Anatomy, Thorax, Lung Pleura And Mediastinum – StatPearls

Navid Mahabadi; Alberto A. Goizueta; Bruno Bordoni.

Author Information and Affiliations

Last Update: October 17, 2022.

Introduction

A pleura is a serous membrane that folds back on itself to form a two-layered membranous pleural sac. The outer layer is called the parietal pleura and attaches to the chest wall. The inner layer is called the visceral pleura and covers the lungs, blood vessels, nerves, and bronchi. There is no anatomical connection between the right and left pleural cavities.[1] With the addition of pleural fluid, the lung pleura allows for easy movement of the lungs and inflation during breathing.

The mediastinum is a central compartment in the thoracic cavity between the pleural sacs of the lungs. It is divided into two major parts, the superior and inferior portions. The inferior portion is then further divided into the anterior, middle, and posterior portions. Each region of the mediastinum contains specific groups of structures. [2]

• Superior mediastinum: Organs: thymus, trachea, esophagus; Arteries: aortic arch, brachiocephalic trunk, left common carotid artery, left subclavian artery; Veins and lymphatics: superior vena cava, brachiocephalic vein, thoracic duct; Nerves: vagus nerve, left recurrent laryngeal nerve, cardiac nerve, phrenic nerve.

• Anterior mediastinum: Organs: thymus; Arteries: small arterial branches; Veins and lymphatics: small branches; Nerves: none.

• Middle mediastinum: Organs: heart, pericardium; Arteries: ascending aorta, pulmonary trunk, pericardiacophrenic arteries; Veins and lymphatics: superior vena cava, azygos vein, pulmonary vein, pericardiacophrenic vein; Nerve: phrenic

• Posterior mediastinum: Organs: esophagus; Arteries: thoracic aorta; Veins and lymphatics: Azygos vein, hemiazygos vein, thoracic duct; Nerve: the vagus nerve.

Structure and Function

The pleural cavity is a space between the visceral and parietal pleura. The space contains a tiny amount of serous fluid, which has two key functions.

The serous fluid continuously lubricates the pleural surface and makes it easy for them to slide over each other during lung inflation and deflation. The serous fluid also generates surface tension, which pulls the visceral and parietal pleura adjacent to each other. This function will allow the thoracic cavity to expand during inspiration. 

NB; when air enters the pleural space, the surface tension will disappear, and the resulting condition is known as a pneumothorax.

Pleural Recesses

Located posteriorly and anteriorly are spaces where the pleural cavity is not totally filled by the lung parenchyma. This space is known as the recess – an area where the adjacent surfaces of the parietal pleura come into contact. The two recesses in the pleural cavity include the following:

• The costomediastinal recess is one of these two spaces, which is found between the mediastinal and costal pleura. The space is located just posterior to the sternum.

• The costodiaphragmatic recess is the other, which is between the diaphragmatic and costal pleura.

The reason these recesses are important is that they provide a space for fluid to accumulate. Pleural effusions usually collect in the costodiaphragmatic recess.

Blood Supply and Lymphatics

The visceral pleura receives its blood supply from the bronchial circulation, while the parietal pleura receives its blood supply from the intercostal arteries.[3][4]

Nerves

The costal and cervical portions of the parietal pleura are innervated by the intercostal nerve, and the diaphragmatic portion is supplied by the phrenic nerve. The parietal pleura is the only portion of the pleura that can sense pain. The visceral pleura receives its nerve supply via the autonomic nervous system (ANS) and lacks sensory innervation.[5]

Surgical Considerations

Pneumothorax is a common clinical event, and it occurs when the pleural space is violated. [6][7] The patient can present with a variety of symptoms depending on the size of the pneumothorax. With a small pneumothorax, the patient may be asymptomatic. But if the pneumothorax is large, the following symptoms will be present:

Percussion and auscultation will reveal a hyper-resonant chest with no breath sounds.

The two types of pneumothorax include:

Spontaneous: These pneumothoraces occur without any traumatic event. They are most common in young males who smoke. The most common cause of a spontaneous pneumothorax is the presence of small blebs on the superior surface of the upper lobes.[6]

Traumatic: Traumatic pneumothorax is very common and may occur as a result of a central line insertion, penetrating chest trauma, or rib fracture.[7]

The treatment of a pneumothorax again depends on the size and presence of symptoms. Most asymptomatic cases can be observed if the patient is reliable and agrees to follow up. Repeat chest X-rays are required to ensure that the pneumothorax is resolving. For patients with large and symptomatic pneumothorax, insertion of a chest tube is the most straightforward treatment. Unlike the past when large-sized chest tubes were inserted, today, several kits are available with small size 8-12 French tubes which can be inserted without causing too much pain.[8]

Clinical Significance

Normally, there is a small amount of pleural fluid found in the pleural cavity. When there is a pathological collection of pleural fluid, it is called a pleural effusion. Pleural effusion is classified as either exudative or transudative and can be caused by multiple mechanisms, including lymphatic obstruction, increased capillary permeability, decreased plasma colloid pressure, increased capillary, venous pressure, and increased negative intrapleural pressure.

The mediastinum is commonly a site for tumors, and specific regions of the mediastinum are prone to certain tumors. Pneumomediastinum can also develop when air is introduced into the mediastinum, most commonly seen in ruptures of the esophagus. A widened mediastinum is a worrisome clinical sign for possible aortic aneurysm or rupture.[9]

The mediastinum is also very important with respect to lung cancer—all lung cancers when in advanced stages, involve the mediastinal lymph nodes. The treatment for a patient with lung cancer without mediastinal lymph node involvement is surgery, and it has a high cure rate. However, surgery alone is not curative once the mediastinal nodes are involved, and patients will need chemotherapy. To determine if the mediastinal lymph nodes are involved, a CT scan of the chest is necessary. If the nodes are greater than 1 cm, then a biopsy is required. The lymph nodes are biopsied using mediastinoscopy. If they turn out to be negative, then lobectomy alone is sufficient.[10]

The status of the mediastinal lymph nodes is also important when dealing with patients with sarcoidosis, lymphoma, and tuberculosis. In each of these cases, a mediastinoscopy is necessary to assess the histology before treatment can be provided.

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Figure

Pleura, Visceral Pleura, Left Lung, Parietal Pleural, Left Pleural Cavity, Mediastinum, Right Pleural Cavity, Right Lung. Contributed Illustration by Beckie Palmer

Figure

Superior mediastinum, anterior mediastinum, middle mediastinum, posterior mediastinum, Superior compartment, Inferior compartment,. Contributed Illustration by Bryan Parker

Figure

The Mediastinum, transverse section of the thorax, showing the contents of the middle and the posterior mediastinum, Left Phrenic nerve, Heart, lungs, Pulmonary pleura, Costal Pleura. Contributed by Gray’s Anatomy Plates

References

1.

Adeyinka A, Pierre L. StatPearls [Internet]. StatPearls Publishing; Treasure Island (FL): Sep 5, 2022. Air Leak. [PubMed: 30020594]

2.

Volpe JK, Makaryus AN. StatPearls [Internet]. StatPearls Publishing; Treasure Island (FL): Jul 25, 2022. Anatomy, Thorax, Heart and Pericardial Cavity. [PubMed: 29494059]

3.

Stauffer CM, Meshida K, Bernor RL, Granite GE, Boaz NT. StatPearls [Internet]. StatPearls Publishing; Treasure Island (FL): Jul 18, 2022. Anatomy, Thorax, Pericardiacophrenic Vessels. [PubMed: 32644668]

4.

Isaka T, Mitsuboshi S, Maeda H, Kikkawa T, Oyama K, Murasugi M, Kanzaki M, Onuki T. Anatomical analysis of the left upper lobe of lung on three-dimensional images with focusing the branching pattern of the subsegmental veins. J Cardiothorac Surg. 2020 Sep 29;15(1):273. [PMC free article: PMC7526204] [PubMed: 32993708]

5.

Cho TH, Kim SH, O J, Kwon HJ, Kim KW, Yang HM. Anatomy of the thoracic paravertebral space: 3D micro-CT findings and their clinical implications for nerve blockade. Reg Anesth Pain Med. 2021 Aug;46(8):699-703. [PubMed: 33990438]

6.

Gilday C, Odunayo A, Hespel AM. Spontaneous Pneumothorax: Pathophysiology, Clinical Presentation and Diagnosis. Top Companion Anim Med. 2021 Nov;45:100563. [PubMed: 34303864]

7.

Tran J, Haussner W, Shah K. Traumatic Pneumothorax: A Review of Current Diagnostic Practices And Evolving Management. J Emerg Med. 2021 Nov;61(5):517-528. [PubMed: 34470716]

8.

Hu K, Chopra A, Kurman J, Huggins JT. Management of complex pleural disease in the critically ill patient. J Thorac Dis. 2021 Aug;13(8):5205-5222. [PMC free article: PMC8411157] [PubMed: 34527360]

9.

Ferreiro L, Toubes ME, San José ME, Suárez-Antelo J, Golpe A, Valdés L. Advances in pleural effusion diagnostics. Expert Rev Respir Med. 2020 Jan;14(1):51-66. [PubMed: 31640432]

10.

Ghigna MR, Thomas de Montpreville V. Mediastinal tumours and pseudo-tumours: a comprehensive review with emphasis on multidisciplinary approach. Eur Respir Rev. 2021 Dec 31;30(162) [PMC free article: PMC9488622] [PubMed: 34615701]

Disclosure: Navid Mahabadi declares no relevant financial relationships with ineligible companies.

Disclosure: Alberto Goizueta declares no relevant financial relationships with ineligible companies.

Disclosure: Bruno Bordoni declares no relevant financial relationships with ineligible companies.

Pleural Disorders | Pleurisy | Pleural Effusion

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Your pleura is a large, thin sheet of tissue that wraps around the outside of your lungs and lines the inside of your chest cavity. Between the layers of the pleura is a very thin space. Normally it’s filled with a small amount of fluid. The fluid helps the two layers of the pleura glide smoothly past each other as your lungs breathe air in and out.

Disorders of the pleura include:

• Pleurisy – inflammation of the pleura that causes sharp pain with breathing
• Pleural effusion – excess fluid in the pleural space
• Pneumothorax – buildup of air or gas in the pleural space
• Hemothorax – buildup of blood in the pleural space

Many different conditions can cause pleural problems. Viral infection is the most common cause of pleurisy. The most common cause of pleural effusion is congestive heart failure. Lung diseases, like COPD, tuberculosis, and acute lung injury, cause pneumothorax. Injury to the chest is the most common cause of hemothorax. Treatment focuses on removing fluid, air, or blood from the pleural space, relieving symptoms, and treating the underlying condition.

NIH: National Heart, Lung, and Blood Institute

• What Are Pleural Disorders?

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• ClinicalTrials. gov: Pleural Diseases

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• ClinicalTrials.gov: Pleural Effusion

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• ClinicalTrials. gov: Pleurisy

  (National Institutes of Health)

• ClinicalTrials.gov: Pneumothorax

  (National Institutes of Health)

• ClinicalTrials. gov: Thoracentesis

  (National Institutes of Health)

• Article: Management of malignant pleural effusion in Italian clinical practice: a nationwide. ..

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Pulmonary emphysema – symptoms, diagnosis, treatment – Axis Medical Center (Zelenograd)

Pulmonary emphysema – a persistent increase in lung space, which is accompanied by the destruction of the walls of the alveoli and other structural elements without the growth of connective tissue. The physiological feature of the bronchi is expansion on inspiration and a slight narrowing on expiration. With emphysema, a person takes a sufficiently effective breath, but cannot fully exhale. This leads to the accumulation of air in the lung tissues, while the alveoli swell and burst, large air sacs (bulls) appear. Gas exchange worsens, the lungs become flabby and do not subside. This is how emphysema of the lungs develops, the treatment of which is limited, since the changes occurring in the lungs are irreversible. Patients are generally advised to reduce physical activity, avoid smoking. With severe respiratory failure, the patient is connected to portable oxygen therapy devices.

Types of pulmonary emphysema

The classification of emphysema is as follows.

Forms of the disease along the course:

1. Acute – develops with sudden exertion, penetration of foreign bodies into the lungs, asthma. This condition can be eliminated, but requires immediate medical attention.
2. Chronic – progresses gradually, leads to disability without action.

By etiology:

1. Primary – develops due to the individual characteristics of the body, can be observed even in newborns. It is characterized by rapid progression and complex therapy.
2. Secondary – develops against the background of obstruction of the lung tissues.

According to the degree of distribution:

1. Diffuse – CT shows that the tissue is affected evenly, the destruction of the alveoli occurs throughout the area, the patient is worried about shortness of breath.
2. Focal – changes are localized near scars, foci of tuberculosis. This is clearly visible on x-rays.

According to anatomical features:

1. Panacinar – all acini are damaged, there is no proliferation of connective tissue and inflammation, but there are signs of impaired gas exchange in the lungs (the type of breathing resembles panting).
2. Centrilobular – the central region of the primary lung lobule is affected, fibrous tissue grows in the area of ​​the affected structures, the rest of the parenchyma is not damaged.
3. Periacinar – affects the acini located near the pleura. This condition is dangerous by the development of pneumothorax – a rupture of the damaged area.
4. Perirubtsovaya – by name it is clear that violations occur around the scars.
5. Bullous – damage to the alveoli and the formation of blisters in their place.
6. Interstitial – rupture of the alveoli leads to the appearance of subcutaneous vesicles.

For reasons:

1. Compensatory – leads to excision of part or the whole lung.
2. Senile – caused by age-related changes.
3. Lobar – in newborns.

Emphysema can also be obstructive or non-obstructive.

Signs of emphysema

“If you experience similar symptoms, we advise you to make an appointment with your doctor. You can also sign up by phone: +7 (499) 214-00-00

The first signs of emphysema are shortness of breath and difficulty breathing air. This may be accompanied by a cough with scanty exudate. Indicators of the degree of severity of gas exchange disorders are the following clinical signs – swelling of the face, bluish coloration of the skin, swelling of the veins in the neck.

Adult patients usually experience severe weight loss. This is due to the need for large energy expenditures to maintain breathing.

Pneumothorax may spontaneously occur in bullous emphysema. Facial discoloration may also be observed. In addition, an increase in the liver is possible due to vascular congestion in the vessels and the descent of the diaphragm.

In the chronic form, the patient’s neck is shortened, the supraclavicular fossae protrude, the chest becomes barrel-shaped, and the abdomen sags.

Important! A reliable diagnosis can not be made only on the basis of symptoms, an X-ray examination is necessary.

Causes of the development of the disease

Causes of development – loss of tissue elasticity and strength, increased pulmonary pressure. The occurrence of a violation of the elasticity and strength of tissues may appear as a result of the following:

1. Congenital abnormal structure of the lung tissue.
2. Hormonal imbalance – a failure between the level of estrogens and androgens.
3. Atmospheric pollution – inhalation of smoke, fine coal particles, toxins. Dangerous oxides of nitrogen and sulfur, emissions from thermal power plants, decay products and fuel processing. All this leads to respiratory failure.
4. Congenital deficiency of alpha-1 antitrypsin – proteolytic enzymes cease to perform their functions and begin to destroy the alveolar walls.
5. Age – as a result of circulatory disorders, susceptibility to toxins in the air increases.
6. Infections – when pulmonary diseases occur, lymphocytes and macrophages are activated. The result is the dissolution of the protein shell of the walls of the alveoli.

An increase in pulmonary pressure may develop in the following cases:

• occupational activities, such as playing wind instruments;
• COPD, in which the patency of the bronchioles worsens;
• foreign object entering the bronchi is an acute form of pathology.

For what reason the bullous form develops, scientists do not know for sure. There are a number of theories that have not yet been proven – vascular, mechanical, infectious, genetic, enzymatic, obstructive.

Treatment of pulmonary emphysema

The initial stage of the disease responds best to therapy, so it is not worth delaying treatment. The principles of emphysema treatment are primarily concerned with smoking cessation.

Medical therapy is practiced in the development of bronchial obstruction. In order to suppress the progression of the pathological process, bronchodilator drugs are used. When using them, some recommendations should be taken into account:

• use in the form of inhalation;
• choose drugs depending on the individual response of the body to treatment;
• combine funds from different groups, this increases the effectiveness of therapy and reduces the risk of side effects;
• to use means of the prolonged action.

Hypoxemia (low tissue oxygen levels) is treated with oxygen. When the upper lobes of the lungs are affected, surgical intervention is indicated – excision of a lobe of the lung. A radical method of therapy is organ transplantation. Operations are most often performed with bullous emphysema. The treatment regimen is determined by the pulmonologist after the patient has undergone diagnostics.

Preparations are prescribed for:

• restoration of bronchial conduction;
• sputum withdrawal;
• relief of respiratory failure,
• improve heart function,
• elimination of the attached infection.

Doses are determined exclusively by a specialist pulmonologist. The duration of treatment depends on the stage and form of the disease.

Prevention consists in giving up bad habits, an active lifestyle, high-quality treatment of viral and bacterial infections, measures to clean the air from dust and toxins.

As for the prognosis, the pathological process that has begun is irreversible, survival with emphysema is a rather relative indicator and depends on a large number of factors.

Benefits of visiting the Axis Medical Center

It is important to choose a clinic for treatment. The Axis Medical Diagnostic Center (Zelenograd) employs highly qualified specialists who will do everything possible for a patient with emphysema. You can get a consultation with a pulmonologist without leaving the walls of the clinic.

Causes and treatment of pulmonary edema in Moscow, terms of treatment with puncture of the pleural cavity lungs.

Pulmonary edema is not an independent disease, but is a consequence of other pathologies. Therefore – how to treat pulmonary edema, or rather its true cause, depends on the nature of the underlying disease.

Pulmonary edema itself is treated by intensive therapy, including the administration of diuretics, sedatives, antihypertensives, narcotic analgesics, protein drugs, cardiac glycosides, nitrates, and oxygen therapy.

Pulmonary edema is considered a serious pathological condition requiring qualified medical care. Therefore, in case of malaise, it is important to undergo an examination and a full course of treatment.

Pulmonary edema: symptoms, signs, treatment

Pathology has a characteristic clinical picture, so it is not difficult to diagnose it. The main symptoms of pulmonary edema are:

• pain in the chest, as well as a feeling of squeezing, that is, the patient does not have enough oxygen. It is difficult for him to inhale and exhale air;
• frequent, short and loud breathing;
• cyanosis of the skin;
• sudden drop in blood pressure;
• cold clammy sweat;
• dry cough, which, as pulmonary edema develops, gradually turns into a wet one, with the release of characteristic pink sputum.

The causes of pulmonary edema can be very diverse. Among them:

• diseases of the cardiovascular system, including congenital and acquired heart defects;
• chest injury;
• bronchial asthma;
• tuberculosis;
• pneumosclerosis;
• chronic bronchitis;
• tumors;
• certain infectious diseases;
• prematurity, bronchopulmonary dysplasia, hypoxia in newborns;
• renal insufficiency;
• cirrhosis of the liver;
• intestinal obstruction;
• acute pancreatitis;
• meningitis, encephalitis and brain surgery;
• poisoning with certain toxic substances;
• ovarian hyperstimulation syndrome and others.

In case of accumulation of fluid in the pleural cavity, treatment, first of all, is reduced to the removal of edema in the shortest possible time. After conducting intensive therapy directly to the pulmonary edema itself, the patient is prescribed a course of therapy aimed at combating the disease that provoked it.

Lung fluid in oncology

Lung fluid in cancer is a fairly common symptom in advanced stages. Lung cancer is one of the most common diagnoses in the structure of oncopathology. With early diagnosis and timely treatment, the prognosis improves, but mortality in this pathology is still at a fairly high level.

Symptoms of fluid accumulation in lung cancer:

• Dyspnea at rest, aggravated by minimal exertion;
• Feeling of discomfort and heaviness in the chest;
• Skin pale with bluish tint;
• Violent hacking cough;
• In case of pulmonary edema, frothy sputum with a pink tint due to leakage of blood cells;
• Pain on the side of the affected lung.

The problem of fluid accumulation is that the lungs cannot perform their functions, and the patient feels an acute lack of air. The reason for this may be:

• Metastasis to the thoracic lymph nodes, and as a result, a violation of the lymphatic outflow;
• With exophytic growth of the tumor in the lumen of the bronchus, the pressure in the pleural cavity gradually decreases, which contributes to the accumulation of fluid;
• Due to increased penetration of pleural sheets;
• Due to a decrease in oncotic pressure due to loss of proteins;
• As complications after applicable treatments, such as after radiation therapy.

Fluid in the lungs in oncology may accumulate gradually or may accumulate over several hours. In any case, this is a reason to start diagnosis and treatment.

Removal of fluid from the lungs

It is important to understand that when fluid accumulates in the pleural cavity, treatment is required immediately under the constant supervision of a physician. In the therapy clinic of the Yusupov hospital, the patient will be advised which doctor to contact if fluid is found in the lungs. Due to the fact that pulmonary edema is not an independent pathology, but develops as a consequence of the underlying disease, the treatment program is developed by a specialized specialist – a cardiologist, oncologist, pulmonologist, gynecologist, otolaryngologist, gastroenterologist. It all depends on the nature of the underlying pathology.

If pulmonary edema occurs due to acute heart failure, the patient is prescribed mild diuretics that are effective for edema, as well as heart medications. Hypoxia is reduced by oxygen inhalations.

When is fluid pumping out of the lungs indicated and what are its consequences? Normally, a healthy person has about 2 ml of fluid in this area. If its volume increases to 10 ml, then a therapeutic effect is necessary.

Removal of fluid by puncture leads to the restoration of the normal breathing process, and also makes it possible to determine its nature. For one procedure, you can remove no more than one liter of fluid.

How many times it is necessary to pump out fluid from the lungs, the doctor determines for each patient individually, depending on the patient’s condition and the results of the procedure.

The treatment of pulmonary edema is a complex process that must be carried out under the constant supervision of a physician. In the Yusupov hospital, treatment is carried out on an outpatient basis or in a hospital, depending on the available indications. In no case should you ignore the symptoms of pathology and expect that your health will improve on its own.