The Cardiovascular System

Introduction

• Discussing the cardiovascular system, focusing on the ATI TEAS Version 7 Human Anatomy and Physiology exam.
• Exploring the importance of the cardiovascular system in transporting glucose and gases.

Blood and Its Functions

• Human blood is always red, varying in shade based on oxygen concentration.
• Misconception: Blood is not blue; veins may appear blue due to optical illusions.
• Blood regulates pH, temperature, and osmotic pressure for homeostasis.
• Functions as a delivery system for hormones, nutrients, and gases.

Components of Blood

• Plasma: Liquid portion of blood containing water, proteins, salts, and lipids.
• Red Blood Cells: Transport gases; contain hemoglobin, which gives blood its red color.
• White Blood Cells: Fight infections.
• Platelets: Aid in blood clotting.

Circulatory System

• Arteries: Carry blood away from the heart, generally oxygen-rich.
  • Exception: Pulmonary arteries carry deoxygenated blood.
• Veins: Return blood to the heart, usually oxygen-poor.
  • Exception: Pulmonary veins carry oxygenated blood.
• Capillaries: Sites of gas exchange between blood and tissues.

Heart Anatomy and Blood Flow

• The heart has four chambers: right/left atrium and right/left ventricle.
• Right side handles deoxygenated blood; left side handles oxygenated blood.
• Blood flow through the heart is crucial for the TEAS exam.

Blood Flow Pathway

1. Deoxygenated blood from the body returns via the vena cava to the right atrium.
2. Passes through the tricuspid valve to the right ventricle.
3. Propelled through the pulmonary valve to the pulmonary artery.
4. Oxygenated in the lungs, returns via pulmonary veins to the left atrium.
5. Moves through the mitral valve to the left ventricle.
6. Pumped out through the aortic valve to the aorta for systemic circulation.

Coronary Circulation

• Heart requires its own blood supply via coronary arteries.
• Deoxygenated blood returns via coronary veins to the right atrium.

Heart Conditions

• Septal Defects: Abnormal openings in the septum cause mixing of oxygen-rich and oxygen-poor blood.
  • Atrial Septal Defects: Involves atrial mixing.
  • Ventricular Septal Defects: Involves ventricular mixing.
• Treatment may include medications or surgery.

Electrical Conduction System

• Sinoatrial Node (SA Node): Primary pacemaker, initiates heartbeat.
• Bachman's Bundle: Transmits signals to the left atrium.
• Atrioventricular Node (AV Node): Delays signal to allow atria to contract fully.
• Bundle of His: Transmits signals to ventricles, splits into right and left bundle branches.
• Purkinje Fibers: Final pathway for electrical signals, trigger ventricular contraction.

Pacemaker Rates

• SA Node: 60-100 beats per minute (bpm).
• AV Node: 40-60 bpm.
• Purkinje Fibers: 20-40 bpm.

ECG Basics

• Isoelectric Line: Baseline of no electrical activity.
• P-Wave: Atrial depolarization.
• QRS Complex: Ventricular depolarization.
• T-Wave: Ventricular repolarization.
• Atrial repolarization occurs during the QRS complex.

Blood Pressure

• Systolic Pressure: Higher number, pressure during heart contraction.
• Diastolic Pressure: Lower number, pressure during heart relaxation.
• Normal range: 120/80 mmHg.

Conclusion

• Understanding the cardiovascular system is key for exams and healthcare professions.
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Note: Additional questions can be asked on the platform for further clarification.