BIOLOGYCONCEPTS & CONNECTIONS
Fourth Edition
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Neil A. Campbell • Jane B. Reece • Lawrence G. Mitchell • Martha R. Taylor
From PowerPoint® Lectures for Biology: Concepts & Connections
CHAPTER 23Circulation
Modules 23.1 – 23.3
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• As with all land animals, the giraffe and the corn snake are constantly subject to the force of gravity
How Does Gravity Affect Blood Circulation?
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• The circulatory system keeps blood pumping despite gravity’s pull
– Muscle contractions help blood travel uphill in the veins of a giraffe’s long legs
– The wriggling of the corn snake squeezes its veins and increases circulation
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Most animals have a circulatory system – It transports O2 and nutrients to cells
– It takes away CO2 and other wastes
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Capillaries are microscopic blood vessels – They form an intricate network among
the tissue cells
23.1 The circulatory system associates intimately with all body tissues
Figure 23.1A
Redbloodcell
Capillary
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
– No substance has to diffuse far to enter or leave a cell
Figure 23.1B
Capillary
INTERSTITIALFLUID
Tissuecell
Diffusion ofmolecules
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• In cnidarians and flatworms, the gastrovascular cavity functions in both – digestion – internal transport
23.2 Several types of internal transport have evolved in animals
MECHANISMS OF INTERNAL TRANSPORT
Figure 23.2A
Mouth
Circularcanal
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Most animals have a separate circulatory system, either open or closed
• Open systems– A heart pumps blood through open-ended
vessels into spaces between cells
Figure 23.2B
PoresTubular heart
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Closed systems– A heart pumps blood through arteries and
capillary beds– The blood returns to the heart via veins
Figure 23.2C
Artery(O2-rich blood)
ArterioleCapillary beds
Venule
Vein
Atrium
VentricleHeartArtery
(O2-poor blood)Gillcapillaries
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• A fish has a single circuit of blood flow
23.3 Vertebrate cardiovascular systems reflect evolution
Figure 23.3A
Gill capillaries
Heart:
Ventricle (V)
Atrium (A)
Systemic capillaries
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• The cardiovascular system of land vertebrates has two circuits
• The pulmonary circuit– conveys blood
between the heart and gas-exchange tissues
• The systemic circuit– carries blood
between the heart and the rest of the body
Figure 23.3B
PULMONARYCIRCUIT
A
Systemic capillaries
Lung capillaries
VRight
SYSTEMICCIRCUIT
A
VLeft
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• The mammalian heart has two thin-walled atria that pump blood into the ventricles– The thick-walled ventricles pump blood to
all other body organs
23.4 The human heart and cardiovascular system typify those of mammals
THE MAMMALIAN CARDIOVACULAR SYSTEM
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 23.4A
Pulmonaryartery
Superiorvena cava
RIGHTATRIUM
Pulmonaryveins
Semilunarvalve
Atrioventricularvalve
Inferiorvena cava
Aorta
Pulmonaryartery
LEFTATRIUM
Pulmonaryveins
Semilunarvalve
Atrioventricularvalve
RIGHTVENTRICLE
LEFTVENTRICLE
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 23.4B
RIGHT VENTRICLE
1
23
Capillariesof right lung
3
Capillariesof left lung
4
LEFT ATRIUM5
LEFT VENTRICLE
6
Aorta
7Capillaries ofHead and arms
8
Capillaries ofabdominal organsand legs
9
Superiorvena cava
10
Inferiorvena cava
11
RIGHT ATRIUM
Pulmonaryvein
Aorta
Pulmonaryvein
Pulmonaryartery
Pulmonaryartery
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• A single layer of epithelial cells forms capillary walls
• Arteries and veins have smooth muscle and connective tissue– Valves in veins prevent the backflow of
blood
23.5 The structure of blood vessels fits their functions
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 23.5
Epithelium
Smoothmuscle
Connectivetissue
ARTERY
ARTERIOLE
CAPILLARY
Epithelium Basementmembrane
Epithelium
Smoothmuscle
Connectivetissue
Valve
VEIN
VENULE
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Diastole– Blood flows from
the veins into the heart chambers
23.6 The heart contracts and relaxes rhythmically
Figure 23.6
Heart isrelaxed.AV valvesare open.
1 2
3
Atriacontract.
Ventriclescontract.Semilunarvalvesare open.
SYSTOLE
DIASTOLE
0.4 sec
0.1 sec
0.3 sec
• Systole– The atria briefly
contract and fill the ventricles with blood
– Then the ventricles contract and propel blood out
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Heart valves prevent backflow
• Cardiac output – The amount of blood pumped into the
aorta by the left ventricle per minute
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• The SA node (pacemaker) generates electrical signals that trigger the contraction of the atria
• The AV node then relays these signals to the ventricles
23.7 The pacemaker sets the tempo of the heartbeat
Figure 23.7
Pacemaker(SA node)
1 2 3 4
Rightatrium
Rightventricle
AV nodeSpecializedmuscle fibers
ECG
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• An electrocardiogram (ECG) is a recording of electrical changes in the skin resulting from the electrical signals in the heart– Control centers in the brain adjust heart
rate to body needs
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• A heart attack is damage that occurs when a coronary feeding the heart is blocked
23.8 Connection: What is a heart attack?
Figure 23.8A
Rightcoronaryartery
Aorta
Leftcoronaryartery
Blockage
Dead muscle tissue
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Blood vessel blockage is usually due to blood clots
Figure 23.8B
Connectivetissue
Smoothmuscle Epithelium Plaque
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Blood pressure depends on– cardiac output– resistance of vessels
23.9 Blood exerts pressure on vessel walls
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Pressure is highest in the arteries– It drops to
zero by the time the blood reaches the veins
Figure 23.9A
Diastolicpressure
Systolicpressure
Relative sizes andnumbersof blood vessels
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Three factors keep blood moving back to the heart– muscle contractions– breathing– one-way valves
Figure 23.9B
Direction ofblood flowin vein
Valve (closed)Skeletal muscle
Valve (open)
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Blood pressure is measured as systolic and diastolic pressures
23.10 Connection: Measuring blood pressure can reveal cardiovascular problems
Figure 23.10
Blood pressure120 systolic80 diastolic(to be measured)
1 2 3 4
Rubber cuffinflated with air
Pressurein cuffbelow120
Pressurein cuffbelow 80
Artery
Pressurein cuffabove120
Soundsaudible instethoscope
Soundsstop
Arteryclosed
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Hypertension is persistent systolic pressure higher than 140 mm Hg and/or diastolic pressure higher than 90 mm Hg– It is a serious cardiovascular problem
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Muscular constriction of arterioles and precapillary sphincters controls the flow through capillaries
23.11 Smooth muscle controls the distribution of blood
Figure 23.111 Sphincters relaxed 2 Sphincters contracted
Precapillary sphincters Thoroughfarechannel
CapillariesArteriole Venule Arteriole Venule
Thoroughfarechannel
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
23.12 Capillaries allow the transfer of substances through their walls
Figure 23.12A
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• The transfer of materials between the blood and interstitial fluid can occur by– leakage through clefts in the capillary
walls– diffusion through the wall– blood pressure– osmotic pressure
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 23.12B
Arterialend of
capillary
Tissue cells
Osmoticpressure
INTERSTITIALFLUID NET PRESSURE
OUT
Bloodpressure
Bloodpressure
Osmoticpressure Venous
end ofcapillary
NET PRESSUREIN
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Plasma is an aqueous solution of various substances
23.13 Blood consists of cells suspended in plasmaSTRUCTURE AND FUNCTION OF BLOOD
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 23.13
Withdrawblood
Place in tubePLASMA 55%
CONSTITUENT MAJOR FUNCTIONS
WaterSolvent forcarrying othersubstances
SaltsOsmotic balance,pH buffering, andregulation ofmembranepermeability
SodiumPotassiumCalciumMagnesiumChlorideBicarbonate
Plasma proteinsOsmotic balance,pH bufferingClottingImmunity
Albumin
FibrinogenImmunoglobins(antibodies)
Substances transported by bloodNutrients (e.g., glucose, fatty acids, vitamins)Waste products of metabolismRespiratory gases (O2 and CO2)Hormones
Centrifuge
CELLULAR ELEMENTS 45%
CELL TYPE NUMBER(per mm3 of blood)
FUNCTIONS
Erythrocytes(red blood cells) 5–6 million Transport of
oxygen (and carbon dioxide)
Leukocytes(white blood cells) 5,000–10,000
Defense andimmunity
BasophilEosinophil
Neutrophil
Lymphocyte
Monocyte
Platelets 250,000–400,000 Blood clotting
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
23.14 Red blood cells transport oxygen
Figure 23.14
• Red blood cells contain hemoglobin – Hemoglobin enables
the transport of O2
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
23.15 White blood cells help defend the body
Figure 23.15
• White blood cells function both inside and outside the circulatory system – They fight infections and cancer
Basophil
Neutrophil
Monocyte
Eosinophil
Lymphocyte
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
23.16 Blood clots plug leaks when blood vessels are injured
Figure 23.16B
• When a blood vessel is damaged, platelets respond– They help trigger
the formation of an insoluble fibrin clot that plugs the leak
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 23.16A
Platelet releases chemicalsthat make nearby platelets sticky
Injury to lining of bloodvessel exposes connectivetissue; platelets adhere
1 2 3Platelet plug forms Fibrin clot trapsblood cells
Connectivetissue
Plateletplug
Clotting factors from:
Platelets
Damaged cells
Calcium andother factorsin blood plasma
Prothrombin Thrombin
Fibrinogen Fibrin
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
23.17 Connection: Stem cells offer a potential cure for leukemia and other blood cell diseases
Figure 23.17
• All blood cells develop from stem cells in bone marrow– Such cells may prove
valuable for treating certain blood disorders
Top Related