chapter 22 gas exchange [compatibility mode]

Chapter 22Chapter 22 Gas Exchange

Copyright © 2009 Pearson Education, Inc.

PowerPoint Lectures for

Biology: Concepts & Connections, Sixth Edition

Campbell, Reece, Taylor, Simon, and Dickey

Lecture by Richard L. MyersTranslated by Nabih A. Baeshen

MECHANISMS OF GAS EXCHANGE

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OF GAS EXCHANGE

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 exchangeThree 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

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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 Cellular respiration requires a continuous supply of oxygen and the disposal of carbon supply of oxygen and the disposal of carbon dioxidedioxide

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

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– Tracheal systems in arthropods

– Lungs in tetrapods that live on land

– Amphibians

– Reptiles

– Birds

– Mammals

22.3 Gills are adapted for gas exchange in aquatic environments

�� GillsGills

– Are extensions of the body

– Increase surface to volume ratio

– Increase surface area for gas exchange

– Oxygen absorbed

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– Carbon dioxide released

�� In a fish, gas exchange is enhanced byIn a fish, gas exchange is enhanced by

– Ventilation of the gills (moving water past the gills)

– Countercurrent flow of water and blood

Gill Arch

Directionof waterflow

Operculum(gill cover)

Blood vessels

Oxygen-richblood

Oxygen-poorblood

Lamella

Water flowbetweenlamellae

Gill Arch

Blood flow

Gillfilaments

lamellae

Countercurrent exchange

Blood flow insimplified capillary,

showing % O2

Diffusionof O2 fromwater toblood

Water flow, showing % O2

100 70 40 15

5306080

The structure of fish gills

Blood flowthrough

capillariesin lamella

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

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– Air is lighter and easier to move

� Air-breathing animals lose water through their respiratory surfaces

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

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– Amphibians use small lungs and their body surfaces

– Nonbird reptiles have lower metabolic rates and simpler lungs

– Birds and mammals have higher metabolic rates and more complex lungs

22.6 In the human respiratory system, branching tubes convey air to lungs located in the chest cavity

�� In mammalsIn mammals, air is inhaled through the nostrils into the nasal cavity

– Air is filtered by hairs and mucus surfaces

– Air is warmed and moisturized

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– Air is warmed and moisturized

– Air is sampled for odors

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

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– 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

Oxygen-richblood

Bronchiole

Oxygen-poorblood

Nasalcavity

Left lung

Pharynx

Larynx

Trachea

Right lung

Bronchus

(Esophagus)

Alveoli

BloodCapillaries

Bronchus

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

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– High surface area of alveoli

� In alveoli

�O2 diffuses into the blood

– CO2 diffuses out of the blood

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

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� Without healthy cilia, smokers must cough to clear dirty mucus from the trachea

22.7 CONNECTION: Smoking is a serious assault on the respiratory system

�� Smoking can causeSmoking can cause

– Lung cancer

– Heart disease

– Emphysema

�� Smoking alsoSmoking also

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– Increases the risk of heart attacks and strokes

– Raises blood pressure

– Increases harmful types of cholesterol

�� Every year in USA, smoking kills about Every year in USA, smoking kills about 440440,,000 000 people, which people, which is more than all deaths from accidents, alcohol, drug abuse, is more than all deaths from accidents, alcohol, drug abuse, HIV, and murders combinedHIV, and murders combined

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 whenInhalation occurs when

– The rib cage expands

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– The rib cage expands

– The diaphragm moves downward

– The pressure around lungs decreases

– And air is drawn into the respiratory tract

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

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– The pressure around the lungs increases

– And air is forced out of the respiratory tract

Lung

Airinhaled

Airexhaled

Rib cageexpands asrib musclescontract

Rib cage getssmaller asrib musclesrelax

Diaphragm contracts(moves down)

Diaphragm relaxes(moves up)

Diaphragm

Inhalation 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

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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

Cerebrospinalfluid

Pons

Medulla

Brain

Nerve signalstrigger contraction

of muscles

1

Breathing controlcenters respondto pH of blood

2

Nerve signalsindicating CO

3

Diaphragm

Rib muscles

indicating CO2and O2 levels

CO2 and O2sensors in aorta

Control centers that regulate breathing

TRANSPORT OF GASES IN THE HUMAN BODY

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IN THE HUMAN BODY

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

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� In the lungs, blood picks up O2 and drops off CO2

� In the body tissues, blood drops off O2 and picks up CO2

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

–O moves from the alveoli of the lungs into the blood

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–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

Alveolarepithelial

cells

CO2 O2

CO2-rich,O2-poorblood

O2-rich,CO2-poor

Exhaled air Inhaled air

Air spaces

AlveolarcapillariesGas transport

and exchange in the body. blood

CO2-poorblood

Tissuecapillaries

Tissue cellsthroughout

body

Interstitialfluid

Heart

CO2 O2

in the body.

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

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– Arthropods

– Iron-containing hemoglobin

– Is used by almost all vertebrates and many invertebrates

– Transports oxygen, buffers blood, and transports CO2

O2 loadedin lungs

Iron atom

O2

O2 unloadedin tissues

Polypeptide chain

O2

Hemoglobin loading and unloading of O2.

Heme group

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

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+ - 2 2 2 3 3Carbon Water Carbonic Hydrogen Bicarbonate Dioxide Acid Ions

CO + H O H CO H + HCO� �

Gas Exchangeتبادل الغازات

المصطلـــــــــــــــــــــــــــــــــح تعريف المصطلــــــــــحMechanisms Of Gas Exchange آليات تبادل الغازات Three Phases Of Gas Exchange مراحل تبادل الغازاتBreathing التنفسTransport Of Oxygen And Carbon Dioxide In Blood

قل ا.كسجين و ثاني اكسد الكربون في الدم

Body Tissues Take Up Oxygen And Release Carbon Dioxide

امتصاص انسجة الجسم ل2كسجين و التخلص من ثاني اكسد الكربون

Cellular Respiration التنفس الخلويRequires A Continuous Supply Of Oxygen

تزويد مستمر با7كسجين والتخلص من ثاني اكسد الكربونRequires A Continuous Supply Of Oxygen And The Disposal Of Carbon Dioxide

تزويد مستمر با7كسجين والتخلص من ثاني اكسد الكربون

Respiratory Surfaces Must Be Thin And Moist For Diffusion Of O2 And CO2

ينبغي للسطوح التنفسية ان تكون رقيقة ورطبة .نتشار ا.كسجين وثاني اكسيد الكربون عبرھا

Earthworms ديدان ا.رضMost Animals Have Specialized Body Parts That Promote Gas Exchange

تمتلك معظم الحيوانات اجزاء متخصصة بالجسم تقوم بعملية تبادل الغازات

Gills لخياشيمTracheal Systems In Arthropods اجھزة القصبات الھوائية في مفصليات ا.رجلTetrapods ا.رجلرباعيات

Gas Exchangeتبادل الغازات

المصطلـــــــــــــــــــــــــــــــــح تعريف المصطلــــــــــح

Amphibians البرمائياتReptiles الزواحف Mammals الثدياتExtensions Of The Body لسطح الجسم تمدداتIncrease Surface To Volume Ratio الحجم الىتزيد من نسبة السطح Gas Exchange تبادل الغازاتVentilation تھويةCountercurrent Flow التيار المعاكسAdvantages فوائدHigher Concentrations تركيزات اكبرRespiratory Surfaces التنفسية اجسامھاسطوح Insect Tracheal Systems القصبية للحشرات ا.جھزةTiny Branching Tubes دقيقة متفرعة انابيبAir Is Piped Directly To Cells يا الىيضخ الھواء مباشرةPالخEvolved In Shallow Water بدأت حياتھا في المياه الضحلةDiverged تفرعتThree Major Lineages رئيسية افرعثPثة Nonbird Reptiles الزواحف غير الطائرةLower Metabolic Rates ايضية منخفضة

Gas Exchangeتبادل الغازات

المصطلـــــــــــــــــــــــــــــــــح تعريف المصطلــــــــــح

Inhaled Through يستنشق الھواء, Nasal Cavity ا.نفيالتجويف

Filtered By Hairs And Mucus Surfaces ا.سطح وعن طريق الشعر ) من العوالق(يرشح الھواء المخاطية

Air Is Warmed And Moisturized تم تدفئة وترطيب الھواء Air Is Sampled For Odors يتم فرز الھواء من اجل تمييز الروائح Nasal Cavity ،ا.نفيالتجويف Pharynx Pharynxالبلعوم البلعومThen Larynx, Past The Vocal Cords الحنجرة مار با. حبال الصوتيةTrachea الى القصبات الھوائيةCartilage Rings مفتوحة بحلقات غضروفية Paired Bronchi الشعب الھوائيةBronchioles الھوائية الشعيباتAlveoli, الحويصPت الھوائيةGrapelike Clusters Of Air Sacs عنقود من ا.كياس الھوائيةHigh Surface Area Of Capillaries مساحة السطح العالية للشعيرات الدمويةHigh Surface Area Of Alveoli ت الھوائيةPمساحة السطح العالية للحويصO2 Diffuses Into The Blood ينتشر ا.كسجين الى الدمCO2 Diffuses Out Of The Blood الكربون خارج الدم اكسيديطرد ثاني

Gas Exchangeتبادل الغازات

المصطلـــــــــــــــــــــــــــــــــح تعريف المصطلــــــــــح

Mucus And Cilia المخاط وا7ھدابProtect The Lungs تحمي الرئتينDamaged By Smoking ان تتلف بالتدخينLung Cancer سرطان الرئةHeart Disease امراض القلبEmphysema ضيق التنفسRisk Of Heart Attacks And Strokes يزيد نوبات القلب والجلطاتRaises Blood Pressure يرفع من ضغط الدم

يزيد من التعرض �نواع الكلسترول الضارةالكلسترول Increases Harmful Types Of Cholesterol

يزيد من التعرض �نواع الكلسترول الضارةالكلسترول الضارة

Accidents, Alcohol, Drug Abuse, HIV, And Murders Combined

تعاطي الكحول وا`دمان على , يفوق الموت من الحوادث المخدرات و ا.يدز و ا.غتيا.ت

Breathing التنفسAlternate Inhalation And Exhalation Of Air (Ventilation)

)التھوية(تعاقب شھيق وزفير الھواء

Inhalation الشھيقRib Cage Expands القفص الصدري ) يتسع(يتمدد Diaphragm Moves Downward ينخفض الحجاب الحاجزPressure Around Lungs Decreases ينخفض الضغط حول الرئة

Gas Exchangeتبادل الغازات

المصطلـــــــــــــــــــــــــــــــــح تعريف المصطلــــــــــح

Air Is Drawn Into The Respiratory Tract يسحب الھواء الى الممرات التنفسية Exhalation الزفيرRib Cage Contracts القفص الصدري ) يضيق (ينقبض Diaphragm Moves Upward يرتفع الحجاب الحاجز الى اعلى Pressure Around The Lungs Increases يزداد الضغط حول الرئتين Air Is Forced Out Of The Respiratory Tract

ويطرد الھواء خارج الممرات التنفسية

Automatic Control Automatic Controlالتحكم ا.وتوماتيكي التحكم ا.وتوماتيكيBreathing Control Centers مراكز التحكم بالتنفس

Respond To CO2 Levels تستشعر مستويات ثاني اكسيد الكربون في الدم وتستجيب لھا

Drop In Blood Ph Increases انخفاض ا#س الھيدروجيني في الدم يزيدRate And Depth Of Breathing معدل وعمق التنفس Transport Of Gases In The Human Body نقل الغازات في جسم ا.نسانHeart Pumps Blood To Two Regions يضخ القلب الدم الى منطقتين Right Side Pumps Oxygen-Poor Blood To The Lungs

يضخ الجانب ا.يمن الدم الفقير الى ا.كسجين الى الرئتين

Left Side Pumps Oxygen-Rich Blood To The Body

ضخ الجانب ا.يسر الدم الغني با7كسجين الى بقية اجزاء الجسم

In The Lungs, Blood Picks Up O2 And Drops Off CO2

اكسيدو يطرد ثاني ا.كسجينفي الرئتين ، يأخذ الدم الكربون

In The Body Tissues, Blood Drops Off O2 And Picks Up CO2

اكسيدويأخذ ثاني ا.كسجينيترك الدم , الجسم انسجةفي الكربون

O2 Moves From The Alveoli Of The Lungs Into The Blood

الدم الىمن الحويصPت الھوائية للرئتين ا.كسجينيتحرك

CO2 Moves From The Blood Into The Alveoli Of The Lungs

الحويصPت الىالكربون من الدم اكسيديتحرك ثاني الھوائية للرئتين

المصطلـــــــــــــــــــــــــــــــــح تعريف المصطلــــــــــح

Gas Exchangeتبادل الغازات

Alveoli Of The Lungs الھوائية للرئتين Tissues Have More CO2 And Less O2 Than In The Blood

وأكسجين اقل مما ھو في الدم اكثرالكربون اكسيدثاني بھا

CO2 Moves From The Tissues Into The Blood

الدم الى ا.نسجةالكربون من اكسيديتحرك ثاني

O2 Moves From The Blood Into The Tissues

ا.نسجة الىمن الدم ا.كسجينيتحرك

Animals Transport O2 Bound To Proteins المرتبط ببروتينات ا.كسجينمعظم الحيوانات تنقل Respiratory Pigments التنفسية الصبغاتCopper-Containing Pigment المحتوية على النحاس الصبغاتMollusca لرخوياتIron-Containing Hemoglobin الھيموجلوبين المحتوي على الحديدVertebrates معظم الفقاريات

المصطلـــــــــــــــــــــــــــــــــح تعريف المصطلــــــــــح

Gas Exchangeتبادل الغازات

Vertebrates معظم الفقارياتInvertebrates الPفقارياتBuffers Blood ويعادل الدمHeme Group الھيممجموعة CO2 In The Blood Is Transported As الكربون في الدم اكسيدينقل معظم ثاني Bicarbonate Ions In The Plasma في البPزما البيكربوناتھيئة ايونات