BIOL 2304/2101/ Human Anatomy CH-21- Respiratory System-Outline The general functions of the respiratory system:1. Pulmonary Ventilation or Ventilation or Breathing 2. External Expiration3. Transport of respiratory gases4. Internal Expiration5. Cellular RespirationElizabeth Maxin & Aniko Szabo Hill 1 of 8BIOL 2304/2101/ Human Anatomy CH-21- Respiratory System-Outline Conducting and respiratory zoneConducting zone with no gas exchangeFunctions of conducting passageways: Respiratory zone with gas exchangeLocation, gross structure, histological structure, and general functions of the individualrespiratory organsMajor OrgansNose and Nasal Cavityexternal nosenasal cavityexternal naresvestibulenasal septumsuperior concha/ meatus - olfactory mucosamiddle concha/ meatusElizabeth Maxin & Aniko Szabo Hill 2 of 8BIOL 2304/2101/ Human Anatomy CH-21- Respiratory System-Outline inferior concha/ meatusparanasal sinuses: frontal, sphenoid, ethmoid, maxillaryPharynxnasopharynxoropharynxlaryngopharynxLarynxFunctions of larynx:Cartilages of larynx:thyroid cartilagecricoid cartilageElizabeth Maxin & Aniko Szabo Hill 3 of 8BIOL 2304/2101/ Human Anatomy CH-21- Respiratory System-Outline arytenoid cartilages (2)cuneiform cartilages (2)cornicualte cartilages (2)epiglottisVocal folds (vocal cords)GlottisTracheacartilage rings (C rings)Tracheal wall layers:(1) mucosa(2) submucosa(3) cartilage layer(4) adventitiaElizabeth Maxin & Aniko Szabo Hill 4 of 8BIOL 2304/2101/ Human Anatomy CH-21- Respiratory System-Outline Bronchi and Bronchial Treeprimary bronchisecondary bronchitertiary bronchismaller & smaller bronchibronchioles (<0.5 mm diameter)terminal bronchiolesrespiratory bronchiolesalveolar ductsalveolar sacsalveoliElizabeth Maxin & Aniko Szabo Hill 5 of 8BIOL 2304/2101/ Human Anatomy CH-21- Respiratory System-Outline Lung Structurelocation: thoracic cavityeach suspended in pleural cavityalveoli + stroma (elastic connective tissue)structure of lungapexbaselobes - supplied by secondary bronchiright lung –left lung cardiac notchlobules - supplied by tertiary bronchiSerous membranesvisceral pleuraparietal pleurapleural fluid pleural spaceElizabeth Maxin & Aniko Szabo Hill 6 of 8BIOL 2304/2101/ Human Anatomy CH-21- Respiratory System-Outline The structural changes in the epithelial membrane and cartilages of therespiratory passageways from the nasal cavity to the alveoliChanges in structure through bronchial tree:(1) decreasing amount of cartilage (2) epithelium changes from pseudostratified to columnar tocuboidal to simple squamous (alveoli) (3) proportion of smooth muscle increasesThe path of air flow from the external nares to the alveoliElizabeth Maxin & Aniko Szabo Hill 7 of 8BIOL 2304/2101/ Human Anatomy CH-21- Respiratory System-Outline The location and histological structure of the respiratory membraneStructure of Alveoli alveoli =Respiratory MembraneCells of alveoli:type I cells - simple squamous epithelium with very thin basementmembranetype II cells - secrete surfactantalveolar macrophages - phagocytize bacteria/debrisAlveoli are closely associated with pulmonary capillaries.Total surface area: = 70-80 m2Elizabeth Maxin & Aniko Szabo Hill 8 of