Cardiovascular Anatomy and Physiology

Questions and Answers

What is the primary function of the myocardium in the heart?

Separates the right and left atria

Lubricates the heart via pericardial fluid

Forms the protective inner lining of the heart

Provides rhythmic contraction for pumping blood (correct)

Which structure is primarily responsible for receiving deoxygenated blood from the upper body?

Right atrium (correct)

Right ventricle

Left atrium

Left ventricle

What is the role of the atrioventricular valves in the heart?

Separate deoxygenated and oxygenated blood

Prevent backflow during ventricular contraction (correct)

Facilitate exchange of oxygen in pulmonary veins

Regulate blood flow from the heart to lungs

Where does the left ventricle pump oxygenated blood to?

Systemic circulation Signup and view all the answers

What type of blood do the pulmonary veins carry?

Oxygenated blood Signup and view all the answers

What is the primary function of the pulmonic valve?

Permits blood flow from the right ventricle to the pulmonary artery Signup and view all the answers

Which artery is referred to as the 'widow maker'?

Left anterior descending artery Signup and view all the answers

During which phase of the cardiac cycle does ventricular contraction occur?

Systole Signup and view all the answers

The coronary arteries primarily supply blood to which part of the body?

Heart myocardium Signup and view all the answers

What role does the cardiac conduction system play in the heart?

Generates and transmits electrical impulses Signup and view all the answers

Study Notes

Cardiovascular Anatomy and Physiology

Heart pump oxygenated blood for systemic circulation through rhythmic contractions and relaxations.
Layers of the Heart:
- Epicardium/Pericardium: Outer layer with lubricating pericardial fluid.
- Myocardium: Muscular middle layer made of myocytes, essential for contraction.
- Endocardium: Innermost layer, protects heart valves.

Heart Structure

Right Side (Deoxygenated Blood):
- Right Atrium: Receives blood from superior/inferior vena cavae and coronary sinus.
- Right Ventricle: Pumps blood to pulmonary circulation via pulmonary artery for reoxygenation.
Left Side (Oxygenated Blood):
- Left Atrium: Receives blood from lungs via four pulmonary veins.
- Left Ventricle: Pumps blood to systemic circulation via the aorta.

Heart Valves

Ensure unidirectional blood flow and prevent backflow.
Atrioventricular Valves:
- Tricuspid: Blood flows from right atrium to right ventricle.
- Bicuspid (Mitral): Blood flows from left atrium to left ventricle.
Semilunar Valves:
- Pulmonic: Blood flows from right ventricle to pulmonary artery.
- Aortic: Blood flows from left ventricle to aorta.

Coronary Arteries

Supply blood primarily to the myocardium.
Left Coronary Artery:
- Left Main Coronary Artery: Divides into:
  - Left Anterior Descending Artery: Supplies anterior heart; known as "widow maker".
  - Circumflex Artery: Feeds left atrium and lateral/posterior left ventricle.
Right Coronary Artery:
- Supplies right heart and inferior left ventricle.
- Posterior Descending Artery supplies the heart's posterior wall.

Cardiac Cycles

Systole: Phase of ventricular contraction (blood ejection).
Diastole: Phase of ventricular relaxation (filling).

Cardiac Conduction System

Generates and transmits impulses to stimulate myocardium contraction.
Physiological Characteristics:
- Automaticity: Initiates impulses independently.
- Excitability: Responds to impulses.
- Conductivity: Transmits impulses between cells.
Key Structures:
- Sinoatrial Node: Primary pacemaker; firing rate of 60-100/min.
- Atrioventricular Node: Secondary pacemaker; firing rate of 40-60/min, coordinates impulse to ventricles.
- Bundle of His: Transmits impulses to ventricles.
- Purkinje Fibers: Final conduction point, stimulating ventricular contraction.

Cardiac Action Potential

Cycle of depolarization and repolarization influenced by potassium, calcium, and sodium.
Phases of Action Potential:
- Phase 0: Rapid depolarization (sodium influx).
- Phase 1: Early repolarization (potassium efflux).
- Phase 2: Plateau (calcium influx).
- Phase 3: Completion of repolarization.
- Phase 4: Resting state.

Dysrhythmia and Refractory Periods

Dysrhythmia: Any abnormal heartbeat pattern.
Refractory Period: Myocardial cells must completely repolarize before depolarizing again.
- Absolute Refractory: Cell unresponsive to stimuli.
- Relative Refractory: Short responsive period after repolarization.

Cardiac Hemodynamics

Blood flow events occur with each heartbeat, based on pressure differentials.
Atrial Systole: Atria contract, boosting ventricular filling.
Ventricular Systole: Pressure increase leads to blood ejection through semilunar valves.

Cardiac Output

Defined as total blood volume pumped by the heart per minute.
Formula: Cardiac Output = Stroke Volume x Heart Rate; normal range is approximately 5 L/min, varying with metabolic needs.

Cardiac Biomarkers

Creatinine Kinase (CK): Indicates muscle injury if elevated.
CK-MB: Specific to heart muscle injury.
Myoglobin: Oxygen-carrying protein, indicates muscle usage.
Troponin I and T: Most reliable cardiac biomarkers for diagnosing myocardial infarction.
Lipid Profile: Evaluates fats in blood; cholesterol normal range for 50 y/o: 40-190 mg/dl.

Diagnostic Procedures

2D Echocardiography: Ultrasound evaluates heart structure/function and measures ejection fraction.
Cardiac Catheterization: Invasive procedure to assess coronary artery conditions and patency; requires careful post-op monitoring.
Angiography: Visualizes heart and vessels using contrast media.

Description

This quiz covers the anatomy and physiology of the cardiovascular system, including the layers of the heart and the structure of its chambers. Participants will explore the functions of various heart valves and the pathways of blood flow through the heart. Test your knowledge of how oxygenated and deoxygenated blood circulate in the human body.