J

Heart and Circulatory System Review

  • Heart Anatomy and Function

    • Right Side of the Heart
      • Pumps deoxygenated blood to the lungs.
      • Important in conditions like right-sided heart failure, where pumping efficiency decreases.
    • Left Side of the Heart
      • Pumps oxygenated blood to the body.
      • Associated with left-sided heart failure, impacting blood flow to systemic circulation.

  • Heart Conditions

    • Congestive Heart Failure: A condition affecting overall heart function.
    • Ectopic Rhythm: Abnormal heartbeat originating from outside the SA node (the heart's natural pacemaker).
    • Understanding normal blood flow direction is crucial for test preparation.

  • Electrical Activity of the Heart

    • SA Node:
      • Functions as the natural pacemaker of the heart.
      • Regulates the rhythm and pace of heartbeats.
    • EKG Basics:
      • P Wave: Atrial depolarization.
      • QRS Complex: Ventricular depolarization.
      • T Wave: Ventricular repolarization.

  • Blood Pressure Measurements

    • Blood pressure is expressed in millimeters of mercury (mmHg).
    • Normal Reading:
      • Systolic (top number): 120 mmHg
      • Diastolic (bottom number): 80 mmHg
    • Pulse Pressure: The difference between systolic and diastolic pressures.
      • Example: For a reading of 120/80, pulse pressure = 120 - 80 = 40 mmHg.
    • Mean Arterial Pressure (MAP):
      • Calculated as Diastolic Pressure + 1/3 Pulse Pressure.
    • Example Calculation: If pulse pressure is 40, then MAP = Diastolic (80) + (1/3 * 40) = 80 + 13.3 ≈ 93.3 mmHg.

  • Stroke Volume and Cardiac Output

    • Stroke Volume: The amount of blood ejected with each heartbeat.
    • Relationship with Heart Rate:
      • An increase in heart rate can lead to a decrease in stroke volume.
      • Important for cardiovascular fitness and understanding body demands.

  • Cardiac Events and Energy Expenditure

    • Warm-up Importance:
      • Preparing the heart for activity reduces the risk of cardiac events.
    • High Demands in Cold Weather:
      • Increased strain on the heart during sudden exertion, especially in unconditioned individuals.

  • Ejection Fraction

    • Indicator of heart function and efficiency.
    • Normal Range: 50% - 60% is considered healthy.
    • Relation to Residual Blood: Not all blood is ejected; some remains in the heart post-contraction.

  • Deep Vein Thrombosis (DVT)

    • Clots from DVT can travel to the lungs, typically blocking smaller pulmonary arteries, which affects oxygenation.

  • Cerebral Blood Flow

    • Basilar Artery: Supplies blood to the brain; blockage can have serious implications including consciousness impairment.
    • Vertebral Arteries supply the basilar artery and are critical for understanding stroke locations.
    • Anterior cerebral artery supplies the frontal lobe; middle cerebral artery is larger and supplies other regions.

  • Pancreas and Digestion

    • The pancreas has endocrine (insulin/glucagon) and exocrine (digestive enzymes) functions.
    • Ducts such as the pancreatic duct carry enzymes and bicarbonate to neutralize stomach acid in the intestines.
    • Hepatic Portal Vein carries nutrients from the digestive system to the liver, crucial for metabolism.
    • CCK (Cholecystokinin): Hormone that stimulates gallbladder contraction and bile release.

  • General Understanding

    • Review key anatomy related to cardiovascular and digestive systems.
    • Focus on high-yield concepts like blood flow direction, heart functions, and key physiological measures (blood pressure, ejection fraction, etc.).
    • Consider relationships between heart function and overall body health, as well as understanding critical conditions impacting health.