Lesson 3: Cardiovascular System

• a muscular pumping device

  heart
• closed system of vessels

  arteries, veins, and capillaries
• vital role of cardiovascular system in maintaining homeostasis

  it depends on the continuous and controlled movement of blood through the thousands of miles of capillaries
• it is in the _____ that blood performs its ultimate transport function

  capillaries
•  a muscular pump that provides the force necessary to circulate the blood to all the tissues in the body

  heart
• how many liters of blood does an adult heart pumps every minute

  5 liters
• how many chambers does a human heart have

  4
• the heart is enclosed in a _____

  pericardial sac
• encloses the heart and keeps it in a stable location mediastinum, facilitates its movements, and separates it from the lungs and other mediastinal structures

  pericardial sac
• 3 layers of the heart wall:

  1. epicardium
  2. myocardium
  3. endocardium
• outer layer of the heart wall

  epicardium
• middle layers of the heart wall

  myocardium
• inner layer of the heart wall

  endocardium
• 4 chambers of the human heart:

  1. right ventricle
  2. right atrium
  3. left ventricle
  4. left atrium
• Differences in thickness of the heart chamber walls are due to variations in the amount of ______ present, which reflects the amount of force each chamber is required to generate.​

  myocardium
• thin-walled chambers that receive blood from the veins

  atria
• thick-walled chambers that forcefully pump blood out of the heart

  ventricles
• receives deoxygenated blood from the body and pumps it to the right ventricle.

  right atrium
• pumps the deoxygenated blood to the lungs

  right ventricle
• receives oxygenated blood from the lungs and pumps it to the left ventricle

  left atrium
• pumps the oxygen-rich blood to the body.

  left ventricle
• allowing deoxygenated blood to leave the right ventricle and flow to the lungs via the pulmonary artery

  pulmonary valve
• its main function is to prevent back flow of blood from the pulmonary artery back into the Right Ventricle in DIASTOLE

  pulmonary valve
• ensure that oxygen-rich blood does not flow back into the left ventricle

  aortic valve
• to control the flow of blood from your heart's top chamber (right atrium) to the bottom chamber (right ventricle). This valve also helps prevent blood from flowing backward into either of these chambers.

  tricuspid valve
• regulates blood flow from the upper left chamber (left atrium) into the lower left chamber (left ventricle)

  mitral valve
• _____ from the heart muscle (the myocardium) cause the heart to contract. 

  Electrical impulses
• heart's natural pacemaker

  sinoatrial node
• what causes the atria to contract

  sinoatrial node
• the contraction of _____ pushes blood through the tricuspid and mitral valves into the resting lower chambers (the right and left ventricles)

  atria
• 1. the phase of the heartbeat when the heart muscle relaxes and allows the chambers to fill with blood.

  diastole
• this is when your heart contracts, pushing blood out of the chambers

  systole
• 2 phases of the heart's pumping cycle

  1. systole
  2. diastole
• The ______ in the ventricles causes the tricuspid and mitral valves to open, and the cycle begins again. 

  lower pressure
• how many times does our heart beat in a minute when we are at rest?

  60 to 80
• as we get older, our resting heart rate _____

  rises
• fluid of life

  blood
• it transports oxygen from the lungs to the body tissue and carbon dioxide from body tissue to the lungs

  blood
• these are  the channels or conduits through which blood is distributed to body tissues.

  blood vessels
• transports blood from the right ventricle to the lungs and back to the left atrium.

  pulmonary vessels