the heart t3

• Where is the heart located in the body?

  In the mediastinum
• What anatomical structures define the mediastinum?


  Extends from the sternum to the vertebral column, the first rib, and between the lungs
• What is the apex of the heart?


  The tip of the left ventricle
• What is the base of the heart?

  The posterior surface
• What is the anterior surface of the heart?


  Deep to the sternum and ribs
• What is the inferior surface of the heart?


  Between the apex and right border
• Which border of the heart faces the right lung?

  The right border
• Which border of the heart is known as the pulmonary border?


  The left border
• What are the main parts of the pericardium?

  • Fibrous pericardium: tough, inelastic, prevents overstretching
  • Serous pericardium: thinner, has parietal and visceral layers
• What is the function of the pericardial fluid?


  It reduces friction between the heart and pericardium
• What are the layers of the heart wall?

  • Epicardium: outer layer, visceral layer of serous pericardium
  • Myocardium: 95% cardiac muscle
  • Endocardium: smooth lining for heart chambers and valves
• What is the role of the auricles in the heart?


  They increase the capacity of the atria
• What are the two types of chambers in the heart?

  Atria and ventricles
• What are sulci in the heart?


  Grooves that contain coronary blood vessels
• What is the coronary sulcus?


  • Encircles most of the heart
  • Boundary between atria and ventricles
  • Contains right coronary, circumflex coronary, and coronary sinus
• What are the anterior and posterior interventricular sulci?


  • Anterior: boundary between right and left ventricles; contains LAD
  • Posterior: distinction between right and left ventricles; contains right coronary
• What is the function of the right atrium?


  Receives blood from the superior vena cava, inferior vena cava, and coronary sinus
• What is the fossa ovalis in the right atrium?


  A remnant of the foramen ovale
• How does blood flow from the right atrium to the right ventricle?

  Through the tricuspid valve
• What forms the anterior surface of the heart?


  The right ventricle
• What are trabeculae carneae?


  Ridges formed by raised bundles of cardiac muscle fiber
• What are chordae tendineae?


  Connective tissues that connect the tricuspid valve to papillary muscles
• How does blood leave the right ventricle?


  Through the pulmonary valve into the pulmonary trunk
• What is the left atrium's primary function?


  Receives blood from the lungs through pulmonary veins
• How does blood flow from the left atrium to the left ventricle?

  Through the bicuspid (mitral) valve
• What is the thickest chamber of the heart?


  The left ventricle
• What happens to blood after it leaves the left ventricle?

  It passes through the aortic valve into the ascending aorta
• What is the ductus arteriosus?


  A fetal structure that shunts blood from the pulmonary trunk to the aorta
• What is the fibrous skeleton of the heart?


  A dense connective tissue that forms between atria and ventricles
• What are the functions of the fibrous skeleton?


  1. Structural foundation
  2. Point of insertion for muscle bundles
  3. Electrical insulator
• What are the types of heart valves?

  • Atrioventricular (AV) valves: Tricuspid and bicuspid
  • Semilunar (SL) valves: Aortic and pulmonary
• How do AV valves function during atrial contraction?


  They open and project into the ventricle
• What happens to the AV valves during ventricular contraction?


  Pressure drives the cusps upward to close the opening
• How do semilunar valves function?


  They open when pressure in the ventricle exceeds pressure in the arteries
• What happens to semilunar valves as ventricles relax?


  Some backflow is permitted, filling the valve cusps and closing them tightly
• What valves guard the entrance to the atria?


  No valves guard the entrance to the atria
• What are the two types of atrioventricular (AV) valves?


  Tricuspid and bicuspid valves
• What happens to the AV valves when the atria contract?


  The AV valve opens, and the cusps project into the ventricle
• What is the state of the papillary muscles and chordae tendinae when the atria are relaxed and the ventricle is contracting?


  The papillary muscles are contracted and the chordae tendinae are taut
• How do the cusps of the AV valves behave during ventricular contraction?


  Pressure drives the cusps upward until their edges meet and close the opening