Gross Anatomy

The pleura is a double-layered serous membrane that lines the walls of the thoracic cavity and the surface of the lungs Lungs Lungs are the main organs of the respiratory system. Lungs are paired viscera located in the thoracic cavity and are composed of spongy tissue. The primary function of the lungs is to oxygenate blood and eliminate CO2. Lungs. Thus, it extends virtually as far and wide as the thoracic cavity.

Boundaries: 

• Superior: root of neck 2–3 cm above rib 1
• Inferior: thoracic surface of the diaphragm Diaphragm The diaphragm is a large, dome-shaped muscle that separates the thoracic cavity from the abdominal cavity. The diaphragm consists of muscle fibers and a large central tendon, which is divided into right and left parts. As the primary muscle of inspiration, the diaphragm contributes 75% of the total inspiratory muscle force. Diaphragm
• Medial: mediastinum Mediastinum The mediastinum is the thoracic area between the 2 pleural cavities. The mediastinum contains vital structures of the circulatory, respiratory, digestive, and nervous systems including the heart and esophagus, and major thoracic vessels. Mediastinum and Great Vessels
• Lateral: inner surface of the rib cage and intercostal muscles

Each lung is enclosed in a serous pleural sac that consists of 2 continuous membranes of visceral and parietal pleura.

• Parietal pleura:
  • Lines the inner surface of the thoracic cavity
  • Separated from the thoracic wall by the endothoracic fascia
  • Parts are classified according to the adjacent structures:
    • Costal pleura
    • Diaphragmatic pleura
    • Mediastinal pleura: forms a sleeve-like membranous tube called the root of the lung and covers the heart and great vessels of the heart
    • Cervical pleura: covered by the suprapleural membrane, a dome-shaped fascia attached to the 1st rib and C7 that serves as a site of insertion for some of the deep muscles of the neck Muscles of the Neck The muscles of the neck can be divided into 3 groups: anterior, lateral, and posterior neck muscles. Each of the groups is subdivided according to function and the precise location of the muscles. Muscles of the Neck
• Visceral pleura:
  • Lines the outer surface of the lungs Lungs Lungs are the main organs of the respiratory system. Lungs are paired viscera located in the thoracic cavity and are composed of spongy tissue. The primary function of the lungs is to oxygenate blood and eliminate CO2. Lungs
  • Covers lung fissures
  • Not sensitive to pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain
  • Continues with parietal pleura at the hilum of each lung
• Recesses: named according to the points of reflection of the pleura
  • Costodiaphragmatic recess:
    • The largest recess
    • Found between the rib cage and the diaphragmatic portion of the pleura in each side of the thoracic cavity  
  • Costomedial recess: 
    • Found anteriorly between the rib cage and the mediastinum Mediastinum The mediastinum is the thoracic area between the 2 pleural cavities. The mediastinum contains vital structures of the circulatory, respiratory, digestive, and nervous systems including the heart and esophagus, and major thoracic vessels. Mediastinum and Great Vessels in each side of the thoracic cavity
    • The left recess is larger than the right due to the cardiac notch of the left lung.
  • Vertebromediastinal recess:
    • Found posteriorly between the rib cage, vertebral column Vertebral column The human spine, or vertebral column, is the most important anatomical and functional axis of the human body. It consists of 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae and is limited cranially by the skull and caudally by the sacrum. Vertebral Column, and the posterior mediastinum Mediastinum The mediastinum is the thoracic area between the 2 pleural cavities. The mediastinum contains vital structures of the circulatory, respiratory, digestive, and nervous systems including the heart and esophagus, and major thoracic vessels. Mediastinum and Great Vessels in each side of the thoracic cavity

Pleural cavity:

• The potential space between the visceral pleura and parietal pleura (virtually nonexistent/undetectable)
• Contains a small amount (0.1–0.2 mL/kg) of serous fluid that helps avoid friction between both pleurae
• The surface tension of the fluid keeps the lungs Lungs Lungs are the main organs of the respiratory system. Lungs are paired viscera located in the thoracic cavity and are composed of spongy tissue. The primary function of the lungs is to oxygenate blood and eliminate CO2. Lungs expanded and in contact with the thoracic wall through the double layer of pleura.

Neurovasculature

Clinical Relevance

Infectious disorders of the pleura

• Pleural effusion Pleural Effusion Pleural effusion refers to the accumulation of fluid between the layers of the parietal and visceral pleura. Common causes of this condition include infection, malignancy, autoimmune disorders, or volume overload. Clinical manifestations include chest pain, cough, and dyspnea. Pleural Effusion: the accumulation of fluid between the layers of the parietal and visceral pleura. Caused by infection, malignancy, autoimmune disorders, or volume overload. Presents as chest pain Chest Pain Chest pain is one of the most common and challenging complaints that may present in an inpatient and outpatient setting. The differential diagnosis of chest pain is large and includes cardiac, gastrointestinal, pulmonary, musculoskeletal, and psychiatric etiologies. Chest Pain, cough, and dyspnea Dyspnea Dyspnea is the subjective sensation of breathing discomfort. Dyspnea is a normal manifestation of heavy physical or psychological exertion, but also may be caused by underlying conditions (both pulmonary and extrapulmonary). Dyspnea. Classified as transudates or exudates, pleural effusions are usually diagnosed clinically, although imaging can confirm the diagnosis. Management is dependent on the underlying condition.
• Pleuritis Pleuritis Pleuritis, also known as pleurisy, is an inflammation of the visceral and parietal layers of the pleural membranes of the lungs. The condition can be primary or secondary and results in sudden, sharp, and intense chest pain on inhalation and exhalation. Pleuritis: also known as pleurisy, an inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body's defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation of the pleura. Results in sudden and intense chest pain Chest Pain Chest pain is one of the most common and challenging complaints that may present in an inpatient and outpatient setting. The differential diagnosis of chest pain is large and includes cardiac, gastrointestinal, pulmonary, musculoskeletal, and psychiatric etiologies. Chest Pain on inhalation and exhalation, and usually presents as part of pneumonia Pneumonia Pneumonia or pulmonary inflammation is an acute or chronic inflammation of lung tissue. Causes include infection with bacteria, viruses, or fungi. In more rare cases, pneumonia can also be caused through toxic triggers through inhalation of toxic substances, immunological processes, or in the course of radiotherapy. Pneumonia. The pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain intensifies upon deep inspiration or coughing. Caused by infection, trauma, cardiac ischemia, and lung cancer Lung cancer Lung cancer is the malignant transformation of lung tissue and the leading cause of cancer-related deaths. The majority of cases are associated with long-term smoking. The disease is generally classified histologically as either small cell lung cancer or non-small cell lung cancer. Symptoms include cough, dyspnea, weight loss, and chest discomfort. Lung Cancer. Management consists of pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain control and the treatment of the underlying condition.

Traumatic disorders of the pleura

• Pneumothorax Pneumothorax A pneumothorax is a life-threatening condition in which air collects in the pleural space, causing partial or full collapse of the lung. A pneumothorax can be traumatic or spontaneous. Patients present with a sudden onset of sharp chest pain, dyspnea, and diminished breath sounds on exam. Pneumothorax: a life-threatening condition in which air collects in the pleural space, causing a partial or full collapse of the lung. Can be traumatic or spontaneous. Patients present with a sudden onset of sharp chest pain Chest Pain Chest pain is one of the most common and challenging complaints that may present in an inpatient and outpatient setting. The differential diagnosis of chest pain is large and includes cardiac, gastrointestinal, pulmonary, musculoskeletal, and psychiatric etiologies. Chest Pain, dyspnea Dyspnea Dyspnea is the subjective sensation of breathing discomfort. Dyspnea is a normal manifestation of heavy physical or psychological exertion, but also may be caused by underlying conditions (both pulmonary and extrapulmonary). Dyspnea, and diminished breath sounds. Diagnosis is made with imaging, although tension pneumothorax is a clinical diagnosis. Management is based on its size and the stability of the patient.
• Hemothorax Hemothorax A hemothorax is a collection of blood in the pleural cavity. Hemothorax most commonly occurs due to damage to the intercostal arteries or from a lung laceration following chest trauma. Hemothorax can also occur as a complication of disease, or hemothorax may be spontaneous or iatrogenic. Hemothorax: a collection of blood in the pleural cavity. Most commonly due to damage to the intercostal arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries from chest trauma. Presents with shortness of breath and chest pain Chest Pain Chest pain is one of the most common and challenging complaints that may present in an inpatient and outpatient setting. The differential diagnosis of chest pain is large and includes cardiac, gastrointestinal, pulmonary, musculoskeletal, and psychiatric etiologies. Chest Pain. Physical exam findings include hypotension Hypotension Hypotension is defined as low blood pressure, specifically < 90/60 mm Hg, and is most commonly a physiologic response. Hypotension may be mild, serious, or life threatening, depending on the cause. Hypotension, tachycardia, decreased lung sounds, and dullness on percussion of the chest. Diagnosis is by upright chest X-ray. Management is usually with tube thoracostomy drainage. Thoracoscopic surgery or thoracotomy may be indicated in specific circumstances.