The Structure-Function Relationship of the Lung of the Australian Sea Liont Neophoc e clnerea by Anthony Nicholson B.V.Sc. A thesis submitted for the degree of Doctor of PhilosoPhY' Department of PathologY' UniversitY of Adelaide February 1984 Frontispiece: Group of four adull female Australian sea lions basking in the sun at Seal Bay, Kangaroo Island. ËF:æ: oo',,, 'å¡ -*-d, l--- --a - .¡* É--- .-\tb.<¡- <} b' \ .ltl '' 4 qÙ CONTENTS Page List of Figures X List of Tables xi Abstract XIV Declaration XV Acknowledge m ents I I. Introduction Chapter \ I I.I Classification of Marine Mammals I I.2', Distribution of Australian Pinnipeds 2 I.3 Diving CaPabilitY 3 PhYsiologY 1.4 Diving 4 Cardiovascular SYstem ' l'.4.I B I.4.2 OxYgen Stores 1l L.4.3 BiochemicalAdaPtations L3 I.4.4 PulmonarYFunction I.4.5 Effects oi Incteased Hydrostatic Pressure T6 l-8 1.5 SummarY and Aims 20 Chapter 2. Materials and Methods 20 ?.I Specimen Collection 2I 2.2 Lung Fixation 2I 2.3 Lung Votume Determination 22 2.4 Parasite Collection and Incubation 22 2.5 M icroscoPY 22 2.5.I Light MicroscoPY Electron Microscopy 23 2..5.2 Trãnsmission 23 2.5.3 Scanning ElectronMicroscopy 25 Chapter 5. Norm al ResPiratorY Structure 25 t.r Introduction 25 Mam maI Respiratory System 3.2 Terrestrial 25 1.2.I MacroscoPtc 27 3.2.2 MicroscoPic 27 SYstem 3.3 Pinniped ResPiratorY 27 3.3.I MacroscoPic 28 3.3.2 MicroscoPic 3I 3.4 Results 3I 1.4.L MacroscoPic 32 3.4.2 MicroscoPic 7B 3.5 Discussion 7B 3.5.I MacroscoPtc 79 3.5.2 MicroscoPic 92 3.6 SummarY IV Page Chapter 4. Lung MorphometrY 94 4.1 Introduction 94 4.2 Methods 97 4.2.I Basic Principles of Point Counting 9B 4.2.2 Sampling Design 9B 4.2.3 Animal and Regional Differences 110 4.2.4 Interspecies ComParisoq tt0 4.3 Results 1r.1 4.1.1 Species Results t1l_ 4.3.2 Animal and Regional Differences lll 4.3.3 Interspecies ComParison 119 4.4 D iscussion I23 4.4.1 Discussion of Methods r23 4.4.2 Discussion of Results 135 4.5 Summary 153 Chapter 5- PulmonarY PathologY D5 5.1 Introduction r55 5.2 Results D5 5.2.I Macroscopic b5 5.2.2 M icroscopic 15B r69 5.3 D iscuss ion 5.3.I In vitro develoPment r69 5.3.2 PathologY r69 170 5.4 Su mm ary Chapter 6. Discussion r7t 6.r Lung Structure r73 6.2 Lung MorphometrY L74 6.t Diving PhysiologY 175 6.J.I Aerobic Dive Limit 175 6.3.2 Bioche m istrY r77 6.3.3 Pulmonary Function r77 6.3.4 Increased Hydrostatic Pressure and Lung Collapse IB2 6.3..5 Nitrogen Absorption and Decompression Sickness tB5 6.4 Conclusion 187 6.5 Future Research r9l Bibliography 193 LIST OF FIGURES Page Figure t. Dorsal view of excised lungs and trachea 3B 3B 2. Ventral view of excised lungs and trachea 39 3. Laleral view of left lung 4. Lateral view of right lung 39 5. Macroscopic view of lung samPle 40 40 6. Low power light micrograph of lung sample 7. Light micrograph of junction between tertiary and lobular bronchi 4I B Higher power light micrograph of junction between tertiary and lobular bronchi 4I 9 scanning electron micrograph of junction between tertiary and lobular bronchi 41, 10. Transmission electron micrograph of transition region between tertiary and lobular bornchi 42 r1. Transmission electron micrograph of transition region 42 r2. Transmission electron micrograph of secretory cells in transition region 43 4J 13. High power transmission electron micrograph of secretory cell 44 14. Transmission electron micrograph of transition region 15. Transmission electron micrograph of non-secretory cells in transition region ¡ 44 16. Transmission electron micrograph of columnar ciliated cell in transition region 45 r7. Transmission electron micrograph of columnar microvillous cell 45 18. Transmission electron micrograph of migralory cell in transition region 46 19. Transmission electron micrograph of lobular bronchus 46 20. Transmission electron micrograph of cuboidal secretory microvillous cells 47 2I High power transmission electron micrograph of cuboidal secretory microvillous cells 47 22. High power transmission electron micrograph of cuboidal secretory micovillous cells 4B 2t. Scanning electron micrograph of lobular bronchus 4B 24. Transmission electron micrograph of lobular bronchus showing its relationshiP to an alveolus 49 49 25. Transmission electron micrograph of lobular bronchus 26. Transmission electron micrograph of columnar secretory microvillous cells in lobular bronchus 50 VI Page ?7. High power transmission electron micrograph of columnar secretory microvillous cells 50 2B High power transmission electron microqraph of apex of columnar secretory microvillous cell 5L 29. Transmission electron micrograph of lobular bronchus 51 30. Transmission electron microqraph of non-secretory microvillous cell ,2 3r. High power transmission electron micrograph of non-secretory microvillous cell 52. 32. Trançmission electron micrograph of non-microvillous cells 5t 33. Transmission electron micrograph of non-microvillous cells 5t 34. Scanning electron micrograph of cuboidal ciliated cell 54 35. Transmission electron micrograph of distal region of lobular bronchus 54 16. scanning electron micrograph of junction between tertiary and lobular bronchi 55 37. Light'micrograph of two adjacent acini 55 38. Light micrograph of terminal lobular bronchus 56 39. Light micrograph of lobular bronchus 56 40. Low power transmission electron micrograph of distal region lobular bronchus 57 4r. Transmission electron micrograph of submucosal mast cell 57 42. Diagram of parenchymal subdivisions 62 43. scanning electron micrograph of tung parenchyma with lobular bronchus 63 44. Scanning electron micrograph of lung parenchyma 63 45. Transmission electron micrograph of thick septum in parenchyma 64 46. Transmission electron micrograph of thick connective tissue septum 64 47. Transmission electron micrograph of thick septum containing a pulmonary venule 65 48. Scanning electron micrograph of alveoli 65 49. scanning electron micrograph of termination of lobular bronchus 66 50. Scanning electrôn micrograph of alveolar duct 66 51. scanning electron micrograph of alveolar duct and sac walls 67 52. Transmission electron micrograph of alveolar duct wall 67 53. Transmission electron micrograph of alveolar duct wall 6B 54. Transmission electron micrograph of alveolar sac wall 6B 55. Transmission electron micrograph of part of alveolar sac wall 69 vil Page 56. Transmission electron micrograph of alveoli showing alveolar 69 duct and sac walls 70 57. Transmission electron microqraph of alveolar septum 58. Higher power transmission electron micrograph of alveolar 70 septu m electron micrograph of alveolar type I epithelial 59. Transmission 7I cell 60. Transmission electron micrograph of alveolar type II epithelial 7L cell Scanningelectronmicrographofalveolarsurfaceshowingtypell 6r. 72 ce lls type 62. High power scanning electron micrograph of alveolar 72 II cells 13 63. Transmission electron micrograph of alveolar type II cells 64. Transmission electron micrograph of alveolar septum containing single capilìarY network 73 double 65. Transmission electron micrograph of alveolar septum rvith capillarY network 74 66. Transmissionelectronmicrographofalveolarseptumwithsingle 14 and double caPillarY networks 74 61. Transmission electron micrograph of alveolar septum 68. Transmissionelectronmicrographofalveolarseptumbetween adjacent alveolar sacs 15 69. Transmissionelectronmicrographofjunctionbetweenalveolar 15 septa from three alveoli 70. TransmissionelecLronmicrographofalveolarseptumwithtypel epithelial cell 75 electron micrograph of alveolar septum with 1L Transmission 15 "pseudo-single" capillary network 72. Transmissionelectronmicrographofalveolarseptumwithdouble capillary network 75 7t. Transmissionelectronmicrographofalveolarseptumwithdouble 75 capillarY network electron micrograph of alveolar septum with 74. Transmission 75 transeptal anastomosis 75. Transmissionelectronmicrographofalveolarseptumwithmixed capillarY networks 75 16. Transmission electron micrograph of double capillary alveolar 76 septu m 77. Highpoweltransmissionelectronmicrographofalveolarseptal 76 interstitiu m 17 78. Transmission electron microqraph of alveolar macrophage 71 19. Scanning electron micrograph of alveolar macrophage vlll Page 100 80. Diagram outlining four-level morphometric sampling design BI. Logarithmic scale used to determine harmonic mean barrier 100 th ickness r20 82. Allometric Plot of lunq volume 83. Allometric plot of alveolar surface area l_20 I2L 84. Allometric plot of capillary surface area T2I 85. Allometric plot of capillary volumer 86. Allometric plot of tissue harmonic mean thickness and I22 cap.illary load ing r22 81. Allometric plot of oxyqen diffusing capacity showing progressive means of perce-ntage of interacinar BB. Graph r26 septal volume occupied by respiratory surf ace 89. Graph showing progressive means of perce-ntage of interlobular septal volume occupied by respiri tory surf ace r27 interlobular 90 Graph showing the contribution of the interacinar and r"pi" to the total respiratory surface volume r29 respiratory 91. Graph showing progressive means of total proportion of rutf""" volume within the true parenchyma I29 92. Graphshowingprogressivemeansforcombinedvolumeporportion of single and ãouble capillary alveolar septa within the true l_10 parenchym a percentage of airspace 93. Graph showing progressive means of the tll volume within true ParenchYma of pulmonary parasites in 94 Diagram showing the distribution I6I Neophoca cinerea 16r 95. Macroscopic view of rostral portion of maxillary turbinates 16r 96. Macroscopic view of ethmoid turbinates Scanning