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• function of cardiovascular system

  -main transport mechanism in the body

  1. nutrients: macro and micronutrients

  2. gases: O2 and CO2

  3. end products of metabolism (hormones)

  -tissue repair, immunity, body temperature
• Components of CV


  heart: central pump, sets driving pressure for blood through vasculature

  vessels: vasculature, move blood around

  blood: fluid of CV
• Heart pumps


  2 pumps

  right: pulmonary circulation

  - lungs

  left: systemic circulation

  - body tissues

  -upper and lower systemic circulation
• Functions of the heart

  1. generating blood pressure

  2. routing blood: separates systemic, coronary and pulmonary circulation

  3. ensuring one-way blood flow: valves

  4. regulating blood supply: giving it too muscles that need it
• Heart location


  Mediastinum of the thoracic cavity
• superior vena cava


  connects to right atrium
• pulmonary trunk


  exits right ventricle
• Apex


  -blunt, rounded point of cone

  -anterior, inferior and to left

  -2/3 heart mass is on left
• Base


  -flat

  -superior, posterior, right
• Pericardium


  Membrane surrounding the heart
• Fibrous pericardium


  -tough dense irregular CT, prevents over-distention, anchors the heart
• serous pericardium


  thinner, transparent, double inner layers, simple squamous epithelium
• parietal pericardium


  -outer layer
• visceral pericardium


  -inner layer

  -epicardium in the heart
• pericardial cavity


  between parietal and visceral layers, contains pericardial fluid (reduces friction)
• Layers of heart wall

  -epicardium (outer layer)

  -visceral pericardium

  -myocardium (middle layer)

  - largest (cardiac muscle)

  -endocardium (inner layer)

  - chamber lining the valves
• chambers of heart


  -2 upper atria (plus auricles which are extensions of the atria)

  -2 lower ventricles
• sulci


  contain fat and coronary blood vessels
• coronary sulcus


  separates atria and ventricles
• anterior interventricular sulcus


  marks the boundary between the ventricles anteriorly
• posterior interventricular sulcus


  marks the boundary between the ventricles posteriorly
• coronary circulation


  blood supply to the heart

  -heart is very active and needs lots of O2

  -when heart relaxes high pressure of blood in aorta pushes blood into coronary vessels
• anastomoses


  provide alternate routes if one artery is blocked
• aortic semilunar valve


  separate ventricle form aorta
• right coronary artery


  -in coronary sulcus

  -exits aorta superior to where aorta exits the heart

  -posterior aspect of heart
• branches of right coronary artery

  -right marginal artery (lateral wall of right ventricle)

  -posterior interventricular artery (supplies posterior and inferior aspects of heart)
• left coronary artery


  exits aorta near right coronary
• branches of the left coronary artery

  anterior interventriuclar sulcus (widow maker)

  circumflex artery (extends to posterior aspect)
• great cardiac vein


  drains the left side of the heart
• small cardiac vein


  drains right side of the heart
• middle cardiac vein


  drains areas supplied by posterior interventricular artery
• coronary sinus


  large venous cavity, empties into right atrium
• trabecular carneae


  only in ventricles
• where are the valves


  valves are on a single plane

  -attached to skeleton of the heart
• skeleton of the heart

  -plate of fibrous connective tissue between atria and ventricles

  -fibrous ring around valves for support, electrical insulation between atria and ventricles and site for muscle attachment
• cardiac muscle


  -elongated, breaching cells, with 1-2 centrally located nuclei

  -contain actin and myosin

  -intercalated disks: specialized cell-cell contact (only in cardiac muscle)

  -fewer nuclei, fewer myofibrils, moe mitochondria

  -desomoses (hold cells together)

  -gap junctions

  -electrically, cardiac muscle of atria and ventricle behave as a single unit due to gap junctions

  -T-tubules larger then skeletal

  -less frequent but larger and prevent where z-discs are
• SA node


  -where the signal starts

  -spontaneous action potentials

  -go to AV node

  -pacemaker
• AV node


  -AP conducted more slowly

  -ensure ventricles receive signal to contract after atria have contracted
• BUNDLE OF HIS/AV BUNDLE

  -passes through hole in cardiac skeleton to reach interventriuclar septum
• right and left bundle branches

  -very fast conduction of AP