Circulatory System - the Heart 

?
View mindmap
  • Circulatory System - the Heart
    • Humans have double circulatory systems
      • Made up of the heart, blood vessels and blood
      • 1. In the 1st ciruit the heart pumps deoxygenated blood (without oxygen) to the lungs. The blood then picks up oxygen in the lungs
      • 2. Oxygenated blood then returns to the heart
      • 3. In the 2nd circuit the heart pumps oxygenated blood around to the other organs of the body, delivering oxygen to the body cells
      • 4. Deoxygenated blood returns to the heart to be pumped out to the lungs again
    • Heart pumps blood around the body
      • Organ with 4 chambers. Walls made up of muscle tissue
      • 1. Blood flows into the 2 atria from the vena cava and the pulmonary vein
      • 2. The atria pump the blood into the ventricles
      • 3. The ventricles pump blood out of the heart
        • Blood from the right ventricle goes through the pulmonary artery to the lungs
        • Blood from the left ventricle goes through the aorta to the rest of the body
      • 4. The blood then flows to the organs through arteries, and returns to the heart through veins
      • 5. The atria fill again - the whole cycle starts over again
      • Valves in the heart stop blood flowing backwards
      • The heart also needs it's own supply of oxygenated blood - from arteries called coronary arteries
        • Which branch off the aorta and surround the heart
    • The heart has a pacemaker
      • Resting heart rate - controlled by a group of cells in the right atrium wall
      • Tell the heart when to pump blood
        • Resting heart rate - controlled by a group of cells in the right atrium wall

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Circulatory system resources »