Surface anatomy – know your landmarks!

Surface anatomy is key to examination, especially when it comes to percussion and auscultation. Here are some of the major landmarks to guide your examinations:

Heart:

  • The apex of the heart is in the mid-clavicular line, 5th intercostal space. This is where the tricuspid valve is best auscultated
  • The mitral valve should be auscultated at the lower left sternal edge, medial to the apex in the 5th intercostal space
  • The pulmonary valve can auscultated just lateral to the sternum in the left 2nd intercostal space
  • The aortic valve should be auscultated just lateral to the sternum in the right 2nd intercostal space

Lung borders:

  • The apices of the lungs extend 3cm above the mid clavicular point
  • In quiet respiration, the inferior margin of the lungs are:
    • T6 (midclavicular)
    • T8 (midaxillary)
    • T10 posteriorly (median plane)
  • Pleura surface markings two ribs lower

Lung Fissures: 

  • Oblique fissure – T3 to 6th costochondral junction
  • Horizontal fissure – from the oblique fissure in the mid-axillary line to the 4th costal cartilage

Spleen:

  • Marked on left side of the back, with its long axis corresponding with that of 10th rib
  • Upper border corresponds to upper border of 9th rib & lower border to lower border of 11th rib

Liver:

  • The upper surface of the liver is percussed at the level of the fifth intercostal space
  • Lower border is the costal margin

Kidneys:

  • Posteriorly: T11-L3 (Right lower than left)
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Quick tip: palpating for a liver edge

The upper surface of the liver is at the level of the fifth intercostal space on the right side and the lower border is at the costal margin. Therefore in healthy adults you often cannot palpate a liver edge.

The liver should always be palpated on inspiration to maximise the potential for a normal or pathological liver edge to be felt. Because the liver is situated just under the diaphragm, the liver will move inferiorly on inspiration as the diaphragm contracts and moves down itself.

Always palpate from the right iliac fossa up to the costal margin. Place your hand lightly on the patient’s abdomen and ask your patient to take deep breaths in and out. Palpate more firmly as your patient breathes in and attempt to feel the liver edge.

Quick tip: percussion

When percussing, most of us will percuss twice in the same spot before moving across the chest or abdomen. Remember to ensure that on the second tap, you remember to immediately lift your percussing finger off at the end, just like you did for the first tap. If you don’t, the first and second notes will not elicit the same resonance or dullness. Specifically, you will get a relatively more dull percussion note is your percussing finger is left down longer.