Module A2: Upper Airway Anatomy & Physiology

1. Module A2: Upper Airway Anatomy & Physiology

2. Objectives • Classify epithelial tissue based on cell type and tissue layers. • Identify location of tissue epithelium in the respiratory system. • Describe the major structures and functions of the upper and lower airways. • Contrast and compare mouth and nose breathing. • Explain how placing an endotracheal tube in the airway will affect the humidification and filtering process.

3. The lung is for gas exchange. John B. West Respiratory Physiology: The Essentials

4. Function of the Lungs/Heart • Provide Ventilation • Provide Respiration • Exchange of Carbon Dioxide and Oxygen • Humidify and Protect • Pump oxygen to vital organs • Cellular metabolism

5. Failure of the Lungs/Heart • Hypoxemia – low oxygen level in the blood • Decreased PaO2 • Hypoxia - low oxygen level at the tissue level • Decreased oxygen at the cellular level can cause death of the tissue • Presence of anaerobic respiration

6. Ventilation • Brain • Muscles • Lungs • Inability of the lungs to remove carbon dioxide leads to hypercarbia, which is an elevated amount of carbon dioxide in the blood stream (PaCO2)

7. ARTIFICIAL AIRWAYS INTUBATION

8. ARTIFICIAL AIRWAYS Tracheotomy with tracheostomy tube:1 - Vocal cords2 - Thyroid cartilage3 - Cricoid cartilage4 - Tracheal cartilages5 - Balloon cuff INTUBATION

9. Intubation – Insertion of an Endotracheal Tube Extubation– Removal of the Endotracheal Tube

10. Tissue Epithelium Upper Airway Lower Airway Site of Gas Exchange Pulmonary Vascular System Neural Control Lungs Mediastinum Thorax Muscles of Ventilation Anatomy of the Respiratory System

11. Four Tissue Types • Epithelial Tissue • Connective Tissue • Bone, Cartilage, Blood, Fibrous • Muscle Tissue • Nervous Tissue • Neurons conduct electrical impulses

12. Epithelial Tissue • Epithelium • Covers and protects the body surface • Lines body cavities • Forms many glands • Specializes in moving substances into and out of the blood

13. Epithelial Cell Type • Squamous Cells • Cuboidal Cells • Columnar Cells

14. HISTOLOGY 101 • Lots of Surface Area • aka Pavement, Sunny-side up egg • Great for Diffusion of Gases • Lots of Volume • Volume = Cytoplasm • Cytoplasm means metabolism • Less diffusion • Height is 2x Width • Usually associated with secretion or absorption of material • Very little diffusion

15. Classification of Epithelium by Layers • Simple Epithelium – Single Layer • Simple squamous • Simple cuboidal • Simple columnar • Stratified Epithelium – Multiple Layers • Pseudostratified – Single Layer but appears stratified • Pseudo means “false”

17. Goblet Cells • Nose to Large Bronchioles • Secrete mucus

18. Stratified Squamous Epithelium • Associated with PROTECTION • Anterior portion of nasal cavity • Oral cavity • Oropharynx • Laryngopharynx

19. Pseudostratified Columnar Epithelium • SECRETION OF AND SWEEPING OF MUCUS • Posterior 2/3 of nose • Tracheobronchial tree • Function of cilia

20. Simple Cuboidal Epithelium • PRIMARY FUNCTION IS SECRETION, FILTRATION & ABSORPTION • Bronchioles • Clara Cells • Non-ciliated cells that secrete “surface-active agents” which prevent collapse. • Simple Cuboidal also found in alveoli (Type II cells that secrete surfactant)

21. Simple Squamous Epithelium • PRIMARY FUNCTION – GAS EXCHANGE • Alveoli (Type I pneumocytes) • Pulmonary capillaries

22. Upper Airway • Anatomy • Nose • Oral Cavity • Pharynx • Throat

23. Upper Airway • Function of the Upper Airway • Conduct Air • To prevent foreign materials from entering the lower airway • Smell/Speech

24. Nose • Function • Heat, Humidify and Filter the incoming gas • Smell • Speech

25. Anatomy of the Nose • Bone and Cartilage • Partition in the nose is called the nasal septum • Air enters through the nostrils or nares • Two nasal passages are called choanae • Vibrissae filter the incoming gas • Whiskers • First 1/3 is stratified squamous epithelium (PROTECTION) • Posterior 2/3 is pseudostratified ciliated columnar epithelium (MUCUS SECRETION)

26. Anatomy of the Nose • Mucous secreting glands are found in the posterior 2/3 of nose • Bony Protrusions on the lateral wall are called nasal turbinates or conchae • Separate incoming gas into turbulent airstreams – more contact • Extensive capillary network • Constrict or dilate to change blood flow

27. Nasal Conchae

28. Deviated Septum • The nasal septum can be deviated to the right or left • More often to the left

30. Rhinitis: Inflammation of the nasal membrane 20% of Population $5.3 Billion/Year

31. Physiology of the Nose • Nose can filter particles down to 5 m (microns) in diameter • Two factors which decrease the humidification and filtering ability of the nose is: • Mouth Breathing • Placement of an ET (endotracheal) tube

32. Paranasal Sinuses • Empty air spaces found in the bones of the skull; Paired • Frontal • Ethmoid • Sphenoid • Maxillary • They contain mucous secreting goblet cells which drain into the nasal cavity

34. Nose and Nasal Cavities

36. Anatomy of the Oral Cavity • Roof of the mouth is formed by the hard and soft palate • Hard – Bony portion • Soft – Fleshy portion • Uvula is the soft fleshy structure • Epithelium is stratified squamous epithelium which is non-ciliated. • Palatine (faucial) tonsils are located on each side of the oral cavity.

37. TONSILS

39. Pharynx - Throat • Nasopharynx • Oropharynx • Laryngopharynx

40. Nasopharynx • Located posterior to nasal cavity • Pseudostratified ciliated columnar epithelium • Includes pharyngeal tonsils or adenoids • Eustachian Tubes (auditory tubes) • Connects the middle ear and nasopharynx • Middle ear infection is called otitis media • Complication of ET tubes

41. Oropharynx • Lies behind the oral cavity • Lingual tonsils lie at the root of the tongue • Statified squamous epithelium

42. Laryngopharynx • Lies between the base of the tongue and the entrance to the esophagus • Lies posterior to the epiglottis • Stratified squamous epithelium • aka Hypopharynx