Lungs Flashcards
What is the mediastinum?
Central compartment of the thoracic cavity located between the two plural sacs, it contains most of the thoracic organs and acts as a conduit
List some structures which are present inside, or run through the mediastinum:
Heart, Thymus, Trachea, Oesophagus…
What is the pleura?
A serous (secreting) membrane which covers the external surface of the lung and lines the thoracic cavity.
What is the visceral pleura?
A thin, slippery membrane that covers the surface of the lungs
What is the parietal pleura?
The outer membrane that lines the inner chest wall and diaphragm
What is the difference between the two pleura layers?
Visceral is more inner than the parietal
What is the pleural cavity?
The space between the visceral and parietal pleura
What is the function of the pleural cavity?
The space is filled with fluid so the two pleura can slip over each other during breathing which reduces friction
Where is the hilum of the lung?
Where the bronchus enter the lungs
Explain the bronchopulmonary segments:
Trachea Right and left bronchi Lobar bronchi Tertiary bronchi Bronchioles Terminal bronchiole Respiratory bronchiole Acinus Alveoli
What is the function of lobar bronchi?
Supply air to each lobe of the lung
What is the function of tertiary bronchi?
Supply air to specific segments of the lung
What structure helps the trachea to stay open?
C-Shaped cartilage rings
What structure surrounds the right and left bronchi?
C-Shaped cartilage and Smooth muscle
What structure surrounds the bronchioles?
Smooth muscle
What is the importance of smooth muscle in the bronchioles?
Helps control airflow as the muscle can contract
What structures are present within the acinus?
Smooth muscle Alveoli Pulmonary artery Pulmonary vein Mucous gland
What are conducting zones?
Tubes proximal to the respiratory bronchioles which transfer air by bulk flow
What are respiratory zones?
Tubes distal to the respiratory bronchioles which are involved in gas exchange
Why is air in the conducting zones referred to as anatomical dead space?
The air in this space is not being involved in gaseous exchange
