The Circulatory System

1. Plasma
   1. Text here
   2. carries chemicals around the body
2. Red blood cells
   1. formed in bone marrow
   2. contain a red, iron-based pigment called haemoglobin
   3. transport oxygen
3. White blood cells
   1. made in bone marrow
   2. fight infection
4. Platelets
   1. made in bone marrow
   2. form blood clots

1. Arteries
   1. carry blood away from the heart
   2. carry blood under high pressure
   3. have thick, strong walls to resist the pressure
2. Veins
   1. carry blood to the heart
   2. carry blood under low pressure
   3. have thin walls
   4. have valves to prevent blood from flowing backwards
3. Capillaries
   1. connect arteries to veins
   2. Are tiny and very numerous
   3. have very thin walls
   4. allow substances to pass in and out

Annotations:

• [Image: http://upload.wikimedia.org/wikipedia/commons/1/1c/Heart_diagram_corrected_labels.JPG]

1. Vena Cava
   1. carries low-oxygen blood from all over the body into the heart
2. Right Atrium
   1. Pumps low-oxygen blood to the right ventrile
3. Valves
   1. prevent backlow of blood
4. Right Ventricle
   1. Pumps low-oxygen blood to the lungs
5. Pulmonary Artery
   1. carries low-oxygen blood from the heart to the lungs
6. septum
   1. seperates low-oxygen and oxygen-rich blood
7. Pulmonary Veins
   1. carry oxygen-rich blood from the lungs to the heart
8. left atrium
   1. pumps oxygen-rich blood to the left ventricle
9. left ventricle
   1. pumps oxygen-rich blood around the body
10. Aorta
    1. carries oxygen-rich blood from the heart to all parts of the body

1. blood flows from the heart to the LUNGS and back to the heart
2. blood flows from the heart to the BODY and back to the heart

1. pulse is caused by the surge of blood in an artery due to a heartbeat
2. avg. pulse rate at rest for an adult is 70 per minute
3. exercise increases the rate of heartbeat and the pulse rate
4. exercise is beneficial to the heart as it:
   1. makes the heart stronger
   2. reduces weight