1. Chapter 17
Respiratory System

2. Objectives Describe the functions of the respiratory system
Describe the structures and functions of the
organs of respiration
Explain the breathing and respiratory process
Discuss how breathing is controlled by neural
and chemical factors
Discuss respiratory disorders
Define the key words that relate to this chapter

3. Respiratory System Functions
Exchange of oxygen and carbon dioxide
Production of sound
Respiration
External respiration
Internal respiration
Cellular respiration or oxidation

4. Respiratory Organs and Structures
Nasal cavity
Pharynx
Larynx
Trachea
Bronchi
Bronchioles
Alveoli
Lungs
Pleura
Mediastinum

5. The Nasal Cavity Anterior nares or nostrils Nasal septum
Turbinates or nasal conchae bones
Cilia
Olfactory nerve
Sinuses

6. The Pharynx Also called the throat Common passageway for food and air
Subdivided
Nasopharynx
Oropharynx
Laryngopharynx
Epiglottis

9. The Larynx Also called voice box Nine fibrocartilaginous plates
Mucous membrane
Glottis

11. The Trachea Also called windpipe Hyaline cartilage
Mucous membrane and ciliated epithelium

12. The Bronchi and the Bronchioles
Right and left bronchus
Bronchi subdivide into bronchioles
Alveolar sacs (alveoli)

14. The Alveoli Sacs of single layer epithelial tissue
Surrounded by bed of capillaries
Surfactant
Exchange of oxygen and carbon dioxide

16. The Lungs Separated by the mediastinum and the heart
Apex is top of each lung; broad lower part is base
Base rests over the diaphragm
Right lung has three lobes; left lung has two lobes

18. The Pleura
A thin, moist, slippery membrane of tough endothelial cells that covers lungs
Each lung encased in double-walled sac
Two pleura membranes
Visceral or pulmonary pleura lines the lungs
Parietal pleura lines the wall of the thorax
Pleural fluid

21. The Mediastinum Also called the interpleural space
Located between the lungs
Contains the thoracic viscera

22. Mechanics of Breathing
Pulmonary ventilation is called breathing
Due to changes in pressure which occur within the chest cavity
Variation in pressure caused by cellular respiration and mechanical breathing movements

23. The Breathing Process Inhalation/inspiration Exhalation/expiration
Respiratory movements and frequency of respiration

24. Control of Breathing Neural factors
Respiratory center is located in the medulla oblongata in
the brain
During inflation, the nerve endings in the walls are
stimulated sending a message to the medulla by way of
the vagus nerve, inhibiting inspiration and stimulating
expiration

25. Controls of breathing Chemical factors
Dependent upon the level of carbon dioxide in the blood
Respiratory center senses the increased carbon dioxide in
the blood and increases the respiratory rate

26. Lung Capacity and Volume
Tidal volume
Amount of air that moves in and out of the lungs with
each breath (normal amount is about 500ml)
Residual volume
Amount of air that cannot be voluntarily expelled from
the lungs
Allows for continuous exchange of gases between breaths
Normal residual volume is 1,500 ml