ELAINE N. MARIEB EIGHTH EDITION 13 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings PowerPoint ® Lecture Slide Presentation by Jerry L. Cook, Sam Houston University ESSENTIALS OF HUMAN ANATOMY & PHYSIOLOGY PART A The Respiratory System

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Organs of the Respiratory system  Nose  Pharynx  Larynx  Trachea  Bronchi  Lungs – alveoli Figure 13.1

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Function of the Respiratory System  Oversees gas exchanges between the blood and external environment  Exchange of gasses takes place within the lungs in the alveoli  Passageways to the lungs purify, warm, and humidify the incoming air

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings The Nose  The only externally visible part of the respiratory system  Air enters the nose through the external nares (nostrils)  The interior of the nose consists of a nasal cavity divided by a nasal septum

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Upper Respiratory Tract Figure 13.2

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Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 1.Nasal Cavity9. Left Lung 2.Pharynx 10. Diaphragm 3.Epiglottis11. True Ribs 4.Larynx 12. Esophagus 5.Trachea 6.Right Bronchus 7.Left Bronchus 8.Right Lung

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Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Trachea Main Bronchus Lobar Bronchus Segmental bronchi

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Bronchi Aveolus Alveolar sac capilaries

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Anatomy of the Nasal Cavity  Olfactory receptors are located in the mucosa on the superior surface  The rest of the cavity is lined with respiratory mucosa  Moistens air  Traps incoming foreign particles

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Anatomy of the Nasal Cavity  Lateral walls have projections called conchae  Increases surface area  Increases air turbulence within the nasal cavity  The nasal cavity is separated from the oral cavity by the palate  Anterior hard palate (bone)  Posterior soft palate (muscle)

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Paranasal Sinuses  Cavities within bones surrounding the nasal cavity  Frontal bone  Sphenoid bone  Ethmoid bone  Maxillary bone

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Paranasal Sinuses  Function of the sinuses  Lighten the skull  Act as resonance chambers for speech  Produce mucus that drains into the nasal cavity

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Pharynx (Throat)  Muscular passage from nasal cavity to larynx  Three regions of the pharynx (throat)  Nasopharynx – superior region behind nasal cavity  Oropharynx – middle region behind mouth  Laryngopharynx – inferior region attached to larynx  The oropharynx and laryngopharynx are common passageways for air and food

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structures of the Pharynx  Auditory tubes enter the nasopharynx  Tonsils of the pharynx  Pharyngeal tonsil (adenoids) in the nasopharynx  Palatine tonsils in the oropharynx  Lingual tonsils at the base of the tongue  Tonsils and adenoids are on the body’s first line of defense—our immune system. They “sample” bacteria and viruses that enter the body through the mouth or nose at the risk of their own infection.

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Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Larynx (Voice Box)  Routes air and food into proper channels  Plays a role in speech  Made of eight rigid hyaline cartilages and a spoon-shaped flap of elastic cartilage (glottis)

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structures of the Larynx  Thyroid cartilage  Largest hyaline cartilage  Protrudes anteriorly (Adam’s apple)  Epiglottis  Superior opening of the larynx  Routes food to esophagus and air toward the larynx

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structures of the Larynx  Vocal cords (vocal folds)  Vibrate with expelled air to create sound (speech)  Glottis – opening between vocal cords

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Trachea (Windpipe)  Connects larynx with bronchi  Lined with ciliated mucosa  Mucus is produced by goblet cells  Beat continuously in the opposite direction of incoming air (WHY?)  Expel mucus loaded with dust and other debris away from lungs  Walls are reinforced with C-shaped hyaline cartilage

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Primary Bronchus  Formed by division of the trachea  Right bronchus is wider, shorter, and straighter than left  Bronchi subdivide into smaller and smaller branches

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Lungs  Occupy most of the thoracic cavity  Apex -base rests on the diaphragm (inferior portion)  Each lung is divided into lobes by fissures  Left lung – two lobes  Right lung – three lobes

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Lungs Figure 13.4b

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Coverings of the Lungs  Pulmonary (visceral) pleura covers the lung surface  Parietal pleura lines the walls of the thoracic cavity  Pleural fluid fills the area between layers of pleura to allow gliding

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Bronchioles  Bronchi get smaller as they branch off Figure 13.5a

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Bronchi  All but the smallest branches have reinforcing cartilage Figure 13.5a

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Bronchi  Terminal bronchi end in alveoli Figure 13.5a

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings HW  What is the purpose of pleural fluid?  Why do cilia move the opposite direction of air?

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Respiratory Zone  Structures  Respiratory bronchi  Alveolar duct  Alveoli  Site of gas exchange

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Alveoli  Structure of alveoli  Alveolar duct  Alveolar sac  Alveolus  Gas exchange takes place within the alveoli in the respiratory membrane

ELAINE N. MARIEB EIGHTH EDITION 13 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings PowerPoint ® Lecture Slide Presentation by Jerry L. Cook, Sam Houston University ESSENTIALS OF HUMAN ANATOMY & PHYSIOLOGY PART A The Human Lung

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Energy Needs  The body consists of trillions of “engines”  Each cells needs glucose and oxygen  The lungs serve as the supplier of oxygen

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Energy Byproducts  In the body glucose is the main source of energy  Carbon Dioxide is the main byproduct and is released from the blood by the lungs  C0 2 drives the breathing rate – not oxygen

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Other Functions of the Lungs  Exchange of 0 2 and C0 2  Keeps the bodies pH (acid) constant  Moisturizes the air  We can “see” our breath in the winter  Play a role in heat exchange  Voice production (power of 1mW)  Air for yawning sighing, laughing, sniffing

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Breathing  We breath about 6 liters of air per minute  This is about the same as the heart pumps  Men breath about 12/minute  Women breath about 18/minute  Infants breath abut 60/minute

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings What We Breath In and Out INSPIRATIONEXPIRATION 80%Nitrogen80% 20%Oxygen16% 0%Carbon Dioxide4%

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings  The lungs have a large surface area  The convoluted surfaces have a surface area of 80m 2  This is at least ½ the size of a tennis court

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings  The lungs have a greater exposure to the environment than any other part of the body – including the skin.  The air we breath contains dust, smoke, bacteria, noxious gases  All come in contact with the blood.

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings  The trachea divides in the right and left stem bronchus  Each bronchus then divides 15 more times  The terminal bronchioles supply air to millions of small sacs called alveoli

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Alveoli  At birth the lungs have 30 million  At age 8 the number is about 300 million  That is about 100,000/day increase  They stay pretty constant after that

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Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Alveoli  They act as tiny interconnected bubbles.  They are 0.2 mm in diameter  The walls are 0.4 micrometers thick

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings  Each alveolus is surrounded by blood so that 0 2 and C0 2 can exchange through diffusion.

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 The airways must be able to remove particles.  The body does this in two ways  1. Coughing removes large particles

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings  2. Small particles are carried upward by millions of small hairs called cilia.  They vibrate about 1000/minute  Mucous moves 1 – 2 cm/minute  It takes 30 minutes to be cleared.

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Kartagener's Syndrome  This is a lung disease that occurs when cilia are unable to move  Individuals have abnormal or absent ciliary motion.  Kartagener's Syndrome is also called Immotile Cilia Syndrome

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Respiratory Membrane (Air-Blood Barrier)  Thin squamous epithelial layer lining alveolar walls  Pulmonary capillaries cover external surfaces of alveoli

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Respiratory Membrane (Air-Blood Barrier) Figure 13.6

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Gas Exchange  Gas crosses the respiratory membrane by diffusion  Oxygen enters the blood  Carbon dioxide enters the alveoli  Macrophages add protection  Surfactant coats gas-exposed alveolar surfaces  helps to prevent the alveoli from collapsing

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Events of Respiration  Pulmonary ventilation – moving air in and out of the lungs  External respiration – gas exchange between pulmonary blood and alveoli

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Mechanics of Breathing (Pulmonary Ventilation)  Completely mechanical process  Depends on volume changes in the thoracic cavity  Volume changes lead to pressure changes, which lead to the flow of gases to equalize pressure

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Inspiration  Diaphragm and intercostal muscles contract  The size of the thoracic cavity increases  External air is pulled into the lungs due to an increase in intrapulmonary volume

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Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings HW 1.Where does gas exchange actually take place in the lungs? 2.How do we do inspiration and expiration?

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Expiration  Largely a passive process which depends on natural lung elasticity  As muscles relax, air is pushed out of the lungs  Forced expiration can occur mostly by contracting internal intercostal muscles to depress the rib cage

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Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Nonrespiratory Air Movements  Can be caused by reflexes or voluntary actions  Examples  Cough and sneeze – clears lungs of debris  Laughing  Crying  Yawn  Hiccup

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Respiratory Volumes and Capacities  Normal breathing moves about 500 ml of air with each breath (tidal volume [TV])  Many factors that affect respiratory capacity  A person’s size  Sex  Age  Physical condition  Residual volume of air – after exhalation, about 1200 ml of air remains in the lungs

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Respiratory Volumes and Capacities  Inspiratory reserve volume (IRV)  Amount of air that can be taken in forcibly over the tidal volume  Usually between 2100 and 3200 ml  Expiratory reserve volume (ERV)  Amount of air that can be forcibly exhaled  Approximately 1200 ml

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Respiratory Volumes and Capacities  Residual volume  Air remaining in lung after expiration  About 1200 ml

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Respiratory Volumes and Capacities  Vital capacity  The total amount of exchangeable air  Vital capacity = TV + IRV + ERV  Dead space volume  Air that remains in conducting zone and never reaches alveoli  About 150 ml

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Respiratory Volumes and Capacities  Functional volume  Air that actually reaches the respiratory zone  Usually about 350 ml  Respiratory capacities are measured with a spirometer

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Respiratory Capacities Figure 13.9

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings HW  Describe the different types of lung volumes.