CIRCULATORY

• How far is the apex of the heart from the midline?

  About 9 cm to the left
• What is the pericardium?

  A thin, fibrous, double-layered sac
• What separates the right ventricle from the left ventricle?

  The interventricular septum
• What is the approximate size of the heart?

  About the size of a clenched fist
• What does the cardiovascular system deliver to cells and organs?

  Oxygen, nutrients, hormones, and other substances
• What role does the cardiovascular system play during activity and stress?

  Helps the body meet demands of activity
• What are the main functions of the cardiovascular system?

  • Transportation
  • Protection
  • Fluid balance
  • Thermoregulation
• What is another name for the blood-vascular system?

  The circulatory system
• What is the heart described as?

  A muscular pumping device
• What is the function of the myocardium?

  Enables the heart to pump
• What is the epicardium?

  The outer layer of the heart
• What are the three layers of the heart?

  • Endocardium: inner layer, endothelial tissue
  • Myocardium: middle layer, muscle fibers
  • Epicardium: outer layer, adherent to heart
• What is the endocardium?

  The inner layer of the heart
• What type of system is the cardiovascular system?

  A closed system of vessels
• Where is the heart located?

  Between the lungs in the thoracic cavity
• What are the two pairs of valves in the heart?

  • Atrioventricular valves
  • Semilunar valves
• What are the atrioventricular valves known for?

  Located between the atria and ventricles
• What are the four chambers of the heart?

  • Right atrium
  • Left atrium
  • Right ventricle
  • Left ventricle
• How is the heart positioned in the thoracic cavity?

  It lies obliquely, more to the left
• What does the right atrium receive?

  Deoxygenated blood from the body
• What are the semilunar valves known for?

  Located between the ventricles and major arteries
• What separates the right atrium from the right ventricle?

  The tricuspid valve
• What shape is the right atrium?

  Quadrilateral in shape
• What is the interior structure of the right atrium divided into?

  Anterior rough part and posterior smooth part
• What is the shape of the right ventricle?

  Triangular chamber
• What does the right ventricle do?

  Pumps blood into the pulmonary trunk
• What gives the interior of the right ventricle a rough texture?

  Muscular rings called trabeculae carnae
• What connects the cusps of valves in the right ventricle?

  Cords known as chordae tendineae
• What are the functions of cardiac valves?

  • Allow blood flow in one direction
  • Prevent regurgitation of blood
  • Open and close due to pressure differences
• What sound does the closure of the atrioventricular valves make?

  The first sound, "LUBB"
• What sound does the closure of the semilunar valves make?

  The second sound, "DUB"
• What is circulation of blood?

  • Blood supply throughout the body
  • Includes heart, lungs, and organs
• What are the three types of blood circulation?

  • Systemic circulation
  • Pulmonary circulation
  • Coronary circulation
• What does pulmonary circulation do?

  Carries oxygen-depleted blood to the lungs
• What is the function of the left side of the heart in mammals and birds?

  Pumps and receives only oxygen-rich blood
• What does systemic circulation do?

  Carries oxygenated blood to the body
• How do open and closed circulatory systems differ?

  In an open system, blood bathes the organs directly, while in a closed system, blood is confined to vessels and distinct from interstitial fluid
• What are the three main components of a closed circulatory system?

  Circulatory fluid (blood), blood vessels, and a muscular pump (the heart)
• What are the three main adaptations of the double circulatory system in amphibians, reptiles, and mammals?

  Amphibians have a three-chambered heart, reptiles have a partially or fully divided ventricle, and mammals and birds have a four-chambered heart
• What is the key difference in the double circulatory system between amphibians, reptiles, and mammals/birds?

  Amphibians have a pulmocutaneous circuit to exchange oxygen through the lungs and skin, while reptiles, mammals, and birds have a pulmonary circuit to exchange oxygen only through the lungs