its volume to surface ratio decreases dramatically.  If the surface area of the organism decreases then the rate at which substances can pass in and out of the organism to its external environment at any given time decreases.

    ·        In addition, substances will have more difficulty reaching and moving from individual cells because of the millions of cells that they have to pass through to reach their destination and the distance and obstacles that things must now travel past.

    A A transport system ensures that the speed and efficiency at which materials are supplied and removed in multicellular organisms are adequate for the survival of every cell in the body. Unicellular organisms do not need such elaborate systems because they get all their requirements by simple diffusion.

    ·        Most multicellular organisms such as plants and animals have developed specialized systems of transport to take various substances they need (eg oxygen and food) to, and waste (eg. Carbon dioxide) from cells in the body.

    ·        In humans or mammals this system is called the cardiovascular, circulatory or blood vascular system.



    Synapses of the circulatory system in man




    Visit my Pages on this blog 

    1. Components of Circulatory system
    2. Discussion on purpose of circulatory system
    3. Practice questions on the circulatory system



     



    References

    Blood plasma - Google Search. (n.d.). Www.google.com. Retrieved May 27, 2022, from https://g.co/kgs/ySX2Y6

    Learning Junction. (2019, March 28). Human Blood Video | Blood Components | Blood Cells. Www.youtube.com. https://www.youtube.com/watch?v=qrE6Y0Se8bw&t=28s

    Michelle. (2017, May 17). Circulatory System| Components of The Blood. Www.youtube.com. https://www.youtube.com/watch?v=0hq_5MgdGtA&t=14s

    Skoolers.com. (2022). Blood Cells and Platelets – Skoolers.com: CSEC / CXC Exam Preparation. Skoolers.com. http://skoolers.com/2015/11/blood-cells-and-platelets/

    Comments

    Post a Comment