The Respiratory System 13 The Respiratory System

II Anatomy and Function of Pathway Organs To The Lungs I Introduction II Anatomy and Function of Pathway Organs To The Lungs A. Nose … … F. Primary Bronchi III Lung Anatomy & General Functions A. Gross Anatomy, B. Respiratory Zone (micro) IV Specifics of Respiratory Functioning– The 4 Events Of Respiration A. Pulmonary Ventilation B. External Respiration C. Respiratory Gas Transport D. Internal Respiration V. Control of Respiration A. Neural Factors B. Chemical Factors VI Respiratory Disorders

I. Introduction A. Overall Functions Lungs: Gases = B. Passageways to the lungs: C. Where gas exchange occurs Nose Pharynx Larynx Trachea Primary Bronchi Lungs

Organs of the Respiratory System Nose, Pharynx, Larynx, Trachea, Bronchi, and Lung-alveoli Nasal cavity Oral cavity Nostril Pharynx Larynx Trachea Left main (primary) bronchus Right main (primary) bronchus Left lung Right lung Diaphragm

II. Anatomy & Functions of Pathway Organs to Lungs A. The Nose 1. External nostrils (nares) 2. Nasal Cavity Shape Nasal Septum Olfactory receptors Respiratory mucosa: function

Cribriform plate of ethmoid bone Sphenoidal sinus Frontal 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 Oropharynx Hard palate Palatine tonsil Soft palate Tongue Lingual tonsil Laryngopharynx Hyoid bone Larynx Epiglottis Esophagus Thyroid cartilage Trachea Vocal fold Cricoid cartilage (b) Detailed anatomy of the upper respiratory tract Figure 13.2b

Palate = hard palate (bone) soft palate (muscle) Disorder: Cleft Lip A. Nose … 2. Nasal Cavity … Palate = hard palate (bone) soft palate (muscle) Disorder: Cleft Lip

Parts … B. Paranasal Sinuses Sinuses: around nasal cavity = Functions: 1) Skull weight: 2) speech:

Sphenoidal sinus Frontal sinus Nasal cavity Nostril Hard palate Soft palate Tongue (b) Detailed anatomy of the upper respiratory tract Figure 13.2b

Parts … C. Pharynx = Throat Muscular passage: nasal cavity  larynx (air) esophagus ( food) Common passageways for: 3 regions-- STUDENTS DO Pharyngotympanic tubes to middle ear Tonsils (3): STUDENTS DO Tonsils

Parts … D. Larynx (Voice Box) Structure & location Made of Cartilage Connected to _______ and ________ Vocal Cords Epiglottis Functions: Epiglottis Thyroid Cartilage

E. Trachea (Windpipe): Location: Lined with ____________ Mucus: Cilia: Function: Cartilage parts Function Esophagus Trachea Cilia

F. Main (Primary) Bronchi = 2 tubes extend from: And Go To: Then, Bronchi subdivide: = Bronchial Tree (to be continued) Primary Bronchi

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

III. Lungs Anatomy & General Functions A. Gross Anatomy 1. Composition Location: Diaphragm 3. Parts: divided into lobes Left lung—2 Right lung—3 4. Coverings: Outside = Serosa Membrane: Pleural cavity fluid

(in pericardial cavity of mediastinum) Intercostal muscle Rib Parietal pleura Lung Pleural cavity Trachea Visceral pleura Thymus Apex of lung Left superior lobe Right superior lobe Oblique fissure Horizontal fissure Right middle lobe Left inferior 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. Figure 13.4a

F. Lungs … 5. Bronchial (Respiratory) Tree Divisions Function: Parts: Secondary bronchi Tertiary bronchi etc … Microscopic Bronchioles Respiratory bronchioles Lead to:

F. Lungs … B. Respiratory Zone (Microscopic) Alveolar Duct Respiratory bronchioles Alveoli (air sacs): STRUCTURE: Tissue: covered by: Alveolar macrophages: Surfactant: Function NEXT SLIDE  Alveolar Sac Alveoli Macrophage Surfactant- secreting cell Inside an Alveolus Red blood cell in capillary

5. Respiratory Zone … Function of ALVEOLI: Oxygen: Carbon dioxide: Red blood cell Endothelial cell nucleus Capillary Alveolar pores O2 Capillary O2 CO2 CO2 Macrophage Alveolus Nucleus of squamous epithelial cell Respiratory membrane Alveolar epithelium Fused basement membranes Capillary endothelium

Figure 13.5b

IV. Specifics Of Respiratory Functioning– Four Events of Respiration OVERVIEW Pulmonary Ventilation— moving air in & out of the lungs (2) External respiration— gas exchange at alveoli (3) Respiratory gas transport—in blood

(4) Internal respiration— gas exchange between blood and cells OVERVIEW … (4) Internal respiration— gas exchange between blood and cells Capillaries Body Cells

III. RESPIRATORY FUNCTION– Four Events of Respiration … A III. RESPIRATORY FUNCTION– Four Events of Respiration … A. Pulmonary Ventilation Depends on volume of thoracic cavity and air Pressure Increase volume  decreases pressure Air flows from high to low pressure Passive VentilationTwo phases 1. Inspiration = inhalation Diaphragm contracts External Intercostals contract Result:

Active Ventilation 2. Expiration = exhalation Muscles relax Diaphragm Intercostals Elasticity of lungs important Active Ventilation

Pulmonary Ventilation … 3. Respiratory Volumes and Capacities Tidal Volume = Normal breathing = average 500 mL air Influencing factors: size, sex, age, … Inspiratory reserve volume = Amount of air that can be taken in forcibly over the tidal volume Usually around 3100 mL

B. External Respiration– gas exchange at alveoli Gases move by diffusion Blood arriving at lung from Pulmonary Artery: Oxygen, O2 Carbon dioxide, CO2 Blood leaving the lungs via the Pulmonary veins: O2 CO2 (a) External respiration in the lungs (pulmonary gas exchange) Oxygen is loaded into the blood and carbon dioxide is unloaded. Alveoli (air sacs) High O2 Low CO2 Loading of O2 Unloading of CO2 Low O2 High CO2 Plasma Red blood cell Pulmonary capillary

C. Gas Transport in the Blood Oxygen transport Most on hemoglobin = oxyhemoglobin small amount dissolved in the plasma Carbon Dioxide: in blood as bicarbonate

(4) Internal Respiration Gas Exchange between blood and body cells Opposite to what occurs in lungs Carbon dioxide diffuses out of tissue to blood (called loading) Oxygen diffuses from blood into tissue (called unloading)

Oxygen is unloaded and carbon dioxide is loaded into the blood. (b) Internal respiration in the body tissues (systemic capillary gas exchange) Oxygen is unloaded and carbon dioxide is loaded into the blood. Tissue cells High CO2 Low O2 Loading of CO2 Unloading of O2 Low CO2 High O2 Plasma Systemic capillary Red blood cell Figure 13.11b

Figure 13.10 Inspired air: Alveoli of lungs: CO2 O2 O2 CO2 O2 CO2 External respiration Pulmonary arteries Alveolar capillaries Pulmonary veins Blood leaving tissues and entering lungs: Blood leaving lungs and entering tissue capillaries: Heart O2 CO2 Tissue capillaries O2 CO2 Systemic veins Systemic arteries Internal respiration CO2 O2 Tissue cells: O2 CO2 Figure 13.10

Brain Breathing control centers Pons centers Medulla centers Afferent Impulses to medulla Efferent nerve impulses from medulla trigger contraction of inspiratory muscles Intercostal nerves Phrenic nerves Breathing control centers stimulated by: CO2 increase in blood (acts directly on medulla centers by causing a drop in pH of CSF) Nerve impulse from O2 sensor indicating O2 decrease Intercostal muscles O2 sensor in aortic body of aortic arch Diaphragm CSF in brain sinus Figure 13.12

B. Chemical Factors (Non-Neural) Influencing Respiratory Rate and Depth Chemical factors: CO2 levels CO2: most important stimulus because it affects blood pH Increased levels of CO2  acidic blood pH  increases rate & depth of breathing to correct O2 levels

V. CONTROL OF RESPIRATION A. Neural Regulation Medulla—sets rhythm of breathing and contains a pacemaker area Pons—smooths out respiratory rate Normal respiratory rate 12 to 15 respirations per minute

VI. Respiratory Disorders: STUDENTS DO Chronic Obstructive Pulmonary Disease (COPD) Chronic Bronchitis Emphysema Lung Cancer Cystic Fibrosis Infant Respiratory Distress Syndrome Sudden Infant Death Syndrome (SIDS) Asthma Affects of TOBACCO

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O2 CO2 CO2 Red blood cell Endothelial cell nucleus Capillary Alveolar pores O2 Capillary O2 CO2 CO2 Macrophage Alveolus Nucleus of squamous epithelial cell Respiratory membrane Alveolar epithelium Fused basement membranes Capillary endothelium Figure 13.6 (2 of 2)

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

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 Figure 13.6 (1 of 2)

intercostals contract) Changes in anterior-posterior and superior-inferior dimensions Changes in lateral dimensions Ribs elevated as external intercostals contract Full inspiration (External intercostals contract) External intercostal muscles Diaphragm moves inferiorly during contraction (a) Inspiration: Air (gases) flows into the lungs Figure 13.7a

Expiration (External intercostals relax) Changes in anterior-posterior and superior-inferior dimensions Changes in lateral dimensions Ribs depressed as external intercostals relax Expiration (External intercostals relax) External intercostal muscles Diaphragm moves superiorly as it relaxes (b) Expiration: Air (gases) flows out of the lungs Figure 13.7b

Oxygen is loaded into the blood and carbon dioxide is unloaded. (a) External respiration in the lungs (pulmonary gas exchange) Oxygen is loaded into the blood and carbon dioxide is unloaded. Alveoli (air sacs) High O2 Low CO2 BODY CELLS Loading of O2 Unloading of CO2 Low O2 High CO2 Plasma Red blood cell Pulmonary capillary Figure 13.11a

(a) Regions of the pharynx Nasopharynx Oropharynx Laryngopharynx (a) Regions of the pharynx Figure 13.2a

Posterior Mucosa Esophagus Submucosa Trachealis Seromucous Lumen of muscle Lumen of trachea Seromucous gland in submucosa Hyaline cartilage Adventitia Anterior Figure 13.3a

Figure 13.3b