Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Chapter 22 Gas Exchange PowerPoint Lectures for Biology: Concepts & Connections, Sixth Edition Campbell, Reece, Taylor, Simon, and Dickey Copyright © 2009 Pearson Education, Inc. Lecture by Richard L. Myers Translated by Nabih A. Baeshen MECHANISMS OF GAS EXCHANGE Copyright © 2009 Pearson Education, Inc. 22.1 Overview: Gas exchange in an animal with lungs involves breathing, transport of gases, and exchange of gases with tissue cells Three phases of gas exchange 1-Breathing: exchange of CO2 produced during cellular respiration with atmospheric O2 2-Transport of oxygen and carbon dioxide in blood by circulatory system. 3- Body cells take up oxygen from the blood and release carbon dioxide to the blood. Cellular respiration requires a continuous supply of oxygen and the disposal of carbon dioxide Copyright © 2009 Pearson Education, Inc. 22.2 Animals exchange O2 and CO2 across moist body surfaces Respiratory surfaces must be thin and moist for diffusion of O2 and CO2 Earthworms and other animals use their skin for gas exchange Most animals have specialized body parts that promote gas exchange – Gills in fish and amphibians – Tracheal systems in arthropods – Lungs in tetrapods that live on land – Amphibians – Reptiles – Birds – Mammals Copyright © 2009 Pearson Education, Inc. 22.3 Gills are adapted for gas exchange in aquatic environments Gills – Are extensions of the body – Increase surface to volume ratio – Increase surface area for gas exchange – Oxygen absorbed – Carbon dioxide released In a fish, gas exchange is enhanced by – Ventilation of the gills (moving water past the gills) – Countercurrent flow of water and blood Copyright © 2009 Pearson Education, Inc. Gill Arch Oxygen-poor blood Lamella Oxygen-rich blood Direction of water flow Gill Arch Blood vessels Operculum (gill cover) Water flow between lamellae Blood flow through capillaries in lamella Countercurrent exchange Water flow, showing % O2 100 70 40 15 Gill filaments Diffusion of O2 from water to blood The structure of fish gills 80 60 30 5 Blood flow in simplified capillary, showing % O2 22.4 The tracheal system of insects provides direct exchange between the air and body cells Compared to water, using air to breathe has two big advantages – Air contains higher concentrations of O2 – Air is lighter and easier to move Air-breathing animals lose water through their respiratory surfaces Copyright © 2009 Pearson Education, Inc. 22.5 EVOLUTION CONNECTION: The evolution of lungs facilitated the movement of tetrapods onto land Tetrapods seem to have evolved in shallow water The first tetrapods on land diverged into three major lineages – Amphibians use small lungs and their body surfaces – Non bird reptiles have lower metabolic rates and simpler lungs – Birds and mammals have higher metabolic rates and more complex lungs Copyright © 2009 Pearson Education, Inc. 22.6 In the human respiratory system, branching tubes convey air to lungs located in the chest cavity In mammals, air is inhaled through the nostrils into the nasal cavity – Air is filtered by hairs and mucus surfaces – Air is warmed and moisturized – Air is sampled for odors Copyright © 2009 Pearson Education, Inc. 22.6 In the human respiratory system, branching tubes convey air to lungs located in the chest cavity From the nasal cavity, air next passes – To the pharynx – Then larynx, past the vocal cords – Into the trachea, held open by cartilage rings – Into the paired bronchi – Into bronchioles – And finally to the alveoli, grapelike clusters of air sacs, where gas exchange occurs Copyright © 2009 Pearson Education, Inc. Oxygen-rich blood Nasal cavity Pharynx (Esophagus) Larynx Oxygen-poor blood Bronchiole Left lung Alveoli Trachea Right lung Bronchus Blood Capillaries Bronchiole Diaphragm (Heart) The anatomy of the human respiratory system (left) and details of the structure of alveoli (right) 22.6 In the human respiratory system, branching tubes convey air to lungs located in the chest cavity Alveoli are well adapted for gas exchange – High surface area of capillaries – High surface area of alveoli In alveoli * O2 diffuses into the blood * CO2 diffuses out of the blood Copyright © 2009 Pearson Education, Inc. 22.7 CONNECTION: Smoking is a serious assault on the respiratory system Mucus and cilia in the respiratory passages – Protect the lungs – Can be damaged by smoking Without healthy cilia, smokers must cough to clear dirty mucus from the trachea Copyright © 2009 Pearson Education, Inc. 22.7 CONNECTION: Smoking is a serious assault on the respiratory system Smoking can cause – Lung cancer – Heart disease – Emphysema Smoking also – Increases the risk of heart attacks and strokes – Raises blood pressure – Increases harmful types of cholesterol Every year in USA, smoking kills about 440,000 people, which is more than all deaths from accidents, alcohol, drug abuse, HIV, and murders combined Copyright © 2009 Pearson Education, Inc. Lung Heart Healthy lungs cancerous lungs 22.8 Negative pressure breathing ventilates our lungs Breathing is the alternate inhalation and exhalation of air (ventilation) Inhalation occurs when – The rib cage expands – The diaphragm moves downward – The pressure around lungs decreases – And air is drawn into the respiratory tract Copyright © 2009 Pearson Education, Inc. 22.8 Negative pressure breathing ventilates our lungs Exhalation occurs when – The rib cage contracts – The diaphragm moves upward – The pressure around the lungs increases – And air is forced out of the respiratory tract Copyright © 2009 Pearson Education, Inc. Rib cage gets Rib cage expands as rib muscles contract Air inhaled smaller as rib muscles relax Air exhaled Lung Diaphragm Diaphragm contracts (moves down) Inhalation Diaphragm relaxes (moves up) Exhalation Negative pressure breathing draws air into the lungs. 22.9 Breathing is automatically controlled Breathing is usually under automatic control Breathing control centers in the brain sense and respond to CO2 levels in the blood A rise in CO2 leading to drop in blood pH increases the rate and depth of breathing Copyright © 2009 Pearson Education, Inc. Cerebrospinal fluid Brain Pons Breathing control centers respond to pH of blood 2 1 Nerve signals trigger contraction of muscles Medulla 3 Nerve signals indicating CO2 and O2 levels CO2 and O2 sensors in aorta Diaphragm Rib muscles Control centers that regulate breathing TRANSPORT OF GASES IN THE HUMAN BODY Copyright © 2009 Pearson Education, Inc. 22.10 Blood transports respiratory gases The heart pumps blood to two regions – The right side pumps oxygen-poor blood to the lungs – The left side pumps oxygen-rich blood to the body In the lungs, blood picks up O2 and drops off CO2 In the body tissues, blood drops off O2 and picks up CO2 Copyright © 2009 Pearson Education, Inc. 22.10 Blood transports respiratory gases Gases move from areas of higher concentration to areas of lower concentration –Gases in the alveoli – have more O2 and less CO2 than gases the blood –O2 moves from the alveoli of the lungs into the blood –CO2 moves from the blood into the alveoli of the lungs –The tissues have more CO2 and less O2 than in the blood – CO2 moves from the tissues into the blood – O2 moves from the blood into the tissues Copyright © 2009 Pearson Education, Inc. Inhaled air Exhaled air Alveolar epithelial cells Air spaces CO2 Gas transport and exchange in the body. O2 Alveolar capillaries CO2-rich, O2-poor blood O2-rich, CO2-poor blood Heart Tissue capillaries Tissue cells throughout body CO2 O2 Interstitial fluid 22.11 Hemoglobin carries O2, helps transport CO2, and buffers the blood Most animals transport O2 bound to proteins called respiratory pigments – Copper-containing pigment in – Mollusca – Arthropods – Iron-containing hemoglobin – Is used by almost all vertebrates and many invertebrates – Transports oxygen, buffers blood, and transports CO2 Copyright © 2009 Pearson Education, Inc. Iron atom O2 loaded in lungs O2 unloaded in tissues Polypeptide chain O2 O2 Heme group Hemoglobin loading and unloading of O2. 22.11 Hemoglobin carries O2, helps transport CO2, and buffers the blood Most CO2 in the blood is transported as bicarbonate ions in the plasma CO2 + H2O Carbon Dioxide Water Copyright © 2009 Pearson Education, Inc. H2CO3 Carbonic Acid H+ + HCO3Hydrogen Ions Bicarbonate تبادل الغازات Gas Exchange المصطلـــــــــــــــــــــــــــــــــح تعريف المصطلــــــــــح Mechanisms Of Gas Exchange آليات تبادل الغازات Three Phases Of Gas Exchange مراحل تبادل الغازات Breathing التنفس Transport Of Oxygen And Carbon Dioxide قل االكسجين و ثاني اكسد الكربون في الدم In Blood Body Tissues Take Up Oxygen And Release امتصاص انسجة الجسم لألكسجين و التخلص من ثاني Carbon Dioxide اكسد الكربون Cellular Respiration التنفس الخلوي Requires A Continuous Supply Of Oxygen تزويد مستمر باألكسجين والتخلص من ثاني اكسد الكربون And The Disposal Of Carbon Dioxide Respiratory Surfaces Must Be Thin And ينبغي للسطوح التنفسية ان تكون رقيقة ورطبة النتشار Moist For Diffusion Of O2 And CO2 االكسجين وثاني اكسيد الكربون عبرها Earthworms ديدان االرض Most Animals Have Specialized Body Parts تمتلك معظم الحيوانات اجزاء متخصصة بالجسم تقوم That Promote Gas Exchange بعملية تبادل الغازات Gills لخياشيم Tracheal Systems In Arthropods اجهزة القصبات الهوائية في مفصليات االرجل Tetrapods رباعيات االرجل تبادل الغازات Gas Exchange تعريف المصطلــــــــــح البرمائيات الزواحف الثديات تمددات لسطح الجسم تزيد من نسبة السطح الى الحجم تبادل الغازات تهوية التيار المعاكس فوائد تركيزات اكبر سطوح اجسامها التنفسية االجهزة القصبية للحشرات انابيب دقيقة متفرعة يضخ الهواء مباشرة الى الخاليا بدأت حياتها في المياه الضحلة تفرعت ثالثة افرع رئيسية الزواحف غير الطائرة ايضية منخفضة المصطلـــــــــــــــــــــــــــــــــح Amphibians Reptiles Mammals Extensions Of The Body Increase Surface To Volume Ratio Gas Exchange Ventilation Countercurrent Flow Advantages Higher Concentrations Respiratory Surfaces Insect Tracheal Systems Tiny Branching Tubes Air Is Piped Directly To Cells Evolved In Shallow Water Diverged Three Major Lineages Nonbird Reptiles Lower Metabolic Rates تبادل الغازات Gas Exchange تعريف المصطلــــــــــح ,يستنشق الهواء التجويف االنفي يرشح الهواء (من العوالق) عن طريق الشعر و االسطح المخاطية تم تدفئة وترطيب الهواء يتم فرز الهواء من اجل تمييز الروائح التجويف االنفي، البلعوم الحنجرة مار باال حبال الصوتية الى القصبات الهوائية مفتوحة بحلقات غضروفية الشعب الهوائية الشعيبات الهوائية الحويصالت الهوائية عنقود من االكياس الهوائية مساحة السطح العالية للشعيرات الدموية مساحة السطح العالية للحويصالت الهوائية ينتشر االكسجين الى الدم يطرد ثاني اكسيد الكربون خارج الدم المصطلـــــــــــــــــــــــــــــــــح Inhaled Through Nasal Cavity Filtered By Hairs And Mucus Surfaces Air Is Warmed And Moisturized Air Is Sampled For Odors Nasal Cavity Pharynx Then Larynx, Past The Vocal Cords Trachea Cartilage Rings Paired Bronchi Bronchioles Alveoli, Grapelike Clusters Of Air Sacs High Surface Area Of Capillaries High Surface Area Of Alveoli O2 Diffuses Into The Blood CO2 Diffuses Out Of The Blood تبادل الغازات Gas Exchange تعريف المصطلــــــــــح المخاط واألهداب تحمي الرئتين ان تتلف بالتدخين سرطان الرئة امراض القلب ضيق التنفس يزيد نوبات القلب والجلطات يرفع من ضغط الدم يزيد من التعرض ألنواع الكلسترول الضارةالكلسترول الضارة يفوق الموت من الحوادث ,تعاطي الكحول واإلدمان على المخدرات و االيدز و االغتياالت التنفس تعاقب شهيق وزفير الهواء (التهوية) الشهيق يتمدد (يتسع) القفص الصدري ينخفض الحجاب الحاجز ينخفض الضغط حول الرئة المصطلـــــــــــــــــــــــــــــــــح Mucus And Cilia Protect The Lungs Damaged By Smoking Lung Cancer Heart Disease Emphysema Risk Of Heart Attacks And Strokes Raises Blood Pressure Increases Harmful Types Of Cholesterol Accidents, Alcohol, Drug Abuse, HIV, And Murders Combined Breathing Alternate Inhalation And Exhalation Of )Air (Ventilation Inhalation Rib Cage Expands Diaphragm Moves Downward Pressure Around Lungs Decreases تبادل الغازات Gas Exchange تعريف المصطلــــــــــح يسحب الهواء الى الممرات التنفسية الزفير ينقبض (يضيق ) القفص الصدري يرتفع الحجاب الحاجز الى اعلى يزداد الضغط حول الرئتين ويطرد الهواء خارج الممرات التنفسية التحكم االوتوماتيكي مراكز التحكم بالتنفس تستشعر مستويات ثاني اكسيد الكربون في الدم وتستجيب لها انخفاض االس الهيدروجيني في الدم يزيد معدل وعمق التنفس نقل الغازات في جسم االنسان يضخ القلب الدم الى منطقتين يضخ الجانب االيمن الدم الفقير الى االكسجين الى الرئتين ضخ الجانب االيسر الدم الغني باألكسجين الى بقية اجزاء الجسم المصطلـــــــــــــــــــــــــــــــــح Air Is Drawn Into The Respiratory Tract Exhalation Rib Cage Contracts Diaphragm Moves Upward Pressure Around The Lungs Increases Air Is Forced Out Of The Respiratory Tract Automatic Control Breathing Control Centers Respond To CO2 Levels Drop In Blood Ph Increases Rate And Depth Of Breathing Transport Of Gases In The Human Body Heart Pumps Blood To Two Regions Right Side Pumps Oxygen-Poor Blood To The Lungs Left Side Pumps Oxygen-Rich Blood To The Body تبادل الغازات Gas Exchange تعريف المصطلــــــــــح المصطلـــــــــــــــــــــــــــــــــح In The Lungs, Blood Picks Up O2 And في الرئتين ،يأخذ الدم االكسجين و يطرد ثاني اكسيد Drops Off CO2 الكربون In The Body Tissues, Blood Drops Off O2 في انسجة الجسم ,يترك الدم االكسجين ويأخذ ثاني اكسيد And Picks Up CO2 الكربون O2 Moves From The Alveoli Of The Lungs يتحرك االكسجين من الحويصالت الهوائية للرئتين الى الدم Into The Blood CO2 Moves From The Blood Into The يتحرك ثاني اكسيد الكربون من الدم الى الحويصالت Alveoli Of The Lungs الهوائية للرئتين Tissues Have More CO2 And Less O2 Than بها ثاني اكسيد الكربون اكثر وأكسجين اقل مما هو في الدم In The Blood CO2 Moves From The Tissues Into The يتحرك ثاني اكسيد الكربون من االنسجة الى الدم Blood O2 Moves From The Blood Into The يتحرك االكسجين من الدم الى االنسجة Tissues تبادل الغازات Gas Exchange تعريف المصطلــــــــــح معظم الحيوانات تنقل االكسجين المرتبط ببروتينات الصبغات التنفسية الصبغات المحتوية على النحاس لرخويات الهيموجلوبين المحتوي على الحديد معظم الفقاريات الالفقاريات ويعادل الدم مجموعة الهيم ينقل معظم ثاني اكسيد الكربون في الدم هيئة ايونات البيكربونات في البالزما المصطلـــــــــــــــــــــــــــــــــح Animals Transport O2 Bound To Proteins Respiratory Pigments Copper-Containing Pigment Mollusca Iron-Containing Hemoglobin Vertebrates Invertebrates Buffers Blood Heme Group CO2 In The Blood Is Transported As Bicarbonate Ions In The Plasma