Cardiovascular System

• 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


  A vital organ that is a muscle that pumps blood to all parts of the body

  
• Blood


  A fluid primarily contained within the blood vessels that has four main components: red blood cells, white blood cells, platelets and plasma
• Blood vessels


  Tubes or channels that carry blood throughout the body, including veins, arteries and capillaries
• The wall of the heart separates into the following layers: epicardium, myocardium, and endocardium

  
• Fibrous pericardium


  A conical-shaped sac that the heart is enclosed in

  
• Serous pericardium


  A layer of serosa that lines the fibrous pericardium and covers the entire surface of the heart

  
• Myocardium


  The thick middle layer of the heart made up of cardiac muscle

  
• Endocardium


  The 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


  A specialized, organized type of muscle tissue that only exists in the heart and is responsible for keeping the heart pumping

  
• Structure of a cardiac muscle fiber

  • Has a single nucleus, is branched, and joined to others by intercalated discs containing gap junctions and desmosomes

  
• Intercalated discs


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

  
• Cardiac mitochondria


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


  Allow direct communication between cardiac muscle cells and mediate the electrical coupling of cardiomyocytes

  
• Intrinsic cardiac conduction system


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

  
• The four chambers of the heart are the left atrium, right atrium, left ventricle, and right ventricle
• Heart rate


  The number of times the heart beats per minute, with a normal resting rate for adults ranging from 60 to 100 beats per minute
• 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


  A special fluid primarily contained within the blood vessels that 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


  The functional component of blood responsible for transporting gases and nutrients, containing the iron-rich protein hemoglobin
• Hemoglobin


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


  The liquid portion of blood that makes up about 55% and transports nutrients, hormones, and proteins while removing waste
• Types of white blood cells

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


  Tiny disc-shaped pieces of cells found in the blood and spleen that help form blood clots to stop bleeding
• 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


  A device that uses centrifugal force to separate the components of blood into layers
• Layers of blood vessels

  • Tunica interna (intima)
  • Tunica media
  • Tunica externa (adventitia)
• Arteries


  Blood vessels that carry blood away from the heart, including elastic, muscular, and arterioles
• Carotid artery


  Major blood vessels that provide blood supply to the brain, with carotid artery disease causing up to one-third of all strokes
• Branches of the carotid artery

  • Maxillary artery
  • Superficial temporal artery
• Common carotid artery


  Artery that branches into the external and internal carotid arteries
• External carotid artery


  One of the two terminal branches of the common carotid artery that supplies structures of the neck, face and head
• Internal carotid artery


  The other terminal branch of the common carotid artery that supplies the intracranial structures
• Subclavian artery


  Artery that lies just below the clavicles and provides blood supply to the upper extremities

  
• Coronary artery


  Arteries that run along the coronary sulcus of the myocardium and supply blood to the heart

  
• Pulmonary artery


  Arteries that carry deoxygenated blood from the heart to the lungs