Lung Anatomy
What are the two principal respiratory organs responsible for gas exchange?
The lungs
How many lobes does the right lung have?
3
What membrane directly covers the surface of the lung?
Visceral pleura
What structure forms the inferior boundary, or floor, of the thoracic cavity?
The diaphragm
What is another name for the hilum?
The root of the lung
What is the shape of the lungs described in the slides?
Conical
How many lobes does the left lung have?
2
What membrane lines the inner thoracic cavity?
Parietal pleura
What structure divides the thoracic cavity into left and right vertical halves?
The mediastinum
Where is the hilum located?
On the medial side of the lung
What are the two major parts of the lung's external shape: the rounded superior portion and the broad inferior surface?
Apex and base
Name the two fissures of the right lung.
Horizontal fissure and oblique fissure
What is found between the visceral and parietal pleura?
The pleural space
How many pleural cavities are in the thoracic cavity?
Two — a right pleural cavity and a left pleural cavity.
Name three things that enter or leave the lung through the hilum.
Examples include:
Why is the left lung smaller than the right lung?
Because the heart occupies space on the left side.
How many bronchopulmonary segments are found in each lung?
Right = 10
👉 Left = 8
Name the three major functions of the pleural space.
👉 Lubrication
👉 Negative pressure
👉 Stabilization
Name four structures found in the mediastinum.
Any four of:
What structure marks the boundary between extrapulmonary and intrapulmonary airways?
The hilum
Extrapulmonary: Trachea + first portion of main stem bronchi
Intrapulmonary: Airways inside lung tissue, beginning where the main stem bronchi enter the lung.
Name the two blood supplies to the lungs and explain what each does.
Pulmonary circulation — involved in gas exchange.
👉 Bronchial circulation — supplies/feeds the lung tissue.
Give the number of segments in each lobe of the right lung.
👉 Superior = 3
👉 Middle = 2
👉 Inferior = 5
Total = 10
Explain why negative pressure in the pleural space is important for breathing.
The lungs naturally tend to recoil inward while the chest wall tends to spring outward. This creates negative pressure in the pleural space, helping keep the lungs attached to the chest wall. When the chest expands during inspiration, the lungs follow.
Name the boundaries of the thoracic cavity.
Superior: Thoracic inlet
Anterior: Sternum and costal cartilages
Posterior: Thoracic vertebrae
Sides: Ribs and intercostal muscles
Inferior: Diaphragm
Put these structures in order from proximal to distal:
Segmental bronchi → trachea → lobar bronchi → alveoli → main stem bronchi
Trachea → main stem bronchi → lobar bronchi → segmental bronchi → alveoli