2. RESPIRATORY SYSTEM
Dr Iram Tassaduq

3. INTRODUCTION
The respiratory system consists of paired lungs and a series of air passages that lead to and from the lungs

4. PORTIONS OF RESPIRATORY SYSTEM
Air passages of respiratory system consist of two portions
Conducting portion
Respiratory portion

5. FUNCTIONS Air conduction Air filtration Gas exchange Speech production
Immune response
Endocrine function

6. NASAL CAVITY
Nasal cavities are paired chambers separated by bony and cartiliginous septum.
Chambers are divided into 3 regions
Vestibule
Respiratory segment
Olfactory segment

7. VESTIBULES
The vestibules (the first ~1.5 cm of the conductive portion following the nostrils) are lined with a keratinised stratified squamous epithelium. Hairs, which filter large particulate matter out of the airstream, and sebaceous glands are also present

8. RESPIATORY SEGMENT
At the transition from the vestibule to the respiratory region of the nasal cavity the epithelium becomes first stratified squamous and then pseudostratified columnar and ciliated. This type of epithelium is characteristic for all conductive passages dedicated to the respiratory system and therefore also called respiratory epithelium. Mucus producing goblet cells are present in the epithelium.

9. CELLS OF RESPIRATORY SEGMENT
Ciliated cells
Goblet cells
Brush cells
Small granule cells
Basal cells

11. CELLS OF OLFACTORY EPITHELIUM

12. FUNCTIONS OF OLFACTORY EPITHELIAL CELLS
OLFACTORY CELLS
The cell membrane covering the surface of the cilia contains olfactory receptors which respond to odour-producing substances, odorants, dissolved in the serous covering the epithelium
SUSTENTACULAR CELLS .
The olfactory cells and their processes receive mechanical and metabolic support from supporting cells
BASAL CELLS
can divide and differentiate into either olfactory or supporting cells.
BRUSH CELLS
Columnar cells with microvilli and are specialized for transduction of general sensation on

13. OLFACTORY GLANDS
The supporting cells and the secretion of the serous glands contain lipofuscin granules, which give a yellow-brown colour to the surface of the olfactory region.

15. LARYNX The wall of the Larynx consists of : Mucosa
Poorly defined submucosa
A series of irregularly shaped cartilages connected by joints of relatively dense fibroelastic tissue.
A group of intrinsic skeletal muscles which act upon the cartilages.

18. LAYERS OF LARYNX

20. TRACHEA
Short, flexible, air tube
2.5 cm
10 cm long
Extent
Function

21. TRACHEA Typical respiratory epithelium -
The lamina propria - contains large amounts of elastin and aggregates of lymphoid tissue (BALT).
The submucosa - contains mucous glands.
C-shaped rings of hyaline cartilage - provide a semirigid supporting skeleton outside the submucosa to prevent collapse of the airway during inspiration.
The adventitia - outermost fibroelastic connective tissue layer.

24. TRACHEAL EPITHELIUM

25. CELLS OF RESPIRATORY EPITHELIUM

26. BRUSH CELL

27. SMALL GRANULE CELL

28. LAYERS OF TRACHEA

29. LAYERS OF TRACHEA

31. Thank You