circulatory system

• what are the chambers of the heart?


  left and right atriums, left and right ventricles
• what vessel bring blood to the right atrium?

  superior vena cava, inferior vena cava, and coronary sinus
• what vessels bring blood to the left atrium?

  right and left pulmonary veins
• what is the function of the valves of the heart?

  prevents blood from flowing back
• what events make up the cardiac cycle?

  atria contract while ventricles relax and then they switch. alternatively, pressures rise and fall.
• what produces the heart sounds heard with a stethoscope?

  the vibrations in the heart tissue due to contraction and relaxation of heart chamber
• what structures can be assessed by the heart sounds?

  valves
• trace an impulse through the cardiac conduction system

  a: SA node

  b: AV node

  c: bundle of HIS

  d: purkinje fibers
• how is the heart affected by potassium?

  increase in potassium = decrease in heart rate
• how is the heart affected by calcium?

  increase in calcium = increase in heart rate
• how is the heart affected by temperature?

  increase in temp = increase in heart rate
• what is the structure of arteries?


  it has 3 layers: tunica intimia, tunica medid, tunica adventitia

  it also contains nerve fibers that stimulate the arteries to constrict or relax
• how is the structure of arterioles different from that of arteries?

  they have thinner walls/branches than arteries
• what determines the density of capillaries within tissues?


  the tissue's needs of oxygen/metabolism
• how is the distribution of blood in the capillaries regulated?

  regulated by pre capillary sphincters, which controls it by either contracting or relaxing
• what is blood pressure?

  force exerted by the blood on the walls of vessels
• what cardiac events are related to systolic and diastolic arterial pressure?


  systolic: maximum pressure in the arteries when the ventricles contract

  diastolic: lowest pressure in the arteries when the ventricles relax
• what is a pulse?

  swelling of blood vessels due to pressure or expansion and recoil of walls of the arteries due to ventricle contraction
• how does heart action influence blood pressure?

  faster movement = increase in blood pressure
• how does blood volume influence blood pressure?


  more blood = increase in blood pressure
• how does peripheral resistance influence blood pressure?

  alcohol: decrease in blood pressure

  nicotine: increase in blood pressure
• how does viscosity influence blood pressure?

  thicker blood/ increase in viscosity = increase in blood pressure
• how does mechanical factor affect cardiac output?


  more fibers in the walls of the ventricle stretch the increasing force of the contraction
• how does neural factor affect cardiac output?

  increase in blood pressure, cardiac sends a message to SA node to increase heart rate
• how does chemical factor affect cardiac output?

  neural endorphins cause changes in the heart rate
• how is peripheral resistance regulated?


  regulated by alternating construction and dilation of blood vessels
• how do the pulmonary and systemic circuits differ?

  pulmonary: pumps blood from heart to lungs

  systemic: pumps blood from heart to rest of body
• sequencing


  1. low O2 and high CO2 blood enters the right atrium
  2. right atrium receives blood from superior, inferior vena cava, and coronary sinus
  3. blood is pushed through the tricuspid valve and enters the right ventricle
  4. right ventricle contracts and blood moves to the pulmonary trunk through the pulmonary arteries
  5. blood enters the lung
  6. oxygenated blood returns to the left atrium through the pulmonary veins
  7. blood is pushed to the left ventricle through the bicuspid valve
  8. left ventricle contracts and blood moves in the aorta
  9. blood gets distributed to all parts of the body