Heart

• Human heart beats over 1000004day
• Superior Vena Cava


  Carries oxygenated blood
• Pulmonary Veins


  Carry oxygenated blood
• Pulmonary Arteries


  Carry deoxygenated blood
• Inferior Vena Cava


  Carries deoxygenated blood
• Lub Dup
• Heart Anatomy Review from Lab

  • Heart Size and Location
  • Heart Layers and Coverings
  • Fibrous Pericardium
  • Serous Pericardium (Parietal Pericardium and Visceral Pericardium)
  • Myocardium
  • Endocardium
  • Heart Chambers (Atria and Ventricles)
  • Heart Valves
  • Major Blood Vessels of Heart

  
• Heart Size


  • About the size of your 2 fists
  • Located in the middle of the chest
  • Tilted to the left
• Apical pulse can be palpated between fifth and sixth ribs, just below left nipple; Best place to hear the heart when auscultating
• Layers of the Heart

  • Epicardium
  • Myocardium
  • Endocardium

  
• Left ventricle is thicker than the right ventricle
• 70% of blood moves from atria to ventricles due to gravity

  
• Atria

  Filling/receiving chambers of the heart
• Right Atrium


  Collects deoxygenated blood from the body
• Left Atrium

  Collects oxygenated blood from the lungs
• Ventricles

  Pumping chambers of the heart
• Right Ventricle

  • Pumps blood into the pulmonary trunk to bring blood to the lungs for oxygen
• Left Ventricle

  • Pumps blood into the aorta to bring blood to the rest of the body

  
• Heart Valves

  • Tricuspid
  • Bicuspid (Mitral)
  • Aortic
  • Pulmonary

  
• Atrioventricular (AV) Valves


  Lie between the atria and the ventricles, prevent backflow into the atria when ventricles contract

  
• Chordae Tendineae

  Anchor AV valves to papillary muscles
• Atrioventricular Valve Function

  1. Atria squeeze to release blood

  2. Papillary muscles contract

  3. Chordae tendineae tighten

  4. AV valves close

  
• Semilunar (SL) Valves

  Aortic SL valve lies between left ventricle and aorta, Pulmonary SL valve lies between right ventricle and pulmonary trunk, prevent backflow of blood into the ventricles

  
• Semilunar Valve Function

  1. Ventricles contract

  2. SL valves open

  3. Blood flows out

  4. Ventricles relax

  5. SL valves close

  
• Heart Sounds

  • Lub: first sound occurs as AV valves close and signifies beginning of ventricular systole
  • Dup: second sound occurs when SL valves close at the beginning of ventricular diastole

  
• Heart Murmurs

  • Abnormal heart sounds
  • If abnormal sound follows first sound, AV valve is affected
  • If abnormal sound after second sound, SL valve is affected

  
• Vessels returning blood to the heart

  • Superior and inferior vena cava
  • Right and left pulmonary veins

  
• Vessels conveying blood away from the heart

  • Pulmonary trunk, which splits into right and left pulmonary arteries
  • Ascending aorta (three branches) – brachiocephalic, left common carotid, and subclavian arteries

  
• • Pulmonary circulation: flow of blood to the right/left lungs
  • Systemic circulation: flow of blood to rest of the body
  • Coronary circulation: flow of blood to the heart

  
• Coronary Circulation

  Functional blood supply to the heart muscle itself

  
• • Coronary arteries include: Aorta, Left Coronary Artery, Right Coronary Artery
  • Cardiac veins include: Coronary Sinus, Great Cardiac Vein, Middle Cardiac Vein, Small Cardiac Vein

  
• Cardiac Muscle

  • Striated, branched, have 1-2 nuclei/cell, and interconnected
  • More mitochondria than skeletal muscle—more dependent on oxygen for aerobic respiration
  • Intercalated Discs anchor cardiac cells together and allow free passage of ions, rapid depolarization of cardiac muscle and synchronization of rhythm
  • Excitable—does not require external motor nerve supply to contract
• Cardiac Muscle Contraction

  • Heart muscle is stimulated by nerves and is self-excitable (automaticity)
  • Contracts as a unit
  • Has a long (250 ms) absolute refractory period
• Cardiac muscle contraction is similar to skeletal muscle contraction
• Cardiac muscle has a longer absolute refractory period (250 ms) compared to skeletal muscle
• Heart Conduction: Sequence of Excitation

  Sinoatrial (SA) node

  
• inucleated

  Having a nucleus
• intercalateddisks

  Disks that are inserted between muscle cells
• notYniformmusclepattern

  Muscle pattern that is not uniform
• uniform musclepattern

  Muscle pattern that is uniform