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Basic Pulmonary Anatomy. The Upper and Lower Airways. Respiratory System. Upper Airways. Nose Paranasal sinuses Pharynx. Filter the air Humidify the air Warm the air Site for sense of small To generate resonance in speech. The Functions of the Nose. The Nose.
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Basic Pulmonary Anatomy The Upper and Lower Airways
Upper Airways • Nose • Paranasal sinuses • Pharynx
Filter the air Humidify the air Warm the air Site for sense of small To generate resonance in speech The Functions of the Nose
The Nose • Rigid structure composed of cartilage and bone • Septal cartilage divides nasal cavity into two nasal fossae • Palate divides nasal cavity and oral cavity • Nose divided into 3 regions
Regions of the nose • Nares or nostrils serve as opening for the nasal fossae—two cavities in middle of the face • Vestibule/vestibular region • Lined with stratified squamous epithelium • Contain vibrissae-nasal hair, first line of defense, function to filter inspired air
Nasal regions • Vestibular area contains sebaceous glands; secrete sebum • Keeps vibrissae soft and filter gases • Olfactory region: pseudostratified columnar epithelium and olfactory cells
Regions of the nose • Respiratory—highly vascular; ciliated, pseudostratified columnar epithelium • Contains turbinates or conchae; increase surface area (166 cm2) for humidification, heating/cooling and filtering of air • Mucous membranes provide up to 650-1000 ml of water/day to humidify air
Respiratory region of nose • Goblet cells in mucus membrane secrete 100 ml/day of mucous; aids in trapping inspired particles and prevents them from entering lower respiratory trace • Each columnar cell contains 200-250 cilia; beat in waves toward oropharynx (mouth), 2cm/min
Sinuses • Air-filled cavities within the skull (cranium) • Aka paranasal sinuses (four pairs) • Function not clear, lighten head and provide voice resonance • Lied with pseudostratified cliated columnar epithelium and goblet cells
Oral Cavity • Alternate respiratory passage • Anterior 2/3 of tongue located in oral cavity • Another “respiratory” muscle • Lined with stratified squamous epithelium
+Pharaynx • (Throat), hollow, upper portion of the airway and the digestive tract • Subdivided into: nasopharynx, oropharynx, laryngopharynx • Nasopharynx • Pseudostratified ciliated columnar epithelium
Nasopharynx • Filters bacteria and foreign particles from inspired air • Carries this to the stomach • Eustachian tube and auditory tube open into lateral surfaces, connect nasopharynx to middle each, equalizes pressure of middle ear
Oropharynx • Between soft palate above and base of tongue below • From tip of uvula to epiglottis • Stratified squamous epithelium • Gas conduction, filtering of air • Defense mechanism: gag reflex
Laryngopharynx • Stratified squamous epithelium • Gas conduction • Connecting zone between upper and lower airway (vocal cords and below)
Begins with true vocal cords and extends to alveoli Larynx Trachea Main stem bronchi Segmental bronchi Subsegmental bronchi Bronchioles Terminal bronchioles Respiratory bronchioles Alveolar ducts Alveolar sacs alveoli Lower Airway
Larynx • Lies between base of tongue and trachea • Protrusion is the thyroid cartilage, aka “Adam’s apple.” • Houses the vocal cords, primary use is vocalization • Connection point-upper and lower airways
Extends from C3 to C6 Pseudostratified ciliated columnar epithelium Functions: Free flow of air to the lungs During inspiration, vocal folds abduct, move apart, and widen glottis Valsalva maneuver and Muller maneuver Larynx
Larynx • Composed of 3 single cartilaginous structures: • Epiglottis-flap, swings down to meet larynx during swallowing • Thyroid-bulk of this forms larynx • Cricoid-circular, keeps head of trachea open
Epiglottis • Covers the rima glottidis during swallowing (glottis=cords & space) • Larynx has poor lymphatic drainge, prone to edema • Epiglottitis is a life-threatening condition (supraglottic croup), bacterial origin • Narrowest part of lower airway in adult
Thyroid • Largest of the laryngeal cartilages • Primary housing the vocal cords • Inflammation below the vocal cords known as laryngotracheobronchitis • Croup • Subglottic croup • Viral orgins
Cricoid • A complete cartilaginous ring • Narrowest portion of the lower airway in a neonate and infant • Actual start of the lower airway
Tracheobronchial Tree • Series of branching airways commonly referred to a “generations” or “orders” • The first generation or order is zero (0), the trachea itself. • Bifucrates at the carina
Cartilaginous -serve only to conduct air between external environment and the sites of gas exchange Non-cartilaginous -serve both as conductors of inspired air and as sites of gas exchange Two Types of Airways
Tracheobronchial Tree • Dichotomous branching (daughter branches) • Airways become progressively narrower, shorter, and more numerous • Cross-sectional area enlarges • Common histology (at the nose) and throughout until the bronchiole generation
Histology • Three major layers • Epithelial lining • Lamina propria • Cartilaginous layer
Tracheal lining • Pseudostratified columnar epithelium with cilia; goblet cells, serous cells, and specialized submucosal bronchial glands • 200+ cilia per cell, 5-7 microns long • Beat cephalid (head) toward oropharynx
Epithelial lining • Pseudostratified ciliated columnar epithelium is homogenous until the level of the bronchioles • Cilia disappear in terminal bronchioles • Cilia absent in respiratory bronchioles
Mucous blanket • Covers the epithelial lining • Composed of • -95% water • -glycoproteins • Carbohydrate lipids • DNA • Cellular debris
Mucous • Mucus produced by • Goblet cells • Found through terminal bronchioles Submucosal (bronchial) glands extend into laminar propria Innervated by vagus nerve (parasympathetic) Produce 100 ml of secretions/day Disappear at end of terminal bronchioles
Two distinct layers Sol layer Gel layer Cilia move through sol layer and strike gel layer propelling it toward mouth At a rate of 2 cm/minute Mucous Blanket
Mucocilliary Escalator • Defense mechanism of lower airways • Mucus propelled up airway to larynx • Cough mechanism moves secretions into oropharynx via sheering forces