Respiratory system

Aka: what’s the heimlich manuever?

Why the respiratory system?

• Large surface area for gas exchange

• Move air to gas exchange area

• Protect gas exchange area from pathogens, dehydration, extreme temperatures

• Make noise!

• Assist smelling ( who cut the cheese?).

Air conducting (moving) path • External nares

• Nasal cavity– guard hairs– Air warmed and moistened– Nasal septum

More path• Oral cavity

– Separated from nasal by palatine/maxillary bones called “hard palate”

• Soft palate- fleshy part beyond hard palate• Oropharynx- contains tonsils for protection

from foreign bodies• Glottis- hole at start of trachea• Epiglottis- covers trachea• Larynx- contains vocal cords or “voice

box”

Cont.• Coughing reflex- triggered when “stuff” hits

vocal cords,

• “cough”-glottis is closed and pressure built up in lungs until glottis is suddenly released

• Tension on vocal cords determines pitch

• Trachea- extends from larynx to branching of bronchi, includes rings of cartilage for support

More• Tracheostomy- inserting a tube through

anterior tracheal wall. “Stoma”

• Bronchi- branching of trachea into primary, secondary and tertiary branches

• Bronchioles- when cartilage is no longer present ( less than 0.04 inch in diameter)

Alveola

• Sack where gas exchange occurs

• Trivia- 150 million alveola / lung

• Gives spongy appearance to lung

• Simple squamous epithelium

• Dust cells- macrophages that roam around eating up dust and debri

• Moist alveoli- why?

• Surfactant- oily secretion that reduces surface tension of moist alveoli

Air movement

• Hypoxia- hypo- low, oxia-?

• Anoxia-?

• Pulmonary ventilation depends on– Pressure gradient-?– Diaphragm- 75% of pulmonary vent.– Rib cage- 25% of pulmonary vent.

Lung volume/ capacity

• Tidal volume- amount of air moved during a single respiratory cycle, normal breath

• Expiratory reserve volume- ( forced exhalation volume) amount voluntarily expelled after a regular exhalation

• Inspiratory reserve volume- (forced inhalation volume) amount voluntarily inhaled after a regular inhalation

• Vital capacity= tidal volume+ERV+IRV, max air you can move

Residual volume- air left in lung even after forceful exhalation