ANPH1002: Cardiovascular System Lecture Notes

Introduction

• Lecture by Viola on the cardiovascular system (Chapter 14, RISO textbook).
• The lecture is a summary; students advised to read Chapter 14 for detailed understanding.

Components of the Cardiovascular System

• Heart: Main pump, composed of cardiac muscle.
  • Beats ~72 times per minute on average.
  • Contains valves to prevent backflow.
• Blood: Transports nutrients, gases, and waste.
• Blood Vessels: Includes arteries, veins, and capillaries.

Interconnection of Body Systems

• Cardiovascular system works closely with:
  • Digestive System: Transports absorbed nutrients.
  • Respiratory System: Transports gases (oxygen and carbon dioxide).
  • Urinary System: Helps excrete waste (ammonia).

Structure and Function of the Heart

Heart Layers

• Myocardium: Cardiac muscle bulk.
• Endocardium: Lines heart chambers.
• Epicardium: Covers the heart, made of visceral and serous pericardium.
• Pericardium: Surrounds the heart with fibrous (anchors heart) and serous layers.

Heart Chambers

• Four Chambers: Right/left atria (upper), right/left ventricles (lower).
• Valves: Atrioventricular (tricuspid on right, bicuspid/mitral on left) and semilunar (pulmonary and aortic).
• Ventricles have thicker walls for pumping blood out.

Blood Flow Through the Heart

• Right Side: Handles deoxygenated blood.
  • Blood enters right atrium via superior/inferior vena cava and coronary sinus.
  • Right ventricle pumps blood to lungs via pulmonary arteries.
• Left Side: Handles oxygenated blood.
  • Blood returns via pulmonary veins to left atrium.
  • Left ventricle pumps blood to body via aorta.

Heart Sounds

• "Lub-Dub" Sounds: Created by valve closures.
  • "Lub": Atrioventricular valves closing.
  • "Dub": Semilunar valves closing.

Circulation Pathways

• Systemic Circulation: Blood supply to/from the body.
• Coronary Circulation: Supply to/from heart muscle.
• Hepatic Portal Circulation: Between intestines and liver.
• Pulmonary Circulation: Between heart and lungs.

Blood Vessels

• Arteries: Thick walls to withstand high pressure.
• Veins: Thinner walls, valves to prevent backflow.
• Capillaries: Site of nutrient and gas exchange.

Cardiac Cycle and Conduction System

• Pacemaker (Sinoatrial Node): Initiates cardiac cycle.
• ECG: Records electrical activity.
• Autonomic Nervous System (ANS): Regulates heart rate (sympathetic speeds up, parasympathetic slows down).

Blood Pressure

• Systolic/Diastolic Measurements: Systole = contraction, Diastole = relaxation.
• Categories: Normal, Prehypertensive, Stage 1 and Stage 2 Hypertensive.

Aging and Cardiovascular Changes

• Decrease in calcium transport, leading to slower muscle contraction.
• Left ventricle enlargement and reduced cardiac output.

Conclusion

• Reinforce understanding by reading Chapter 14.
• Utilize checklist provided in the textbook for learning outcomes.

Reflection Questions

• Consider the major blood vessels emptying into the superior and inferior vena cava.
• How does aging affect the cardiovascular system?

Note: Diagrams referenced in the lecture are available in the textbook for visual aid.