Anatomy: Pleura and Pericardium

Blood Flow to the Pericardium

- branches of the internal thoracic artery - branches of the thoracic and abdominal aorta

What is Pancost tumor, and what are its effects?

- lung tumor located at the apex of the lung. The growing tumor can cause compression of a brachiocephalic vein, subclavian artery, phrenic nerve, recurrent laryngeal nerve, vagus nerve, or, characteristically, compression of a sympathetic ganglion resulting in a range of symptoms known as Horner's syndrome.

Pericardium Intro/Definition

- the sac that surrounds the heart and protects it - the pericardium has 2 serous layers and one fibrous outer layer

DISEASES OF THE PLEURA

1. Acute/chronic inflammation of the pleura = pleuritis 2. Pleural effusion 3. Hemothorax/Hydrothorax

Which of the following about costomediastinal recesses is/are correct A. there is only one costomediastinal recess B. the right is larger than the left C. It is part of the pleural cavity where the costal and mediastinal pleura meet D. It is located where the mediastinal meets the diaphragmatic pleura

C. It is part of the pleural cavity where the costal and mediastinal pleura meet

Insertion of a needle for pericardiocentesis is best performed through which route? A. 5th right intercostal space B. 5th left intercostal space C. 6th right intercostal space D. 6th left intercostal space E. Left infrasternal angle E. Right infrasternal angle

can be inserted to the left of the sternum in the 5th or 6th intercostal spaces over the bare area of the pericardium OR infraternal just to the left of the xiphoid process Drainage of fluid from pericardial sac with a wide-bore needle inserted through the : left 5th or 6th ICS near the sternum, in the area of the cardiac notch of left lung = 'bare area', infrasternal angle : needle is passed supero-posteriorly, aiming at the left shoulder : . Stay left and medial . Stay low (infrasternal) . Angle up

A tumor in posterior mediastinum may involve which structures?

descending aorta, esophagus, thoracic duct, azygos, splanchnics/sympathetic chain,

Suprapleural membrane =

fibrous endothoracic fascia that covers the cervical pleura,

A Marfan's patient with aneurysm of the arch of aorta is likely to experience compression of which structure (s)?

pulmonary trunk, vagus nerve/recurrent laryngeal nerve, trachea, etc

Pericardial Recesses/Sinuses

• Transverse Pericardial Sinus o located between the ascending aorta and the pulmonary trunk and the S.V.C. → the aorta and pulmonary trunk can be gently lifted and fingers or surgical machinery can be inserted there for termination and diversion of blood flow during surgery • Oblique Pericardial Sinus o a cul-de-sac posterior to the left atrium; a useful place in surgery, both open heart and transesophageal echocardiography (very close to the esophagus)

A thoracocentesis for pleural effusion at the midaxillary line is best performed in which intercostal spaces? A. Sixth and seventh B. Seventh and eighth C. Eighth and ninth D. Ninth and tenth

C. Eighth and ninth

Pleura:

This is a serous membrane which is lined by mesothelium (epithelium that covers all serous membranes), and associated supporting connective tissue. Pleura is divided into two major types based on location; parietal or wall pleura & visceral or organ pleura.

Diseases of the Pericardium

- acute pericarditis → inflammation/irritation of the pericardium - pericardial effusion → abnormal accumulation of fluid in the pericardial cavity - cardiac tamponade → compression of the heart due to pericardial effusion

The Pleura:

- begin without a lung inside it; the lung invaginate the pleura and becomes the inner organ - a serous covering of the lungs that is lined by mesothelium and connective tissue

- there are 2 pleural sacs (one surrounding each lung) made up of 2 pleural layers

1) parietal pleura + found along the thoracic wall + can be divided into 4 parts - cervical - costal - mediastinal - diaphragmatic 2) visceral pleura + inseparable from the lung organs

A tumor seen in a radiograph at the level of sternal angle would likely affect which structures in the thoracic cavity?

Aorta, pulmonary trunk, esophagus, tracheal bifurcation, etc

Pleuritis

Causes: (a) viral; more common in the young, otherwise healthy persons, (b) rib fracture clinical Features: (a) Pain due to acute pleural inflammation is sharp, localized, made worse by coughing, sneezing, deep breathing or movement. It may be referred to the shoulder if the diaphragmatic parietal pleura is involved, (b) Dyspnea/Tachypnea. Management: (a) Treat underlying cause, (b) Palliation: NSAIDs and antitussive (Codeine if there is no evidence of respiratory depression).

Hemothorax

Definition: Bleeding into the pleural cavity. May improve or get worse with time Clinical features: similar to pleural effusion Treatment: (a) drainage by a wide-bore thoracostomy tube, (b) discourage further bleeding with pleurodesis.

THE ____ COSTOMEDIASTINAL RECESS IS LARGER

LEFT

Pleural effusion

Mechanism of pleural fluid generation: hydrostatic pressure drives 1% of blood volume into interstitial space at the arterial end of Parietal pleural capillaries. Oncotic pressure enables the lymphatics to reabsorb most of the 1% fluid at the venous end of parietal pleural capillaries. On balance, about 5 - 15 ml of pleural fluid is left in the pleural space. Pleural effusion is the abnormal accumulation of pleural fluid in the pleural space. There are 2 types of pleural effusion: transudate (<3.5% protein) and exudate (> 3.5% protein).

Uremic Pericarditis

This is a complication of renal failure (even when the patient is stabilized by dialysis). The pericardium is characteristically "shaggy" because the effusion is both hemorrhagic and exudative. Fever is characteristically absent, and tamponade is fairly common. Systemic glucocorticoids are characteristically ineffective. Definitive treatment is the treatment of the underlying cause, dialysis & a pericardial window.

1. The thoracic cavity is divided into three compartments;

a central mediastinum and two lateral pulmonary cavities. The mediastinum is the central compartment of the thoracic cavity that contains all thoracic viscera including the heart covered by the pericardium, except the lungs;,

Pulmonary ligament =

a redundant sleeve of parietal pleura, part of visceral pleura,

A tumor located just superior to the root of right lung is likely to obstruct which vein?

azygos arches over the root of the right lung to enter the superior vena cava

1. the lungs and heart, in development, each invaginates a pre - existing sac known as

pleura and pericardium, respectively; pleura is serous whereas pericardium is fibro - serous,

Where is pleural effusion located, and how do posture and gravity affect it?

pleural effusion is a buildup of fluid between the two layers of pleura. When upright, gravity will pull the liquid into the costodiaphragmatic recess

• the pleura is larger than the lung that it holds and there are two recesses (spaces) in each pleural sac A pleural recess is spaces between parietal and visceral layers

• costodiaphragmatic recess (aka the costophrenic space/angle) o a space between the parietal and visceral pleura that lies on the inferior border of the thoracic cavity; the space is between ribs 8 and 10 and it is the place chosen for a thoracocentesis (laterally between ribs 8-10) • costalmediastinal recess o a potential space between the costal pleura and the mediastinal pleura; this space is larger on the left than on the right because it accounts for the heart

Serous Pericardium

• made up of two layers o the outer layer, which is continuous with the fibrous pericardium o the inner layer, continuous with the heart muscle and known as the epicardium • in between these two layers there is potential space, called the pericardial cavity, that contains a thin film of fluid that permits heart movement • the two layers of the pericardium are continuous (fold over to make both layers) at the base of the great vessels

Pericadiocentesis

• needle and catheter are inserted at the 5th or 6th intercostal space at the infrasternal angle, aiming up towards the shoulder • performed to remove fluid from the pericardial sac

Innervation of the Pericardium

• the Phrenic Nerve (C 3, 4, 5) innervates the Pericardium o so pain of the pericardium is transmitted by the phrenic nerve to the shoulder and supraclavicular region • the Intercostal Nerves innervate some of the peripheral pericardium

Fibrous Pericardium

• the apex of the fibrous pericardium fuses with the roots of the great vessels and it is attached to the sternum by the superior and inferior sterno-pericardial ligaments • the phrenic nerves and their accompanying vessels are embedded in the fibrous paricardium on their way to the thoracic diaphragm