MS

• Oxygenation


  Process that gives oxygen to our cells
• Cells - Tissue - Organ - System - Organism


  1. Cells need energy to survive

  2. Gas exchange in capillaries

  3. Oxygen moves by diffusion from high to low concentration

  4. Cells receive oxygen and glucose from bloodstream

  5. Glucose is stored in cells

  6. Glucose moves from low to high concentration via active transport

  7. ATP is the energy of the cell

  8. Gas exchange produces waste (carbonic acid)
• Respiration


  1. Internal respiration (between cells and blood)

  2. External respiration (between lungs and blood)
• Ventilation


  • Movement of air in and out of the lungs
• Organs involved in oxygenation

  • Lungs
  • Heart
  • Blood
  • Vessels
• If oxygenation fails


  Cells/tissues will have hypoxia (low oxygen)
• Organ damage or failure can occur from hypoxia
• Organs affected by hypoxia


  • Brain
  • Heart
  • Lungs
  • Liver
  • Kidneys
• Heart chambers


  • Receiving chambers (right atrium, left atrium)
  • Discharging/pumping chambers (right ventricle, left ventricle)
• Heart valves


  • Unidirectional blood flow
  • Prevent backflow
• Major heart valves


  • Atrioventricular valves (tricuspid, bicuspid)
  • Semilunar valves (pulmonary, aortic)
• Heart sounds


  • S1 (lub) - atria and ventricles close
  • S2 (dub) - ventricles relax, longer sound
  • S3 - ventricular gallop, abnormal
  • S4 - atrial gallop, abnormal
• Cardiac activity


  • Contraction = depolarization
  • Relaxation = repolarization
  • Based on electrical impulses
• Stages of cardiac activity


  • Atrial depolarization (P wave)
  • Ventricular depolarization and atrial repolarization (QRS complex)
  • Ventricular repolarization (T wave)
• Coronary arteries supply blood to the heart
• Electrical conduction system


  • Controlled by medulla oblongata and autonomic nervous system
  • SA node is the pacemaker
  • AV node, bundle branches, Purkinje fibers
• Infectious disorders


  • Caused by microorganisms (bacteria, virus, fungi, protozoa, parasites)
  • Diagnosed by culture and sensitivity, PCR
  • Inflammation indicated by "-itis" suffix
• Group A beta hemolytic streptococcus causes pharyngitis and can lead to rheumatic fever and scarlet fever
• Cardiac infectious disorders


  • Endocarditis
  • Myocarditis
  • Pericarditis
• Endocarditis


  • Valve damage (stenosis, prolapse, regurgitation)
  • S3 ventricular gallop, lub dub tigidug
• Myocarditis


  • Decreased pumping action
  • Decreased perfusion
  • Angina pectoris
  • Activation of platelet aggregating factors leading to MI and cardiac arrest
• Pericarditis


  • Pericardial effusion
  • Decreased myocardial stretch
  • Aortic and vena cava compression leading to cardiac tamponade
• Diagnostic tests


  • Antistreptolysin O titer
  • Echocardiogram
  • ECG/EKG
• Coronary artery disease


  • Arteriosclerosis - deposition of dead tissues, calcium, fats
  • Atherosclerosis - deposition of fats
  • Increased brittleness and loss of elasticity
  • Risk of injury, clot formation, aneurysm
• Risk factors for coronary artery disease


  • Non-modifiable: age, sex, familial tendency, DM type 1
  • Modifiable: smoking, sedentary lifestyle, DM type 2, diet
• Arteriosclerosis


  General term for the deposition of dead tissues, calcium and fats
• Atherosclerosis


  Specific term for the deposition of FATS
• Both arteriosclerosis and atherosclerosis involve deposition
• Arteriosclerosis and atherosclerosis


  • Increase brittleness or rigidity or loss of elasticity
• When there is fat deposition and a calcium layer, it can easily rupture
• Early stage of coronary artery disease (CAD) involves small clots that can cause total obstruction if dislodged
• Asymptomatic CAD has no symptoms due to lack of obstruction
• Non-modifiable risk factors for CAD

  • Age and sex
  • Familial tendency
  • Diabetes mellitus type 1
• Non-modifiable risk factors


  • Common in men at age 45
  • Women at risk after age 55 due to estrogen/menopausal stage
  • Hereditary/genetic factors
  • High homocysteine levels
• Modifiable risk factors for CAD

  • Smoking
  • Sedentary lifestyle
  • Diabetes mellitus type 2
  • Diet high in trans and saturated fats
  • Oral contraceptive pills
  • Alcoholism
• Coronary arteries are small, narrow, and have numerous twists and turns
• CAD trigger symptoms


  • Extreme exertion
  • Extreme emotion
  • Extreme temperature
  • Excessive eating
  • Extreme increase in heart rate
  • Decrease in relaxation time
  • Decrease in artery perfusion
  • Eating leading to blood shunting to the GI tract
• Trigger symptoms lead to myocardial ischemia, injury, and later necrosis
• Angina pectoris is the first symptom of CAD
• Stable angina


  Relieved by rest, oxygen, and 3 sublingual nitroglycerin tablets