229 Ch 21 lecture

Overview of Cardiac Anatomy and Physiology

Key Concepts

  • Heart Structure

    • Four Chambers: Right Atrium, Right Ventricle, Left Atrium, Left Ventricle

    • Septum: Separates right and left sides of the heart

    • Three Layers of Heart Tissue

      • Epicardium: Outer layer, fibrous connective tissue

      • Myocardium: Middle layer, muscular layer responsible for contractions

      • Endocardium: Inner layer, smooth and thin, in contact with blood

    • Pericardium: Surrounds and supports the heart; has two layers (parietal and visceral)

      • Pericardial space: Lubricates and reduces friction during heartbeats

Function of the Heart

  • Cardiac Cycles:

    • Systole: Contraction phase

    • Diastole: Relaxation phase

  • Blood Flow and Pumps

    • Right Side: Pumps deoxygenated blood to lungs (pulmonary circulation)

    • Left Side: Pumps oxygenated blood to the body (systemic circulation)

Important Cardiac Properties

  • Electrical Activity of Heart: Ensures rhythmic contractions

  • Cardiac Output: Amount of blood ejected by the left ventricle per minute (normal 4-8 liters)

  • Stroke Volume: Amount of blood pumped per heartbeat (normal range 65-70 mL)

Essential Components for Effective Cardiac Function

  • Oxygenation: Open airway and normal respiration

  • Blood Volume: Maintain normal blood levels

  • Electrical Activity: Effective heart rhythm and contraction strength

  • Valvular Function: Proper opening and closing of valves to prevent backflow

  • Arterial and Venous Function

    • Arterial system: Delivers oxygenated blood; high-pressure system

    • Venous system: Returns deoxygenated blood; lower pressure system

Cardiac Assessment Parameters

Patient Scenarios and Assessments

  • Vital Sign Monitoring: Temperature, blood pressure, pulse, respiration

  • Assessing Cardiac Rhythm: Regularity and pattern of heartbeats

  • Physical Exam Considerations:

    • General appearance and pain evaluation

    • Assessment of peripheral pulses and skin condition (color, temperature, edema)

    • Examination of jugular veins: Distension can indicate heart problems

  • Mental Status Evaluation: Changes can signal cardiac issues

Common Laboratory Tests for Cardiac Health

  • Basic Labs: BUN, creatinine, calcium, potassium, sodium

  • Imaging Studies: MRI, echocardiography

  • Advanced Monitoring: Central venous pressure, pulmonary artery wedge pressure

Important Clinical Considerations

  • Patient History: Family history of cardiac issues, medication use, exercise habits

  • Risk Factors: High-risk illicit drug use (e.g., meth and cocaine)

  • Lifestyle Factors: Diet, sleep, and stress management

Schedule and Class Structure

  • Upcoming Topics and Review Plan:

    • Focus on Chapter 21: Anatomy and Physiology of the Heart

    • Utilize patient scenarios for practical understanding

    • Introduce Chapter 22 after fall break to maintain continuity