1. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Chapter 22 The Respiratory System Part A

2. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Respiratory System  Consists of:  The respiratory zone  The conducting zone  Respiratory zone:  Site of gas exchange  Consists of:  Bronchioles  Alveolar ducts  Alveoli

3. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Respiratory System  Conducting zone:  Passageways for air to reach gas exchange sites  Includes all respiratory structures other than the resp. zone’s  They include nose, nasal cavity, pharynx, trachea  Respiratory muscles:  Diaphragm  Other muscles (intercostal) that promote breathing  Part of the muscular system PLAY InterActive Physiology ®: Anatomy Review: Respiratory Structures, page 3

4. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Respiratory System Figure 22.1

5. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Major Functions of the Respiratory System  Supply the body with oxygen  Dispose off carbon dioxide  In respiration, four distinct processes must happen:  Pulmonary ventilation:  Moving air into and out of the lungs  External respiration:  Gas exchange between the lungs and the blood

6. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Major Functions of the Respiratory System  Transport:  Transport of O 2 & CO 2 between the lungs and tissues  Internal respiration:  Gas exchange between systemic blood vessels and tissues

7. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Function of the Nose  The only externally visible part of the respiratory system that functions by:  Providing an airway for respiration  Moistening and warming the entering air  Filtering inspired air and cleaning it of foreign matter  Serving as a resonating chamber for speech  Housing the olfactory receptors

8. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structure of the Nose  The nose is divided into two regions:  External nose  Internal nasal cavity

9. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structure of the Nose Figure 22.2b

10. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Nasal Cavity (cont’d)  Lies in and posterior to the external nose  Is divided by a midline nasal septum  Opens posteriorly into the nasal pharynx via internal nares  The ethmoid and sphenoid bones form its roof  The floor is formed by the hard and soft palates

11. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Nasal Cavity (cont’d)  Vestibule:  Nasal cavity superior to the nares  Vibrissae:  Hairs that filter coarse particles in inspired air  The rest of the nasal cavity is lined with two types of mucosa:  Olfactory mucosa  Lines the superior nasal cavity  Contains smell receptors

12. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Nasal Cavity (cont’d)  Respiratory mucosa  Lines the balance of the nasal cavity  Pseudostratified columnar epithelium  With scattered goblet cells.  Below the mucosa, the lamina propria is richly supplied with:  Mucous glands:  Secrete mucus  Serous glands:  Secrete watery fluid containing enzymes

13. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Nasal Cavity (cont’d)  Mucus helps trap:  Dust  Debris  Bacteria  Mucus contains:  A lysozyme (antibacterial enzyme) that destroys bacteria.  Epithelial cells of respiratory mucosa secrete:  Defensins (natural antibiotics)

14. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Nasal Cavity Figure 22.3b

15. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Nasal Cavity (cont’d)  Inspired air is:  Humidified by:  The high water content in secreted mucus  Warmed by:  The rich plexuses of capillaries  Ciliated cells remove contaminated mucus to:  Pharynx (to be swallowed), then goes to  Stomach (to be digested)

16. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Nasal Cavity (cont’d)  There are three mucosa-covered projections on nasal cavity  They protrude from each lateral wall of the nasal cavity  They include:  Superior conchae  Middle conchae  Inferior conchae

17. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Nasal Cavity (cont’d)  They nasal conchae :  Increase mucosal area  Enhance air turbulence  Help filter air  Sensitive mucosa triggers:  Sneezing reflex when stimulated by:  irritating particles

18. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Functions of the Nasal Mucosa and Conchae  During inhalation the conchae and nasal mucosa:  Filter air  Heat air  Moisten air  During exhalation these structures:  Reclaim both heat and moisture  Thus, minimizing heat and moisture loss

19. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Paranasal Sinuses  Cavities in bones that surround the nasal cavity  Include:  Frontal  Sphenoid  Ethmoid  Maxillary  Functions of sinuses:  Lighten the skull  Help (with nasal cavity) warm & moisten air

20. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Pharynx  Funnel-shaped tube of skeletal muscle that connects to the:  Nasal cavity and mouth superiorly  Larynx and esophagus inferiorly  Extends:  From the base of the skull  To the level of the 6 th cervical vertebra

21. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Pharynx  It is divided into three regions  Nasopharynx  Oropharynx  Laryngopharynx

22. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Nasopharynx  Lies:  Posterior to the nasal cavity  Inferior to the sphenoid  Superior to the level of the soft palate  Strictly an air passageway  Lined with pseudostratified columnar epithelium

23. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Nasopharynx  Closes during swallowing to prevent food from entering the nasal cavity  The pharyngeal tonsil lies high on the posterior wall  Pharyngotympanic (auditory) tubes open into the lateral walls

24. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Oropharynx  Extends inferiorly:  From the level of the soft palate  To the epiglottis  Opens:  To the oral cavity  Via an archway called the fauces  Serves as:  A common passageway for food and air

25. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Oropharynx (cont’d)  The epithelial lining is:  Protective stratified squamous epithelium  Palatine tonsils lie:  In the lateral walls of the fauces  Lingual tonsil:  Covers the base of the tongue

26. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Laryngopharynx  Serves as:  A common passageway for food and air  Lies:  Posterior to the upright epiglottis  Extends:  To the larynx, where the respiratory and digestive pathways diverge

27. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Larynx (Voice Box)  Attaches to the hyoid bone  Opens into the laryngopharynx superiorly  Continuous with the trachea posteriorly  The three functions of the larynx are:  To provide a patent airway  To act as a switching mechanism (routes air and food into the proper channels)  To produce voice

28. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Framework of the Larynx  Cartilages of the larynx:  Thyroid (hyaline) cartilage (single) :  Anterosuperior shield-shaped  With a midline laryngeal prominence (Adam’s apple)  Cricoid (hyaline) cartilage (single) :  Anteroinferior ring–shaped  Three pairs of small (hyaline) cartilages:  Arytenoid, cuneiform, and corniculate cartilages  Epiglottis (single):  Elastic cartilage  Covers the laryngeal inlet during swallowing

29. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Framework of the Larynx Figure 22.4a, b

30. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Vocal Ligaments  Attach the arytenoid cartilages to the thyroid cartilage  Composed of elastic fibers that form mucosal folds called true vocal cords  The medial opening between them is the glottis  They vibrate to produce sound as air rushes up from the lungs  False vocal cords  Mucosal folds superior to the true vocal cords  Have no part in sound production

31. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Trachea  Flexible and mobile tube  Extends:  From the larynx  Into the mediastinum  Composed of:  Mucosa, submucosa, & adventitia  Adventitia:  Outermost layer  Made of C-shaped rings of hyaline cartilage

32. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Trachea Figure 22.6a