Circulatory

• Circulatory system


  The system that transports blood, oxygen and nutrients to the body
• Main parts of the human circulatory system

  • Heart
  • Blood vessels
  • Blood

  
• Heart


  • Vital organ
  • Muscle that pumps blood to all parts of the body
  • Provides the body with oxygen and nutrients it needs to function
• Pericardium


  Covering of the heart, consists of fibrous and serous layers

  
• Myocardium


  Cardiac muscle that makes up the thick middle layer of the heart

  
• Endocardium


  Innermost layer of the heart that lines the chambers and extends over structures like valves

  
• Types of muscle tissue

  • Cardiac muscle
  • Smooth muscle
  • Skeletal muscle

  
• Cardiac muscle


  • Specialized, organized type of tissue that only exists in the heart
  • Responsible for keeping the heart pumping and blood circulating

  
• Intercalated discs


  Specialized junctions between cardiac muscle fibers that allow for rapid electric transmission and nutrient exchange

  
• Mitochondria


  Powerful organelles in cardiac muscle that supply energy to support the high ATP consumption of the beating heart
• Gap junctions

  Allow direct communication between cardiac muscle cells, mediating electrical coupling and dictating speed/direction of cardiac conduction

  
• Intrinsic cardiac conduction system


  Specialized subpopulations of cells that either spontaneously generate electrical activity or preferentially conduct it throughout the heart chambers

  
• The heart has four chambers: left atrium, right atrium, left ventricle, right ventricle
• Heart rate


  Normal resting heart rate for adults ranges from 60 to 100 beats per minute, lower rate implies more efficient heart function and better cardiovascular fitness
• Four main functions of the heart

  • Pumping oxygenated blood to other body parts
  • Pumping hormones and other vital substances
  • Receiving deoxygenated blood and carrying metabolic waste to the lungs
  • Maintaining blood pressure
• Blood


  Special fluid primarily contained within the blood vessels, has four main components: red blood cells, white blood cells, platelets, and plasma
• Components of blood


  • Red blood cells
  • White blood cells
  • Platelets
  • Plasma
• Red blood cells


  Functional component responsible for transporting gases and nutrients, contain hemoglobin protein
• Hemoglobin


  Iron-containing protein in red blood cells that allows for the transport of oxygen throughout the bloodstream
• Plasma


  Liquid portion of blood that transports nutrients, hormones, and proteins, and removes waste products from the body
• Types of white blood cells

  • Granulocytes (neutrophils, eosinophils, basophils)
  • Agranulocytes (lymphocytes, monocytes)
• Platelets


  Tiny disc-shaped pieces of cells that help form blood clots to stop bleeding and aid wound healing
• Hemostasis


  1. Bleeding occurs

  2. Vascular spasm

  3. Platelet plug formation

  4. Coagulation/blood clotting

  5. Clot removal through fibrinolysis
• Blood types


  Determined by the presence or absence of certain antigens on the surface of red blood cells
• Centrifuge


  Device that uses centrifugal force to separate the components of blood into layers
• Blood vessels

  Tubes or channels that carry blood throughout the body, including veins, arteries, and capillaries
• Layers of blood vessels

  • Tunica intima
  • Tunica media
  • Tunica externa