Cristy Hecao

• Cardiovascular System


  The system responsible for circulating blood throughout the body
• Three Components of the Cardiovascular System

  • Heart
  • Blood vessels
  • Blood
• Heart


  • A specialized muscle type that acts as a pump
• Blood vessels


  • Network of tubes distributed all throughout the body
• Blood


  • Connective tissue consisting of a liquid matrix containing cells and cell fragments
• Functions of the Heart

  • Generating blood pressure
  • Routing blood
  • Ensuring one-way blood flow
  • Regulating blood supply

  
• Generating blood pressure


  Contractions of the heart generate blood pressure, which is responsible for moving blood through the blood vessels
• Routing blood


  The heart separates the pulmonary and systemic circulations and ensures better oxygenation of the blood flowing to the tissues
• Ensuring one-way blood flow

  The valves of the heart ensure a one-way flow of blood through the heart and blood vessels

  
• Regulating blood supply


  The rate and force of heart contractions change to meet the metabolic needs of the tissues, which vary depending on such conditions as rest, exercise, and changes in body positions
• Functions of the Circulatory System (blood vessels)

  • Carries blood
  • Exchanges nutrients, waste products, and gases with tissues
  • Transport substances
  • Helps regulate blood pressure
  • Directs blood flow to tissues

  
• Carries blood


  Blood vessels carry blood from the heart to almost all body tissues and back to the heart
• Exchanges nutrients, waste products, and gases with tissues

  • Nutrients and oxygen diffuse from blood vessels to cells in all areas of the body
  • Waste products and carbon dioxide diffuse from cells, where they are produced, to blood vessels
• Transport substances


  Hormones, components of the immune system, molecules required for coagulation, enzymes, nutrients, gases, waste products, and other substances are transported in the blood to all areas of the body
• Helps regulate blood pressure


  The circulatory system and the heart work together to maintain blood pressure within a normal range

  
• Directs blood flow to tissues


  The circulatory system directs blood to tissues when increased blood flow is required to maintain homeostasis
• Functions of the Blood

  • Transport of gases, nutrients, and waste products
  • Transport of regulatory molecules
  • Regulation of pH and osmosis
  • Maintenance of body temperature
  • Protection against foreign substances
  • Clot formation
• Transport of gases, nutrients, and waste products

  • Oxygen and carbon dioxide enter in and out of the blood and tissues
  • Blood transport ingested nutrients, ions, and water from the digestive tract to the cells, and blood transport the cell's waste product to the kidney for elimination
• Transport of regulatory molecules

  The blood carries the hormones and many enzymes that regulate the body processes from one part of the body to another
• Regulation of pH and osmosis

  • Buffers help keep the blood's pH within its normal range of 7.35-7.45
  • The osmotic composition of the blood is also critical for maintaining normal fluid and ion balance
• Maintenance of body temperature

  Movement of warm blood from the interior of the body, to its surface where the heat is released, is one of several mechanisms that regulate body temperature
• Protection against foreign substances

  Certain cells and chemicals in the blood make up an important part of the immune system, protecting against foreign substances, such as microorganisms and toxins
• Clot formation


  • When blood vessels are damaged, blood clotting protects against excessive blood loss
  • When tissues are damaged, blood clots that also forms is also the first step in tissue repair and restoration of the normal function
• Size, Shape, and Location of the Heart

  • The adult heart is shaped like a blunt cone and is approximately the size of a closed fist
  • Average mass of 250g in females and 300g in males
  • The blunt, rounded point of the heart is the apex
  • The larger, flat part at the opposite end of the heart is the base
  • The heart is located in the mediastinum – a midline partition of the thoracic cavity that also contains the trachea, the esophagus, the thymus, and associated structures
  • The base of the heart is located deep to the sternum and extends to second intercostal space
  • The apex is located deep to the fifth intercostal space, approximately 7-9 cm to the left of sternum and medial to the midclavicular line (a perpendicular line that extends down from the middle line of the clavicle)

  
• Layers of the Heart Wall

  • Epicardium (visceral pericardium)
  • Myocardium
  • Endocardium

  
• Epicardium


  Thin serous membrane that constitutes the smooth, outer surface of the heart

  
• Myocardium


  Thick, middle layer of the heart, composed of cardiac muscle cells and is responsible for the heart's ability to contract

  
• Endocardium


  Smooth, inner surface of the chambers of the heart

  
• Chambers of the Heart

  • Two atria
  • Two ventricles
• Major Veins Carrying Blood to the Heart

  • Superior vena cava
  • Inferior vena cava
  • Four pulmonary veins
• Superior and inferior vena cava

  Carry blood to the right atrium

  
• Pulmonary veins


  Carry blood to the left atrium
• Major Arteries Exiting the Heart

  • Aorta
  • Pulmonary trunk
• Aorta


  Carries blood from the left ventricle
• Pulmonary trunk


  Carries blood from the right ventricle to the lungs
• Three Main Types of Blood Vessels

  • Arteries
  • Capillaries
  • Veins
• Arteries


  Carry blood away from the heart
• Capillaries


  The most common type of blood vessel, where most exchanges between blood and tissues occur
• Veins


  Carry blood toward the heart
• Heart Chambers and Valves

  • Right Atrium
  • Left Atrium
  • Right Ventricle
  • Left Ventricle
  • Atrioventricular (AV) Valves
  • Semilunar Valves