Download 5-gas exchange

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