1_Blood & Circulation

Red Blood Cells
1. Contain no nucleus ( have a dip in the centre)>more oxygen carried
2. Large surface area compared to volume > oxygen close to surface
Platelets
1. Platelets clot the blood after a wound > prevents infection and blood loss
2. People with haemophilia have a faulty gene for the clotting process
White Blood Cells
1. Larger than red blood cells, flexible shape to help engulf disease organism
2. Protects against infection by digesting harmful microbes, bacteria digested inside WBC
3. Able to squeeze out of capillaries to defend different tissues
Plasma
1. Contains mostly water, dissolved food, urea, hormones and carbon dioxide
2. Pale yellow fluid carries blood cells, useful substances and waste around the body through blood vessels
Pulmonary Artery > Carries blood from the heart to the lungs
Aorta (Artery) > Carries blood from heart to body
Pulmonary Vein > Carries blood from lung to heart
Vena Cava (Vein) > Carries blood from body to heart
heart
1. how is works
  1. blood flows into the atrias from the vena cava and pulmonary vein
    1. atria contracts pushing blood into the ventricles
      1. ventricles contract forcing blood to the lungs through the pulmonary artery and to the body through the aorta
        blood flows to the heart from the bady through the vena cava and from the lungs through the pulmonary vein
        this refills the atrias and restarts the process
blood vessels
1. Arteries = Away
  1. Arteries have thick walls because the blood pressure is very high. They also have thick elastic walls
2. Capillaries = Small cells
  1. walls are one cell thick to allow substances to be transferred
3. veins=away
  1. veins have valves to prevent backflow

Next up

1_Blood & Circulation

Description

Resource summary

Similar

	Created by Scott Church over 8 years ago

	Copied by jaeg lawson over 8 years ago