Thoracic Cavity and Lung Anatomy

Thoracic Cavity

• The thoracic cavity houses the lungs, heart, and other vital organs.
• The thoracic cavity is separated from the abdominal cavity by the diaphragm.

Lung Lobes, Surfaces, and Fissures

• The right lung has three lobes: superior, middle, and inferior.
• The left lung has two lobes: superior and inferior.
• The lobes are separated by fissures, which are deep grooves in the lung tissue.

Lung Pleura

• The lungs are covered by a serous membrane called the pleura.
• The visceral pleura adheres directly to the lung surface.
• The parietal pleura lines the thoracic cavity wall.
• The space between the visceral and parietal pleura is called the pleural cavity.

Medial Surface of the Lung

• The medial surface of the lung is where the bronchi, pulmonary blood vessels, and nerves enter and exit the lung.
• The hilum is the point where these structures enter and exit.

Bronchi and Bronchopulmonary Segments

• The bronchi are the main airways that branch from the trachea into the lungs.
• Bronchopulmonary segments are the functional units of the lung.
• Each segment is supplied by its own bronchus and pulmonary artery and vein.

Airways and Parenchyma

• The alveoli are the tiny air sacs in the lungs where gas exchange occurs.
• The parenchyma is the functional tissue of the lung, which includes the alveoli, bronchioles, and capillaries.

Heart and Pulmonary Vasculature

• The pulmonary arteries carry deoxygenated blood from the right ventricle of the heart to the lungs.
• The pulmonary veins carry oxygenated blood from the lungs to the left atrium of the heart.

Bronchial Arteries and Veins

• The bronchial arteries supply the bronchi and other lung tissues with oxygenated blood.
• The bronchial veins return deoxygenated blood from the bronchi and other lung tissues to the heart.

Innervation

• The lungs are innervated by both the sympathetic and parasympathetic nervous systems.
• The sympathetic nervous system dilates the bronchioles, while the parasympathetic nervous system constricts the bronchioles.

Lymphatic Drainage

• The lymphatic vessels of the lungs drain into the lymph nodes in the mediastinum.

Pneumothorax

• A pneumothorax is a condition in which air enters the pleural cavity.
• It can cause collapse of the lung.

Bronchoscopy

• Bronchoscopy is a procedure used to visualize the interior of the bronchi.
• It can be used to diagnose and treat lung conditions.

Mediastinum

• The mediastinum is the space between the two lungs, containing the heart, great vessels, trachea, esophagus, and other structures.
• Structures within the mediastinum are separated by a series of fascial compartments.