Animal Circulation and Respiration SUNY Orange at S. S. Seward Institute S. S. Seward Institute.
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Transcript of Circulation and Respiration Unifying concepts of animal circulation The human cardiovascular...
Circulation and Respiration Unifying concepts of animal circulation
The human cardiovascular system
Unifying concepts of animal respiration
The human respiratory system
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, and
– a circulatory system, which facilitates the exchange of materials for all but the simplest animals.
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Open and Closed Circulatory Systems
• Circulatory systems typically consist of a
– central pump,
– vascular system, and
– circulating fluid.
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• In an open circulatory system,
– the heart pumps blood into large open-ended vessels and
– fluid circulates freely among cells.
• Open circulatory systems are found in many invertebrates, including
– arthropods and
– most molluscs.
Open and Closed Circulatory Systems
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• In a closed circulatory system, blood
– stays within a set of tubes and
– is 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, and
– vertebrates.
Open and Closed Circulatory Systems
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Figure 23.1
(a) Open circulatory system (b) Closed circulatory system
Tubularheart
Circulating fluid
Interstitial fluidHeart
Heart
Vessels
VesselsCapillaries
Artery(O2-richblood)
Artery(O2-poor blood)
Vessels
CapillariesArteriole
Venule
Vein
HeartVentricleAtrium
• The cardiovascular system of vertebrates consists of the
– heart and
– blood vessels.
• In the heart,
– the atrium receives blood and
– the ventricle pumps blood away from the heart.
Open and Closed Circulatory Systems
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• Blood is confined to three main types of blood vessels:
1. Arteries carry blood away from the heart into smaller arterioles as they approach the
organs.
2. Capillaries are the site of exchange between blood and interstitial fluid.
3. Venules collect blood from the capillaries and converge to form veins, which return blood
back to the heart.
Open and Closed Circulatory Systems
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THE HUMAN CARDIOVASCULAR SYSTEM
• In the human cardiovascular system, there are three main components:
– 1. the central pump is the heart,
– 2. the vascular system is the blood vessels, and
– 3. the circulating fluid is the blood.
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The Path of Blood
• Humans and other terrestrial vertebrates have a double circulation system consisting of
– a pulmonary circuit between the heart and lungs and
– a systemic circuit between the heart and the rest of the body.
© 2013 Pearson Education, Inc.
Figure 23.2
(a) Pulmonary circuit (b) Systemic circuit
O2-rich blood
O2-poor blood
LungLung
Heart
CO2
O2
CO2
CO2 CO2
O2
O2 O2
• One complete trip through the human cardiovascular system
– takes about one minute and
– requires two passes through the heart.
The Path of Blood
© 2013 Pearson Education, Inc.
Figure 23.3-7
O2-rich bloodO2-poor blood
Capillaries ofhead, chest,and arms
Capillaries ofabdominal regionand legs
Capillariesof left lung
Capillariesof right lung
Pulmonaryartery
Pulmonaryartery
Superiorvena cava
Pulmonary vein
Inferiorvena cava
Pulmonary vein
Left ventricle
Left atriumRight atrium
Right ventricle
Aorta
27
5
461
54
33
Know this!
How the Heart Works
• The human heart
– is a muscular organ about the size of a fist,
– is located under the breastbone, and
– has four chambers.
• The path of blood flow through the human heart functions as two pumps moving blood between
– the heart and lungs and
– the heart and the rest of the body.
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Figure 23.4
O2-rich blood
O2-poor blood
Right atriumLeft atrium
Leftventricle
Rightventricle
From body
Rightlung
Leftlung
Frombody
To body
Valves Valves
Know this!
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.
• A heart murmur is a sound that may indicate a defect in one or more of the heart valves.
© 2013 Pearson Education, Inc.
Figure 23.5-3
Heart is relaxed.Blood flows in.
DIASTOLE0.4sec
Atria contract. Blood isforced into ventricles.
0.1sec
SYSTOLE
Ventricles contract.Blood is pumped out.
0.3sec0.8
sec
1
2
3
The Pacemaker and the Control of Heart Rate
• The pacemaker, or SA (sinoatrial) node,
– sets the tempo of the heartbeat and
– is composed of specialized muscle tissue in the wall of the right atrium.
• Impulses from the pacemaker spread quickly through the walls of both atria, prompting the atria to contract at the same time.
• The AV (atrioventricular) node
– is a relay point that delays the signal and
– sends impulses to the ventricles.© 2013 Pearson Education, Inc.
Figure 23.6Pacemaker(SA node)
Right atrium
AV node
Right ventricle
Wire leadingto SA node
Artificialpacemaker
Heart
Pacemaker generateselectrical impulses.
Impulses spreadthrough atria.
Impulses reachventricles.
(b) Artificial pacemaker
(a) The heart’s natural pacemaker
1 2 3
• The impulses sent by the pacemaker can be
– detected by electrodes placed on the skin and
– recorded as an electrocardiogram (ECG or EKG).
• 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.
The Pacemaker and the Control of Heart Rate
© 2013 Pearson Education, Inc.
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.
Blood Vessels
© 2013 Pearson Education, Inc.
Figure 23.7
From heart
Epithelium
Smoothmuscle
Connectivetissue
Artery
Arteriole
Capillary
Venule
Vein
ValveTo heart
Epithelium
Epithelium
Smoothmuscle
Connectivetissue
Blood Flow through Arteries
• The force that blood exerts against the walls of blood vessels is blood pressure.
– Blood pressure pushes 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.
Blood Flow through Arteries
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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, with the exception of the brain
• Blood flow through capillaries may be diverted from one part of the body to another, depending on need.
• This is called shunting
• There are three main locations which demand blood: the brain, muscles, digestion
• In general, the body does one of these at a time© 2013 Pearson Education, Inc.
• 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 interstitial fluid, and then into the capillary bloodstream.
Blood Flow through Capillary Beds
© 2013 Pearson Education, Inc.
Figure 23.8
(a) Capillaries (b) Chemical exchange
Capillary
Red blood cell
Tissue cell
Interstitial fluid
Diffusionof O2 and
nutrients outof capillary
and intotissue cells
Diffusionof CO2 andwastes outof tissuecells and
into capillary
Fromartery
LM
To vein
To vein
Figure 23.8a
(a) Capillaries
Capillary
Red blood cell
LM
Figure 23.8b
(b) Chemical exchange
Tissue cell
Interstitial fluid
Diffusionof O2 and
nutrients outof capillary
and intotissue cells
Diffusionof CO2 andwastes outof tissuecells and
into capillary
Fromartery
To veinTo vein
Blood Return through Veins
• Blood returns to the heart
– after chemicals are exchanged between the blood and body cells and
– at a pressure that has nearly dropped to zero.
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• Blood moves back toward the heart because of
– surrounding skeletal muscles that compress the veins and
– one-way valves that permit blood flow only toward the heart.
Blood Return through Veins
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Figure 23.9To heart
Valve (open)
Skeletal muscle
Valve (closed)
Blood: know all of this
• An adult human has about 5 L (11 pints) of blood.
• By volume, blood is
– a little less than half cells and
– a little more than half plasma, consisting of about
– 90% water and
– 10% dissolved salts, proteins, and other molecules.
© 2013 Pearson Education, Inc.
Figure 23.10
Blood
Platelets
White blood cells(leukocytes)
Red blood cells(erythrocytes)
Cellular elements (45%)
Plasma(55%)
Water (90%of plasma)
Proteins
Dissolved salts(such as sodium,potassium, calcium)
Substances beingtransported (suchas O2, CO2, nutrients,wastes, hormones)
Figure 23.10a
Platelets
White blood cells(leukocytes)
Red blood cells(erythrocytes)
Cellular elements (45%)
Plasma(55%)
Water (90%of plasma)
Proteins
Dissolved salts(such as sodium,potassium, calcium)
Substances beingtransported (suchas O2, CO2, nutrients,wastes, hormones)
Blood
• Suspended in plasma are three types of cellular elements:
1. red blood cells,
2. white blood cells, and
3. platelets.
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Red Blood Cells and Oxygen Transport
• Red blood cells (erythrocytes)
– are the most numerous type of blood cell and
– are shaped like discs with indentations in the middle.
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Figure 23.12
Red Blood Cells(cells that carry oxygen)
White Blood Cells (cells that fight infection)
Platelets(bits of membrane-enclosedcytoplasm that aid clotting)
CELLULAR COMPONENTS OF BLOOD
Fibrin
Red blood cell
Co
lori
zed
SE
M
Co
lori
zed
SE
M
Co
lori
zed
SE
M
Co
lori
zed
SE
M
Co
lori
zed
SE
M
• Carbohydrate-containing molecules on the surface of red blood cells determine the blood type. These are called surface antigens
Blood Typing
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BloodGroup(Phenotype) OGenotypes
AntibodiesPresent inBloodRed Blood Cells
Reactions When Blood from Groups Below Is Mixed with Antibodies from Groups at Left
A B AB
O
A
B
AB
ii
IAIB
IBIB
or
IBi
IAIA
or IAi
CarbohydrateA
CarbohydrateB
Anti-A
Anti-B
Anti-AAnti-B
—
Figure 9.20
Blood Typing
Figure 9.20c
• Each red blood cell contains approximately 250 million molecules of hemoglobin, which
– contains iron and
– transports oxygen throughout the body.
Red Blood Cells and Oxygen Transport
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Red Blood Cells and Oxygen Transport
• Anemia may result from
– an abnormally low amount of hemoglobin or
– a low number of red blood cells.
• The hormone erythropoietin (EPO) boosts production of red blood cells.
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White Blood Cells and Defense
• White blood cells (leukocytes)
– fight infections,
– are larger than red blood cells,
– lack hemoglobin, and
– are much less abundant than red blood cells (about 700 times fewer).
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Figure 23.12b
White Blood Cells (cells that fight infection)
Co
lori
zed
SE
M
Platelets and Blood Clotting
• Blood contains two components that aid in clotting:
1. platelets, bits of cytoplasm pinched off from larger cells in the bone marrow, and
2. clotting factors released from platelets that convert fibrinogen, a protein found in plasma, into a threadlike protein called fibrin.
© 2013 Pearson Education, Inc.
Figure 23.12c
Platelets(bits of membrane-enclosedcytoplasm that aid clotting)
Fibrin
Red blood cell
Co
lori
zed
SE
M
Co
lori
zed
SE
M
• In the inherited disease hemophilia, excessive and sometimes fatal bleeding can occur from even minor cuts and bruises.
• Hemophilia is caused by a genetic mutation in one of several genes that code for clotting factors.
Platelets and Blood Clotting
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• Leukemia
– is cancer of white blood cells and
– may require treatment using
– radiation,
– chemotherapy, and/or
– bone marrow transplantation.
Stem Cells and the Treatment of Leukemia
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• 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, and
– defending against foreign invaders.
Cardiovascular Disease
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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, and
– kills more than 1 million people each year.
Cardiovascular Disease
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• Coronary arteries
– supply the heart muscle and
– can narrow or close, contributing to a heart attack.
Cardiovascular Disease
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Figure 23.13
Coronary artery(supplies oxygento the heart muscle)
Dead muscletissue
Blockage
Aorta
• Atherosclerosis
– is a chronic cardiovascular disease and
– results from fatty deposits called plaque that develop in the inner walls of arteries, clogging the passages through which blood can flow.
Cardiovascular Disease
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Figure 23.14
Connectivetissue
Smoothtissue
PlaqueEpithelium
Normal artery Artery partially blocked by plaque
Partially blockedpassageway
Passagewayfor blood
• Cardiovascular disease
– involves inherited factors but
– can be reduced by
– not smoking,
– exercising regularly, and
– eating a heart-healthy diet.
Cardiovascular Disease
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UNIFYING CONCEPTS OF ANIMAL RESPIRATION
• Cells using cellular respiration
– need a steady supply of oxygen and
– must continuously dispose of CO2.
• The respiratory system promotes this gas exchange.
Figure 23.UN01
Environment
Cell
Glucose Oxygen Water EnergyCellular
respiration Carbondioxide
C6H12O66 O2 6 CO2 6 H2O ATP
CO2O2
The Structure and Function of Respiratory Surfaces
• Animals can get oxygen from
– the atmosphere, which contains about 21% oxygen, and
– bodies of water, which contain about 3–5% oxygen.
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The Structure and Function of Respiratory Surfaces
• Gas exchange occurs at the respiratory surface, which must be
– large enough to take up oxygen for every cell in the body and
– adapted to the lifestyle of the organism.
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• Moist skin is used as a respiratory surface in earthworms.
• In aquatic environments, the main respiratory surfaces are
– skin and
– extensions of the body surface called gills.
The Structure and Function of Respiratory Surfaces
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Figure 23.15
Cross section ofrespiratory surface (the skin covering the body)
Respiratorysurface (gill)
Body surface
CapillariesCapillariesCO2
CO2
O2O2
(a) Skin (b) Gills
• In most land-dwelling animals, the respiratory surfaces are
– folded into the body and
– open to the air only through narrow tubes.
The Structure and Function of Respiratory Surfaces
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• Insects breathe using a tracheal system, an extensive network of internal tubes called tracheae that
– branch throughout the body and
– extend to nearly every cell.
The Structure and Function of Respiratory Surfaces
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Figure 23.16
Respiratorysurface(tracheae)
Body cells(no capillaries)
Respiratorysurface(within lung)
Bodysurface
Bodysurface
Capillary
(a) Tracheae (b) Lungs
CO2
CO2
CO2
O2
O2
O2
• Lungs
– are located in only one part of the body and
– are the most common respiratory surface of snails, some spiders, and terrestrial vertebrates.
• The circulatory system transports gases between the respiratory surface and the rest of the body.
The Structure and Function of Respiratory Surfaces
© 2013 Pearson Education, Inc.
Figure 23.17
Skin(entire body
surface)
Gills(extensions of the
body surface)
Tracheae(branching
internal tubes)
Lungs(localized
internal organs)
RESPIRATORY ORGANS
Moist skin of a leech Gills of a sea slugTracheae of a silkmoth caterpillar
Model of a pair ofhuman lungs
Tracheae(internaltubes)
Gills
THE HUMAN RESPIRATORY SYSTEM
• The human respiratory system has three phases of gas exchange:
1. breathing, the ventilation of the lungs by alternate
inhalation and exhalation,
2. transport of oxygen from the lungs to the rest of the body via the circulatory system, and
3. diffusion of oxygen from the blood and release of CO2 into the blood by cells of the body.
© 2013 Pearson Education, Inc.
Figure 23.18-3
Circulatory system
Breathing
Lung
CO2
O2
Transport of gases bythe circulatory system
Exchange of gaseswith body cells
Mitochondria
Capillary
Cell
CO2
O2
2
1
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,
– the larynx (voice box) and trachea (windpipe),
– the bronchi (one bronchus to each lung),
– the bronchioles, the smallest branches of the tubes within the lungs, and
– the alveoli, the air sacs where gas exchange primarily occurs.
© 2013 Pearson Education, Inc.
Figure 23.19
Larynx (voice box)
Trachea (windpipe)
(a) Overview of the human respiratory system (b) The structure of alveoli
Pharynx
Right lung
Bronchus
Bronchiole
Diaphragm
EsophagusNasal cavity
Left lung
Bronchiole
Bloodcapillaries
Fromheart
Toheart
AlveoliHeart
O2-richblood
O2-poorblood
O2
CO2
• 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.
The Structure and Function of the Human Respiratory System
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Taking a Breath
• Breathing is the alternating process of
– inhalation and
– exhalation.
• During inhalation, the chest is expanded by the
– upward movement of the ribs and
– 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.
© 2013 Pearson Education, Inc.
Figure 23.20
Inhalation(Air pressure is higher in
atmosphere than in lungs.)
Exhalation(Air pressure is lower in
atmosphere than in lungs.)
Diaphragmrelaxes(moves up)
Diaphragmcontracts(movesdown)
Rib cageexpands asrib musclescontract
Rib cage getssmaller asrib musclesrelax
Airinhaled
Airexhaled
Lung
• 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 and
– regulate breathing rate in response to CO2 levels in the blood.
Taking a Breath
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Figure 23.21-3
CO2 levels in theblood rise as aresult of exercise.
Brain
Breathing controlcenters in the brainmonitor the rising CO2 levels in the blood.
Breathing controlcenters
Nerve signals trigger contraction of muscles to increase breathingrate and depth.
Rib musclesDiaphragm
1
2
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.
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Figure 23.22
AlveolusAir spaces
Capillariesof lung
Tissuecapillaries
CO2-rich,
O2-poor
blood
O2-rich,
CO2-poor
blood
O2 in
inhaled airCO2 in
exhaled air
CO2 O2
Tissue cells throughout body
CO2 O2
Heart
O2
CO
2
O 2CO2
Interstitialfluid
• However, there is one problem with this simple gas delivery system.
– Problem: Oxygen does not readily dissolve in blood plasma.
– Solution: Oxygen is carried in hemoglobin molecules within red blood cells.
• A shortage of iron
– causes a decrease in the rate of hemoglobin synthesis and
– can lead to anemia.
The Role of Hemoglobin in Gas Transport
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Figure 23.23
Hemegroup
Ironatom
Polypeptide chain
O2 loadedin lungs
O2 unloadedin tissues
O2
O2
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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• 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), and
• Tobacco smoke
– damages the cells that line the bronchi and trachea and
– interferes with the normal cleansing mechanism of the respiratory system, allowing more toxin-laden smoke particles to reach and damage the lungs’ delicate alveoli.
How Smoking Affects the Lungs
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