heart

• Heart is located in mediastinum.
• Right side - pulmonary circulation
• Left side - systemic circulation
• pulmonary artery carries deoxygenated blood from the heart to the lungs
• pulmonary veins carry O2 blood to LA.
• interventricular septum divides the heart into left and right sides.
• thick-walled ventricles pump blood out of the heart
• thin walled atria receive CO2 blood from the body and pumps blood into RV.
• Atrioventricular valve is located in the entrance of ventricle.
• semilunar valve is found in the exit of ventricles
• tricuspid valve is between RA and RV
• mitral/bicuspid valve is between LA and LV
• Chordae Tendineae: collagen fibers that anchor AV valves
• layers of the heart:

  • epicardium
  • myocardium
  • endocardium
• Sinoatrial (SA) node “pacemaker”: posterior wall of RA. generates impulses (60-100bpm) that are conducted over atria
• P wave: depolarization of atria, atria contracts. ventricles relax
• QRS complex: depolarization of ventricles (ventricular contraction, pressure increases)
• T wave: ventricular repolarization (ventricles relax= ventricular pressure drop) 
• S1 “lub”: AV valve closure. best heard at apex of the heart
• S2 “dub”: Semilunar valve closure, best heard at base of the heart
• heart sound is produced by the closure of AV and semilunar valves.
• Murmurs: turbulent blood flow, “swishing”/”blowing” sound over the precordium. 
• preload: degree of stretch of heart muscle before contraction.  (greater preload, greater SV)
• afterload: pressure against which heart muscle has to eject blood during contraction. (increased afterload, decrease SV) squeeze
• NECK VESSELS

  1. stand on the right side of the patient, supine position, head elevated to 45 deg.
  2. ask client to turn head to left.
  3. shine a tangential light onto the neck
  4. observe pulsation
• Measure JVPressure

  1. Supine, elevate 45 deg
  2. Have client’s head turn to the right.
  3. Shine a tangential light
• right side is best to measure because it is directly connected to the RA.
• JVP reflects pressure in RA (central venous pressure)
• auscultate first b4 palpating bc it may increase or slow HR changing the strength of carotid impulse!!
• asking the patient to roll on the his/her left side displaces the heart toward the chest wall.
• If u detect irregular rhythm, auscultate for pulse rate deficit: palpating radial pulse while auscultating apical pulse in a full minute.
• murmur: swishing sound caused by turbulent blood flow through heart valves/great vessels.
• capillaries have thin walls
• arteries have thick walls and high pressure.
• veins have thinner walls than arteries, has valves, and has a lower pressure.
• Coronary artery - supplies blood to the heart.
• valves prevent the backward flow of blood
• SYSTOLE (emptying)

  • ventricular contraction
  • AV valves close = S1
  • semilunar valves open
• DIASTOLE (“filling”)

  • relaxation (ventricles) phase
  • atria is contracting
  • semilunar valves close
  • AV valve open
• Coronary artery - supplies blood to the heart.