Maintenance of the Body
Unit 4: The Respiratory System
Unit outline
Part 1: Anatomy of the Respiratory System
- Conducting zone
- Respiratory zone
- The Lungs
Part 2: The Process of Breathing – Pulmonary Ventilation
- Pulmonary ventilation
- Nervous control of ventilation
- Factors that affect the rate and depth of ventilation
- Respiratory volumes and capacities
Part 3: Gas Exchange
- External respiration
- Internal respiration
Part 4: Transport of Gases
- Oxygen transport in blood
- Factors affecting oxygen dissociation from hemoglobin
- Carbon dioxide transport in the blood
Part 5: Modifications in Respiratory Functions
- Hyperventilation
- Hypoxia
Learning Objectives
At the end of this unit, you should be able to:
I. Describe the location and function(s) of the major components of the human respiratory system.
II. Explain the mechanism of ventilation (inspiration and expiration) in humans, including the roles of the structures involved.
III. Describe the nervous control of breathing.
IV. Describe how carbon dioxide, oxygen and hydrogen ions control the rate of breathing.
V. Interpret a spirogram and define the respiratory volumes and capacities a spirogram depicts.
VI. Explain the basic principle governing the reciprocal exchange of gases between the alveoli and the blood, and between the blood and individual cells.
VII. Describe the mechanisms by which oxygen and carbon dioxide are transported in the blood.
VIII. Define hyperventilation and specify some of its causes and physiological consequences.
IX. Define hypoxia and specify some of its causes and physiological consequences.
Learning Objectives and Guiding Questions
At the end of this unit, you should be able to complete all the following tasks, including answering the guiding questions associated with each task.
I. Describe the location and function(s) of the major components of the human respiratory system.
- Draw a series of fully-annotated diagrams showing the structure of the respiratory system. Include the location, general structure and function of all the following components:
- External nares
- Nasal cavity
- Internal nares
- Oral cavity
- Pharynx
- Epiglottis
- Glottis
- Larynx
- Trachea
- Bronchus
- Bronchiole
- Alveolus
- Visceral pleura
- Parietal pleura
- Pleural cavity
II. Explain the mechanism of ventilation (inspiration and expiration) in humans, including the roles of the structures involved.
- Describe the mechanism of pulmonary ventilation in humans, including a detailed description of the processes of quiet inspiration (inhalation) and quiet expiration (exhalation). Refer in your explanation to:
- The skeletal muscles required for quiet inhalation
- The two passive processes required for quiet exhalation
- Changes in the volume of the thoracic cavity at each step
- Changes in the intra-alveolar pressure at each step
- The direction of air travel at each step
III. Describe the nervous control of breathing.
- Describe how breathing is modulated by the nervous system, m