Heart & Thorax

Thorax: Landmarks

1. Sternal angle
2. Superior border
3. Anterior border
4. Inferior border
5. Lateral border
6. Mediastinum 

Thorax: Landmarks

• Sternal angle

  1. aortic arch

  2. The crossing of the thoracic duct

  3. The bifurcation of the trachea [7]

  4. The bifurcation of the pulmonary trunk

  5. The body of vertebrae T4

  6. The drainage of the azygos vein into the superior vena cava 

Thorax: Landmarks

• Mediastinum

Thorax: Landmarks

• Middle Mediastinum

  • the heart enclosed in the pericardium

  • the ascending aorta
  • the lower half of the superior vena cava with the azygos veinopening into it
  • the bifurcation of the trachea and the two bronchi
  • the pulmonary artery dividing into its two branches
  • the right and left pulmonary veins
  • the phrenic nerves
  • some bronchial lymphatic glands
  • pericardiocophrenic vessels

Thorax: Landmarks

• Posterior Mediastinum
  • artery: thoracic part of the descending aorta
  • veins (azygos, hemiazygos, and accessory hemiazygos vein)
  • nerves
    • vagus nerve
    • splanchnic nerves
    • sympathetic chain
  • esophagus
  • thoracic duct
  • some lymph glands

Thorax: Landmarks

• Superior Mediastinum
  • trachea
  • esophagus
  • thoracic duct
  • remains of the thymus
  • some lymph glands
  • anterior longitudinal ligament

Thorax: Components

1. Diaphragm
   1. Phrenic nerve (?)
2. Vertebral level for the exit of 
   1. Inferior vena cava?
   2. Esophagus?
   3. Abdominal Aorta?
3. Lungs
4. Heart

Thorax: Lungs

1. Not in the Pleural cavity but surrounded by it
2. Visceral layer vs. the Parietal layer
3. Pleural recess (pneumothorax)
4. Lobes (right __?__, left __?__), Hilus

Thorax: Respiration

1. Inspiration: active process
2. Expiration: passive
3. Accessory muscles: eg. scalenes, SCM
4. Bronchial arteries run on bronchi to supply oxygenated blood
5. Parasympathetic (X)
6. Sympathetic (T2 - T5) -> dilate bronchioles

Heart

1. Pericardium (attached to the diaphragm and sternum)
   1. Parietal
      1. Serous (mesothelial cells)
      2. Fibrous
   2. Visceral
2. Epicardium
3. Myocardium
4. Endocardium
5. Posterior is the left ventricle, Anterior is the right

Heart: Components

1. Pectinate Muscle (atrium)
2. Fossa Ovalis - fetal flow
3. Number of leaflets in mitral valve (__?__)
   • which side (__?__)
4. Cardiac skeleton (Fibrous trigone)
5. Intraventricular septum is a muscular membrane
6. What are chordae tendenae? Papillary muscles?

Heart: Blood Flow

1. 2 Brachiocephalics -> 1 sup. venacava & inf. vena cava
2. Drain into right atrium
3. Blood moves into right ventricle
4. Out pulmonary artery
5. Lungs (oxygenation)
6. Pulmonary Vein
7. Left atrium
8. Left ventricle
9. Aorta
10. Coronary artery (LAD/Great cardiac vein, Left Circumflex, Right Sinuatrial, right marginal, Posterior IV/Middle cardiac vein)
11. Coronary veins into coronary sinus (right atrium)

Heart: Innervation

1. Parasympathetics (decrease HR)
2. Sympathetics (Increase HR and force of contraction)
3. LA: Left anterior for Vagus