Circulatory Systems Chapter 34. Circulatory Systems 2Outline Transport in Invertebrates Open versus Closed Circulatory Systems Transport in Vertebrates

Circulatory Systems

Chapter 34

2Circulatory SysCirculatory Systemstems

OutlineOutline

Transport in InvertebratesTransport in InvertebratesOpen versus Closed Circulatory Open versus Closed Circulatory SystemsSystems

Transport in VertebratesTransport in VertebratesTransport in HumansTransport in Humans

HeartbeatHeartbeatVascular PathwaysVascular PathwaysBlood PressureBlood Pressure

Cardiovascular DisordersCardiovascular DisordersBloodBlood

ComponentsComponentsClottingClotting


Transport in InvertebratesTransport in Invertebrates

Small aquatic animals with no circulatory Small aquatic animals with no circulatory systemsystemMay rely on external water in May rely on external water in gastrovascular cavity to service cellsgastrovascular cavity to service cells

Roundworms and other pseudocoelomatesRoundworms and other pseudocoelomatesUse a fluid-filled body cavity as a means of Use a fluid-filled body cavity as a means of transporting substancestransporting substances

Fluid-filled cavity can also act as a Fluid-filled cavity can also act as a hydrostatic skeleton hydrostatic skeleton

Animals that have a rigid skeletonAnimals that have a rigid skeletonMay still rely on body fluids for the May still rely on body fluids for the purpose of locomotionpurpose of locomotion

Bivalves pump hemolymph into the foot Bivalves pump hemolymph into the foot for digging into mudfor digging into mud

4Aquatic OrganismsWithout a Circulatory

System

5Circulatory SysCirculatory SystemstemsOpen vs. ClosedOpen vs. Closed

Invertebrate CirculationInvertebrate CirculationTwo 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 Gases and materials diffuse to and from nearby cellsnearby cells

Vessels return blood to heart without it Vessels return blood to heart without it contacting tissuescontacting tissues

6Open vs. Closed Circulatory Systems


Transport in the VertebratesTransport in the VertebratesAll vertebrates have a closed cardiovascular All vertebrates have a closed cardiovascular systemsystem

Vertebrate heart:Vertebrate heart: Atrial chamber(s) of heart receive blood from Atrial chamber(s) of heart receive blood from general circulationgeneral circulation

Ventricle chamber(s) of heart pump blood out Ventricle 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 tissue Capillaries - Exchange materials with tissue fluidfluid

Venules - Lead to veinsVenules - Lead to veins Veins - Return blood to heartVeins - Return blood to heart

8Transport in Birds and Mammals

9Comparison of Circulatory Circuits

in Vertebrates

10Circulatory SysCirculatory SystemstemsComparison of Circulatory Comparison of Circulatory

PathwaysPathwaysFish - Blood flows in single loopFish - Blood flows in single loop

Single atrium and single ventricleSingle atrium and single ventricle

Amphibians - Blood flows in double Amphibians - Blood flows in double looploop

Two atria with single ventricleTwo atria with single ventricle

Other vertebrates - Blood flows in a Other vertebrates - Blood flows in a double loopdouble loop

Heart divided by septum into separate Heart divided by septum into separate sidessides


Transport in HumansTransport in Humans

Human HeartHuman Heart

Fist-sizedFist-sized

Cone-shapedCone-shaped

Very muscular organ (special cardiac Very muscular organ (special cardiac fibers)fibers)

Lies within a fluid-filled sac (the Lies within a fluid-filled sac (the pericardium)pericardium)

12Circulatory SysCirculatory SystemstemsHuman Heart:Human Heart:

Gross AnatomyGross Anatomy

Septum separates heart into left & Septum separates heart into left & right halvesright halves

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

13External Heart Anatomy

14Internal View of the Heart

15Circulatory SysCirculatory SystemstemsHuman Heart:Human Heart:

ValvesValves

Valves open and close to control blood Valves open and close to control blood flow through heartflow through heart

Atrioventricular valves Atrioventricular valves

TricuspidTricuspid

BicuspidBicuspid

Semilunar valvesSemilunar valves

PulmonaryPulmonary

AorticAortic


Transport in HumansTransport in HumansBlood returning to heart from systemic circuitBlood returning to heart from systemic circuit

Enters right atriumEnters right atrium Right atrium pumps through tricuspid valve to Right atrium pumps through tricuspid valve to right ventricleright ventricle

Right ventricle pumps blood through Right ventricle pumps blood through pulmonary valve to the pulmonary circuitpulmonary valve to the pulmonary circuit

Blood returning to heart from pulmonary Blood returning to heart from pulmonary circuitcircuit Enters left atriumEnters left atrium Left atrium pumps through mitral valve to left Left atrium pumps through mitral valve to left ventricleventricle

Left ventricle pumps blood through aortic Left ventricle pumps blood through aortic valve to the systemic circuitvalve to 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)


HeartbeatHeartbeatSystole - Contraction of heart chambersSystole - Contraction of heart chambersDiastole - Relaxation of heart chambersDiastole - Relaxation of heart chambersPulse - Two-part pumping action that takes Pulse - 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 Pushes blood through tricuspid and mitral valves into the resting lower ventriclesvalves into the resting lower ventricles

This phase (the longer of the two) is called the This 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 After blood moves into the pulmonary artery and aorta, the ventricles relaxand aorta, the ventricles relax

18Conduction System of the Heart


HeartbeatHeartbeatRhythmic contraction due to cardiac Rhythmic contraction due to cardiac conduction systemconduction system

Sinoatrial node (SA) keeps the heartbeat Sinoatrial node (SA) keeps the heartbeat regularregular

Atrioventricular node (AV) signals ventricles Atrioventricular node (AV) signals ventricles to contract - Purkinje Fibersto contract - Purkinje Fibers

Electrocardiogram (ECG)Electrocardiogram (ECG)

A recording of electrical changes that A recording of electrical changes that occurring in myocardium during cardiac occurring in myocardium during cardiac cyclecycle

When SA node triggers an impulse, the When SA node triggers an impulse, the atrial fibers produce an electrical charge (P atrial fibers produce an electrical charge (P wave)wave)


Vascular PathwaysVascular Pathways

Human cardiovascular system includes Human cardiovascular system includes two major circular pathways:two major circular pathways:

Pulmonary CircuitPulmonary Circuit

Takes oxygen-poor blood to the lungs Takes oxygen-poor blood to the lungs and returns oxygen-rich blood to the and returns oxygen-rich blood to the heartheart

Systemic CircuitSystemic Circuit

Takes blood throughout the body from Takes blood throughout the body from the aorta to the vena cavathe aorta to the vena cava

21Path of Blood

22Velocity and Blood Pressure

23Cross Section of a Valve in a Vein


Blood PressureBlood PressureThe beat of the heart supplies pressure The beat of the heart supplies pressure that keeps blood moving in the arteriesthat keeps blood moving in the arteriesSystolic Pressure results from blood Systolic Pressure results from blood forced into the arteries during ventricular forced into the arteries during ventricular systolesystole

Diastolic Pressure is the pressure in the Diastolic Pressure is the pressure in the arteries during during ventricular diastolearteries during during ventricular diastole

Skeletal muscle contraction pushes blood Skeletal muscle contraction pushes blood in the veins toward the heartin the veins toward the heart

Blood pressureBlood pressureNormally measured with a Normally measured with a sphygmomanometer on the brachial arterysphygmomanometer on the brachial artery

Expressed in the form: Systolic “over” Expressed in the form: Systolic “over” DiastolicDiastolic


Cardiovascular DisordersCardiovascular DisordersHypertension - High blood pressureHypertension - High blood pressure

Atherosclerosis - Accumulation of fatty Atherosclerosis - Accumulation of fatty materials in inner linings of arteriesmaterials in inner linings of arteries

Stroke - Cranial arteriole bursts or is Stroke - Cranial arteriole bursts or is blocked by an embolusblocked by an embolus

Heart attack – (Myocardial infarction) Heart attack – (Myocardial infarction) Coronary artery becomes partially Coronary artery becomes partially blockedblocked

Angina pectoris – Painful squeezing Angina pectoris – Painful squeezing sensation from myocardial oxygen sensation from myocardial oxygen insufficiencyinsufficiency

26Circulatory SysCirculatory SystemstemsBlood:Blood:

Homeostasis FunctionsHomeostasis Functions

Transports substances to and from Transports substances to and from capillaries for exchange with tissue capillaries for exchange with tissue fluidfluid

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


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-containing Each associated with an iron-containing hemeheme

Manufactured continuously in bone Manufactured continuously in bone marrow of skull, ribs, vertebrae, and marrow of skull, ribs, vertebrae, and ends of long bonesends of long bones


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 and Neutrophils enter tissue fluid and phagocytize foreign materialphagocytize foreign material

Lymphocytes (T Cells) attack infected Lymphocytes (T Cells) attack infected cellscells

Antigens cause body to produce Antigens cause body to produce antibodiesantibodies

29Composition of Blood


PlateletsPlatelets

PlateletsPlatelets

Result from fragmentation of Result from fragmentation of megakaryocytesmegakaryocytes

Involved in coagulationInvolved in coagulation

Blood clot consists of:Blood clot consists of:

PlateletsPlatelets

Red blood cellsRed blood cells

All entangled within fibrin threadsAll entangled within fibrin threads

31Blood Clotting


Capillary ExchangeCapillary Exchange

Capillaries very narrow – Tiny RBCs Capillaries very narrow – Tiny RBCs must go through single filemust go through single file

Wall of capillaries very thin to Wall of capillaries very thin to facilitate diffusion of nutrients, facilitate diffusion of nutrients, gasses and wastesgasses and wastes

Oxygen and nutrients exit a capillary Oxygen and nutrients exit a capillary near the arterial endnear the arterial end

Carbon dioxide and waste molecules Carbon dioxide and waste molecules enter a capillary near the venous endenter a capillary near the venous end

33Capillary Exchange

34Capillary Bed


ReviewReview

Transport in InvertebratesTransport in InvertebratesOpen versus Closed Circulatory Open versus Closed Circulatory SystemsSystems

Transport in VertebratesTransport in VertebratesTransport in HumansTransport in Humans

HeartbeatHeartbeatVascular PathwaysVascular PathwaysBlood PressureBlood Pressure

Cardiovascular DisordersCardiovascular DisordersBloodBlood

ComponentsComponentsClottingClotting

Circulatory Systems

Ending Slide Chapter 34

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Circulatory Systems Chapter 34. Circulatory Systems 2Outline Transport in Invertebrates Open versus Closed Circulatory Systems Transport in Vertebrates