pleura and mediastinum

Question 1

Plura description

Answer 1

lungs are enveloped in a twin walled serous sac – two layers of the pleura – that meet at the hilum to form the pulmonary ligament.
A potential space exists between the two pleural layers (visceral and parietal), which contains a thin film of serous fluid.

Question 2

Describe mediastinum

Answer 2

space between the two pleural sacs and is divided into four regions by the pericardium:
Superior (below thoracic inlet) Middle (contains pericardial contents) Anterior (behind sternum) Posterior (above diaphragm)

Question 3

Lines of pleural reflection

Answer 3

Apex – lies 4 cm above the clavicle

Behind the sternoclavicular joint

Behind the sternum at the second costochondral junction

On the left – lateral sternal edge at the fourth cartilage

On the right – down to the costoxiphoid angle

Eighth rib – mid-clavicular line

Tenth rib – mid-axillary line

Twelfth rib – posterior to the costovertebral angle