heart

• heart function

  transport: nutrients, waste, hormones, regulates: pH, temperature, protects against: infection and blood loss, pumps blood
• dense, non elastic connective tissue of the heart is the___layer

  fibrous pericardium
• pericardium

  protects the heart and anchors it
• serous pericardium

  parietal layer: attached to fibrous layer, visceral layer: outer surface of the heart wall (epicardium)
• pericardial fluid


  lubricates the space between the visceral and parietal pericardium
• epicardium (visceral pericardium)

  superficial wall of the heart
• myocardium


  cardiac muscle tissue, middle layer of the wall of the heart
• endocardium

  endothelium (simple squamous epithelial tissue), deepest layer of the heart wall
• location of the heart

  middle mediastinum
• base of heart

  superior medial and posterior
• apex of heart

  inferior anterior and lateral
• heart has 4 chambers

  upper 2 are the right and left atria, lower 2 are the right and left ventricle
• right heart

  right atrium and right ventricle, deoxygenated blood from the body to the lungs for oxygenation
• left heart

  left atrium and left ventricle, oxygenated pulmonary blood from the lungs to the body (systemically), stronger part of the heart
• which chambers of the heart have oxygenated blood

  left atrium and left ventricle
• top part of the heart

  weak pump, right and left atria
• bottom part of the heart

  strong pump, right and left ventricles. main pump for the pulmonary and systemic circuits
• atrioventricular valves

  open to allow blood to flow from the atria into ventricles, close to prevent blood flowing ventricles to atria. right- tricuspid valve, left- bicuspid or mitral valve
• outflow (semilunar) valves

  open to allow blood to flow from ventricles into arteries, close to prevent flowing from arteries to ventricles. right- pulmonary valve, left- aortic valve
• blood going out of the right ventricle goes to the

  pulmonary semilunar valve
• when the atria contract, blood goes through the

  atrioventricular valves
• chord tendinae and papillary muscles


  handle high forces
• autorhythmic means


  it generates its own action potentials in the heart
• cardiac conduction system

  spread action potentials through the heart
• sinoatrial (SA) node

  normal pacemaker of the heart (fastest self-depolarization)
• thickest layer of myocardium is found in the left ventricle


  strongest chamber, sending the oxygenated blood.to the farthest areas of the body
• cardiac conduction cycle sequence

  SA node -> internal fibers -> AV node -> bundle of his (AV bundle) -> right and left bundle branches -> purkinje fibers -> regular myocardium in ventricles
• Refractory period in cardiac muscle is longer than the contraction


  another contraction cannot begin until relaxation is well underway
• ECG (EKG)


  a recording of the electrical changes on the surface of the body resulting from the (de)(re)polarization and of the myocardium.
• which wave of EKG is depolarization of the atria

  p wave
• atrial repolarization + ventricular depolarization

  QRS wave
• ventricular repolarization


  t wave
• what structure is found in the veins but not the arteries

  valves, they stop blood from flowing backwards. arteries have the pressure from the heart pumping to keep the blood moving forward. veins also have to work against gravity in the limbs
• atrial systole


  atria contract, ventricles relax
• ventricular systole


  ventricles contract, atria relax
• diastole


  relaxation phase
• systole


  contraction phase
• cardiac cycle


  All events associated with one heartbeat, including diastole (relaxation phase) and systole (contraction phase) of both the atria and the ventricles
• cardiac output (CO)

  stroke volume (SV) x heart rate (HR) per min
• cardia reserve


  difference between the CO at rest and the maximum CO the heart can generate