The Respiratory System is an open tract. (Other 3. ) 1 The Respiratory System is an open tract. (Other 3?) 1. What structure (membrane) lines the passageways of this tract? 2. What epithelium lines the opening of this tract? 3. What epithelium lines most of this tract? 4. What specific C.T. supports the large passageways of this tract? 5. Speech is a voluntary action. What kind of muscle controls the larynx (voicebox)? 6. What kind of muscle would you expect to be in the walls of the passageway? 7. What nerve probably supplies the passageways of this tract? The diaphragm? 8. What part of the brain contains the reflex center that controls breathing?

Functions Exchange of gases (O2 and CO2) Maintaining pH Influencing blood pressure Maintaining body temperature

Nasal cavity Oral cavity Nostril Pharynx Larynx Intercostal muscles Trachea Left main (primary) bronchus Carina of trachea Right main (primary) bronchus Left lung Right lung Diaphragm 802

Epithelia? Function? 23 Levels Of Branch-ing Elastic

Figure 22.8a Respiratory zone structures. 23 Levels of Branching Alveoli Alveolar duct Respiratory bronchioles Alveolar duct Terminal Bronchiole (1 mm) Alveolar sac (a) 812

(b) External skeletal framework Bones ? Frontal bone Nasal bone Septal cartilage Maxillary bone (frontal process) Lateral process of septal cartilage Hyaline Cartilage Minor alar cartilages Dense fibrous connective tissue Major alar cartilages (b) External skeletal framework 803

Sympathetic vs. Parasympathetic Vagus (Para.) -Pleura -Constricts sm. Muscle of passageways -Skeletal muscle of pharynx and larynx Nasal cavity Oral cavity Nostril Pharynx Larynx Trachea Left main (primary) bronchus Carina of trachea Right main (primary) bronchus Left lung Right lung Diaphragm Phrenic -Diaphragm Intercostal -Intercostal and abdominal muscles 802

Air & Mucous memb. vibrissae 804 Cribriform plate of ethmoid bone Frontal sinus Sphenoid sinus Posterior nasal aperture Nasal cavity Nasal conchae (superior, middle and inferior) Nasopharynx Pharyngeal tonsil Nasal meatuses (superior, middle, and inferior) Opening of pharyngotympanic tube Nasal vestibule Uvula Nostril vibrissae Oropharynx (st. sq) Hard palate Palatine tonsil Soft palate Isthmus of the fauces Tongue Lingual tonsil Laryngopharynx Hyoid bone Larynx Epiglottis Esophagus Vestibular fold Thyroid cartilage Vocal fold (cords) Cricoid cartilage Trachea Thyroid gland (c) Illustration 804

Figure 22.3b The upper respiratory tract. Pharynx Nasopharynx Oropharynx Laryngopharynx (b) Regions of the pharynx 804

Figure 22.4a The larynx. Epiglottis (Elastic Cart.) Body of hyoid bone 9 hyaline cartilages Epiglottis (Elastic Cart.) Body of hyoid bone Thyrohyoid membrane Thyroid cartilage -Speech -Open airway -Routes air/food Laryngeal prominence (Adam’s apple) Cricothyroid ligament Cricoid cartilage Cricotracheal ligament Tracheal cartilages (a) Anterior superficial view 807

Figure 22.4b The larynx. Epiglottis Body of hyoid bone Thyrohyoid membrane Thyrohyoid membrane Fatty pad Cuneiform cartilage Vestibular fold (false vocal cord) Corniculate cartilage Arytenoid cartilage Thyroid cartilage Arytenoid muscles Vocal fold (true vocal cord) Cricoid cartilage Cricothyroid ligament Cricotracheal ligament Tracheal cartilages (b) Sagittal view; anterior surface to the right 807

. Epiglottis Laryngeal inlet Corniculate cartilage Posterior Extrinsic skeletal muscle Posterior cricoarytenoid muscle on cricoid cartilage Trachea (d) Photograph of posterior aspect 807

Figure 22.5 Movements of the vocal folds. Base of tongue Epiglottis Vestibular fold (false vocal cord) Vocal fold (vocalis) (true vocal cord) Glottis Inner lining of trachea Cuneiform cartilage Corniculate cartilage (a) Vocal folds in closed position; closed glottis (b) Vocal folds in open position; open glottis Mucous membrane with stratified squamous 808

(a) Cross section of the trachea and esophagus Posterior Mucosa Pseudostratified cilitated columnar Esophagus Submucosa Trachealis muscle Seromucous gland in submucosa Lumen of trachea Hyaline cartilage 16-20 Adventitia Anterior (a) Cross section of the trachea and esophagus 810

23 Levels of branching Trachea Superior lobe of left lung Left main (primary) bronchus Superior lobe of right lung Lobar (secondary) bronchus Segmental (tertiary) bronchus Middle lobe of right lung R Primary -short -wider -more vertical Inferior lobe of right lung Inferior lobe of left lung 811

Respiratory bronchiole Terminal bronchiole Respiratory bronchiole Smooth muscle Elastic fibers Gas Exchange Alveolus Capillaries (a) Diagrammatic view of capillary-alveoli relationships 813

IRDS 813 Red blood cell Nucleus of type I (squamous epithelial) cell Alveolar pores Capillary O2 Capillary Type I cell of alveolar wall CO2 Alveolus Macrophage Alveolus Endothelial cell nucleus Alveolar epithelium Fused basement membranes of the alveolar epithelium and the capillary endothelium Respiratory membrane Red blood cell in capillary Alveoli (gas-filled air spaces) Type II (surfactant- secreting) cell IRDS Capillary endothelium (c) Detailed anatomy of the respiratory membrane 813

Intercostal muscle Cone Rib Parietal pleura Trachea Lung Pleural cavity Visceral pleura Thymus Apex of lung Right superior lobe Left superior lobe Horizontal fissure Heart (in mediastinum) Oblique fissure Right middle lobe Left inferior lobe Oblique fissure Right inferior lobe Diaphragm Base of lung Cardiac notch (a) Anterior view. The lungs flank mediastinal structures laterally. 814

(b) Photograph of medial view of the left lung. Apex of lung Left superior lobe Pulmonary artery Oblique fissure Left main bronchus Left inferior lobe Pulmonary vein Pulmonary Hilum (depression) Impression of heart Oblique fissure Aortic impression Root Lobules (b) Photograph of medial view of the left lung. 814

2 serous membranes Pleurisy Posterior Esophagus (in mediastinum) Vertebra Root of lung at hilum Right lung Parietal pleura • Left main bronchus • Left pulmonary artery Visceral pleura • Left pulmonary vein Left lung Pleural cavity Thoracic wall Pulmonary trunk Pericardial membranes Heart (in mediastinum) Anterior mediastinum Sternum Anterior (c) Transverse section through the thorax, viewed from above. Lungs, pleural membranes, and major organs in the mediastinum are shown. 814

Atmospheric pressure Parietal pleura Thoracic wall Visceral pleura 760 mmHg Atmospheric pressure Parietal pleura Thoracic wall Visceral pleura Pleural cavity Transpulmonary pressure 760 mm Hg –756 mm Hg = 4 mm Hg 756 Intrapleural pressure 756 mm Hg (–4 mm Hg) 760 Inhale and Exhale Change Cavity Intrapulmonary pressure 760 mm Hg (0 mm Hg) Lung Diaphragm 817

-Ext. intercostals & diaphragm contract -Increase size of cavity -Decreases pressure -Muscles relax -Decreases size of cavity -Increases pressure 818

Diaphragm and External Intercostals Contract 756 754 760 759 760 Muscles Relax and Elastic Recoil of Lungs Forced Inspiration? Forced Expiration? 5.23

Clicker Question: Which of the following statements are correct. 1 Clicker Question: Which of the following statements are correct? 1. Normal exhalation during quiet breathing is an active process involving intensive muscle contraction? 2. Normal exhalation results from elastic recoil of the chest wall and lungs. 3. Air flow during breathing is due to a pressure gradient between the lungs and the atmospheric air. 4. During normal breathing, the pressure between the two pleural layers (intrapleural pressure) is always subatmospheric. 5. Surfactant within the alveoli increase surface tension and improve inhalation. A. 1,2,3 b. 2,3,4 c. 3,4,5 d. 1,3,5 e. 2,3,5

Figure 22.16a Respiratory volumes and capacities. Inspiratory reserve volume 3100 ml Inspiratory capacity 3600 ml Vital capacity 4800 ml Total lung capacity 6000 ml Tidal volume 500 ml Expiratory reserve volume 1200 ml Functional residual capacity 2400 ml Residual volume 1200 ml (a) Spirographic record for a male Dead Air Space 822

Medullary Rhythmicity Center Exp. & Insp. centers Pons Medulla Pontine respiratory centers interact with the medullary respiratory centers to smooth the respiratory pattern. Pons Ventral respiratory group (VRG) contains rhythm generators whose output drives respiration. Medullary Rhythmicity Center Exp. & Insp. centers Pons Medulla Medulla Obl. Dorsal respiratory group (DRG) integrates peripheral sensory input and modifies the rhythms generated by the VRG. To inspiratory muscles Sensory input Diaphragm External intercostal muscles 834

Skeletal Muscles so voluntary control ≈15 times/min Smoothes Transition Prevents Over Expansion Ext Stretch Receptor Skeletal Muscles so voluntary control 5.25

Breath holding Hyperventilation Hering-Breuer Reflex 50% CO2 , H+ Higher brain centers (cerebral cortex—voluntary control over breathing) Breath holding Hyperventilation Other receptors (e.g., pain) and emotional stimuli acting through the hypothalamus + – + – Respiratory centers (medulla and pons) Hering-Breuer Reflex Peripheral chemoreceptors O2 , CO2 , H+ + 50% + – Stretch receptors in lungs Central Chemoreceptors CO2 , H+ – + Irritant receptors Receptors in muscles and joints movement 835

Table on 825 .04% or .3mmHg

Nitrogen? Venous blood Arterial blood 826 Inspired air: P 160 mm Hg Alveoli of lungs: P 104 mm Hg P 40 mm Hg Nitrogen? O2 O2 CO2 CO2 External respiration Pulmonary arteries Pulmonary veins (P 100 mm Hg) O2 Blood leaving tissues and entering lungs: P 40 mm Hg P 45 mm Hg Blood leaving lungs and entering tissue capillaries: P 100 mm Hg P 40 mm Hg Venous blood O2 Arterial blood CO2 O2 CO2 Heart Systemic veins Systemic arteries Internal respiration Tissues: P less than 40 mm Hg P greater than 45 mm Hg O2 CO2 826

pulmonary capillary (s) Oxygen carrying capacity -Amount of hemoglobin is limiting P 104 mm Hg PO2 Temp. pH PCO2 O2 Improve oxygen unloading Time in the pulmonary capillary (s) Start of capillary 20 ml. Oxygen/100 ml. blood End of capillary 826

Figure 22.22b Transport and exchange of CO2 and O2. Alveolus Fused basement membranes CO2 CO2 (dissolved in plasma) Slow CO2 CO2 + H2O H2CO3 HCO3– + H+ HCO3– Chloride shift (out) via transport protein Fast CO2 Cl– CO2 + H2O H2CO3 HCO3– + H+ Carbonic anhydrase Cl– CO2 CO2 + Hb HbCO2 (Carbamino- hemoglobin) Red blood cell O2 + HHb HbO2 + H+ 19.5 ml as oxyhemoglobin 101 40 O2 O2 O2 (dissolved in plasma) .5 ml Blood plasma (b) Oxygen pickup and carbon dioxide release in the lungs 20 ml. oxygen/ 100 ml. blood 833b

10% (flexible) 70% 20% Bohr Effect 833a Tissue cell Interstitial fluid CO2 CO2 (dissolved in plasma) Binds to plasma proteins Slow CO2 CO2 + H2O H2CO3 HCO3– + H+ CO2 70% HCO3– Chloride shift (in) via transport protein Fast Cl– CO2 CO2 + H2O H2CO3 HCO3– + H+ Carbonic anhydrase Cl– CO2 HHb CO2 CO2 + Hb HbCO2 (Carbamino- hemoglobin) 20% Red blood cell HbO2 O2 + Hb Bohr Effect CO2 O2 O2 O2 (dissolved in plasma) Blood plasma (a) Oxygen release and carbon dioxide pickup at the tissues 833a

Clicker Question: Which of the following would cause oxygen to dissociate more readily from hemoglobin? 1. Low PO2 2. An increase in pH 3. Hypothermia (low body temperature) 4. High PCO2 5. A decrease in pH a. 1,2,3,4 b. 1,3,4,5 c. 1,2,4 d. 1,4,5 e. 3,4,5

Arterial Blood normally pH of 7.41 and pCO2=40 mmHg >7.45 <7.35 pCO2 >45 pCO2< 35 Pneumonia, emphysema mucous Hypoventilation -morphine, alcohol Low BP, nervousness, muscle spasms Drowsy, disoriented, High BP, coma