CIRCULATORY SYSTEM

• Functions of the circulatory system

  • Deliver oxygen & nutrients
  • Removes wastes products
  • Helps in the coagulation process
  • Regulates body temperature
  • Important in body defenses (WBC's in the blood)
• Two main components of the circulatory system

  • Cardiovascular System
  • Lymphatic System
• Cardiovascular System


  • Heart
  • Blood vessels
  • Blood
• Lymphatic System


  • Lymph
  • Lymph nodes
  • Lymph vessels
• Heart


  Hollow muscular organ that has four chambers and is surrounded by a thin, fluid-filled sac called pericardium
• Size of the heart


  About that of a person's clenched fist
• Pericardium / Pericardial Sac


  A sac that anchors and protects the heart
• Functions of the pericardium


  • Keeps the heart contained in the chest cavity
  • Prevents the heart from overexpanding when blood volume increases
  • Limits heart motion
• Layers of the pericardium

  • Fibrous pericardium
  • Serous pericardium
• Fibrous pericardium


  Tough, fibrous connective tissue outer layer
• Serous pericardium


  The inner layer of flat epithelial cells, with a thin layer of connective tissue
• Portions of the serous pericardium

  • Parietal pericardium
  • Visceral pericardium / Epicardium
• Layers of the heart wall

  • Epicardium (Outer)
  • Myocardium (Middle)
  • Endocardium (Inner)
• Epicardium


  Covers the heart and is attached to the pericardium
• Myocardium


  Pumps blood into the arteries
• Endocardium


  Lines the valves and interior chambers
• Chambers of the heart

  • Right Atrium (Upper right)
  • Right Ventricle (Lower right)
  • Left Atrium (Upper left)
  • Left Ventricle (Lower left)
• Right Atrium


  Receives deoxygenated blood from the body
• Right Ventricle


  Receives blood from the right atrium and pumps it to the pulmonary artery
• Left Atrium


  Receives oxygenated blood from the lungs and pumps it into the left ventricle
• Left Ventricle


  Receives blood from the left atrium and pumps it into the aorta
• Valves of the heart

  • Right AV valve (Tricuspid valve)
  • Left AV valve (Bicuspid or mitral valve)
  • Right semilunar valve (Pulmonary valve)
  • Left semilunar valve (Aortic valve)
• Right AV valve (Tricuspid valve)

  Located between RA and RV, closes as RV contracts preventing blood from flowing back to the RA
• Left AV valve (Bicuspid or mitral valve)

  Located between LA and LV, closes as LV contracts preventing blood from coming back to the LA
• Right semilunar valve (Pulmonary valve)


  Located at the entrance of the pulmonary artery, closes when the RV relaxes preventing blood from flowing back to the RV
• Left semilunar valve (Aortic valve)

  Located at the entrance of the aorta, closes when the LV relaxes preventing blood from flowing back to the LV
• Septa


  • Interatrial septum
  • Interventricular septum
• Interatrial septum


  Separates the right from the left atria
• Interventricular septum


  Separates the right and the left ventricles
• Functions of the human heart

  • Cardiac Cycle
  • Electrical Conduction System
  • ECG
  • Heart sound
  • Heart Rate and Cardiac Output
  • Pulse
  • Blood Pressure
• Cardiac Cycle


  Systole and diastole lasts about 0.8 seconds
• Electrical Conduction System


  Sends impulses which is initiated by the sinoatrial (SA) node pacemaker
• ECG


  Graphical representation of the cardiac cycle
• Heart sounds


  • Lubb
  • Dupp
• Lubb


  Has a lower pitch than the second; occurs at the beginning of ventricular systole and results from closure of the AV valves
• Dupp


  Occurs at the beginning of ventricular diastole and results from closure of the semilunar valves
• Heart Rate


  Average heart rate is 72 bpm
• Cardiac Output


  Volume of blood pumped per minute (slightly more than 5 L/min.)
• Pulse


  Rhythmic throbbing from the expansion of the artery
• Blood Pressure


  Force exerted by the blood on the walls of the blood vessel