1. The Respiratory System
Explain the gross anatomy and functions of the respiratory system.
Discuss the structure and functions of the upper and lower respiratory tracts in detail, including a description of the histology in each region.
Identify the pleural cavities, its membranes and the muscles of ventilation.

2. Respiratory System Function
Major Functions
Upper respiratory system:
Air conditioning
Defense against pathogens
Lower respiratory system:
Speech & other respiratory sounds
Gas exchange
Maintenance of homeostasis, e.g. pH
Fig 24-1

3. Respiratory Epithelium
Mucus escalator
Structure?
Mucus produced by ________
Defense by means of
filtering hairs
ciliary escalator
sticky mucous

4. Nasal Conchae Superior, middle and inferior
Other name: “Turbinate bones” because they create ______
Advantage ?
! Respirator breathing !
Fig 24.3
Conchae moistening by large surface area of conchae

5. Upper Respiratory System
1) Nose
external and internal nares
turbinates or conchae (superior, middle, and inferior)
nasal septum
hard palate
2) Pharynx - shared passageway for respiratory and digestive systems
nasopharynx - part above uvula and posterior to internal nares
oropharynx – portion visible in mirror when mouth is wide open
uvula - posterior edge of soft palate
laryngopharynx – between the hyoid bone & the esophagus
Fig 24.3c

6. Lower Respiratory SystemC3 C4
Anything below Pharynx
Larynx: Cartilaginous cylinder (from C4- C7) 
Made up of 9 cartilages
– 3 large unpaired (know these!)
– 3 small paired (involved in construction of voice box
Stabilized by ?? C5 C6 C7
Fig 24.4

7. Trachea Passageway to lungs (attached via ligament to ?) Lining ?
Incomplete cartilage rings (C- shaped) - completed by trachealis muscle. Significance?
Annular ligament
Fig 24-7

8. Tracheal Blockage Heimlich Maneuver or abdominal thrust or
Tracheostomy

9. From Bronchi to Lungs
Fig 24.9
1 bronchi (enter lungs at hilus, complete cartilage rings)
2 bronchi (from now on cartilage plates)
3 bronchi
Bronchioles
Terminal bronchioles
Respiratory bronchioles
Alveolar ducts
Alveolar sacs
Conducting portion
Fig 24.11
Respiratory portion

10. Paired Lungs Situated in _________
Subdivided into lobes (each supplied by 2 bronchus)
Right lung: 3 lobes (rel. broad and short)
Left lung: 2 lobes (long and narrow)
Right and left lung separated by __________
Lung hilus
Fig 24-8
Why?
Fig 24-8

11. Alveolar Organization
Alveoli are site of gas exchange
Close association with capillaries
Lots of elastic fibers in alveolar wall
Alveolar cells
Type I cells – respiratory epitheliocytes
Type II cells – septal cells – produce surfactant
Alveolar Macrophages – dust cells – phagocytic
Fig 24-11
Fig 24-12

12. Respiratory Membrane Different from respiratory epithelium
Super thin. Made up of 4 layers:
epithelium of alveolus
its basement membrane back to back and fused to the
basement membrane of capillary endothelium
endothelium of capillary

13. Emphysema
Chronic progressive enlargement of alveoli accompanied by destruction of their wall
Due to prolonged exposure to respiratory irritants (??)

15. Pleural Cavities and Membranes
Two cavities separated by mediastinum
Lining of cavities?
pleurisy
Pneumothorax
Conducting blood supply to the lungs via bronchial arteries. Venous return to pulmonary veins (consequence ?)
Fig 24-13

16. Pulmonary Embolism Causes for development of emboli in veins of legs:
See p. 805
Causes for development of emboli in veins of legs:
Immobilization
Trauma
Long surgeries
Oral contraceptives
Obesity
Cigarette smoking
Hypertension

17. Respiratory Muscles Diaphragm: depresses  inhalation
External intercostals: elevate ribs  inhalation
Internal intercostals: depress ribs  active exhalation
Accessory muscles - serratus anterior, scalenes, pectoralis minor, sternocleidomastoid, internal and external obliques, transverse abdominus, rectus abdominus
Fig 24-14

18. the end