Unit 14

Pleura and Lungs

Quiz

Clinical Case

A 55 year old man reported to his family physician that

he had a solid swelling in his scrotum. There was no

ulceration of the scrotal skin and a red glow could not be

seen using transillumination. The lump was diagnosed as an advanced carcinoma of

the testis.

Plate 242

Three divisions to the thorax:

2 Pleural Cavities and

a Mediastinum

The 2 Pleural Cavities

are closed and

separate spaces

M

PP

Directions:

1. Make a horizontal cut from

the xiphisternal junction laterally to midaxillar

y line

Plate 185

1

2

3

4

5

6

7

8

910

11

12

STERNUM

Saw Cuts

2. Cut through the ribs in a

superior direction to rib 2 – midaxillary line

4. Pry the rib cage upward

and separate

any pleura

3. Saw through the sternal angle and use a scalpel to

cut through muscles in the

intercostal spaces

Plate 185

1

2

3

4

5

6

7

8

910

11

12

STERNUM

Saw Cuts

Remember, the Internal

Thoracic artery

terminates as the

Musculophrenic and Superior

Epigastric arteries

Superior Epigastric

Musculophrenic

Internal Thoracic Artery

Anterior Intercostal

Arteries

Sternum

Identify the Internal Thoracic

artery and any

Parasternal lymph nodes

Plate 191 Internal Thoracic Cage

Subclavian Artery

If the parietal pleura was freed intact from the thoracic wall,

incise it parasternally and reflect it laterally to expose the lungs in their respective pleural

cavities.The visceral pleura is a covering on the surface of the lungs. The parietal pleura lines the pleural cavity. The space between the two membranes is the pleural

cavity. The visceral and parietal pleura are continuous with one another at the root

(hilum) of the lung.

Lung bud expands into primitive

pleural cavity-5th week; this is the first of 3 body

cavities

Identify the parts of the

parietal pleura

MEDIASTINUM

Pleura and Cavity

Serous fluid

Pleura

Locate the Costodiaphragmat

ic and Costomediastinal

Recesses

Pleura-lined “gutters”

Plate 196

Right and Left Costodiaphragmatic Recesses

Costomediastinal recess

Cardiac Notch of Left Lung

Pleura and Cavity

Anterior View

Plate 197 Pleura and Cavity

Left Costodiaphragmatic Recess

Right Costodiaphragmatic Recess

Posterior View

Plate 196

Cardiac Notch of Left Lung

Lingula

Apex

Base Base

IdentifyCardiac Notch

LingulaApex Base

Retract the lungs laterally to expose the Mediastinal

pleura covering the Fibrous Pericardium

Plate 193

Mediastinal Part of Parietal

Pleura

Fibrous Pericardium of

Heart Sac

Lungs

If you separate the Mediastinal pleura from the heart sac

you will find the Phrenic Nerve and

the Pericardiacophrenic vessels anterior to the ROOT of the

LUNG

Plate 211

Phrenic Nerve

Pericardiacophrenic Vessels

Lungs

Left Phrenic Nerve

C3

C4

C5

Ventral Rami

Diaphragm

Mediastinal Part of Parietal

Pleura

C345 keeps the

diaphragm alive!

Plate 193

There may be

adhesions

Transect the root of the each lung

and remove the lungs from the pleural cavities

What is in the Root of the lung?

Identify:Pulmonary ArteryBronchi Pulmonary Veins Lymph NodesPulmonary Ligament

Plate 199B Lungs

Apex

Base

Lingula

Superior Lobe

Inferior Lobe

Superior Lobe

Oblique Fissure

Cut Pleur

a

Anterior

Pulmonary Ligament

Left Pulmonary ArteryLeft Main BronchusLeft Superior Pulmonary VeinsHilar Lymph NodesLeft Inferior Pulmonary Vein

Superior Lobe

Middle Lobe Inferior Lobe

Identify the same components on the right lung and on the corresponding

mediastinal surface

Plate 199A Lungs

Oblique Fissure

Horizontal Fissure

Rt. Lobar BronchiRt. Pulmonary ArteryRt. Superior Pulmonary VeinsHilar Lymph NodeRt. Inferior Pulmonary Vein

Anterior

Identify the Vagus

Nerve as it passes

behind the root of the

lung

Note that the Phrenic

nerve passes in

front of the root of the

lung

Plate 231 Lungs

Vagus Nerve

Phrenic Nerve

DiaphragmPosterio

r

Left Side

Mediastinal Pleura

Phrenic Nerve

Vagus Nerve

Posterior

Diaphragm

Do the same on the right

side

Plate 230 Lungs

Right Side

Posterior

Mediastinal Pleura

Plate 198 Lungs

Three lobes: Superior, Middle, InferiorTwo fissures: Horizontal and Oblique

Two lobes: Superior, Inferior One fissure: Oblique

S

M

I

S

ILingul

a

Cardiac Notch

Horizontal Fissure

Oblique

Fissure

Base Base

Oblique Fissure

Right lung – shorter and wider due to liver

IdentifyApex

extends into the

neck

The Primary Bronchi divide into

Lobar Bronchi which divide into

Segmental Bronchi (~10 for

each lung); a bronchopulmonary segment is that

portion of lung supplied by a

segmental bronchus and

pulmonary artery branch

This is the

bronchial tree

Plate 202

Trachea

Primary Bronchi

Lobar BronchiLobar

BronchiSegmental Bronchi

Segmental Bronchi

T4-T5

Bronchopulmonary Segments

Plate 201

Bronchopulmonary segments are surgically separable: important in removal of tumors or

abscesses

Lungs

10 8-10

A bronchopulmonary segment contains a segmental bronchus, a branch of the pulmonary artery, and a branch of the bronchial

artery which run together in the central part of the segment.Lymphatics and veins

drain along the borders Arteries run with Airways

If a person inhales a foreign

object, it lodges in the right

bronchus. Why?

1. Shorter in length

2. Wider in diameter3. More vertical25 45

Plate 202 Lungs

Right

Plate 202 Lungs

Typical Pathway of a Foreign Body

Atelectasis of the right lung – total homogeneous opacity of

right side.

Atelectasis of the right middle and lower lobes of the lung – the intermediate

bronchus leads to dilated and occluded branches in the shrunken middle and

lower lobes. The rest of the right side is occupied by branches of upper lobe.

AP of right lungLateral of right lung

U

Bronchoscopic view of the

carina and left and right

primary bronchi

Distortions in the position of the carina may

indicate metastasis of bronchogenic

carcinoma into the

tracheobronchial lymph nodes

Carina

Air in Trachea

Pulmonary Artery

Diaphragm

Rib

V

Plate 213

Left Primary Bronch

us

In order for inspiration to occur, the lungs must expand. This increases lung

volume and decreases the pressure in the lungs to 758 mm Hg or below

atmospheric pressure (760 mm Hg). The lungs expand because the diaphragm increases the vertical diameter of the thorax and the external intercostals

elevate the ribs. Air will flow into the lungs because of this pressure difference.

Expiration is a passive process and occurs when the pressure in the lungs is

greater than the pressure in the atmosphere. Elastic recoil of the chest

wall and lungs occurs.Intrapleural pressure (in the pleural space) is

4 mm Hg below atmospheric pressure. This acts like a “suction” and keeps the alveoli

inflated.

Bucket Handle - Lateral

Pump Handle - AP Plus diaphragm movements

Movements of the thoracic cage which increase or decrease the

intrathoracic volume resulting in pressure changes causing inspiration or expiration.

Page 89

Moore

The entry of air into the

pleural cavity is called a

pneumothorax. As a result,

the lung collapses and

the pleural cavity

becomes a real space.

The pneumothorax

can be spontaneous due to a rupture of a bleb or bulla on

the lung surface - seen in men 20-

40 years

Moore page 118

Typically in a patient with no known lung disease, but can occur secondary to

diseases of the lung.

Simple Pneumothorax

Detail

Common presentation:

Tall, thin male teenager

Abrupt onset dyspneaChest pain

Hyperresonant percussion on affected

sideBreath sounds

diminished

This is another type of pneumothorax - an open pneumothorax; air flows easily in and out of the open wound. Mediastinal structures are pushed to the opposite side with inspiration but return with expiration.

In a tension pneumothorax, the wound is covered by skin, muscle or clothing. The air becomes trapped in the pleural space and Mediastinal structures are pushed to the opposite side. One lung is collapsed and the other lung is compressed. Trachea deviates away from the lesion. This is a lethal condition. Pressure must be relieved!

Clinical signs: distended neck veins, shifted trachea, decreased breath sounds in both lungs, hypotension,

agitation

Classic signs of a tension pneumothorax:

Deviation of trachea away from side of tension

Shift in mediastinum

Depression of hemi-diaphragm

Post-mortem chest X-ray of left tension pneumothorax

Cardiovascular function

compromised due to venous obstruction of

heart

Tension pneumothoraxidentified on CT scan

Moore, page 119

To remove blood or other fluids, a needle is inserted closer to the upper border of the rib below to avoid nerves. The 9th interspace in the midaxillary line

during expiration is a safe place - above the diaphragm.

Hydrothorax: due to a pleural effusion (escape of fluid into the pleura space)

Hemothorax: blood entering the pleural space – e.g., from a chest wound

Page 119 Moore

9

10

CLINICAL CASEA woman was stabbed in the right side

of her lower neck. The stab wound was approximately 2.5 cm superior to

the medial third of the clavicle. Shortly after the bleeding was controlled, the woman began breathing rapidly and

was given oxygen by the paramedics. Physical examination revealed a significant shift of mediastinal

structures and poor breath sounds were heard on the right side of the

chest.

Laboratory