CHAPTER 24 Respiratory System
RESPIRATION INCLUDES Air moves in and out of lungs Continuous replacement of gases in alveoli (air sacs) Gas exchange between blood and air at alveoli Transport of respiratory gases Between the lungs and the cells of the body Performed by the cardiovascular system Gas exchange in capillaries between blood and tissue cells 2
Nasal cavity Sphenoidal sinus Internal nares Frontal sinus Nasal conchae Nose UPPER RESPIRATORY SYSTEM LOWER RESPIRATORY SYSTEM Nasopharynx Hyoid bone Larynx Trachea Bronchus Clavicle Bronchioles RIGHT LUNG LEFT LUNG Ribs FIGURE 24.1 STRUCTURES OF THE RESPIRATORY SYSTEM Diaphragm
FUNCTIONS OF THE RESPIRATORY SYSTEM 1. Provides area for gas exchange between air and blood 2. 3. 4. Produces sound involved in verbal communication 5. Assists in regulation of blood volume, blood pressure, and body fluid ph
RESPIRATORY EPITHELIUM cells Except for the pharynx, smaller bronchi, and alveoli Function: cells Found in the pharynx Function: cells Found in the nasal cavity and lower respiratory tract Function:
Nasal cavity Internal nares Entrance to auditory tube Pharyngeal tonsil Pharynx Nasopharynx Oropharynx Laryngopharynx Frontal sinus Nasal conchae Superior Middle Inferior Nasal vestibule External nares Soft palate Epiglottis Glottis Vocal fold Thyroid cartilage Trachea Thyroid gland a A sagittal section of the head and neck FIGURE 24.4A RESPIRATORY STRUCTURES IN THE HEAD AND NECK 2015 Pearson Education, Inc.
Dens of axis (C 2 ) Tongue Inferior nasal concha Hard palate Soft palate Nasopharynx Uvula Oropharynx Laryngopharynx Spinal cord C 6 C 5 C 4 C 3 Epiglottis Hyoid bone Vestibular fold Vocal fold C 7 Thyroid cartilage T 1 Esophagus Trachea T 2 Tracheal cartilages T 3 Pleural cavity FIGURE 24.5 RESPIRATORY STRUCTURES IN THE HEAD AND NECK 2015 Pearson Education, Inc.
RESPIRATORY SYSTEM: AIR FLOW 1. Air enters 2. Passes by the 3. Enters 4. Enters and flows in and around 5. Air enters 6. Air enters nasopharynx area laryngopharynx 7. 8. Bronchus 9. Bronchioles
NASAL CAVITY CONSISTS OF: Nasal bones Nasal septum Cartilage External nares Alar Cartilage Dorsum and apex of the nose Nasal conchae
Lateral nasal cartilage Dorsum of nose Major alar cartilage Apex Minor alar cartilage External nares FIGURE 24.3 RESPIRATORY STRUCTURES IN THE HEAD AND NECK, 2015 Pearson Education, Inc.
LOWER RESPIRATORY SYSTEM: THE LARYNX Cylinder with cartilaginous walls stabilized by ligaments and skeletal muscle Begins at level and vertebra C3 or C4 and ends at C7. Unpaired Cartilage Thyroid cartilage Cricoid cartilage Epiglottis Paired Cartilage Arytenoid cartilage Corniculate cartilage Cuneiform cartilage
Epiglottis Lesser cornu Hyoid bone Thyrohyoid ligament (extrinsic) Larynx Thyroid cartilage Laryngeal prominence Cricoid cartilage Cricothyroid ligament (intrinsic) Cricotracheal ligament (extrinsic) Trachea Tracheal cartilages FIGURE 24.6A ANATOMY OF THE LARYNX 2015 Pearson Education, Inc.
Epiglottis Vestibular ligament Thyroid cartilage Vocal ligament Arytenoid cartilage Cricoid cartilage Tracheal cartilages FIGURE 24.6B ANATOMY OF THE LARYNX 2015 Pearson Education, Inc.
FIGURE 24.7A THE VOCAL CORDS POSTERIOR Corniculate cartilage Cuneiform cartilage Vestibular fold Glottis (open) Aryepiglottic fold Vocal fold Epiglottis Root of tongue ANTERIOR a Glottis in the open position. 2015 Pearson Education, Inc.
SOUND PRODUCTION Air passing through vocal cords Amplification of sound occurs in sinus cavities Production of definite sounds depends on movement of the lips, tongue, and cheeks Pitch depends on the diameter, length, and tension in vocal cords Children have slender, short vocal folds = high-pitched sound At puberty, vocal cords of males become thicker and longer = deeper voice than females
Corniculate cartilage Cuneiform cartilage Vestibular fold Vocal fold Epiglottis Root of tongue POSTERIOR Glottis (open) Aryepiglottic fold ANTERIOR Corniculate cartilage Glottis (closed) Vocal fold Vestibular fold Epiglottis a Glottis in the open position. b Glottis in the closed position. FIGURE 24.7AB THE VOCAL CORDS 2015 Pearson Education, Inc.
1 Tongue forces compacted bolus into oropharynx Hard palate Soft palate Tongue Bolus Epiglottis Larynx Trachea 2 Laryngeal movement folds epiglottis; pharyngeal muscles push bolus into esophagus Soft palate Bolus Epiglottis 3 Bolus moves along esophagus; larynx returns to normal position Epiglottis FIGURE 24.8 MOVEMENTS OF THE LARYNX DURING SWALLOWING Bolus Trachea 2015 Pearson Education,
UPPER RESPIRATORY SYSTEM LOWER RESPIRATORY SYSTEM Nasal cavity Sphenoidal sinus Internal nares Nasopharynx Esophagus Frontal sinus Nasal conchae Nose Tongue Hyoid bone Larynx Trachea Bronchus Clavicle Bronchioles RIGHT LUNG LEFT LUNG Ribs FIGURE 24.1 STRUCTURES OF THE RESPIRATORY SYSTEM Diaphragm 2015 Pearson Education, Inc.
TRACHEA Size: 11 cm by 2.5 cm diameter Bifurcates at the carina into right and left bronchi at T5 Contains 15-20 tracheal cartilages Each cartilage is a C-shaped ring Tracheal cartilages are connected by annular ligaments
Esophagus Trachealis muscle Lumen of trachea Thyroid gland Respiratory epithelium Tracheal cartilage The trachea LM 3 FIGURE 24.9B ANATOMY OF THE TRACHEA AND PRIMARY BRONCHI 2015 Pearson Education, Inc.
Larynx Root of right lung Root of left lung Lung tissue Primary bronchi Secondary bronchi RIGHT LUNG LEFT LUNG FIGURE 24.9A ANATOMY OF THE TRACHEA AND PRIMARY BRONCHI 2015 Pearson Education, Inc.
FIGURE 24.11 BRONCHI AND BRONCHIOLES Primary bronchus Cartilage ring Root of lung Secondary (or inferior lobar) bronchus LEFT LUNG Secondary (or superior lobar) bronchus Cartilage plates Visceral pleura BRONCHIOLE Respiratory epithelium Tertiary (or segmental) bronchi Smooth muscle Bronchioles Lobule Respiratory bronchioles Terminal bronchiole 2015 Pearson Education, Inc.
RIGHT LEFT Bronchopulmonary segments of superior lobe Bronchopulmonary segments of superior lobe Bronchopulmonary segments of middle lobe Bronchopulmonary segments of inferior lobe Bronchopulmonary segments of inferior lobe a Gross anatomy of the lungs showing the bronchial tree and its divisions. FIGURE 24.12A THE BRONCHIAL TREE AND DIVISIONS OF THE LUNGS 2015 Pearson Education, Inc.
PRIMARY BRONCHI Each primary bronchus enters lung at the point of The is also the point of entrance and exit of the pulmonary blood vessels The combination of the bronchus, artery, and The combination of the bronchus, artery, and vein is called the root
LUNGS AND PLEURA Around each lung is a flattened sac of serous membrane called pleura Parietal pleura outer layer Visceral pleura directly on lung Pleural cavity slit-like potential space filled with pleural fluid Lungs can slide but separation from pleura is resisted (like film between 2 plates of glass) Lungs cling to thoracic wall and are forced to expand and recoil as volume of thoracic cavity changes during breathing
CXR (chest x-ray) 26
FIGURE 24.10A SUPERFICIAL ANATOMY OF THE LUNGS Superior vena cava Trachea Superior lobe Aortic arch Horizontal fissure Middle lobe Right lung Left lung Superior lobe Fibrous layer of pericardium a Oblique fissure Inferior lobe Falciform ligament Anterior view of the opened chest showing the relative positions of the left and right lungs and heart Liver, right lobe Liver, left lobe Oblique fissure Inferior lobe Cut edge of diaphragm 2015 Pearson Education, Inc.
FIGURE 24.10B SUPERFICIAL ANATOMY OF THE LUNGS Lateral Surfaces b Diagrammatic views of the lateral surfaces of the isolated right and left lungs Superior lobe Apex Apex Superior lobe Inferior lobe Middle lobe Horizontal fissure Oblique fissure Cardiac notch Oblique fissure Inferior lobe Base Base RIGHT LUNG LEFT LUNG 2015 Pearson Education, Inc.
FIGURE 24.10C SUPERFICIAL ANATOMY OF THE LUNGS Medial Surfaces c Diagrammatic views of the medial surfaces of the isolated right and left lungs Apex Pulmonary arteries Superior lobe Pulmonary veins Horizontal fissure Hilum Cardiac impression Pulmonary veins Oblique fissure Inferior lobe Oblique fissure Base RIGHT LUNG LEFT LUNG 2015 Pearson Education, Inc.
STRUCTURE OF THE LUNGS The apex points superiorly and the base inferiorly The lung has lobes Superior, middle, and inferior lobes Consists of a horizontal fissure and an oblique fissure The lung has lobes Superior and inferior lobes Contains the oblique fissure Left lung has a cardiac notch
RIGHT LEFT Apicoposterior Bronchopulmonary segments of superior lobe Apical Posterior Anterior Anterior Superior lingular Inferior lingular Bronchopulmonary segments of superior lobe Bronchopulmonary segments of middle lobe Lateral Medial Anterior basal Lateral basal Anterior basal Lateral basal Medial basal Posterior basal Superior Bronchopulmonary segments of inferior lobe Bronchopulmonary segments of inferior lobe Posterior basal Medial basal Superior a Gross anatomy of the lungs showing the bronchial tree and its divisions. FIGURE 24.12A THE BRONCHIAL TREE AND DIVISIONS OF THE LUNGS 2015 Pearson Education,
FIGURE 24.12B THE BRONCHIAL TREE AND DIVISIONS OF THE LUNGS Apical Apicoposterior Bronchopulmonary segments of superior lobe Posterior Anterior Anterior Superior lingular Bronchopulmonary segments of superior lobe Bronchopulmonary segments of middle lobe Bronchopulmonary segments of inferior lobe Medial Lateral Superior Lateral basal Medial basal Posterior basal Inferior lingular Superior Medial basal Posterior basal Anterior basal Lateral basal Bronchopulmonary segments of inferior lobe Anterior basal Right lung, costal surface Left lung, costal surface b Isolated left and right lungs have been colored to show the distribution of the bronchopulmonary segments. 2015 Pearson Education, Inc.
FIGURE 24.11 BRONCHI AND BRONCHIOLES Primary bronchus Cartilage ring Root of lung Secondary (or inferior lobar) bronchus LEFT LUNG Secondary (or superior lobar) bronchus Cartilage plates Visceral pleura BRONCHIOLE Respiratory epithelium Tertiary (or segmental) bronchi Smooth muscle Bronchioles Lobule Respiratory bronchioles Terminal bronchiole 2015 Pearson Education, Inc.
Trachea Respiratory epithelium Bronchiole Branch of pulmonary artery Left primary bronchus Visceral pleura Tertiary bronchi Secondary bronchus Bronchial artery (red), vein (blue), and nerve (yellow) Terminal bronchiole Respiratory bronchiole Smooth muscle around terminal bronchiole Alveoli in a pulmonary lobule Smaller bronchi Bronchioles Terminal bronchiole Respiratory bronchiole Branch of pulmonary vein Elastic fibers Capillary beds Arteriole Alveolar duct Lymphatic vessel Alveoli Bronchopulmonary segment Alveolar sac Interlobular septum Visceral pleura Pleural cavity Parietal pleura a The structure of one portion of a single pulmonary lobule FIGURE 24.13A BRONCHI AND BRONCHIOLES 2015 Pearson Education, Inc.
FIGURE 24.14A ALVEOLAR ORGANIZATION Respiratory bronchiole Alveolar duct Smooth muscle Elastic fibers Alveolus Alveolar sac Capillaries a Basic structure of a lobule, cut to reveal the arrangement between the alveolar ducts and alveoli. A network of capillaries surrounds each alveolus. These capillaries are surrounded by elastic fibers.
FIGURE 24.14B ALVEOLAR ORGANIZATION Alveoli Alveolar sac Alveolar duct Lung tissue LM 125 b SEM of lung tissue showing the appearance and organization of the alveoli. 2015 Pearson Education, Inc.
AVEOLAR DUCTS AND ALVEOLI Each lung has approx 150 million alveoli Network of capillaries surround each alveolus Capillaries drop off carbon dioxide and pick up oxygen Elastic tissue surrounds each alveolus Maintains the shape and position of each alveolus during inhalation and exhalation
CELLS ASSOCIATED WITH ALVEOLI The cells associated with alveoli The lining consists of a single layer of These are called are scattered among the type I pneumocytes secrete surfactant Surfactant prevents alveolar collapse wander around phagocytizing particulate matter
GAS EXCHANGE AT THE ALVEOLI Pulmonary arteries transport carbon dioxide to the alveolar capillaries Carbon dioxide leaves the capillaries and enters the alveolar sacs Oxygen leaves the alveolar sacs and enters the capillaries Oxygen enters the pulmonary veins and returns to the heart to be pumped to all parts of the body
FIGURE 24.14D ALVEOLAR ORGANIZATION Red blood cell Capillary lumen Endothelium Nucleus of endothelial cell 0.5 µm Fused basal laminae Alveolar epithelium Surfactant Alveolar air space d The respiratory membrane. 2015 Pearson Education, Inc.
THE PLEURAL CAVITIES AND PLEURAL MEMBRANES The pleural cavity between the visceral and parietal membranes consists of: Pleural fluid Reduces friction when the lungs move upon inhalation and exhalation Pleurisy A condition in which the membranes produce too much pleural fluid or the membranes adhere to the thoracic wall thereby resulting in pain upon inhalation and exhalation
FIGURE 24.15 ANATOMICAL RELATIONSHIPS IN THE THORACIC CAVITY Pericardial cavity Right lung, middle lobe Oblique fissure Right pleural cavity Atria Esophagus Aorta Right lung, inferior lobe Spinal cord Body of sternum Ventricles Rib Left lung, superior lobe Visceral pleura Left pleural cavity Parietal pleura Bronchi Posterior mediastinum Left lung, inferior lobe 2015 Pearson Education, Inc.
RESPIRATORY MUSCLES AND PULMONARY VENTILATION Respiratory Muscles The muscles involved in pulmonary ventilation (breathing) are: Diaphragm External intercostals Internal intercostals
RESPIRATORY MUSCLES AND PULMONARY VENTILATION Diaphragm Contracts (lowers) to cause inhalation Relaxes (raises) to cause exhalation External intercostals Elevate the ribs to aid in inhalation Internal intercostals Depress the ribs to aid in exhalation
1 The Respiratory Muscles Accessory Respiratory Muscles (Inhalation) Sternocleidomastoid muscle Scalene muscles Pectoralis minor muscle Serratus anterior muscle Primary Respiratory Muscles (Inhalation) Diaphragm Primary Respiratory Muscles (Inhalation) External intercostal muscles Accessory Respiratory Muscles (Exhalation) Internal intercostal muscles Transversus thoracis muscle External oblique muscle Rectus abdominis Internal oblique muscle FIGURE 24.16 RESPIRATORY MUSCLES AND PULMONARY VENTILATION (1 OF 4) 2015 Pearson Education, Inc.
2 The Mechanics of Breathing FIGURE 24.16 RESPIRATORY MUSCLES AND PULMONARY VENTILATION (2 OF 4) Ribs and sternum elevate Diaphragm contracts 2015 Pearson Education, Inc.
RESPIRATORY MUSCLES AND PULMONARY VENTILATION Respiratory Movements Respiratory movements can be classified two ways: eupnea or hyperpnea : quiet breathing May involve diaphragmatic (deep) breathing or costal breathing (shallow breathing) or both During pregnancy, due to the uterus pushing upward on the diaphragm, women typically use costal breathing : forced breathing Generally requires the use of accessory breathing muscles
RESPIRATORY CHANGES AT BIRTH Prior to Birth Pulmonary arterial resistance is high Pulmonary vessels are collapsed Rib cage is compressed Lungs and passageways contain no air but do contain small amounts of fluid At Birth Air enters and forces the fluid out Closure of: Foramen ovale and ductus arteriosus
AGING AND THE RESPIRATORY SYSTEM The respiratory system becomes less efficient as we age Noteworthy changes include: Elastic tissue begins to deteriorate Lungs cannot expand or constrict as much as they used to Movements of the ribs are restricted due to arthritis Some degree of emphysema, which hinders breathing With age, roughly 1 square foot of respiratory membrane is lost each year after age 30
There are many diseases of the respiratory system, including asthma, cystic fibrosis, COPD (chronic obstructive pulmonary disease with chronic bronchitis and/or emphysema) and epiglottitis example: normal emphysema 50
YOU MIGHT WANT TO THINK TWICE ABOUT SMOKING. How does the histology of the respiratory track change when one 51 smokes?