HBS 3.1.1-3.1.3

Cardiovascular Study Guide: Sections 3.1.1 - 3.1.3

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### Heart Anatomy

#### Key Structures:

- Right Atrium (R. Atrium): Receives deoxygenated blood from the body.

- Left Atrium (L. Atrium): Receives oxygenated blood from the lungs.

- Right Ventricle (R. Ventricle): Pumps deoxygenated blood to the lungs via the pulmonary artery.

- Left Ventricle (L. Ventricle): Pumps oxygenated blood to the body via the aorta.

- Aorta: The largest artery, distributing oxygenated blood.

- Pulmonary Veins: Carry oxygenated blood from the lungs to the heart.

- Pulmonary Artery: Transports deoxygenated blood to the lungs.

- Superior & Inferior Vena Cava: Bring deoxygenated blood back to the heart.

- Valves:

  - Bicuspid (Mitral) Valve: Between the left atrium and left ventricle.

  - Tricuspid Valve: Between the right atrium and right ventricle.

  - Pulmonary Valve: Between the right ventricle and pulmonary artery.

  - Aortic Valve: Between the left ventricle and aorta.

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### Blood Vessels

#### Major Differences Between Arteries and Veins:

- Arteries:

  - Thick muscular walls to handle high pressure.

  - No valves.

- Veins:

  - Thinner walls and larger lumens.

  - Valves prevent blood backflow.

#### Varicose Veins:

- Cause: Weak or damaged valves cause blood pooling and backward flow.

- Why Arteries Don’t Have Varicose Issues: Arteries lack valves.

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### Blood Pressure (BP)

#### Hypertension (High BP) Causes:

- Increased blood volume.

- Narrowed lumens in blood vessels.

#### Hypotension (Low BP) Causes:

- Blood loss.

- Dehydration.

- Heart attack.

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### Cardiac Output

#### Key Concepts:

- Definition: The amount of blood the heart pumps in a minute.

- Factors Influencing Cardiac Output:

  - Stroke Volume: The amount of blood ejected with each heartbeat.

  - Heart Rate: Number of beats per minute.

#### Importance of Cardiac Output:

- Normal Output: Delivers oxygen and nutrients to tissues.

- High Output (e.g., during exercise): Strengthens the heart.

- Low Output: Can cause tissue damage or abnormal blood pressure.

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### Atherosclerosis, Arteriosclerosis, and Peripheral Artery Disease (PAD)

#### PAD Overview:

- Definition: Blood vessels in extremities become stiff, narrowed, or blocked.

- Symptoms: Pain, coldness, or numbness in limbs. Severe cases may lead to limb loss.

- Assessment Tool:

  - Ankle-Brachial Index (ABI): Compares blood pressure in the arms and legs to evaluate circulation.

#### ABI Interpretation:

- Formula: ABI = (Ankle Systolic Pressure) / (Arm Systolic Pressure).

- Ranges:

  - Normal: 1.0 - 1.4

  - Mild PAD: 0.91 - 0.99

  - Moderate PAD: 0.41 - 0.90

  - Severe PAD: ≤ 0.40

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### Nodal Tissue and EKG

#### Key Components:

- SA Node: Natural pacemaker; initiates the heartbeat.

- AV Node: Delays signal to ensure proper blood flow.

- Bundle of His: Transmits signals to the septum.

- Purkinje Fibers: Trigger ventricular contraction.

#### EKG Waves:

- P Wave: Atrial contraction.

- QRS Complex: Ventricular contraction.

- T Wave: Ventricular relaxation.

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### Arrhythmias and AED Use

#### Common Arrhythmias:

- Sinus Tachycardia: Fast heart rate.

- Sinus Bradycardia: Slow heart rate.

- Ventricular Tachycardia: Very fast heart rhythm.

- Ventricular Fibrillation: Chaotic and life-threatening rhythm.

#### AED Indications:

- Required For:

  - Ventricular Fibrillation.

  - Ventricular Tachycardia.

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### Tips for Studying

1. Memorize heart anatomy and blood flow using diagrams.

2. Understand the differences between arteries and veins.

3. Practice calculating ABI and interpreting results.

4. Study EKG components and their corresponding heart functions.

5. Use flashcards for arrhythmia types and treatments.

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