Respiration Pulmonary ventilation (breathing): movement of air into and out of the lungs External respiration: O 2 and CO 2 exchange between the lungs and the blood Transport: O 2 and CO 2 in the blood Internal respiration: O 2 and CO 2 exchange between systemic blood vessels and tissues Respiratory system Circulatory system

Figure 22.1 Nasal cavity Nostril Oral cavity Pharynx Larynx Trachea Carina of trachea Left main (primary) bronchus Right main (primary) bronchus Right lung Left lung Diaphragm

Figure 22.2b Frontal bone Nasal bone Septal cartilage Maxillary bone (frontal process) Lateral process of septal cartilage Minor alar cartilages Major alar cartilages Dense fibrous connective tissue (b) External skeletal framework

Figure 22.3c Sphenoid sinus Frontal sinus Nasopharynx Uvula Opening of pharyngotympanic tube Oropharynx Laryngopharynx Vocal fold (at the glottis) Esophagus (c) Illustration Nasal conchae (superior, middle and inferior) Nostril (external nare) Nasal cavity Hard palate Soft palate Tongue Epiglottis Hyoid bone Larynx Thyroid cartilage Vestibular fold (false vocal cords) Thyroid gland Trachea Cribriform plate of ethmoid bone Internal nare

Figure 22.4a Body of hyoid bone Epiglottis Tracheal cartilages Thyroid cartilage Laryngeal prominence (Adam’s apple) (a) Anterior superficial view

Figure 22.4b Epiglottis Body of hyoid bone Vestibular fold (false vocal cord) Vocal fold (true vocal cord) Thyroid cartilage Tracheal cartilages (b) Sagittal view; anterior surface to the right Glottis

Figure 22.6b (b) Photomicrograph of the tracheal wall (320x) Hyaline cartilage Lamina propria (connective tissue) Submucosa Mucosa Seromucous gland in submucosa Pseudostratified ciliated columnar epithelium

Tracheal Cross Section

Trachea Superior lobe of right lung Middle lobe of right lung Inferior lobe of right lung Superior lobe of left lung Left main (primary) bronchus Lobar (secondary) bronchus Segmental (tertiary) bronchus Inferior lobe of left lung Cardiac notch Hilus/hilum of left lung (triangular depression on posterior surface) Figure 22.7 Base Apex

Thoracic Cross Section Showing Pleura

Figure 22.8a (a) Alveolar duct Alveoli Alveolar sac Respiratory bronchioles Terminal bronchiole

Microscopic View of Lung Tissue

Capillary Type II (surfactant- secreting) cell Type I cell of alveolar wall Endothelial cell nucleus Macrophage Alveoli (gas-filled air spaces) Red blood cell in capillary Alveolar pores Capillary endothelium Fused basement membranes of the alveolar epithelium and the capillary endothelium Alveolar epithelium Respiratory membrane Red blood cell O2O2 Alveolus CO 2 Capillary Alveolus Nucleus of type I (squamous epithelial) cell (c) Detailed anatomy of the respiratory membrane

Figure 22.9a Elastic fibers (a) Diagrammatic view of capillary-alveoli relationships Smooth muscle Alveolus Capillaries Terminal bronchiole Respiratory bronchiole

Respiratory Volumes Used to assess a person’s respiratory status –Tidal volume (TV) –Inspiratory reserve volume (IRV) –Expiratory reserve volume (ERV) –Residual volume (RV)

Using a Wet Spirometer

Respiratory Volumes and Capacities Normal breathing moves about 500 ml of air with each breath (tidal volume [TV]) Factors Affecting Respiratory Capacity: Size, Gender, Age, Condition Expiratory reserve volume (ERV) –Amount of air that can be forcibly exhaled –Approximately 1200 ml Inspiratory reserve volume (IRV) –Amount of air that can be taken in forcibly over the tidal volume –Usually ml

Residual volume –Air remaining in lung after expiration –About 1200 ml Vital capacity –The total amount of exchangeable air –Vital capacity = TV + IRV + ERV –Dead space volume ~ 150 ml Air that remains in conducting zone and never reaches alveoli Functional volume –Air that actually reaches the respiratory zone –Usually about 350 ml Respiratory Volumes and Capacities

Figure 22.16a Inspiratory reserve volume 3100 ml Tidal volume 500 ml (a) Spirographic record for a male Expiratory reserve volume 1200 ml Residual volume 1200 ml Functional residual capacity 2400 ml Inspiratory capacity 3600 ml Vital capacity 4800 ml Total lung capacity 6000 ml