1. Oversees gas exchange between blood and external environment
Respiratory System
Oversees gas exchange between blood and external environment

2. Anatomy of Respiratory System
Nose
Purify, humidify, and warms (by veins) incoming air
Cilia propel mucus to pharynx
Sinuses – lighten skull, act as resonance chamber for speech
Pharynx (throat)
Muscular passageway
Tonsils – lymphatic system
Larynx (voice box)
Thyroid (Adams apple)
Epiglottis (closes when swallow)
Trachea (windpipe)
Ciliated mucosa propel debris away from lungs
Bronchi
Subdivisions (bronchioles) branch off and enter lungs
Lungs
R. lung 3 lobes, L. lung 2 lobes
Pleura – surface lining
Alveoli – air sacs at terminal ends

3. Alveoli: Site of gas exchange
Simple squamous epithelial tissue
Covered in a cobweb of pulmonary capillaries
Macrophages move in/out of alveoli
Cuboidal cells secrete surfactant
lipid coats alveoli
Prevents alveoli collapse
Begins to function at weeks during gestation

4. Respiration Physiology
Pulmonary Ventilation
Continuously refreshing the air in the lungs
External Respiration
Gas exchange between blood and alveoli
Respiratory Gas Transport
O2 & CO2 transported via blood
Internal Respiration
Gas exchange between blood and tissues

5. Mechanics of Breathing
Inspiration
Diaphragm and external intercostals muscles contracts
Size of thoracic cavity increases, lung volume increases (lung pressure decreases below atm pressure) and creates a partial vacuum
Air enters lungs
Expiration
Inspiratory muscles relax, resuming initial size
Lungs recoil (effortless)
Air is exhaled

6. Respiratory Volumes and Capacities
Spirometer – measures respiratory capacities
Vital Capacity
Tidal Volume
Normal quiet breathing (500mL ea/breath)
Inspiratory Reserve Volume
Air taken in forcibly ( mL over TV)
Expiratory Reserve Volume
Air forcibly expelled (1200mL)
Residual Volume
Air remaining in lungs that cannot be expelled (1200mL)
Allows gas exchange between breaths, keeps alveoli inflated
Dead Space Volume
Air remains in “passageways” and never reaches alveoli (150mL)

7. Control of Respiration
Neural Regulation
Nerve impulses from medulla and pons
Maintain a rate of breaths/minute
Other Influential Factors
Physical Factors
Talking, coughing, exercising, increase body temp
Conscious Control
Singing, swallowing, swimming
Limited/ignored if O2 levels get low or CO2 levels get too high
Emotional
Hypothalamus reflex (scared, gasp, etc)
Chemical
Levels CO2 and decreased blood pH

8. Interesting Respiratory Topics
Smoking and its effect on respiratory system
Cleft Palate
Rhinitis (Cold) & Sinusitis
Atelectasis (lung collapse)
Hypoxia (inadequate O2)
Hyperventilation & Hypoventilation
Apnea
Cyanosis
COPD (chronic obstructive pulmonary disease)
Cystic Fibrosis
SIDS (sudden infant death syndrome)
Asthma
Bronchitis & pneumonia
Tuberculosis