Transcript O 2 - Saint Demetrios Astoria School

Chapter 23
Circulation and Respiration
PowerPoint® Lectures for
Campbell Essential Biology, Fourth Edition
– Eric Simon, Jane Reece, and Jean Dickey
Campbell Essential Biology with Physiology, Third Edition
– Eric Simon, Jane Reece, and Jean Dickey
Lectures by Chris C. Romero, updated by Edward J. Zalisko
© 2010 Pearson Education, Inc.
Biology and Society:
The ABCs of Saving Lives
• The transport of gases into and out of the body relies upon a close
relationship between the:
– Circulatory system
– Respiratory system
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Figure 23.00
• In emergency situations, rescuers follow a set of procedures
known as the ABCs of lifesaving:
– A is for airway
– B is for breathing
– C is for circulation
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UNIFYING CONCEPTS OF ANIMAL
CIRCULATION
• Every organism must exchange materials with its environment,
relying upon:
– Diffusion, the spontaneous movement of molecules from an area of
higher concentration to an area of lower concentration
– A circulatory system, for all but the simplest animals
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Open and Closed Circulatory Systems
• Circulatory systems consist of a:
– Central pump
– Vascular system
– Circulating fluid
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O2-rich blood
O2-poor blood
Interstitial fluid
Gill
Capillary
capillaries bed
Heart
Capillary beds
Arteriole
Artery
(O2-rich blood)
Venule
Vein
Gill
capillaries
Atrium
Ventricle
Heart
Artery
(O2-poor blood)
(b) Closed circulatory system
Figure 23.1b
• In a closed circulatory system, blood is:
– Confined to vessels
– Distinct from the interstitial fluid, the fluid that fills the spaces around
cells
• Closed circulatory systems are found in:
– Many invertebrates, including earthworms and octopuses
– Vertebrates
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• The cardiovascular system of vertebrates consists of the:
– Heart
– Blood vessels
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• In the heart the:
– Atrium receives blood
– Ventricle pumps blood away from the heart
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• Blood is confined to three main types of blood vessels:
– Arteries carry blood away from the heart
– Capillaries are the site of exchange between blood and interstitial fluid
– Veins return blood back to the heart
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THE HUMAN CARDIOVASCULAR SYSTEM
• In the human cardiovascular system, the:
– Central pump is the heart
– Vascular system is the blood vessels
– Circulating fluid is the blood
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The Path of Blood
• Humans and other terrestrial vertebrates have a double circulation
system.
• A double circulation system consists of a:
– Pulmonary circuit between the heart and lungs
– Systemic circuit between the heart and the rest of the body
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CO2
CO2
O2
CO2
Lung
Lung
O2
O2
Heart
O2
O2-rich blood
O2-poor blood
CO2
(a) Pulmonary circuit
(b) Systemic circuit
Figure 23.2
CO2
CO2
Lung
Lung
O2
O2
Heart
O2-rich blood
O2-poor blood
(a) Pulmonary circuit
Figure 23.2a
CO2
O2
O2
O2-rich blood
O2-poor blood
CO2
(b) Systemic circuit
Figure 23.2b
• One complete trip through the human cardiovascular system:
– Takes about one minute
– Requires two passes through the heart
Animation: Path of Blood in Mammals
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Capillaries of
head, chest,
and arms
Superior
vena cava
Pulmonary
artery
Pulmonary
artery
Capillaries
of lung
Pulmonary
vein
Right atrium
Right ventricle
Inferior
vena cava
O2-rich blood
O2-poor blood
Aorta
Capillaries
of lung
Pulmonary vein
Left atrium
Left ventricle
Capillaries of
abdominal region
and legs
Figure 23.3-11
How the Heart Works
• The human heart:
– Is a muscular organ about the size of a fist
– Is located under the breastbone
– Has four chambers
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• The path of blood flow through the human heart functions as two
pumps moving blood between the:
– Heart and lungs
– Heart and the rest of the body
Blast Animation: Anatomy of the Heart
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O2-rich blood
O2-poor blood
From
body
To
body
Right
lung
Left
lung
Right atrium
Left atrium
Valves
Valves
Left
Right
From ventricle ventricle
body
Figure 23.4
The Cardiac Cycle
• The heart relaxes and contracts throughout our lives.
– Diastole is the relaxation phase of the heart cycle.
– Systole is the contraction phase.
Blast Animation: Cardiac Cycle Overview
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Atria contract. Blood is
forced into ventricles.
Heart is relaxed.
Blood flows in.
0.1
sec
Diastole
0.8
sec
0.3
sec
Systole
0.4
sec
Ventricles contract.
Blood is pumped out.
Figure 23.5-3
The Pacemaker and the Control of Heart Rate
• The pacemaker, or SA (sinoatrial) node:
– Sets the tempo of the heartbeat
– Is composed of specialized muscle tissue in the wall of the right atrium
Blast Animation: Electrical Coordination of the Cardiac Cycle
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Wire leading
to SA node
Pacemaker
(SA node)
Heart
Artificial
pacemaker
AV node
Right
atrium
Right ventricle
Impulses
Pacemaker
spread
generates
through
electrical
atria.
impulses.
(a) The heart’s natural pacemaker
Impulses
reach
ventricles.
(b) Artificial pacemaker
Figure 23.6
• In certain kinds of heart disease, the heart fails to maintain a
normal rhythm.
• The remedy for this failure of the electrical control of the heart is:
– An artificial pacemaker, a small electronic device surgically implanted
near the SA node
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Blood Vessels
• If the heart is the body’s “pump,” then the “plumbing” is the
system of arteries, veins, and capillaries.
– Arteries carry blood away from the heart.
– Veins carry blood toward the heart.
– Capillaries allow for exchange between the bloodstream and tissue cells.
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• All blood vessels are lined by a thin layer of tightly packed
epithelial cells.
• Structural differences in the walls of the different kinds of blood
vessels correlate with their different functions.
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From
heart
To
heart
Epithelium
Epithelium
Smooth
muscle
Connective
tissue
Valve
Epithelium
Smooth
muscle
Connective
tissue
Artery
Vein
Venule
Arteriole
Capillary
Figure 23.8
Blood Flow through Arteries
• The force that blood exerts against the walls of blood vessels is
blood pressure.
– Blood pressure is the main force driving the blood from the heart to the
capillary beds.
– A pulse is the rhythmic stretching of the arteries caused by the pressure
of blood forced into the arteries during systole.
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• Optimal blood pressure for adults is below 120 systolic and below
80 diastolic.
• High blood pressure, or hypertension, is:
– Persistent systolic blood pressure higher than 140 and/or
– Diastolic blood pressure higher than 90
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Blood Flow through Capillary Beds
• At any given time, only about 5–10% of the capillaries have a
steady flow of blood.
• The regulation of blood flow through capillaries
– Is controlled by muscles
– Reflects shifting demands by organs of the body
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Capillary
Tissue cell
Red blood cell
Diffusion of
O2 and
nutrients out
of capillary
and into
tissue cells
Diffusion
of CO2 and
wastes out
of tissue
cells and
into capillary
To vein
LM
Interstitial
fluid
(a) Capillaries
(b) Chemical exchange
Figure 23.9
• The walls of capillaries are thin and leaky.
– At the arterial end of the capillary, blood pressure pushes fluid rich in
oxygen, nutrients, and other substances into the interstitial fluid.
– At the venous end of the capillary CO2 and other wastes diffuse from
tissue cells into the capillary bloodstream.
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Blood Return through Veins
• Blood returns to the heart:
– After chemicals are exchanged between the blood and body cells
– At a pressure that has nearly dropped to zero
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• Blood moves back towards the heart because of:
– Surrounding skeletal muscles that compress the veins
– One-way valves that permit blood flow only toward the heart
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To
heart
Valve (open)
Skeletal muscle
Valve (closed)
Figure 23.10
Blood
• An adult human has about 5 L (11 pints) of blood.
• By volume, blood is about:
– 45% cells and
– 55% plasma, consisting of about:
– 90% water
– 10% dissolved salts, proteins, and other molecules
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Plasma Cellular
(55%)
elements (45%)
Red blood cells
(erythrocytes)
Water (90%
of plasma)
Proteins
Dissolved salts
(such as sodium,
potassium, calcium)
Substances being
transported (such as
O2, CO2, nutrients,
wastes, hormones)
Blood
White blood cells
(leukocytes)
Platelets
Figure 23.11
Red Blood Cells and Oxygen Transport
• Red blood cells (erythrocytes) are:
– Shaped like discs with indentations in the middle
– The most numerous type of blood cell
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CELLULAR COMPONENTS OF BLOOD
Platelets
(bits of membrane-enclosed
cytoplasm that aid clotting)
White Blood Cells
(cells that fight infection)
Colorized SEM
Red Blood Cells
(cells that carry oxygen)
Colorized SEM
Colorized SEM
Colorized SEM
Fibrin
Red blood cell
Figure 23.12
• Carbohydrate-containing molecules on the surface of red blood
cells determine the blood type.
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Blood
Antibodies Reactions When Blood from Groups Below Is
Group
Genotypes Red Blood Cells Present in Mixed with Antibodies from Groups at Left
(Phenotype)
Blood
A
B
AB
O
Carbohydrate A
IAIA
Anti-B
A
or
IAi
Carbohydrate B
IBIB
B
Anti-A
or
IBi
AB
IAIB
—
O
ii
Anti-A
Anti-B
Figure 9.20
• Each red blood cell contains large amounts of the protein
hemoglobin, which:
– Contains iron
– Transports oxygen throughout the body
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• Anemia may result from:
– An abnormally low amount of hemoglobin or
– A low number of red blood cells
• The hormone EPO boosts production of red blood cells.
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White Blood Cells and Defense
• White blood cells (leukocytes) fight:
– Infections
– Cancer
• There are about 700 times more red blood cells than white blood
cells.
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Colorized SEM
White Blood Cells
(cells that fight infection)
Figure 23.12b
Platelets and Blood Clotting
• Blood contains two components that aid in clotting:
– Platelets, bits of cytoplasm pinched off from larger cells in the bone
marrow
– Clotting factors released from platelets that convert fibrinogen, a protein
found in plasma, into a threadlike protein called fibrin
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Stem Cells and the Treatment of Leukemia
• Leukemia:
– Is cancer of white blood cells
– May require treatment using:
– Radiation
– Chemotherapy, and/or
– Bone marrow transplantation
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Colorized SEM
Platelets
(bits of membrane-enclosed
cytoplasm that aid clotting)
Colorized SEM
Fibrin
Red blood cell
Figure 23.12c
Cardiovascular Disease
• The cardiovascular system contributes to homeostasis by:
–
Exchanging nutrients and wastes with the interstitial fluid
–
Controlling the composition of blood by moving it through the lungs,
liver, and kidneys
–
Helping to regulate temperature by moving blood to or away from the
skin
–
Distributing hormones
–
Defending against foreign invaders
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• Cardiovascular disease:
– Includes all diseases affecting the heart and blood vessels
– Accounts for 40% of all deaths in the United States
– Kills more than 1 million people each year
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• Coronary arteries:
– Supply the heart muscle
– Can narrow or close, contributing to a heart attack
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Aorta
Coronary artery
(supplies oxygen
to the heart muscle)
Dead muscle
tissue
Blockage
Figure 23.13
• Atherosclerosis:
– Is a chronic cardiovascular disease
– Results from the buildup of cholesterol and other substances in the walls
of arteries
– Gradually narrows arteries throughout the body
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Plaque
Connective
tissue
Smooth
muscle
Epithelium
Normal artery
Artery partially blocked by plaque
Figure 23.14
• Heart disease:
– Involves inherited factors but
– Can be reduced by:
–
Not smoking
–
Exercising regularly
–
Eating a heart-healthy diet
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UNIFYING CONCEPTS OF ANIMAL
RESPIRATION
• Cellular respiration:
– Uses oxygen and glucose
– Produces water, carbon dioxide, and usable energy in the form of ATP
• Cells using cellular respiration:
– Need a constant supply of oxygen
– Must continuously dispose of CO2
• The respiratory system promotes this gas exchange.
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O2
CO2
Environment
Cell
C6H12O6
Glucose
6 O2
6 CO2
Cellular
Oxygen respiration Carbon
dioxide
6 H2O
ATP
Water
Energy
Figure 23.UN1
The Structure and Function of Respiratory
Surfaces
• Animals can get oxygen from:
– The atmosphere, about 21% oxygen
– Bodies of water, about 3–5% oxygen
• Gas exchange occurs at the respiratory surface, which must be:
– Large enough to take up oxygen for every cell in the body
– Adapted to the lifestyle of the organism
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• In most land-dwelling animals, the respiratory surfaces are:
– Folded into the body
– Open to the air only through narrow tubes
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Body surface
Respiratory
surface
(within lung)
CO2 O2
CO2
O2
Capillary
(b) Lungs
Figure 23.16b
• Lungs are:
– The most common respiratory surface of terrestrial organisms
– Located in only one part of the body
• The circulatory system transports oxygen from the respiratory
surface to the rest of the body.
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RESPIRATORY ORGANS
Skin
(entire body surface)
Gills
(extensions of the
body surface)
Tracheae
(branching internal
tubes)
Lungs
(localized internal
organs)
Gills
Tracheae
(internal
tubes)
Moist skin of a leech
Gills of a sea slug
Tracheae of a silk
moth caterpillar
Air
pore
Model of a pair of
human lungs
Figure 23.17
THE HUMAN RESPIRATORY SYSTEM
• The human respiratory system has three phases of gas exchange:
– Breathing
– Transport of oxygen from the lungs to the rest of the body via the
circulatory system
– Removal of oxygen from the blood and release of CO2 into the blood by
cells of the body
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O2
Breathing
CO2
Lung
Transport of gases by
the circulatory system
Circulatory system
Servicing of cells within
the body tissues
Mitochondria
O2
CO2
Capillary
Cell
Figure 23.18-3
The Structure and Function of the Human
Respiratory System
• Air moves sequentially from the mouth and nose:
– To the pharynx, where digestive and respiratory systems meet
– To the larynx (voice box) and trachea (windpipe)
– To the bronchi (one bronchus to each lung)
– To the bronchioles, the smallest branches of the tubes within the lungs
and
– To the alveoli, the air sacs where gas exchange primarily occurs
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Pharynx
To
heart
Esophagus
Nasal cavity
Larynx (voice box)
Trachea
(windpipe)
Left lung
Right lung
From
heart
O2-rich
blood
O2-poor
blood
Bronchiole
Bronchus
Bronchiole
O2
Diaphragm
Heart
(a) Overview of the human respiratory system
CO2
Alveoli
Blood
capillaries
(b) The structure of alveoli
Figure 23.19
• Muscles in the voice box can stretch vocal cords within the
larynx.
• During exhalation, outgoing air can produce vocal sounds as air
passes by the stretched vocal cords.
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Taking a Breath
• Breathing is the alternating process of:
– Inhalation
– Exhalation
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• During inhalation, the chest is expanded by the:
– Upward movement of the ribs
– Downward movement of the diaphragm
• Air moves into the lungs:
– By negative pressure breathing
– As the air pressure in the lungs is lowered by the expansion of the chest
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Rib cage
expands as
rib muscles
contract
Air
inhaled
Rib cage gets
smaller as
rib muscles
relax
Air
exhaled
Lung
Diaphragm
contracts
(moves
down)
Inhalation
(Air pressure is
higher in atmosphere
than in lungs.)
Diaphragm
relaxes
(moves up)
Exhalation
(Air pressure is
lower in atmosphere
than in lungs.)
Figure 23.20
• Breathing can be controlled:
– Consciously, as you deliberately take a breath, or
– Unconsciously
• Breathing control centers in the brain stem:
– Automatically control breathing most of the time
– Regulate breathing rate in response to CO2 levels in the blood
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Brain
Breathing control
centers in the brain
monitor the rising
CO2 levels in the
blood.
CO2 levels in the
blood rise as a
result of exercise.
Rib muscles
Breathing control
centers
Nerve signals trigger
contraction of muscles
to increase breathing
rate and depth.
Diaphragm
Figure 23.21-3
The Role of Hemoglobin in Gas Transport
• The human respiratory system:
– Takes in O2
– Expels CO2, but
– Relies on the circulatory system to shuttle these gases between the lungs
and the body’s cells
Animation: CO2 From Blood to Lungs
Animation: CO2 From Tissues to Blood
Animation: O2 From Blood to Tissues
Animation: O2 From Lungs to Blood
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CO2 in
exhaled air
O2 in
inhaled air
Air spaces
Alveolus
CO2
O2
Capillaries
of lung
CO2-rich,
O2-poor
blood
O2-rich,
CO2-poor
blood
Tissue Heart
capillaries
CO2
O2
Tissue cells throughout body
Figure 23.22
• However, there is one problem with this simple gas delivery
system.
– Problem: Oxygen does not dissolve readily in blood.
– Solution: Oxygen is carried in hemoglobin molecules within red blood
cells.
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Heme
group
Iron
atom
O2 loaded
in lungs
O2 unloaded
in tissues
O2
O2
Polypeptide chain
Figure 23.23
• A shortage of iron:
– Causes a decrease in the rate of hemoglobin synthesis
– Can lead to anemia
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How Smoking Affects the Lungs
• Breathing exposes your respiratory tissues to potentially
damaging chemicals, including one of the worst pollutants,
tobacco smoke.
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• Tobacco smoke:
– Irritates the cells that line the bronchi and trachea
– Inhibits their ability to remove foreign substances from the airways
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• Smoking:
–
Kills half of all people who smoke, about 440,000 Americans every
year,
–
Causes 90% of all lung cancer (one of the deadliest forms of cancer)
–
Causes more deaths than the combined total of:
– All accidents
– Alcohol and other drug abuse
– HIV
– Murders
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Lung
Heart
(a) Healthy lungs (nonsmoker)
(b) Cancerous lungs (smoker)
Figure 23.24
Evolution Connection:
Choked Up
• The Heimlich maneuver:
– Involves quick thrusts to the diaphragm
– Compresses the lungs
– Forces air rapidly out of the chest
– May dislodge food or other objects obstructing the breathing pathway
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• The food and air passageways pass through a common tube in the
rear of the pharynx.
• Choking results when food or other substances get diverted from
the food to the air pathway.
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• The common passageway of food and air reflects the remodeling
of the food passageway during the evolution of the respiratory
system in shallow-water fishes.
• Choking is thus a consequence of the evolutionary remodeling of
the throat.
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Figure 23.25