HBS

Here are in-depth study notes covering all the questions from your study guide:

1. Vocabulary Definitions

• Cardiovascular System – The system comprising the heart and blood vessels, responsible for circulating blood, oxygen, and nutrients throughout the body.

• Artery – A blood vessel that carries oxygenated blood away from the heart to the body (except the pulmonary artery, which carries deoxygenated blood to the lungs).

• Vein – A blood vessel that carries deoxygenated blood back to the heart (except the pulmonary vein, which carries oxygenated blood from the lungs to the heart).

• Capillary – The smallest blood vessels that connect arteries and veins; they facilitate the exchange of oxygen, carbon dioxide, and nutrients between blood and tissues.

• Heart Rate – The number of times the heart beats per minute (bpm).

• Pulse – The rhythmic expansion and recoil of arteries due to the beating of the heart; commonly felt at the wrist or neck.

• Cardiac Output – The amount of blood pumped by the heart per minute; calculated as Heart Rate × Stroke Volume.

• Stroke Volume – The amount of blood ejected by the left ventricle per beat.

• Blood Pressure – The force exerted by circulating blood on the walls of blood vessels, measured in mmHg (systolic/diastolic).

• Sphygmomanometer – A device used to measure blood pressure.

• Systolic Pressure – The pressure in the arteries when the heart contracts (top number in BP readings).

• Diastolic Pressure – The pressure in the arteries when the heart relaxes between beats (bottom number in BP readings).

• EKG (Electrocardiogram) – A test that records the electrical activity of the heart.

• SA Node (Sinoatrial Node) – The heart’s natural pacemaker, which initiates the electrical impulses that regulate heartbeats.

• AV Node (Atrioventricular Node) – A part of the heart’s electrical system that delays the impulse before sending it to the ventricles.

• Bundle of His – A pathway of fibers that transmits electrical impulses from the AV node to the ventricles.

• Purkinje Fibers – Fibers that distribute electrical impulses through the ventricles, causing contraction.

• Arrhythmia – An irregular heart rhythm, which can be too fast, too slow, or erratic.

2. Structural Differences Between the Left and Right Side of the Heart

• Left Side:

• Thicker and more muscular because it pumps oxygenated blood to the entire body (systemic circulation).

• Generates higher pressure to ensure blood reaches all tissues.

• Right Side:

• Thinner because it only pumps deoxygenated blood to the lungs (pulmonary circulation).

• Works at a lower pressure since the lungs are nearby.

Why?

The left ventricle needs to exert more force to push blood throughout the body, while the right ventricle only needs to send blood a short distance to the lungs.

3. Blood Flow Through the Heart

1. Deoxygenated blood enters the right atrium via the superior and inferior vena cava.

2. Blood flows through the tricuspid valve into the right ventricle.

3. Right ventricle pumps blood through the pulmonary valve into the pulmonary artery, leading to the lungs.

4. Oxygenated blood returns from the lungs via the pulmonary veins into the left atrium.

5. Blood flows through the mitral (bicuspid) valve into the left ventricle.

6. Left ventricle pumps blood through the aortic valve into the aorta, which distributes oxygen-rich blood to the body.

4. Major Arteries and Veins

• Major Arteries:

• Aorta (largest artery, carries oxygenated blood to the body)

• Pulmonary Artery (carries deoxygenated blood to the lungs)

• Coronary Arteries (supply the heart itself)

• Carotid Arteries (supply the brain)

• Femoral Arteries (supply the legs)

• Major Veins:

• Superior and Inferior Vena Cava (return deoxygenated blood to the heart)

• Pulmonary Veins (carry oxygenated blood from lungs to the heart)

• Jugular Veins (drain blood from the brain)

• Femoral Vein (returns blood from the legs)

5. Cardiac Output Calculation

Formula:

• Given Heart Rate = 68 bpm

• Assume Stroke Volume = 70 mL (0.07 L)

Per minute:

Per hour:

Per day:

Per year:

6. Complications of High and Low Blood Pressure

• High Blood Pressure (Hypertension):

• Increased risk of stroke, heart attack, kidney damage, and aneurysms.

• Low Blood Pressure (Hypotension):

• Can cause dizziness, fainting, and shock (dangerously low blood flow to organs).

7. What is ABI?

• Ankle-Brachial Index (ABI) compares blood pressure in the ankles and arms.

• Used to diagnose Peripheral Artery Disease (PAD), which causes poor blood circulation in the legs.

8. ABI Practice – Normal vs. Concerning Numbers

• ABI Calculation:

• ABI = Ankle BP / Arm BP

• Normal ABI: 1.0 - 1.4

• Mild PAD: 0.9 - 0.7

• Severe PAD: Below 0.4

If the ABI in the given numbers is below 0.9, it suggests possible PAD.

9. What is PAD?

• Peripheral Artery Disease (PAD): A condition where narrowed arteries reduce blood flow to the limbs, often caused by atherosclerosis.

• Symptoms: Leg pain while walking (claudication), cold feet, slow-healing wounds.

10. EKG Waves and Their Meaning

• P Wave – Atrial depolarization (atria contracting).

• QRS Complex – Ventricular depolarization (ventricles contracting).

• T Wave – Ventricular repolarization (ventricles relaxing).

Final Study Tips:

• Memorize key terms and their functions.

• Practice tracing blood flow through the heart.

• Understand blood pressure readings and their implications.

• Learn how to calculate cardiac output.

• Familiarize yourself with EKG waveforms and their meanings.

Let me know if you need anything clarified!