Anatomy: Lungs And Plurae

GROSS

LUNGS AND PLEURAE KARLOS R. ALETA, M.D.

The Pleura •Serous layer of mesothelium that invest & enclose each lung •Visceral pleura – lines the lung itself •Parietal pleura – lines the chest wall •Pleural cavity – contains a layer of serous pleural fluid for lubrication (100mL produced and absorbed daily )

THE PARIETAL PLEURA •Costal pleura – in the ribs •Mediastinal pleura •Diaphragmatic pleura – on top of the diaphragm •Cervical pleura/suprapleural membrane Left: • Pleural reflection moves laterally from the midline then inferiorly up to the 6th costal cartilage • Left lung is more deeply indented by the cardiac notch Right: • Pleural reflection continues inferiorly from 4th to 6th costal cartilage • Lung parallels pleural reflection closely Pleural reflection pass: -lateral at 6th rib

Gross Anatomy

-reach the Midclavicular line at 8th costal cartilage -10th rib at Midaxillary line -12th rib at the scapular line

Inferior Margin of the lungs reach: -Midclavicular line at 6th rib -Midaxillary line at 8th rib -Scapular line at 10th rib

Clinical Importance: Posteriorly the pleural may go beyond the costal margin – Prone to injury during abdominal surgery During kidney surgery, injury to the pleura may occur and cause air to enter into the thoracic or pleural cavity Surgical pleurae/Pleural Cupola – covering in the apical area ‐ Right and left

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GROSS

LUNGS AND PLEURAE KARLOS R. ALETA, M.D. ‐ ‐ ‐ ‐

Most superior part is below the 1st rib but never above the neck of the 1st rib Extends in the superior thoracic aperture to go to the neck Dome shaped groove Because of position,if there is injury to neck (laceration, gunshot wound, ice pick), the pleural may also be injured and also the underlying lung.

Pleura reflection ends 2 finger breaths above the most inferior costal margin Pleural Recesses •On full inspiration – lungs fill up cavities •Quiet respiration – 3 parts not occupied •Area of acute P R – “parietal on parietal pleura reflection” -R&L Costodiaphragmatic recesses -Costomediastinal Recess Disorders of the Pleura Hydrothorax -fluid accumulation in the thorax or pleural cavity -can be anything ie. blood, chyle, pus -as fluid increases the lungs will be more collapsed and near the hilum -if you want to breath you can’t utilize the whole parenchyma because its squished -the fluid prevents expansion Classic signs: •Dullness on percussion •Decreased breath sounds •Mediastinal displacement - (organs are pushed to the other side) •Transudate vs Exudate •Total protein 0.5

Gross Anatomy

•LDH 0.6 •Unilateral or Bilateral

Transudate (high pressure) Common causes: •Congestive heart failure •Renal insufficiency •Cirrhosis Treat the primary cause- Correct fluid balance

Exudate Common causes: •Infection •Malignancy •Treatment: •Drainage •Antibiotics (for parapneumonic effusions and empyemas) •Pleurodesis (for malignant effusions)

Thoracentesis • Draining the fluid in the thorax w/ a needle • Patient’s back to Physician w/ elbows forward & raised 90° • Allows to move scapula tip laterally – away from field of puncture • Insert needle on appropriate ICS~top of rib (decrease chances of hitting the VAN bundle) Pneumothorax -normal parenchyma balloons • Usually due to rupture of subpleural cyst or bulla • Air in the pleural space • Primary: it just happened • Secondary: pt has an already existing lung problem • Pt is usually dyspneic, breath sounds absent or decreased • Other PE…??? Tachypnia, eyes are enlarged, engorged neck vein

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GROSS

LUNGS AND PLEURAE KARLOS R. ALETA, M.D.

•

Diagnosis is confirmed with chest xray

•Treatment: –Drainage with a chest tube For persistent air leaks or recurrences: –Video Assisted Thoracoscopic Surgery (VATS) –Thoracotomy

The Lungs

–Oversewing of bleb –Pleural scarification/abrasion Hemothorax • Accumulation of blood in the thorax • Usually seen in chest trauma, blunt or penetrating • Anticoagulant therapy • Treatment • Chest tube drainage • For trauma cases: Thoracotomy for control of hemorrhage (>200ml/hr drainage) • Blood can rise and fill upthe whole lungs until it collapse. Empyema Thoracis - pus • Develops from untreated or inadequately treated parapneumonic effusions • Post op patients (lung resections or pleural procedures) *pus has its own lining • Empyemectomy - removing the pus as a whole • Decortication – prolonged cases; pus has hardened; stripping the lining out of the lung in order for the lungs to expand again Chylothorax • Accumulation of lymph in the pleural cavity • Tumor • Injury to Thoracic Duct (the aqueduct of the lymph)

Gross Anatomy

• If persistent beyond 3 to 4 weeks • Ligation of Thoracic Duct • Talc Pleurodesis Pleuroperitoneal shunt – direct chyle to the peritoneum to the abdomen to be absorbed

• Essential organs of respiration • Normally light, soft & spongy • Left & Right separated fr @ other by mediastinum • Attached: heart & trachea by the “root of the lung” Inferior Pulmonary ligament -cardiopulmonary machine - lung surgery -in newborns: light and spongy -mediastinum in the middle - no communication bet. R&L lungs Trachea connects to the lung itself Surface Anatomy • Cervical pleurae & apices • Pass through superior thoracic aperture into the supraclavicular fossa • Anterior borders of lungs • Adjacent to anterior lines of reflection of the parietal pleura up to level of 4th costal cartilages Fissures Oblique - extends from spinous process of T2 vertebra to 6th costal cartilage - Coincides w/3 vertebral border of scapula when arm is elevated Horizontal - is at the 4th rib & costal cartilage anteriorly

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GROSS

LUNGS AND PLEURAE KARLOS R. ALETA, M.D.

•Superior: cardica notch,lingula •Inferior - 2 lobes Lingula- homologue of the middle lobe of the right

•Upper •Middle: wedgeshaped •Lower - 3 lobes middle lobe - most anterior

Surfaces 1.) Costal - curvature of the ribs 2.) Medial a. Mediastinal -contains root/hilum of lung -Cardiac impression b. Vertebral 3.) Diaphragmatic -“base” Borders 1.)Anterior - Overlaps pericardium 2.)Posterior - Thick & rounded 3.)nferior - Thin & sharp - Costodiaphragmatic recess Trachea and Bronchi •Main bronchi (1°) @ divides into lobar bronchi

Lobes Left

Right

(2°)segmental bronchi (3°) •Right – wider, shorter ─ more vertical > left Foreign Bodies Mucus membrane- last defense for foreign objects Trachea - Midline tubular structure w/ 22 rings Carina -divides R&L Pediatric pt - swallowed objects usually found in the right bronchi Mucus membrane

Gross Anatomy

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GROSS

LUNGS AND PLEURAE KARLOS R. ALETA, M.D.

Brochopulmonary Segment •Pyramidal-shaped lung segment •Largest subdivision of a lobe •Supplied independently -Segmental bronchus -Supplied by 3° branch of pulmonary artery -drained by intersegmental parts of pulmonary vein •Named acc to segmental bronchus supplying it •Surgically resectable

Lower • superior basal

Lower • superior basal

•

medial basal

•

anterior basal

•

anterior basal

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lateral basal

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lateral basal

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posterior basal

• posterior basal Apico-posterior : merged as one segment Superior-inf: lingular segment

Right (10 segments) Left (8 segments) Upper Upper • apical • apico-posterior •

posterior

• anterior Middle • lateral •

•

anterior

•

superior

•

inferior

medial

Gross Anatomy

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GROSS

LUNGS AND PLEURAE KARLOS R. ALETA, M.D.

Disorders of the Lungs

•Primary mode of treatment is medical (antibiotics)

Lung Cancer • Most common malignant tumor affecting males & females • Smoking • What do we know?  Most cases are caused by the environment, primarily from tobacco exposure  Absent smoking, lung cancer would be uncommon  Genes have a role in susceptibility, but which ones and the extent is unclear Causes: -Smoking -Radon gas - Asbestos -Recurring lung inflammation -Lung scarring secondary to tuberculosis -Family history -Exposure to other carcinogens such as bis(chloromethyl)ether, polycyclic aromatic hydrocarbons, chromium, nickel and organic arsenic compounds

-Can involve a segment or a lot of segments Hemoptysis =coughing of blood Pathophysiology: •Impaired airway defense & ↓ Immunologic mechanisms ~permit colonization & infection •Bacteria & inflammatory cells elaborate proteolytic & oxidative molecules •Progressively destroy muscular & elastic components ~ fibrous tissue - Chronic airway inflammation - Airway w/ thick purulent secretions •↑ vascularity, hypertrophied vessels Clinical Presentation: •Daily persistent cough + purulent sputum production ~correlate w/ extent •↑ symptoms & respiratory impairment ~ ↑ airway obstruction •Hemoptysis – chronically inflamed friable airway mucosa -Massive ~ erosion of hypertrophied bronchial arteries =fatal

Goal of Treatment: –Identify tumor, get tissue diagnosis –Determine the stage of the disease –Surgery –Chemotherapy –Radiation Therapy

Diagnostics: •Chest CT– x-section bronchial architecture •CXR – lung hyperinflation, bronchiectatic cysts,dilated thich-walled bronchi from hila •Sputum culture •Spirometry – severity of airway obstruction

Bronchiectasis •Persistent abnormal dilatation of the bronchi generally at the subsegmental level •Localized or diffuse – medium-sized airways •Congenital or acquired •Chronic cough with purulent sputum •50% present with hemoptysis

Management: •Optimize secretion clearance •Use of bronchodilators •Correct reversible underlying causes •Chest physiotherapy •Acute exacerbations ~ broad-spectrum antiBx •Surgical resection – refractory to Med tx

Gross Anatomy

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GROSS

LUNGS AND PLEURAE KARLOS R. ALETA, M.D.

•Preserve as much lung tissue Physiotherapy - promote drainage of sputum Endobronchial tumors can occur in any part of the bronchial tree -Endoscopy -Bulky tumors- can cause obstruction --mechanical resection + laser if needed --tracheal resection: resect then connect _END

Gross Anatomy

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