The document provides an overview of the human respiratory system, including its key structures and functions. It discusses the five main steps of respiration: ventilation, external respiration, circulation, internal respiration, and cellular respiration. The major structures involved are the nose, pharynx, larynx, trachea, lungs, and bronchial tree. The document also covers respiratory air volumes and capacities, neural control of breathing, and nonrespiratory air movements like coughing and sneezing.
5. 5
Steps of respiration
• Movement of air in and out of lungs (ventilation).
• Exchange of O2 and CO2 in the lungs between air
spaces and blood (external respiration).
• Transport of O2 and CO2 in the bloodstream
(circulation).
• Exchange of O2 and CO2 between blood and
cells (internal respiration)
• Use of O2 and production of CO2 (cellular
respiration).
6. 6
Structures of the respiratory
system
• Nose/mouth
• Pharynx
• Larynx
• Trachea
• Lungs/bronchial tree
7. 7
Nose
• Nasal cavity lined with mucous membrane which is rich
in goblet cells that secrete mucus.
• Olfactory receptors for the sense of smell
• Air that is breathed in...
• air is warmed
• air is moistened
• particles are trapped (cilia beats toward the
pharynx... why?)
9. 9
Sinuses
• Air-filled spaces within bones of the skull
• Reduce weight and add resonance to the voice
• frontal
• maxillary
• sphenoid
• ethmoid
• Why do people have sinus problems?
10. 10
Pharynx
• Throat
• Posterior to the nasal cavity and oral cavity
• Three parts:
• nasopharynx/oropharynxlaryngopharynx
• Dual passageway for:
• air into the larynx
• food into the esophagus
11. 11
Larynx
• Passageway for air into the trachea.
• Composed of cartilages and muscles... and
houses the vocal cords (vocal folds of tissue)
• Thyroid cartilage: Adam’s Apple (why named?)
• Epiglottis... function?
24. 24
Drug addiction: Smoking...
• #1 preventable cause of death!
• Cilia slowed/paralyzed/destroyed
• excess mucus clogs airways (decreased air intake and increased
infections)
• bronchial lining thickening, decrease elasticity of airways
• coughing ruptures alveolar sacs
• emphysema (15x nonsmokers)
• lung cancer (80% due to smoking)
• heart disease/stroke
• Addiction due to nicotine
• Many changes are reversible if a person quits...
25. 25
Environmental tobacco
smoke (ETS)
• Second-hand smoke
• 4000 chemicals in cigarette smoke
• Estimated 53,000 nonsmokers die each year in
the US from ETS
• (46,000 heart disease, 3,400 lung cancer, 2-
3,000 infant deaths...)
• In areas where new laws ban smoking in bars,
restaurants, and workplaces, hospital admission
for heart attacks have dropped 20%!
