8/06/2010

Blood as a Transport Medium and Protection

Blood
  • a fluid that transport subtances around the body
  • contains cells

3 kinds of blood:

  1. Blood Cell

    • red blood cell (erythrocytes)
    • white blood cell (leucocytes) - phagocytes
    • lymphocytes

  2. Plasma

  3. Platelets

BLOOD AS TRANSPORTATION

  • Red Blood Cell - carries oxygen to our body

  • Plasma

- carries nutrients like amino acid, sugar, fatty acid
- caries waste products like urea, CO2, hormones, heat

BLOOD AS PROTECTION

  • Phagocytes (white blood cell) - destroy and ingest foreign particles

  • Lymphocytes (white blood cell) - produce antibodies

  • Platelets - helps to clot the blood to prevent excessive loss of blood

RED BLOOD CELL

  • biconcave shape

  • no nucleus

  • red pigment called hemoglobin (contains iron)

WHITE BLOOD CELL

  • irregular shape

  • has nucleus

  • colorless

  • fight pathogens

RATIO OF RED BLOOD CELL - WHITE BLOOD CELL >> 700:1


BLOOD VESSELS

  • arteries

- carry blood away from the heart

- carry oxygenated bloof except pulmunary artery (deoxygenated blood)

  • capillaries - they deliver nutrients, oxygen and remove waste products

  • veins

- carry blood back to the heart

- deoxygenated blood except pulmunary veins (carries oxygenated blood)

- has valves that prevent the back flow of the blood

HEART

  • pumps blood to all parts of the body

  • four chambers : atria lower and upper, and ventricle lower and upper

  • lub and dub sound (heart beat)

BLOOD PRESSURE

  • a face axcerted on the blood vessels

  • measured by instrument called sphygmomanometer

  • highest when heart contracts (exercise,etc)





P.S. This is my note when my science teacher explained


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