Download The Respiratory System

The Respiratory
System
Respiratory Anatomy
• Upper
respiratory tract
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Nose
Nasal passages
Pharynx
Larynx
Respiratory Anatomy
• Functions of the upper respiratory
tract:
– Provide entry for inhaled air
Respiratory Anatomy
• Functions
– Nasal mucosa
• Traps bacteria
& foreign
particles
• Warms &
moistens
incoming air
• Part of natural
immunity
Respiratory Anatomy
• Pharynx
• Part of the digestive and respiratory
systems
• Allows for passage of both air and
food
• Mucosa of pharynx is part of immune
system, source of antibodies &
protective substances
Respiratory Anatomy
• Larynx
– Lined with squamous epithelium
and enclosed in cartilage for
support and protection
– Organ of speech
– Improperly functioning larynx can
lead to aspiration of food or liquid
into lungs
Lower Respiratory
Tract
•
•
•
•
Trachea
Bronchii
Bronchioles
Terminal alveoli in lungs
Respiratory Anatomy
• Trachea
• Leads to the L & R bronchi
• Lined with:
– Ciliated cells
– Mucus producing cells
– Neuroendocrine cells
– Basal cells
• With chronic smoking basal cells
change-> basal squamous
metaplasia Lung CA
Respiratory Anatomy
• L and R bronchi enter the L and R
lungs
– Branch many times, becoming narrower into bronchioles
then avleolar ducts and alveolar sacs (alveoli)
• Alveoli
– Lined with pneumocytes
• Thin cells that allow for gaseous exhange
• Cells that produce a pulmonary surfactant
that coats the alveoli and keeps them from
collapsing.
Respiratory Anatomy
• Pulmonary
lobules
– many lobules
make up the
pulmonary
lobes
• 3 on the Right
and 2 on the
Left
Pulmonary Blood
Supply
• Dual blood supply
– Pulmonary artery
• Brings de-oxygenated (venous) blood
from the R ventricle into the lungs
• Blood is oxygenated in lungs
– Pulmonary vein
• Brings oxygenated blood from lungs
into L atrium
Respiratory Anatomy
• Outer surface of lungs= pleura
– Moist surface
– Filters air, keeps air moist, and
retains large particles and
bacteria.
– Provides protection against
infection
Function of Lungs
• Major function of the lungs:
– Respiration
• Metabolic function of the lungs:
– Maintain acid-base balance
• Prevention of acidosis or alkalosis
– Affects the kidneys, gastrointestinal tract
Important Terminology
• Dyspnea- SOB
• Cyanosis- bluish color of eh skin and
mucous membranes
• Clubbing- thickening and widening of
terminal phalanges of fingers and toes
• Hypoxia- diminished availability of O2 to
body tissues
• Normal resting rate of ventilation: 12-20
breaths per minute
Signs and Symptoms
of Pulmonary Disease
•
•
•
•
•
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Cough
Dyspnea
Cyanosis
Chest pain
Abnormal chest shape
Abnormal sputum
Respiratory Diseases
• Major Diseases
– Infectious
– Immune
– Environmentally Induced
– Circulatory
– Neoplastic (Tumors)
Infectious Diseases
• Upper Respiratory Infections (URI)
– Etiology & Pathogenesis
•
•
•
•
viral
short lived
heal spontaneously
Acute inflammation of the nose, paranasal
sinuses, throat, or larynx
Infectious Disease
• Clinical Findings
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–
–
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Nasal congestion
General malaise
Mild fever
Rhinorrheah (runny nose)
Infectious Disease
• Middle Respiratory System
– More prevalent among children
– croup
• Barking cough due to spasm of vocal cords
– Whooping cough
Infectious Diseases
• Pneumonia
– Inflammation of the lung
• Bacterial infection (75%) or viral
infection
• Less frequently by fungi, protozoa or
parasites
• Inhalation of smoke, dust, gases
• Aspiration of food or liquid
Infectious Diseases
• Pneumonia
– Clinical manifestations:
• Pleuritic chest pain
• Fever
• Hacking, productive cough
– Blood tinged sputum
• SOB
• Fever
• Generalized fatigue
Infectious Diseases
• Tuberculosis (TB)
– Chronic bacterial infection
• Localized lung infection
• Inhalation of infected airborne
particles
• Remains clinically unrecognized in
95% of the cases
– Ultimately impair lung function and
potentially other organs as well
Tuberculosis
• Symptoms:
– Productive cough
– General body symptoms
• Diagnosis
– Chest x-ray
– Skin test
Chronic Obstructive
Pulmonary Disease
(COPD)
• Lung diseases with chronic
airway obstruction
• Includes:
– Chronic bronchitis
– Emphysema
Emphysema
• Enlargement of the airspaces distal
to the terminal bronchioles
• Destruction of the alveolar walls
• Obstruction results from changes in
lung tissues
• Loss of elasticity in lung tissue
narrows or collapses bronchioles
Emphysema
• Clinical manifestations:
– Dyspnea
– Cough is uncommon
– Barrel chest
– Anxiety
Chronic Bronchitis
• Productive cough lasting at least
3 months for 2 years
• Inflammation and scaring of
bronchial lining
• Increases mucus production
Chronic Bronchitis
• Clinical manifestations:
– Persistent, productive cough
– SOB
– Recurrent infections
COPD
• Two prototypic groups
– Predominant bronchitis- “blue bloaters”
• Prolonged coughing, dyspnea, cyanosis
– Predominant emphysema- “pink puffers”
• Chest is over-expanded or barrel chested,
hyper-ventillation, over-inflation with a small
heart
Immune Diseases
• Allergic Rhinitis
– Hay fever
• Type I hypersensitivity reaction
affecting the nasal mucosa to
exogenous allergens
• Acute vasomotor response mediated
by histamine and related vasoactive
substances
Asthma
• Acute, reversible, inflammatory, obstructive
lung disease
• Inflammation of bronchia mucosa,
increased permeability of blood vessels in
bronchi, and contraction and spasm of
smooth muscle in bronchi
• Two major forms:
– Extrinsic (allergic)
– Intrinsic (non allergic)
Asthma
• Signs & Symptoms
– Wheezing
– Dyspnea
– Cough
– Goal is to reduce exposure to the irritant
that induces the bronchospasm
Silicosis & Asbestosis
• Diseases caused by the
inhalation of substances
• Causes various types of lung
diseases
• Symptoms
• Pulmonary fibrosis
• Pleural fibrosis & pleural plaques
• Lung cancer
Adult Respiratory
Distress Syndromes
(ARDS)
• Severe impairment in oxygenation of blood
• Mechanism of lung injury varies depending
on cause:
– Shock
• Trauma
• Burns
• Acute cardiac failure
– Pneumonia
• Viral or bacterial
– Toxic lung injury
– Aspiration of fluids
• Near drowning
ARDS
• Clinical manifestations:
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Increased respiratory rate
Pulmonary edema
Atelectasis
Dyspnea
Can progress to MODS (multiple organ
dysfunction syndrome)
– Severe distress
– SOB
ARDS
• Prognosis
– Mortality rate of 50-70%
– Survivors asymptomatic in several
months and have normal lung
function in 1 yr
Ventilatory Failure
•
•
•
•
Spinal cord injury
Poliomyelitis
Tetanus
Myesthenia gravis
– Affects the neuromuscular junction
• Muscular dystrophy (Duchenne)
• Cystic fibrosis
Atelactasis
• Incomplete expansion or collapse of
the alveoli
– Deficiency of surfactant
– Compression of the lungs from outside
– Resorption of air distal to bronchial
obstruction
Neoplasms of the
Respiratory Tract
• Carcinoma of the larynx
– Linked to smoking & chronic alcohol intake
• Affects males 7x more than females
• Lung Carcinoma
– Leading cause of cancer death in the USA &
most other Western industrialized countries
– In most cases, it is caused by smoking
• 90% of patients are smokers
• 5 year survival rate 10-15%, incurable
Lung Carcinoma
• Classified as:
– Small cell lung cancer (SCLC)
– Non SCLC (NSCLC)
• Prognosis:
– Curability is poor
Pleural Diseases
• Accumulation of fluid in the
pleural cavity
– Hydrothorax or Pleural effusion
• Fluid can be transudate or exudate
• Accumulation of air in pleura
cavity
– pneumothorax