Heart

• The Circulatory System


  • Cardiovascular System: Heart Blood Vesselslee
  • Lymphatic System Lymph nodes, Tonsils, Thymus Spleen, Baze
• The Cardiovascular System


  • Functions of circulatory system:
  • 1-Transport nutrients, hormones, and gases (CO2, 02)
  • 2-Helps maintain a constant body temperature
  • gets rid of waste materials (eg.CO)
• HEART


  • It is a tough, saclike double membrane surrounds the heart
  • Function: 1. Surrounds the heart (protect the heart)
  • 2 Secrets a fluid that reduces friction as the heart beats.
• Chambers


  • Upper Chambers: Atriums (atria): (Right atrium & Left atrium)
  • Right atrium :receives deoxygenated blood from body via superior & inferior vena c
• The heart pumps blood through a network of blood vessels
• The heart is slightly larger than a fist
• The heart is located behind the sternum, within the thoracic cavity between the lungs
• The heart has Structures: Pericardium, 4 Chambers, 4 Valves, attached blood vessels
• Pericardium


  A tough, saclike double membrane that surrounds the heart
• The pericardium surrounds the heart
• Function of pericardium


  • Surrounds the heart to protect it
  • Secrets a fluid that reduces friction as the heart beats
• Atrium


  Upper chambers of the heart
• Right atrium


  Receives deoxygenated blood from the body via superior & inferior vena cava
• Left atrium


  Receives oxygenated blood from the lungs via pulmonary veins
• Ventricle


  Lower chambers of the heart
• Right ventricle


  Pumps deoxygenated blood to the lungs via pulmonary arteries
• Left ventricle


  Pumps oxygenated blood to all parts of the body via aorta
• The left ventricle is the thickest chamber because it has to do the most work to pump blood to all parts of the body
• Septum


  Wall that divides the heart vertically into left side & right side
• Right side of heart

  • Contains poor-oxygen blood
  • Receives blood from the body parts (RA)
  • Pumps blood to the lungs (RV)
• Left side of heart

  • Contains rich-oxygen blood
  • Receives blood from the lungs (LA)
  • Pumps blood to the body parts (LV)
• Both atrioventricular valves prevent blood flowing backward into atriums
• Both atrioventricular valves are opened when atriums are contracted and closed when ventricles are contracted
• Vena cava largest vein
• Superior vena cava it sends deoxygenated blood from the upper body to the right atrium
• Inferior vena cava it sends deoxygenated blood from the lower body to the right atrium
• Pulmonary artery it sends deoxygenated blood from Right ventricule to the lungs
• Pulmonary veins return oxygenated blood from lungs to the left atrium
• Aorta it sends oxygenated blood from left atrium to all parts of the body
• oxygenated blood is bright red in arteries

  deoxygenated blood is blue dark red in veins
• When ventricles contract the blood pressure closes the atrioventricular valve
• Superior vena cava


  Sends deoxygenated blood from upper body to right atrium
• Right atrium


  Sends blood to the right ventricle
• Right ventricle


  Sends blood to the pulmonary artery
• Inferior vena cava


  Sends deoxygenated blood from lower body to right atrium
• Circulation in the heart

  1. Superior & inferior vena cava (veins) sends deoxygenated blood (O2-poor) from upper and lower parts of the body to the right atrium

  2. The right atrium is contracted, the tricuspid valve is opened, & the deoxygenated blood enters the right ventricle

  3. As the right ventricle contracts, tricuspid valve is closed, pulmonary valve is opened, & the deoxygenated is sent to the pulmonary artery

  4. The pulmonary artery sends the deoxygenated blood to the lungs

  5. In the lungs, CO2 diffuses out of the blood & O2 diffuses into the blood

  6. The oxygenated blood returns from lungs to the left atrium via pulmonary veins

  7. When the left atrium contracts, bicuspid valve (mitral) is opened, aortic valve is closed, & the blood enters the left ventricle

  8. When the left ventricle contracts, bicuspid valve is closed, aortic valve is opened, & the blood is forced in to the aorta

  9. Aorta sends oxygenated blood to all parts of the body except the lungs
• Aorta


  Sends oxygenated blood to the coronary arteries, the brain, and the rest of the body
• Pulmonary arteries


  Send blood to the lungs
• Pulmonary veins


  Return oxygenated blood to the left atrium from the lungs
• Left atrium


  Sends blood to the left ventricle