Respiratory- Anatomy And Physiology

Question 1

Respiratory lower anatomy and physiology

Answer 1

• At the end of tidal expiration, the dome of the diaphragm extends high into the thorax, level with the anterior end of the 5th rib, slightly lower on the left
• the lower lateral ribs therefore overlie the liver on the right and the stomach and spleen on the left, with the parietal pleura extending lower than the lungs on the lateral chest wall
• posteriorly, the lung fields extend much lower, approaching the 12th rib of full inspiration
• ## the lung apex lies immediately beneath the brachial plexus, so apical lung tumours commonly disrupt T1 root fibres, causing pain and numbness in the inner upper arm and wasting in hands

Question 2

Anatomy and physiology

Answer 2

• in the mid and lower mediastinum tumours can invade and compromise the pericardium, atria and oesophagus
• in healthy lungs optimise gas exchange by close matching of regional ventilation and perfusion
• airway parenchymal lung disease disrupts mismatching, causing hypoxia and cyanosis and commonly stimulate breathing through lung afferent nerves, leading to a history of breathlessness and tachypnoea upon examination