6. Anatomy of the Respiratory System
Lungs
Right Lung
3 lobes
Left Lung
2 lobes
7. Physiology of Breathing
Diaphragm contracts and the thoracic cage
expands, creating negative pressure in the lungs
Negative pressure in the lungs allows air to flow in
as the elastic fibers around the alveoli passively
contract
Air goes out through sympathetic activation,
producing smooth muscle relaxation and
bronchodilation
8. Pressures Associated with Breathing
Atmospheric Pressure
Pressure in the outside air
Only changes with altitude changes
Alveolar Pressure
Pressure in the alveoli
Intrapleural Pressure
Pressure in the pleural cavity
Always negative because of opposing forces
Outward force of chest wall MINUS the inward force
of surfactant and elastic tissue
9. Inspiration
Active process requiring energy
Contraction of muscles
Volume of thoracic cavity increases
Pressure in thoracic cavity decreases
Atmospheric Pressure > Alveolar Pressure
10. Expiration
Passive process
Relaxation of muscles
Elastic tissue of lung recoils
Inward pull of surface tension because of
alveolar fluid
Volume of thoracic cavity decreases
Pressure in thoracic cavity increases
Alveolar Pressure > Atmospheric Pressure
11. Alveolar and Systemic Gas Exchange
Alveolar Level
Oxygen diffuses from
alveolar air and into
blood in pulmonary
capillaries
Carbon dioxide diffuses
from blood in
pulmonary capillaries
into alveoli
Tissue Level
Oxygen diffuses from the
blood into systemic capillaries
and into the tissues
Carbon dioxide diffuses from
tissues and into the blood in
systemic capillaries to be
carries back to the lungs
12. Infectious Pulmonary Disorders
Pneumonia
Viral, bacterial, or fungal
1 lobe or 2 lobes
Tuberculosis
Spread by oral droplets; can survive in dry sputum
Can go dormant for long periods of time
Disease resurfaces when the immune system is
compromised
Diagnosis: skin test, chest x-Ray, or sputum culture
Treatment: long multi-drug treatment for 1 year;
disease has grown more resistant to treatment
13. Obstructive Pulmonary Disorders
Cystic Fibrosis
Results from a single gene mutation
Increases mucus in the lungs and risk of infections
14. Obstructive Pulmonary Disorders
Asthma
Type 1 Hypersensitivity Reaction
Forms IgE in response to an allergen
Inflammation of mucosa causes
bronchoconstriction and obstructive mucus
Can cause atelectasis
Presents with: hypoxia, alkalosis, cyanosis,
cough, chest tightness, thick mucus, and
tachycardia
Treatment: inhalers and glucocorticoids
15.
16. Obstructive Pulmonary Disorders
Chronic Obstructive Pulmonary Disease
Emphysema
Pink Puffers – red face, over-inflation
Destruction of alveolar walls results in permanent inflation
Smoking eliminates anti-trypsin that inhibits the enzyme that
destroys elastin, so elastin is destroyed
Loss of septae b/w alveolar sacs results in decreased surface
area for gas exchange
17. Obstructive Pulmonary Disorders
Chronic Obstructive Pulmonary Disease
Chronic Bronchitis
Blue Bloater
Inflammatory obstruction results in repeated infections
and progressive, irreversible damage of the bronchioles
Hypertrophy, hyperplasia of mucous glands, and fibrosis
Present with constant cough, shortness of breath, and
cyanosis
Treatment: smoking cessation, oxygen
supplementation, and vaccinations
18.
19. Obstructive Pulmonary Disorders
Lung Tumor
Inflammation and bleeding in the lungs leads to
coughing up blood
Pleural Effusion, Pneumothorax
Lung Cancer
90% of cases are smoking related
Third most common cancer
Can be the result of metastasis
20. Restrictive Pulmonary Disorders
Pneumoconiosis
Exposure to irritants produces inflammation leading to
fibrosis, or stiff lung
Insidious onset
Vascular Disorders
Fluid collects in alveoli and interstitial
Lung expansion and blood oxygen levels decrease
Cause pulmonary hypertension and edema
Pulmonary Embolism
Blood clot from the veins that’s pumped to the lungs
21. Restrictive Pulmonary Disorders
Atelectasis
Collapse of the
lung, has various
causes
Obstructed airway,
compression, or
increased surface
tension prevent
expansion
22. Restrictive Pulmonary Disorders
Pleural Effusion
Fluid in the pleural cavity increases
proteins and white blood cells to
respond to inflammation
Pressure is increased in the pleural
cavity, the lung layers separate, and
lung expansion is prevented
Present with increased respiratory or
heart rate
23. Restrictive Pulmonary Disorders
Pneumothorax
Air in the chest cavity causes the lungs to
collapse
Open: air enters through the hole in the
chest cavity
Closed: air enters through a rupture on the
inside of the chest cavity
Tension: air is allowed to enter the cavity
and there’s no natural way to remove it
24.
25. Restrictive Pulmonary Disorders
Adult Respiratory Distress Syndrome
Rapid, shallow respirations
increased heart rate and confusion
Caused by shock, sepsis, burns, or multi-
organ failure
27. Differential Diagnosis: Breathing
Labored indicates an obstruction
Wheezing/Whistling indicates an
obstruction of small airways
Stridor indicates an obstruction of small
airways