Structure of the Heart

• • The heart contains muscle tissue that allows it to pumpblood around the body
• The heart has four chambers; the left and right atria, and the left and right ventricles

  • The right side of the heart pumps blood to the lungs
  • The left side of the heart pumps blood to the body
• The left and right sides are divided into upper and lower chambers:

  • The upper chambers are the atria (singular atrium); they receive blood from either the body or the lungs and pump it to the lower chambers
  • The lower chambers are the ventricles; they receive blood from the atria and pump it to either the body or the lungs
• • Valves within the heart prevent blood from flowing backwards