© 2012 Pearson Education, Inc. Organs of the Respiratory System Nose Pharynx Larynx Trachea Bronchi Lungs—alveoli

© 2012 Pearson Education, Inc. Nasal cavity Nostril Larynx Right main (primary) bronchus Trachea Right lung Oral cavity Pharynx Left main (primary) bronchus Left lung Diaphragm Figure 13.1

© 2012 Pearson Education, Inc. Functions of the Respiratory System Gas exchanges between the blood and external environment Occurs in the alveoli of the lungs Passageways to the lungs purify, humidify, and warm the incoming air

© 2012 Pearson Education, Inc. The Nose Three Functions 1.Warm, moisten & filter incoming air 2.Detect olfactory stimuli 3.Modify speech vibrations

© 2012 Pearson Education, Inc. Internal Nose Olfactory receptors are located in the mucosa on the superior surface The rest of the cavity is lined with respiratory mucosa that Moisten air Trap incoming foreign particles

© 2012 Pearson Education, Inc. Anatomy of the Internal Nose 1.Nasal Cavity – Space within the internal nose 2.Vestibule – Region just inside the nostrils 3.Nasal Septum – Vertical partition that divides the nasal cavity into right and left sides

© 2012 Pearson Education, Inc. Cribriform plate of ethmoid bone Sphenoidal sinus Posterior nasal aperture Nasopharynx Pharyngeal tonsil Opening of pharyngotympanic tube Uvula Oropharynx Palatine tonsil Lingual tonsil Laryngopharynx Esophagus Trachea Frontal sinus Nasal cavity Nasal conchae (superior, middle and inferior) Nasal meatuses (superior, middle, and inferior) Nasal vestibule Nostril Hard palate Soft palate Tongue Hyoid bone Larynx Epiglottis Thyroid cartilage Vocal fold Cricoid cartilage (b) Detailed anatomy of the upper respiratory tract Figure 13.2b

© 2012 Pearson Education, Inc. Oral Cavity Palate – Horizontal structure separating the oral and nasal cavities 1.Hard Palate – Made of the Maxillae and Palantine bones. 2.Soft Palate – Muscular attachment to the posterior portion of the hard palate. Helps close the nasal cavity during swallowing 3.Uvula – Terminal posterior bulb of soft tissue on the soft palate

© 2012 Pearson Education, Inc. Pharynx (Throat) Muscular passage from nasal cavity to the split of the Esophagus and Larynx Three regions of the pharynx 1.Nasopharynx—superior region behind nasal cavity 2.Oropharynx—middle region behind mouth 3.Laryngopharynx—inferior region attached to larynx The oropharynx and laryngopharynx are common passageways for air and food

© 2012 Pearson Education, Inc. Pharynx Nasopharynx Oropharynx Laryngopharynx (a) Regions of the pharynx Figure 13.2a

© 2012 Pearson Education, Inc. Larynx (Voice Box) Routes air and food into proper channels Plays a role in speech

© 2012 Pearson Education, Inc. Structures of the Larynx 1.Thyroid cartilage – AKA Adam’s Apple Large shield-like plate of the hyaline cartilages Glottis – Region inside the Thyroid cartilage. Consists of true vocal cords, the Rima Glottidis True vocal cords – site where sound is produced through vibration

© 2012 Pearson Education, Inc. Structures of the Larynx 2.Cricoid Cartilage – Hyaline cartilage that forms the inferior wall of the larynx, attaches to the first ring on tracheal cartilage 3.Epiglottis Leaf-shaped piece of elastic cartilage that covers the glottis during swallowing Routes food to the esophagus and air toward the trachea

© 2012 Pearson Education, Inc. Cribriform plate of ethmoid bone Sphenoidal sinus Posterior nasal aperture Nasopharynx Pharyngeal tonsil Opening of pharyngotympanic tube Uvula Oropharynx Palatine tonsil Lingual tonsil Laryngopharynx Esophagus Trachea Frontal sinus Nasal cavity Nasal conchae (superior, middle and inferior) Nasal meatuses (superior, middle, and inferior) Nasal vestibule Nostril Hard palate Soft palate Tongue Hyoid bone Larynx Epiglottis Thyroid cartilage Vocal fold Cricoid cartilage (b) Detailed anatomy of the upper respiratory tract Figure 13.2b

© 2012 Pearson Education, Inc. Trachea (Windpipe) Four-inch-long tube that connects larynx with bronchi Walls are reinforced with C-shaped hyaline cartilage Lined with ciliated mucosa Beat continuously in the opposite direction of incoming air Expel mucus loaded with dust and other debris away from lungs

© 2012 Pearson Education, Inc. Posterior Mucosa Submucosa Seromucous gland in submucosa Hyaline cartilage Adventitia Anterior Lumen of trachea Trachealis muscle Esophagus Figure 13.3a

© 2012 Pearson Education, Inc. Figure 13.3b

© 2012 Pearson Education, Inc. Bronchiole Tree 1.Right & Left Primary Bronchi (1°) – formed when the Trachea divides, one branch going to each lung 2.Secondary Bronchi (2°) – One branch to each lung lobe, 3 in the right lung & 2 in the left lung 3.Tertiary Bronchi (3°) – Smaller branches that inundate lung tissue 4.Terminal Bronchioles – Smallest branches ~25

© 2012 Pearson Education, Inc. Bronchiole Tree Cont. 5.Alveolar Ducts – Branches of terminal bronchioles about which alveolar sacs and alveoli are arranged 6.Alveolus (alveoli) – Cup-shaped pouch where respiration occurs between the body and the atmosphere 7.Alveolar Sac – 2 or more alveoli that share a common alveolar duct

© 2012 Pearson Education, Inc. Alveolar duct Alveoli Alveolar duct Alveolar sac Alveolar pores Alveolar duct Alveolus (a) Diagrammatic view of respiratory bronchioles, alveolar ducts, and alveoli Terminal bronchiole Respiratory bronchioles Figure 13.5a

© 2012 Pearson Education, Inc. Figure 13.5b

© 2012 Pearson Education, Inc. Respiratory Membrane (Air-Blood Barrier) Thin squamous epithelial layer lines alveolar walls Pulmonary capillaries cover external surfaces of alveoli On one side of the membrane is air and on the other side is blood flowing past

© 2012 Pearson Education, Inc. Figure 13.6 (1 of 2) Endothelial cell nucleus Alveolar pores Capillary Macrophage Nucleus of squamous epithelial cell Respiratory membrane Alveoli (gas- filled air spaces) Red blood cell in capillary Surfactant- secreting cell Squamous epithelial cell of alveolar wall

© 2012 Pearson Education, Inc. Figure 13.6 (2 of 2) Endothelial cell nucleus Alveolar pores Capillary Macrophage Nucleus of squamous epithelial cell Respiratory membrane Capillary endothelium Fused basement membranes Alveolar epithelium Alveolus CO 2 O2O2 Capillary Red blood cell O2O2 CO 2

© 2012 Pearson Education, Inc. Lungs Occupy most of the thoracic cavity Heart occupies central portion called mediastinum Each lung is divided into lobes by fissures Left lung—two lobes (Cardiac notch) Right lung—three lobes

© 2012 Pearson Education, Inc. Trachea Thymus Apex of lung Right superior lobe Horizontal fissure Right middle lobe Oblique fissure Right inferior lobe Heart (in pericardial cavity of mediastinum) Diaphragm Base of lung (a) Anterior view. The lungs flank mediastinal structures laterally. Left inferior lobe Oblique fissure Left superior lobe Visceral pleura Pleural cavity Parietal pleura Rib Intercostal muscle Lung Figure 13.4a

© 2012 Pearson Education, Inc. Coverings of the Lungs Parietal pleura - lines the walls of the thoracic cavity Pulmonary (visceral) pleura - covers the lung surface Pleural Cavity – space between the two pleura membranes Pleural fluid fills the pleural cavity allowing the lungs to expand and contract easily

© 2012 Pearson Education, Inc. Posterior Esophagus (in posterior mediastinum) Root of lung at hilum Left main bronchus Left pulmonary artery Left pulmonary vein Left lung Thoracic wall Pulmonary trunk Anterior mediastinum Anterior (b) Transverse section through the thorax, viewed from above. Lungs, pleural membranes, and major organs in the mediastinum are shown. Sternum Pericardial membranes Pleural cavity Visceral pleura Parietal pleura Right lung Vertebra Heart (in mediastinum) Figure 13.4b