Chapter 15 The Respiratory System - PowerPoint Presentation

Slide1

Chapter 15

The Respiratory System

Slide2

Respiratory/Circulatory A Cooperative Effort

Oxygen delivery

to the tissues and

waste product removal

requires a

cooperative effort

of the respiratory and circulatory systems

The

respiratory

system

oxygenates

the blood and

removes

carbon dioxide

The

circulatory

system

transports

these gases in the bloodstream

Slide3

Lung Components

System of

tubes

to conduct air into and out of the lungs

•

Bronchi: largest conducting tube

•

Bronchioles (little bronchi): next in size

•

Terminal Bronchioles: smallest

•

Respiratory Bronchioles: tubes distal to terminal bronchioles; they have alveoli projecting from their walls. Transport air but also participate in gas exchange

Alveoli

where oxygen and carbon dioxide exchange between air and pulmonary capillaries

Lung divided into large segments called

lobes,

each one consisting of

smaller units, lobules

Slide4

Structure Terminal Air Passages

Slide5

Respiration: Function

Acinus

or

respiratory unit:

functional unit of the lung

Respiration has two functions

Ventilation

Air movement caused by movement of ribs and diaphragm

Gas exchange

Gases diffuse between blood, tissues, and pulmonary alveoli due to differences in their partial pressures

Slide6

Pulmonary Function Tests

Vital capacity

One-second forced expiratory volume (FEV

1

)

Arterial PO

2

and PCO

2

Slide7

The Pleural Cavity

Lungs

are

covered

by a

thin membrane

called

pleura,

which

also extends

over the internal surface of the chest wall

The

potential space

between the

lungs

and the

chest wall

is called

pleural cavity

Intrapleural pressure

is

less

than the

intrapulmonary

pressure

The

negative intrapleural pressure

is caused by the tendency of the stretched lung to pull away from the chest wall

A release of the vacuum in the

pleural cavity leads to a

collapse of the

lung -

Atelectasis

Slide8

How Does the Vacuum get released?

A hole is created in the pleura – known as a pneumothorax

The hole can be one from the outside of the body “traumatic pneumothorax” – example – knife wound – this allows higher pressure outside air to enter the pleural space

The hole can be one from the inside where an surface alveoli bursts “spontaneous pneumothorax”– this allows higher pressure lung air to enter the pleural space

The air in the pleural space can cause a collapse of the lung “atelectasis”

Slide9

Pneumothorax Pathogenesis/Manifestations

Pathogenesis

Lung injury or pulmonary disease that allows air to escape into the pleural space

Stab wound or penetrating injury to the chest wall

Spontaneous

– generally in young healthy persons

Manifestations

Chest pain

Shortness of breath

Air in pleural cavity

Tension

pneumothorax

Slide10

Tension Pneumothorax

Development of a higher than atmospheric pressure in the pleural cavity – creating a tension

Can accompany any type of pneumothorax

Upon inhalation air enters pleural space – due to drop in intrapleural pressure

On exhalation – air gets trapped due to the edges of the tear compressing as a result of the increased intrapleural pressure – thus the pressure in the intrapleural space is getting greater and greater

Heart and Mediastinal structures shifted away from pneumothorax

Slide11

Pneumothorax Treatment

A chest

tube

is inserted into the

pleural cavity

and left in place until tear in lung heals

Prevents accumulation

of

air

in

pleural cavity

Aids

reexpansion

of lung

Slide12

Atelectasis

An incomplete expansion of the lung, a

collapse

of a part of the lung

There are two types

1.

Obstructive

atelectasis:

complete

bronchial obstruction by

Mucous secretions, tumor, foreign object

Resulting in collapse of the part of the lung supplied by the blocked bronchus

Can also develop as a postoperative complication, where because of the pain, the patient does not cough or breathe deeply, accumulating mucous secretions

Slide13

Atelectasis

2.

Compression

atelectasis

External

compression on the lung

Fluid, air, or blood in the pleural cavity, reducing its volume and preventing lung expansion

Slide14

Pneumonia

An

inflammation

of the lung

The

exudate spreads

unimpeded through the lung

Filling the

alveoli

The affected portions of the lung become relatively solid (

consolidation

)

At times, the exudate

reaches

the

pleural surface

Slide15

Pneumonia Classification

Classification

Etiology: most important because it serves as a

guide for treatment

Bacteria,

chlamydia, mycoplasmas, rickettsiae, viruses

, fungi

Anatomic distribution of the inflammatory process- describes

what part of the lung

is involved

Lobar:

entire

lung (bacteria, neutrophil infiltration)

Bronchopneumonia (bacteria, neutrophil infiltration):

parts

of one or more lobes adjacent to the

bronchi – bronchopulmonary segments

Slide16

Pneumonia Classification

Interstitial pneumonia or primary atypical pneumonia (virus or mycoplasma; lymphocyte, monocyte, and plasma cell infiltration): alveolar septa affected

Predisposing factors

that lead to its development

Any condition associated with

poor lung ventilation and retention of bronchial secretions

Postoperative – atelectasis and secondary bacterial infection

Aspiration

Obstruction

Slide17

Clinical features of pneumonia

Manifestations of systemic infection

Feeling ill

Elevated temperature

Increased white blood cell count

Manifestations of lung inflammation

Cough

Purulent sputum

Pain on respiration if involves pleura

Shortness of breath

Slide18

Legionnaires’ Disease

First

known

occurrence 1976 at American Legion Convention in Philadelphia

Gram-negative rod shaped bacteria called Legionella pneumophila

Found in moist environments

Airborne infection – not spread from human to human

Treated by appropriate antibiotics

Slide19

SARSSevere Acute Respiratory Syndrome

A

highly communicable

serious pulmonary infection, caused by an unusual

coronavirus

that has

spread rapidly

through several

countries

since it was

first identified

in late

2002

In 2003 a Chinese Physician became ill while staying in a hotel in Hong Kong along with 12 other hotel occupants – they flew out to other countries and it spread

Many become seriously ill and some die (5% of patients –higher rate in patients with other diseases like diabetes) from Respiratory Distress Syndrome

Slide20

The SARS-associated virus is a unique RNA virus not closely related to other coronaviruses and the

first one

to

cause severe disease

in people. The virus has crown like (corona) spikes projecting from its surface

The virus probably was an

animal virus

that

mutated

and was able to infect humans

Virus present in the blood during early stages then in feces later

Can survive in the environment for up to 3 hours.

Incubation period 2 to 7 days but may be up to 10 days.

Illness begins with chills, fever and sometimes mild respiratory symptoms and occasionally diarrhea. After 3 -7 days it manifests as a lower respiratory tract infection with varying severity.

The most infected need mechanical ventilation

Can be

transmitted

from person to person through

coughing, sneezing, by hands, towels, and other items

contaminated with the virus

There are

no effective antiviral drugs

that can influence the course of the disease

Slide21

Swine Flu

Swine influenza

(also

swine flu

) refers to

influenza

caused by any virus of the family

Orthomyxoviridae

, that is

endemic

to

pig

(swine) populations. Strains endemic in swine are called

swine influenza virus

(

SIV

), and all known strains of SIV are classified as

Influenza virus A

(common) or

Influenza virus C

(rare).

Influenzavirus B

has not been reported in swine. All three

classes

, Influenzavirus A, B, and C, are

endemic in humans

Slide22

People who work with poultry and swine, especially people with intense exposures, are at risk of infection from these animals if the animals carry a strain that is also able to infect humans. SIV can mutate into a form that allows it to pass from human to human. The strain responsible for the

2009 swine flu outbreak

is believed to have undergone this mutation.

In humans, the symptoms of swine flu are similar to those of

influenza

and of

influenza-like illness

in general

Slide23

Signs and Symptoms

Main symptoms of swine flu in humans.

According to the

Centers for Disease Control and Prevention

(CDC), in humans the symptoms of swine flu are similar to those of

influenza

and of

influenza-like illness

in general. Symptoms include fever, cough, sore throat, body aches, headache, chills and fatigue. A few more patients than usual have also reported

diarrhea and vomiting.

Slide24

Because these symptoms are not specific to swine flu, a

differential diagnosis

of

probable

swine flu requires not only symptoms but also a high likelihood of swine flu due to the person's recent history. For example, during this

2009 swine flu outbreak in the United States

, CDC advised physicians to "consider swine influenza infection in the differential diagnosis of patients with acute febrile respiratory illness who have either been in contact with persons with confirmed swine flu, or who were in one of the five U.S. states that have reported swine flu cases or in Mexico during the 7 days preceding their illness onset.“

[

A diagnosis of

confirmed

swine flu requires laboratory testing of a respiratory sample (a simple nose and throat swab).

Slide25

Pathophysiology

Influenza viruses bind through

hemagglutinin

onto

sialic acid

sugars on the surfaces of

epithelial cells

; typically in the nose, throat and

lungs

of mammals and

intestines

of birds (Stage 1 in infection figure).

[17]

Swine flu in humans

People who work with poultry and swine, especially people with intense exposures, are at increased risk of

zoonotic

infection with influenza virus endemic in these animals, and constitute a population of human hosts in which

zoonosis

and

re-assortment

can co-occur.

Slide26

Transmission of influenza from swine to humans who work with swine was documented in a small surveillance study performed in 2004 at the University of Iowa. This study among others forms the basis of a recommendation that people whose jobs involve handling poultry and swine be the focus of increased public health surveillance.

The

2009 swine flu outbreak

is an apparent

re-assortment

of several strains of

influenza A virus subtype H1N1

, including a strain

endemic in humans

and two strains endemic in pigs, as well as an

avian influenza

.

Slide27

The

CDC

reports that the symptoms and transmission of the swine flu from human to human is much like that of seasonal flu.

Common symptoms include fever, lethargy, lack of appetite and coughing, while runny nose, sore throat, nausea, vomiting and diarrhea have also been reported.

It is believed to be spread between humans through

coughing

or

sneezing

of infected people and

touching something with the virus on it and then touching their own nose or mouth

.

Swine flu cannot be spread by pork products, since the virus is not transmitted through food.

The swine flu in humans is most contagious during the

first five days of the illness

although some people, most commonly children, can remain contagious for up to ten days.

Slide28

Diagnosis

made by sending a specimen, collected during the first five days, to the CDC for analysis.

Treatment

The swine flu is susceptible to four drugs licensed in the United States,

amantadine

,

rimantadine

,

oseltamivir

and

zanamivir

, however, for the 2009 outbreak it is recommended it be treated under medical advice only with

oseltamivir

and

zanamivir

to avoid drug resistance.

The vaccine for the human seasonal H1N1 flu does not protect against the swine H1N1 flu, even if the virus strains are the same specific variety, as they are

antigenically

very different.

Slide29

Prevention

Recommendations to prevent infection by the virus consist of the

standard personal precautions

against influenza. This includes frequent washing of hands with soap and water or with alcohol-based hand sanitizers, especially after being out in public. People should avoid touching their mouth, nose or eyes with their hands unless they've washed their hands. If people do cough, they should either cough into a tissue and throw it in the garbage immediately, cough into their elbow, or, if they cough in their hand, they should wash their hands immediately.

Vaccines that are effective against the current strain are being developed

.

Slide30

Pneumocystis Pneumonia

Humans and many animals harbor this

microorganism – Pneumocystis carinii

Caused by

protozoan parasite

of low pathogenicity

Does

not

affect

normal

persons

Affects

immunocompromised persons

Persons with AIDS

Persons receiving immunosuppressive drugs

Premature infants whose immune defenses are poorly

developed

Organisms

injure alveoli, leading to exudation of protein-rich material into alveoli

Dyspnea

Cough

Pulmonary consolidation

Slide31

Cysts demonstrated by special stains

Within the cysts are sporozoites- when released from the cysts these organisms mature and enlarge into trophozoites. Some trophozoites give rise to more cysts, repeating the cycle but some attack the lining of the alveoli (destruction).

Evidence

of pulmonary consolidation visualized on chest radiograph

Diagnosis established by biopsy of lung tissue obtained by bronchoscopy

Treatment

Drugs that inhibit growth of organism

Infection has high mortality

Slide32

Tuberculosis

It is a

special type

of

pneumonia

caused by

Mycobacterium

tuberculosis – an acid – fast bacteria

Because

the tubercle bacillus has a capsule composed of waxes and fatty substances, it is

more resistant to destruction

than

others – thick cell wall

As a result of this organism’s resistance – monocytes accumulate around the bacteria – many fuse with the bacteria attempting phagocytosis – but the fusion produces a large multinucleated “giant cell”. Lymphocytes and plasma cells surround the area – followed by fibrous tissue proliferation. The central portion becomes necrotic – thus a

granuloma

is formed. TB is termed a

granulomatous disease.

Slide33

Manifestations

Course of infection

Acquired from organisms inhaled in airborne droplets

Organisms lodge within pulmonary

alveoli where they proceed to multiply

Initially the organisms do not elicit a marked inflammatory reaction because they do not produce any toxins or destructive enzymes

Macrophage phagocytose the bacteria but are unable to destroy them – they may even carry the organisms to other parts of the lung and into regional lymph nodes.

After several weeks cell-mediated

immunity develops

Sensitized T- cytotoxic lymphocytes attract and activate macrophages – the activated

macrophages attack and destroy many of the

organisms forming the characteristic

granulomas formed

In the majority of cases the person is unaware they have been infected – no symptoms

Infection

arrested in majority of cases

Outcome depends

Number of organisms inhaled

State of body’s defenses

May heal by scarring or progress to cavitation

Slide34

Sometimes the granuloma is large enough to be seen on X-ray but most of the times it is too small

The positive skin test reveals the infection

Cell-mediated immunity

generally

controls the infection

The healed granuloma may contain small numbers of viable organisms and the infection may become reactivated when the immune system drops

In some individuals the primary infection does not respond favorably to the immune system fight

The granuloma may extend into a nearby bronchus and necrotic inflammatory tissue is discharged into it

A cavity may form

If the person gets reactivation of the bacteria (becomes active) and they have cavitation (into bronchus) their sputum can be infectious to others

Slide35

Most cases of active TB do not result from the initial infection – but rather by a reactivation – however some are due to a reinfection (new case)

How does reactivation occur- it is due to a drop in the immune system action as a result of AIDS, other debilitating diseases, treatment with corticosteroids, treatment with immunosuppressive therapy

Slide36

Miliary and tuberculous pneumonia are two uncommon but extremely serious forms of TB

Miliary

Tuberculosis

Mass of tuberculous inflammatory tissue erodes into a large blood

vessel thus dissemination

of organisms by bloodstream

Miliary is derived from the resemblance of multiple foci of disseminated TB (seen in liver, spleen, kidney and other tissues) to millet seeds. These are foci of small white nodules from about 1 – 2 mm in diameter (like millet seeds)

TB pneumonia is an overwhelming infection characterized by extensive TB consolidation on one or more lobes of the lung. Persons with AIDs and other immunocompromised persons are prone to this type of rapidly progressive infection

Slide37

Extrapulmonary tuberculosis

Result of hematogenous spread of tubercle bacilli – thus a secondary infection

Sites

Kidneys

Bone

Uterus

Fallopian tubes

Sometimes the secondary infection may progress even though the pulmonary infection has healed leading to an active extrapulmonary TB without clinically apparent pulmonary TB

Slide38

Tuberculosis

Diagnosis

Skin test (

Mantoux

): a positive test reveals

recent

infection

chest x-ray: when the

granuloma

is large enough to be

detected – or see pulmonary infiltrates

sputum

culture – acid fast bacteria

Slide39

The

tuberculosis

skin test (also known as the tuberculin test or

PPD

test) is a test used to determine if someone has developed an immune response to the bacterium that causes tuberculosis (TB). This response can occur if someone currently has TB, if they were exposed to it in the past, or if they received the

BCG

vaccine against TB (which is not performed in the U.S.).

The tuberculin skin test is based on the fact that infection with

M. tuberculosis

produces a delayed-type hypersensitivity skin reaction to certain components of the bacterium.

Slide40

The components of the organism are contained in extracts of culture filtrates and are the core elements of the classic tuberculin PPD (also known as purified protein derivative). This PPD material is used for skin testing for tuberculosis. Reaction in the skin to tuberculin PPD begins when specialized immune cells, called

T cells

, which have been sensitized by prior infection, are recruited by the immune system to the skin site where they release chemical messengers called lymphokines. These lymphokines induce

induration

(a hard, raised area with clearly defined margins at and around the injection site) through local vasodilation (expansion of the diameter of blood vessels) leading to fluid deposition known as

edema

, fibrin deposition, and recruitment of other types of inflammatory cells to the area.

Slide41

An incubation period of two to 12 weeks is usually necessary after exposure to the TB bacteria in order for the PPD test to be positive.

Slide42

Tuberculosis

Treatment

Cell-mediated immunity

generally controls the infection

The

healed

granulomas,

however, may contain small numbers of

viable organisms

, and the

infection

may become

reactivated

Not all primary infections respond as favorably

If a

large number

of organisms are inhaled or if the

host is compromised

(body’s defenses are inadequate), the inflammation will progress, causing more destruction of lung tissue

Slide43

Tuberculosis

People who have

active progressive

tuberculosis with a

tuberculous cavity

can

infect others

because they can discharge large numbers of tubercle bacilli in the sputum

Treatment

Antibiotics

and Chemotherapeutic agents

Drug-resistant tuberculosis treatment

More prolonged

Results less satisfactory

Drugs recommended

Following conversion of a negative into positive skin test reaction

Patients with inactive tuberculosis who have increased risk

 

Slide44

Bronchitis

An

inflammation

of the tracheobronchial mucosa

Acute

bronchitis

Common and self-limiting

Chronic

bronchitis – often associated with emphysema in COPD

Secondary to chronic irritation by smoking or atmospheric pollution

Slide45

Bronchiectasis

Walls weakened by inflammation and dilate

Distended bronchi retain secretions

Chronic cough

Production of large amounts of purulent sputum

Diagnosed with bronchogram

A specialized X-ray which consists of taking films after instilling a radiopaque oil into the trachea and bronchi.

The oil covers the mucosa of the bronchi, and the abnormal bronchi can be recognized as dilated

Only

effective treatment is surgical resection of affected segments of lung

Slide46

Upper Respiratory System

– From nose and mouth down to Lungs – (includes nose, mouth, pharynx, larynx, and trachea

Lower Respiratory System

– Mainstem bronchus to Alveoli

Upper Airway

– From nose and mouth to and inclusive of larynx (voice box)

Lower Airway

– Trachea down to alveoli

Slide47

Chronic Obstructive Pulmonary Disease

COPD

Slide48

Chronic Obstructive Pulmonary Disease

Emphysema

and

chronic bronchitis

occur together so frequently that they are usually considered a

single entity

, designated

COPD

Emphysema is

characterized by loss of elasticity (increased

pulmonary compliance

) of the lung tissue caused by destruction of structures feeding the alveoli

Chronic

bronchitis –

Secondary to chronic irritation by smoking or atmospheric pollution

Clinical

manifestations

Dyspnea

Cyanosis

Slide49

Chronic Obstructive Pulmonary Disease

The chief clinical manifestations of

any

type of chronic pulmonary disease are

Dyspnea: sensation of

shortness of breath

Cyanosis:

blue tinge

of skin and mucous membrane from an excessive amount of

reduced hemoglobin

in the blood

Slide50

The three main anatomic derangements in COPD are

Inflammation and narrowing of the terminal bronchioles

Dilatation and coalescence of pulmonary air spaces

Loss of lung elasticity

Slide51

Derangements of pulmonary structure and function

Inflammation and narrowing of terminal bronchioles

Causes swelling of bronchial mucosal

Reduces caliber of bronchi and bronchioles

Stimulates increased bronchial secretions

Air can enter lungs more readily than it can be expelled – leads to trapped air

Nonuniform ventilation of alveoli reduces efficiency of

ventilation

Dilation and coalescence of pulmonary air spaces

Enlargement of air spaces and reduction of capillary bed reduces efficiency of gas exchange

Movement of air into and out of enlarged spaces is impeded by bronchiolar obstruction

Slide52

Loss of lung elasticity

Expiration requires active expiratory effort

Pressure required to force air out of lungs raises intrapleural pressure and compresses the lungs

Bronchi and bronchioles tend to collapse during expiration

Obstructs air flow

Traps more air in

lungs

Slide53

Emphysema

•

The

air spaces

distal to the terminal bronchioles are

enlarged

and their

walls

are

destroyed

•

The normally

fine alveolar structure of the lung

is

destroyed

•

The

large cystic air spaces form throughout

the lung

•

The destructive process usually

begins

in the

upper lobes

but eventually may affect all lobes

•

Once

emphysema

has

developed

, the damaged lungs

cannot

be restored to

normal

Slide54

Pathogenesis of emphysema – secondary to bronchitis

Chronic irritation from cigarette smoking or inhalation of injurious agents produces chronic bronchitis

Inflammatory swelling of mucosa

Narrows bronchioles

Increases bronchioles resistance to expiration

Causes air to be trapped in the lung

Leukocytes that accumulate in bronchioles and alveoli may contribute to damage

Release proteolytic enzymes

Enzymes attack elastic fibers

Slide55

Emphysema as a result of alpha, antitrypsin deficiency

Antitrypsin

Prevents lung damage from lysosomal enzymes

Released from leukocytes in lung

Deficiency permits enzymes to damage lung tissue

Develop progressive pulmonary emphysema

Manifest in adolescence or early adulthood

Tends to affect lower lobes of lungs

Less common type of emphysema

Slide56

Prevention and treatment

Refrain from smoking

Avoid inhalation of injurious agents

Treatment

Will not restore damaged lung

Will prevent further progression

May improve pulmonary

function

Slide57

Bronchial Asthma

Spasmodic contraction

of smooth muscles in the walls of the

smaller bronchi and bronchioles

It causes

shortness of breath

and

wheezing

respiration

Exerts a

greater effect

on

expiration

than on inspiration

Attacks are

precipitated by

allergens

: inhalation of dust, pollens, animal dander, or other allergens

Treated with drugs such as

epinephrine or theophylline

that relax bronchospasms and block the release of mediators from mast cells

Slide58

Bronchial Asthma

Pathogenesis

Spasmodic contraction of smooth muscles in walls of smaller bronchi and bronchioles

Associated with increased secretions from bronchial mucous glands

Clinical manifestations

Shortness of breath

Wheezing respirations

Air flow impeded more on expiration than on inspiration

Air trapped in lungs

Lungs become overinflated

Slide59

Attacks precipitated by allergens

Interact with mast cells coated with IgE antibody

Release chemical mediators that induce bronchospasm

Treatment

Drugs that relax bronchospasm

Epinephrine

Theophylline

Drugs that block release of mediators from mast cells

 

Slide60

Neonate Respiratory Distress Syndrome

It occurs

soon after birth

Due to

inadequate surfactant

in the lungs, which cause the alveoli

not to expand

normally during

inspiration

and tend to

collapse

during

expiration

Predisposed

groups

Premature

infants

Infants born by

cesarean

section

Infants with

diabetic mothers

Slide61

Neonatal respiratory distress syndrome

Pathogenesis

Inadequate surfactant

Alveoli do not expand normally during inspiration

Promotes collapse

Groups predisposed to syndrome

Premature infants

Infants born by cesarean section

Infants with diabetic mothers

Treatment

Adrenal corticosteroid hormones administered to mother within twenty-four hours before delivery

Infants who develop respiratory distress after delivery treated by instillation of surfactant-type material

Slide62

Adult Respiratory Distress Syndrome

Pathogenesis

1.

Conditions that cause shock

, causing fall in blood pressure, and reduced blood flow to lungs

The shock may result from any type of severe injury (traumatic shock) or from a serious systemic infection (septic shock)

2.

Direct lung damage:

caused by aspiration of acid gastric contents, inhalation of irritant or toxic gases, of damage caused by SARS

Damaged alveolar capillaries

leak

fluid and protein

Impaired

surfactant

production from damaged alveolar lining cells

Slide63

Adult respiratory distress syndrome / ARDS / shock lung

Pathogenesis

Conditions that cause shock which leads to

Fall in blood pressure

Reduced blood flow to lungs

Impaired lung perfusion

Direct lung damage

Trauma

Gastric aspiration inhalation of irritants or toxic gases

Derangement

Damaged alveolar capillaries leak fluid and protein

Impaired surfactant production from damaged alveolar lining cells

Formation of hyaline membranes

Slide64

Treatment

Correct shock

Treat underlying condition that initiated respiratory distress

Improve oxygenation by administering oxygen under positive pressure

Slide65

Pulmonary Fibrosis

May be caused by lungs continually exposed to injurious substances such as

irritant gases

discharged into the atmosphere and many kinds of

airborne organic

and

inorganic particles

Fibrous thickening

of alveolar septa make the

lungs

increasingly

rigid

,

restricting

normal

respiratory

excursions

Causes progressive respiratory disability

similar

to that in

emphysema

Collagen diseases-

may

lead

to pulmonary fibrosis

Slide66

Pulmonary Fibrosis

Pneumoconoisis

: lung injury produced by

inhalation

of

injurious dust

or

other particulate material

The best known are

Silicosis

: a type of progressive nodular pulmonary fibrosis caused by inhalation of

rock dust

Asbestosis

: a diffuse pulmonary fibrosis caused by inhalation of

asbestos

fibers

Inhalation of

coal dust, cotton fibers

,

certain types of fungus spores

, and many other substances attending

certain occupations

also may cause pulmonary fibrosis

Slide67

Pulmonary Fibrosis

Fibrous thickening of alveolar septa

Lungs become rigid

Respiratory excursions restricted

Diffusion of oxygen and carbon dioxide between alveolar air and pulmonary capillaries hampered

Pathogenesis

Collagen diseases

Pneumoconoisis

Silicosis

Inhalation of rock dust

Progressive nodular pulmonary fibrosis

Slide68

Asbestosis

Inhalation of asbestos fibers

Diffuse pulmonary fibrosis

Increased incidence of other diseases

Lung carcinoma

Pleural malignant mesothelioma

Other substances inhaled in course of occupations

Treatment

No specific treatment

Prevent occupational exposure

 

Slide69

Lung Carcinoma

Usually

smoking-related

neoplasm

Common malignant tumor in both

men and women

Mortality

from lung cancer in

women

exceeds breast cancer

Arises

from mucosa of bronchi and bronchioles

Slide70

Lung Carcinoma Classification

Because the neoplasm of lung cancer usually arises from the bronchial mucosa, the term

bronchogenic

carcinoma,

is often used

Classification

Squamous cell carcinoma: very common

Adenocarcinoma: very common

Large cell carcinoma: large, bizarre epithelial cells

Small cell carcinoma: very poor prognosis

Slide71

Accounts for 1/3 of all cancer deaths in the U.S.90% of all patients with lung cancer were smokersThe three most common types are:Squamous cell carcinoma (20-40% of cases) arises in bronchial epitheliumAdenocarcinoma (25-35% of cases) originates in peripheral lung areaSmall cell carcinoma (20-25% of cases) contains lymphocyte-like cells that originate in the primary bronchi and subsequently metastasize

Lung Cancer

Slide72

Lung Carcinoma

Because of the rich lymphatic and vascular network in the lung, the

neoplasm

readily gains

access to lymphatic channels

and

pulmonary blood vessels

and soon

spreads

to regional lymph nodes and distant sites

Treatment

usually consists of

surgical resection

of one or more lobes of the lung

Radiation

and anticancer

chemotherap

y rather than surgery are used to treat small cell carcinoma and tumors that are

too far advanced

for surgical resection

Slide73

Lung Carcinoma

Pathogenesis

Smoking-related neoplasm

Most common malignant tumor in men

Mortality from lung cancer in women exceeds breast cancer

Arises from mucosa of bronchi and bronchioles

Classification

Squamous cell carcinoma

Adenocarcinoma

Large cell carcinoma

Small cell carcinoma

 

Slide74

Prognosis

Differs due to several histologic types

Poor prognosis due to early spread to distant sites

Treatment

Surgical resection of one or more lobes

Small cell carcinoma treated by chemotherapy and radiation