2. 2
Circulatory SystemsCirculatory Systems
OutlineOutline
Transport in InvertebratesTransport in Invertebrates
Open versus Closed Circulatory SystemsOpen versus Closed Circulatory Systems
Transport in VertebratesTransport in Vertebrates
Transport in HumansTransport in Humans
HeartbeatHeartbeat
Vascular PathwaysVascular Pathways
Blood PressureBlood Pressure
Cardiovascular DisordersCardiovascular Disorders
BloodBlood
ComponentsComponents
ClottingClotting
3. 3
Circulatory SystemsCirculatory Systems
Transport in InvertebratesTransport in Invertebrates
Small aquatic animals with no circulatorySmall aquatic animals with no circulatory
systemsystem
May rely on external water inMay rely on external water in
gastrovascular cavity to service cellsgastrovascular cavity to service cells
Roundworms and otherRoundworms and other
pseudocoelomatespseudocoelomates
Use a fluid-filled body cavity as a meansUse a fluid-filled body cavity as a means
of transporting substancesof transporting substances
Fluid-filled cavity can also act as aFluid-filled cavity can also act as a
hydrostatic skeletonhydrostatic skeleton
Animals that have a rigid skeletonAnimals that have a rigid skeleton
May still rely on body fluids for theMay still rely on body fluids for the
purpose of locomotionpurpose of locomotion
Bivalves pump hemolymph into the footBivalves pump hemolymph into the foot
5. 5
Circulatory SystemsCirculatory Systems
Open vs. ClosedOpen vs. Closed
Invertebrate CirculationInvertebrate Circulation
Two types of circulatory fluids:Two types of circulatory fluids:
Blood - contained within blood vesselsBlood - contained within blood vessels
Hemolymph - flows into hemocoelHemolymph - flows into hemocoel
Open Circulatory SystemOpen Circulatory System
Heart pumps hemolymph via vesselsHeart pumps hemolymph via vessels
Vessels empty into tissue spacesVessels empty into tissue spaces
Closed Circulatory SystemClosed Circulatory System
Heart pumps blood to capillariesHeart pumps blood to capillaries
Gases and materials diffuse to and from nearbyGases and materials diffuse to and from nearby
cellscells
Vessels return blood to heart without itVessels return blood to heart without it
7. 7
Circulatory SystemsCirculatory Systems
Transport in the VertebratesTransport in the Vertebrates
All vertebrates have a closed cardiovascularAll vertebrates have a closed cardiovascular
systemsystem
Vertebrate heart:Vertebrate heart:
Atrial chamber(s) of heart receive blood fromAtrial chamber(s) of heart receive blood from
general circulationgeneral circulation
Ventricle chamber(s) of heart pump blood outVentricle chamber(s) of heart pump blood out
through blood vesselsthrough blood vessels
Vertebrate vessels:Vertebrate vessels:
Arteries - Carry blood away from heartArteries - Carry blood away from heart
Arterioles – Lead to capillariesArterioles – Lead to capillaries
Capillaries - Exchange materials with tissueCapillaries - Exchange materials with tissue
fluidfluid
Venules - Lead to veinsVenules - Lead to veins
10. 10
Circulatory SystemsCirculatory Systems
Comparison of Circulatory PathwaysComparison of Circulatory Pathways
Fish - Blood flows in single loopFish - Blood flows in single loop
Single atrium and single ventricleSingle atrium and single ventricle
Amphibians - Blood flows in double loopAmphibians - Blood flows in double loop
Two atria with single ventricleTwo atria with single ventricle
Other vertebrates - Blood flows in aOther vertebrates - Blood flows in a
double loopdouble loop
Heart divided by septum into separateHeart divided by septum into separate
sidessides
11. 11
Circulatory SystemsCirculatory Systems
Transport in HumansTransport in Humans
Human HeartHuman Heart
Fist-sizedFist-sized
Cone-shapedCone-shaped
Very muscular organ (special cardiacVery muscular organ (special cardiac
fibers)fibers)
Lies within a fluid-filled sac (theLies within a fluid-filled sac (the
pericardium)pericardium)
12. 12
Circulatory SystemsCirculatory Systems
Human Heart:Human Heart:
Gross AnatomyGross Anatomy
Septum separates heart into left & rightSeptum separates heart into left & right
halveshalves
Each half has two chambersEach half has two chambers
Upper two chambers are the atriaUpper two chambers are the atria
Thin-walledThin-walled
Receive blood from circulationReceive blood from circulation
Lower two chambers are the ventriclesLower two chambers are the ventricles
Thick-walledThick-walled
Pump blood away from heartPump blood away from heart
15. 15
Circulatory SystemsCirculatory Systems
Human Heart:Human Heart:
ValvesValves
Valves open and close to control bloodValves open and close to control blood
flow through heartflow through heart
Atrioventricular valvesAtrioventricular valves
TricuspidTricuspid
BicuspidBicuspid
Semilunar valvesSemilunar valves
PulmonaryPulmonary
AorticAortic
16. 16
Circulatory SystemsCirculatory Systems
Transport in HumansTransport in Humans
Blood returning to heart from systemic circuitBlood returning to heart from systemic circuit
Enters right atriumEnters right atrium
Right atrium pumps through tricuspid valve toRight atrium pumps through tricuspid valve to
right ventricleright ventricle
Right ventricle pumps blood through pulmonaryRight ventricle pumps blood through pulmonary
valve to the pulmonary circuitvalve to the pulmonary circuit
Blood returning to heart from pulmonary circuitBlood returning to heart from pulmonary circuit
Enters left atriumEnters left atrium
Left atrium pumps through mitral valve to leftLeft atrium pumps through mitral valve to left
ventricleventricle
Left ventricle pumps blood through aortic valveLeft ventricle pumps blood through aortic valve
to the systemic circuitto the systemic circuit
Oxygen-poor blood never mixes with oxygen-Oxygen-poor blood never mixes with oxygen-
rich blood (in humans)rich blood (in humans)
17. 17
Circulatory SystemsCirculatory Systems
HeartbeatHeartbeat
Systole - Contraction of heart chambersSystole - Contraction of heart chambers
Diastole - Relaxation of heart chambersDiastole - Relaxation of heart chambers
Pulse - Two-part pumping action that takesPulse - Two-part pumping action that takes
about a secondabout a second
Blood collects in atria, the atria contractBlood collects in atria, the atria contract
Pushes blood through tricuspid and mitral valvesPushes blood through tricuspid and mitral valves
into the resting lower ventriclesinto the resting lower ventricles
This phase (the longer of the two) is called theThis phase (the longer of the two) is called the
diastolediastole
Second part begins when ventricles fillSecond part begins when ventricles fill
Ventricles contractVentricles contract
This is called systoleThis is called systole
After blood moves into the pulmonary artery andAfter blood moves into the pulmonary artery and
aorta, the ventricles relaxaorta, the ventricles relax
19. 19
Circulatory SystemsCirculatory Systems
HeartbeatHeartbeatRhythmic contraction due to cardiacRhythmic contraction due to cardiac
conduction systemconduction system
Sinoatrial node (SA) keeps the heartbeatSinoatrial node (SA) keeps the heartbeat
regularregular
Atrioventricular node (AV) signalsAtrioventricular node (AV) signals
ventricles to contract - Purkinje Fibersventricles to contract - Purkinje Fibers
Electrocardiogram (ECG)Electrocardiogram (ECG)
A recording of electrical changes thatA recording of electrical changes that
occurring in myocardium during cardiacoccurring in myocardium during cardiac
cyclecycle
When SA node triggers an impulse, theWhen SA node triggers an impulse, the
20. 20
Circulatory SystemsCirculatory Systems
Vascular PathwaysVascular Pathways
Human cardiovascular system includesHuman cardiovascular system includes
two major circular pathways:two major circular pathways:
Pulmonary CircuitPulmonary Circuit
Takes oxygen-poor blood to the lungs andTakes oxygen-poor blood to the lungs and
returns oxygen-rich blood to the heartreturns oxygen-rich blood to the heart
Systemic CircuitSystemic Circuit
Takes blood throughout the body from theTakes blood throughout the body from the
aorta to the vena cavaaorta to the vena cava
24. 24
Circulatory SystemsCirculatory Systems
Blood PressureBlood Pressure
The beat of the heart supplies pressureThe beat of the heart supplies pressure
that keeps blood moving in the arteriesthat keeps blood moving in the arteries
Systolic Pressure results from bloodSystolic Pressure results from blood
forced into the arteries during ventricularforced into the arteries during ventricular
systolesystole
Diastolic Pressure is the pressure in theDiastolic Pressure is the pressure in the
arteries during during ventricular diastolearteries during during ventricular diastole
Skeletal muscle contraction pushes bloodSkeletal muscle contraction pushes blood
in the veins toward the heartin the veins toward the heart
Blood pressureBlood pressure
Normally measured with aNormally measured with a
sphygmomanometer on the brachial arterysphygmomanometer on the brachial artery
Expressed in the form: Systolic “over”Expressed in the form: Systolic “over”
25. 25
Circulatory SystemsCirculatory Systems
Cardiovascular DisordersCardiovascular Disorders
Hypertension - High blood pressureHypertension - High blood pressure
Atherosclerosis - Accumulation of fattyAtherosclerosis - Accumulation of fatty
materials in inner linings of arteriesmaterials in inner linings of arteries
Stroke - Cranial arteriole bursts or isStroke - Cranial arteriole bursts or is
blocked by an embolusblocked by an embolus
Heart attack – (Myocardial infarction)Heart attack – (Myocardial infarction)
Coronary artery becomes partiallyCoronary artery becomes partially
blockedblocked
Angina pectoris – Painful squeezingAngina pectoris – Painful squeezing
sensation from myocardial oxygensensation from myocardial oxygen
26. 26
Circulatory SystemsCirculatory Systems
Blood:Blood:
Homeostasis FunctionsHomeostasis Functions
Transports substances to and fromTransports substances to and from
capillaries for exchange with tissue fluidcapillaries for exchange with tissue fluid
Guards against pathogen invasionGuards against pathogen invasion
Regulates body temperatureRegulates body temperature
Buffers body pHBuffers body pH
Maintain osmotic pressureMaintain osmotic pressure
Clots prevent blood/fluid lossClots prevent blood/fluid loss
27. 27
Circulatory SystemsCirculatory Systems
Red Blood CellsRed Blood Cells
Small, biconcave disksSmall, biconcave disks
Lack a nucleus and contain hemoglobinLack a nucleus and contain hemoglobin
Hemoglobin containsHemoglobin contains
Four globin protein chainsFour globin protein chains
Each associated with an iron-containingEach associated with an iron-containing
hemeheme
Manufactured continuously in bone marrowManufactured continuously in bone marrow
of skull, ribs, vertebrae, and ends of longof skull, ribs, vertebrae, and ends of long
bonesbones
28. 28
Circulatory SystemsCirculatory Systems
White Blood CellsWhite Blood Cells
Most types larger than red blood cellsMost types larger than red blood cells
Contain a nucleus and lack hemoglobinContain a nucleus and lack hemoglobin
Important in inflammatory responseImportant in inflammatory response
Neutrophils enter tissue fluid andNeutrophils enter tissue fluid and
phagocytize foreign materialphagocytize foreign material
Lymphocytes (T Cells) attack infectedLymphocytes (T Cells) attack infected
cellscells
Antigens cause body to produceAntigens cause body to produce
antibodiesantibodies
32. 32
Circulatory SystemsCirculatory Systems
Capillary ExchangeCapillary Exchange
Capillaries very narrow – Tiny RBCs mustCapillaries very narrow – Tiny RBCs must
go through single filego through single file
Wall of capillaries very thin to facilitateWall of capillaries very thin to facilitate
diffusion of nutrients, gasses and wastesdiffusion of nutrients, gasses and wastes
Oxygen and nutrients exit a capillary nearOxygen and nutrients exit a capillary near
the arterial endthe arterial end
Carbon dioxide and waste moleculesCarbon dioxide and waste molecules
enter a capillary near the venous endenter a capillary near the venous end
35. 35
Circulatory SystemsCirculatory Systems
ReviewReview
Transport in InvertebratesTransport in Invertebrates
Open versus Closed Circulatory SystemsOpen versus Closed Circulatory Systems
Transport in VertebratesTransport in Vertebrates
Transport in HumansTransport in Humans
HeartbeatHeartbeat
Vascular PathwaysVascular Pathways
Blood PressureBlood Pressure
Cardiovascular DisordersCardiovascular Disorders
BloodBlood
ComponentsComponents
ClottingClotting