The Respiratory System

1. 22 The Respiratory System

2. I. The Respiratory System A. Basic functions of the respiratory system 1. supplies body with oxygen 2. disposes of carbon dioxide B. Four processes involved in respiration ► Pulmonary ventilation – move air in and out ► External respiration – transport of gases in lungs ► Transport of respiratory gases – movement through blood ► Internal respiration – transport of gases in tissues

3. II. Anatomy of the Respiratory System A. Respiratory organs 1. Nose, nasal cavity, and paranasal sinuses 2. Pharynx, larynx, and trachea 3. Bronchi and smaller branches 4. Lungs and alveoli B. Conducting zone 1. respiratory passageways that convey air 2. filter, humidify, and warm incoming air C. Respiratory zone 1. site of gas exchange in the lungs 2. includes structures that have alveoli

4. Oral cavity Nasal cavity Pharynx Nostril Left main(primary)bronchus Larynx Trachea Bronchi Carina oftrachea Alveoli Right main(primary)bronchus Left lung Diaphragm Right lung Parietalpleura

5. Oral cavity Pharynx Left main(primary)bronchus Bronchi Alveoli Left lung Diaphragm

6. Oral cavity Pharynx Left main(primary)bronchus Bronchi Alveoli Left lung Diaphragm

8. III. The Nose A. Functions ► Provides an airway for respiration ► Moistens and warms air ► Filters inhaled air ► Resonating chamber for speech ► Houses olfactory receptors B. Size variation due to differences in nasal cartilages C. Skin of nose is thin and contains many sebaceous glands

9. Frontal bone Nasal bone Septal cartilage Root and bridgeof nose Maxillary bone(frontal process) Lateral process ofseptal cartilage Dorsum nasi Ala of nose Minor alar cartilages Apex of nose Dense fibrousconnective tissue Naris (nostril) Major alarcartilages Philtrum Surface anatomy External skeletal framework

10. Cribriform plateof ethmoid bone Frontal sinus Sphenoidal sinus Nasal cavity Nasal conchae(superior, middle,and inferior Nasopharynx Pharyngeal tonsil Nasal meatuses(superior, middle,and inferior) Opening ofpharyngotympanictube Nasal vestibule Uvula Nostril Oropharynx Hard palate Palatine tonsil Soft palate Isthmus of thefauces Tongue Lingual tonsil Laryngopharynx Hyoid bone Larynx Epiglottis Vestibular fold Thyroid cartilage Esophagus Vocal fold Cricoid cartilage Trachea Thyroid gland Illustration

11. IV. The Nasal Cavity A. External nares – the nostrils B. Divided by nasal septum C. Continuous with nasopharynx D. Olfactory mucosa 1. Near roof of nasal cavity 2. Houses olfactory (smell) receptors E. Respiratory mucosa 1. Lines nasal cavity 2. Epithelium is pseudostratified ciliated columnar

12. F. The Nasal Conchae 1. project medially from the lateral wall of the nasal cavity 2. superior and middle nasal conchae - part of the ethmoid bone 3. inferior nasal conchae - separate bone ► particulate matter - deflected to mucus-coated surfaces ► during inhalation - filter, heat, and moisten incoming air ► during exhalation - moisture and heat are reclaimed G. The Nasal Meatuses – passageway of air through conchae

13. Nasal cavity Nasal conchae(superior, middle,and inferior Nasal meatuses(superior, middle,and inferior) Uvula Nostril Hard palate Soft palate Tongue Hyoid bone Larynx Esophagus Trachea Illustration

14. VI. Paranasal Sinuses A. Sinuses open into nasal cavity B. Paranasal sinuses are located within: ► frontal sinus in the frontal bone ► maxillary sinuses in the maxillary bones ► sphenoid sinus in the sphenoid bone ► ethmoid sinus in the ethmoid bone

15. Cribriform plateof ethmoid bone Frontal sinus Sphenoidal sinus Nasal conchae(superior, middle,and inferior Nasal meatuses(superior, middle,and inferior) Uvula Nostril Hard palate Soft palate Tongue Hyoid bone Larynx Esophagus Trachea Illustration

16. VII. The Pharynx A. Funnel-shaped passageway B. Connects nasal cavity and mouth C. Divided into three sections by location ► nasopharynx ► oropharynx ► aryngopharynx D. The tonsils – lymphatic tissue ► pharyngeal tonsil (adenoids) ► palatine tonsil ► linguil tonsil

17. Nasopharynx Oropharynx Laryngopharynx Larynx Trachea Illustration

18. Nasal cavity Nasal conchae(superior, middle,and inferior Nasopharynx Pharyngeal tonsil Nasal meatuses(superior, middle,and inferior) Nasal vestibule Uvula Nostril Oropharynx Hard palate Palatine tonsil Soft palate Tongue Lingual tonsil Laryngopharynx Hyoid bone Larynx Esophagus Trachea Illustration

19. Nasal cavity Nasal conchae(superior, middle,and inferior Nasal meatuses(superior, middle,and inferior) Nasal vestibule Nostril Hard palate Soft palate Tongue Lingual tonsil Hyoid bone Larynx Illustration

20. Illustration

21. VIII. The Nasopharynx A. Superior to the point where food enters B. Only an air passageway C. Closed off during swallowing D. Uvula (tiny “punching bag”) reflects superiorly E. Is continuous with nasal cavity F. Pharyngeal tonsil (adenoids) 1. located on posterior wall 2. Destroys entering pathogens G. Opening to the pharyngotympanic tube (auditory tube)

22. IX. The Oropharynx A. Archlike entranceway – fauces (arch in back of mouth) 1. Extends from soft palate to the epiglottis B. Two types of tonsils in the oropharynx 1. Palatine tonsils—in the lateral walls of the fauces 2. Lingual tonsils—cover the posterior surface of the tongue

23. X. The Laryngopharynx A. Passageway for both food and air B. Continuous with the esophagus and larynx C. Extends to inferior boundary of cricoid cartilage

24. XI. The Larynx A. Attaches to hyoid bone superiorly 1. opens into laryngopharynx B. Routes air and food into the proper channels ► voice production ► provides an open airway ► closed during swallowing ► open during breathing C. Sphincter function of the larynx - Valsalva’s maneuver—straining D. Framework is arrangement of nine cartilages

25. E. 9 sements of cartilage • 1. unpaired - thyroid, epiglottic, cricoid • 2. paired - arytenoid, corniculate, cuneiform • a. thyroid cartilage (Adam's apple) • b. epiglottis - covers larynx to route food • glottis - vocal folds (cords) for sound • c. cricoid cartilage - attaches larynx to trachea • d. arytenoid cartilage - attached to vocal folds

26. F. Voice Production • 1. ventricular folds (false cords) • a. hold breath against thoracic air pressure • b. vocal cords (true cords) • i. vibrate to produce different frequencies • 2. pharynx, mouth, sinuses, nose, tongue, lips • i. modify the sound

27. Epiglottis Thyrohyoidmembrane Body of hyoid bone Thyroid cartilage Laryngeal prominence(Adam’s apple) Cricothyroid ligament Cricoid cartilage Cricotracheal ligament Trachealcartilages Anterior view

28. Epiglottis Thyrohyoidmembrane Body of hyoid bone Thyrohyoid membrane Cuneiform cartilage Fatty pad Vestibular fold(false vocal cord) Corniculate cartilage Arytenoid cartilage Thyroid cartilage Arytenoid muscle Vocal fold(true vocal cord) Cricoid cartilage Cricothyroid ligament Cricotracheal ligament Tracheal cartilages Sagittal section (anterior on the right)

29. Body of hyoid bone Laryngeal prominence(Adam’s apple) Cricoid cartilage Sternal head Sterno-cleidomastoid Clavicular head Clavicle Jugular notch Surface view

30. Epiglottis Hyoid bone Thyrohyoidmembrane Corniculate cartilage Arytenoid cartilage Thyroidcartilage Cricoid cartilage Glottis Tracheal cartilages Photograph of cartilaginous framework of the larynx,posterior view

31. Anterior Thyroid cartilage Cricoid cartilage Vocal ligamentsof vocal cords Glottis Lateralcricoarytenoid muscle Arytenoid cartilage Corniculate cartilage Posteriorcricoarytenoid muscle Posterior Epiglottis Vestibular fold (false vocal cord) Vocal fold (true vocal cord) Glottis Inner lining of trachea Cuneiform cartilage Corniculate cartilage Vocal folds in closed position; closed glottis Vocal folds in open position; open glottis

32. XII. The Trachea A. Descends into the mediastinum B. C-shaped cartilage rings keep airway open C. Carina - marks where trachea divides into two primary bronchi D. Lined with pseudostratified ciliated eipthelium

33. Mucosa Posterior Pseudostratifiedciliated columnarepithelium Lamina propria(connective tissue) Esophagus Submucosa Trachealis Seromucous glandin submucosa Lumen oftrachea Hyaline cartilage Adventitia Anterior Cross section of the tracheaand esophagus Photomicrograph of the trachealwall (320) Scanning electron micrograph of cilia in the trachea (2500)

34. XIII. Bronchi in the Conducting Zone A. Bronchial tree ► Primary bronchi (main) ► Secondary bronchi (lobar) [2 on right; 3 on left] ► Tertiary bronchi (segmental) ► Bronchioles (less than 1 mm in diameter ► Terminal bronchioles (less than 0.5 mm in diameter) B. Epithelium changes: 1. initially is pseudostratified ciliated columnar 2. replaced by simple columnar, then simple cuboidal epithelium

35. D. Smooth muscle becomes important 1. airways widens with sympathetic stimulation 2. airways constricts under parasympathetic direction

36. Trachea Superior lobeof right lung Superior lobeof left lung Left main(primary)bronchus Lobar(secondary)bronchus Segmental(tertiary)bronchus Inferior lobeof left lung Inferior lobeof right lung Middle lobeof right lung The branching of the bronchial tree

37. XIV. The Respiratory Zone A. Consists of air-exchanging structures B. Respiratory bronchioles 1. gas exchange occurs where smooth muscle is absent 2. branch from terminal bronchioles ► lead to alveolar ducts ► lead to alveolar sacs C. Alveoli 1. about 400 million alveoli - huge surface area for gas exchange 2. Surface area = 1500 square feet (~140 square meters)

38. Alveoli Alveolar duct Respiratorybronchioles Alveolar duct Alveolar sac Terminalbronchiole

39. Respiratorybronchiole Alveolarpores Alveolarduct Alveoli Alveolarsac

40. XV. Alveoli A. Structure of alveoli 1. type I alveolar cells a. single layer of simple squamous epithelial cells 2. Respiratory membrane - alveolar and capillary walls 3. type II alveolar cells a. are scattered among type I alveolar cells b. are cuboidal epithelial cells c. secrete surfactant - reduces surface tension within alveoli

41. B. Alveolar macrophages 1. remove tiniest inhaled particles 2. migrate into bronchi a. ciliary action takes alveolar macrophages to pharynx C. Features of alveoli 1. surrounded by elastic fibers 2. interconnect by way of alveolar pores 3. internal surface – site for movement of alveolar macrophages

42. Terminal bronchiole Respiratory bronchiole Smoothmuscle Elastic fibers Alveolus Capillaries Diagrammatic view of capillary-alveoli relationships

43. Scanning electron micrograph of pulmonary capillary casts.Tissue forming the alveoli has been removed, leaving only thecapillary network (300).

44. Red bloodcell Nucleus of type Ialveolar cell Alveolar pores Capillary O2 Capillary CO2 Macrophage Alveolus Endothelial cell nucleus Alveolus Alveolar epithelium Respiratorymembrane Fused basement membranesof the alveolar epitheliumand the capillary endothelium Capillary endothelium Alveoli (gas-filledair spaces) Red blood cellin capillary Type II alveolar cell(surfactant-secreting) Type Ialveolar cell Detailed anatomy of the respiratory membrane

45. Alveolar changes in emphysema SEM of alveolifrom the lung of apatient withemphysema (25) SEM of alveolifrom a normallung (25)

46. XVI. Gross Anatomy of the Lungs A. Major landmarks of the lungs 1. Apex - superior tip of lung 2. Base - concave inferior surface 3. Hilum - indentation on mediastinal surface a. location where blood vessels, bronchi, and nerves enter and exit the lung 4. Root - structures that enter and leave the lung at the hilum a. blood vessels, bronchi, and nerves

47. B. Left lung 1. superior and inferior lobes 2. 1 fissure - oblique 3. cardiac notch - the depression that accommodates the heart C. Right lung 1. Superior, middle, and inferior lobes 2. 2 fissures - oblique and horizontal

48. superior lobe Superior lobe Oblique fissure Oblique fissure Horizntal fissure Inferior lobe Middle lobe Inferior lobe Left lung Right lung Distribution of bronchiopulmonary segments on lateral surface of lungs

49. Intercostal muscle Rib Parietal pleura Lung Pleural cavity Visceral pleura Trachea Thymus Apex of lung Leftsuperior lobe Right superior lobe Obliquefissure Horizontal fissure Left inferiorlobe Right middle lobe Oblique fissure Right inferior lobe Heart(in mediastinum) Diaphragm Cardiac notch Base of lung Anterior view. The lungs flank mediastinal structures laterally.

50. Apex of lung Pulmonary artery Left mainbronchus Leftsuperior lobe Obliquefissure Pulmonaryvein Left inferiorlobe Impressionof heart Hilum Obliquefissure Aortic impression Lobules Photograph of medial view of the left lung