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.