You Gotta HaveYou Gotta Have

The Circulatory SystemThe Circulatory System

Circulatory System Consists Circulatory System Consists of…of…

•Blood Blood VesselsVessels

•BloodBlood

•HeartHeart

OverviewOverview

• The Heart pumps blood through The Heart pumps blood through the body through blood vessels the body through blood vessels (arteries, capillaries and veins)(arteries, capillaries and veins)

• Arteriestake blood away from the Arteriestake blood away from the heart, veins return blood to the heart, veins return blood to the heartheart

• Blood carries OBlood carries O22 (food) towards (food) towards and COand CO22 (waste) away from (waste) away from tissuestissues

• The lungs are not part of the The lungs are not part of the circulatory system!!circulatory system!!

Circulatory SystemCirculatory System

BLOOD VESSELSBLOOD VESSELS

Two PathwaysTwo Pathways

• Pulmonary CirculationPulmonary Circulation– Carries blood to lungs and Carries blood to lungs and

backback

• Systemic CirculationSystemic Circulation– Carries blood to body and Carries blood to body and

backback

Your Blood Vessels: Your Blood Vessels: Pathway of CirculationPathway of Circulation

• 3 types of vessels3 types of vessels– Arteries(Shown as Red Arteries(Shown as Red

because blood has Obecause blood has O22))– Capillaries(Red and Capillaries(Red and

Blue because some OBlue because some O22 lost to tissues)lost to tissues)

– Veins(Shown as Blue Veins(Shown as Blue because Obecause O22 lost to lost to tissues)tissues)

Red Blood and Blue BloodRed Blood and Blue Blood• Blood is never blue!!!!!!!!!!!!!!!!!!Blood is never blue!!!!!!!!!!!!!!!!!!• Oxygenated blood is bright red and Oxygenated blood is bright red and

deoxygenated blood is dark red deoxygenated blood is dark red • Veins appear blue because of the way Veins appear blue because of the way

light reflects off the blood vessellight reflects off the blood vessel• We don’t see arteries because they are We don’t see arteries because they are

too deep.too deep.• We draw them blue to distinguish them We draw them blue to distinguish them

on diagrams and simplify thingson diagrams and simplify things

Arteries vs. VeinsArteries vs. Veins

What you need to know about the STRUCTURAL differences between Arteries and Veins:

-Artery walls are much thicker, very elastic and have more muscle.

-Veins are thin walled and contain valves to psh the blood along

Arteries vs. VeinsArteries vs. Veins

• Why are arteries and veins the Why are arteries and veins the way they are?way they are?– Blood is under very high pressure Blood is under very high pressure

when it leaves the heart and enters when it leaves the heart and enters the arteriesthe arteries• Therefore, arteries need to be strong!Therefore, arteries need to be strong!

– Once it has left the tissues and Once it has left the tissues and enters the veins, the blood is under enters the veins, the blood is under a very low pressurea very low pressure• Therefore, veins are weakTherefore, veins are weak

Arteries:Arteries:carries blood carries blood Away from heartway from heart

– LargeLarge– Thick-walled, MuscularThick-walled, Muscular– ElasticElastic– Oxygenated blood Oxygenated blood

• Exception Pulmonary ArteryException Pulmonary Artery– Carried under great pressureCarried under great pressure– Steady pulsating (used to measure pulse)Steady pulsating (used to measure pulse)ArteriolesArterioles: smaller vessels, enter tissue: smaller vessels, enter tissue

CapillariesCapillaries

– Smallest vesselSmallest vessel– MicroscopicMicroscopic– Walls one cell thickWalls one cell thick– Located at the Located at the

tissuetissue– Nutrients and gases Nutrients and gases

(O(O22, CO, CO22) diffuse ) diffuse herehere

Veins:Veins: Caries blood to the heart Caries blood to the heart

– Carries blood that contains Carries blood that contains waste and COwaste and CO22

• Exception pulmonary veinException pulmonary vein

– Blood under low pressureBlood under low pressure– ValvesValves to prevent back to prevent back

flow due to gravityflow due to gravity

VenulesVenules: small veins, larger : small veins, larger than capillariesthan capillaries

Blood VesselsBlood Vessels

http://www.kscience.co.uk/animations/blood_system.swfAnimation of blood flow

The Aorta – The largest blood The Aorta – The largest blood vesselvessel

http://www.kscience.co.uk/animations/vessels_label.swfBlood Vessel Animation

Circulatory SystemCirculatory System

BLOODBLOOD

The BloodThe Blood

• Body contains 4-6 LBody contains 4-6 L• Consists of Consists of

– WaterWater– Red Blood CellsRed Blood Cells– PlasmaPlasma– White blood cells and White blood cells and

plateletsplatelets

Your Blood: Fluid TransportYour Blood: Fluid TransportLiquid Portion Carries Liquid Portion Carries

• Blood cells (Blood cells (made in bone made in bone marrowmarrow))– Erythrocytes (RBC - red blood Erythrocytes (RBC - red blood

cells)cells)– Leucocytes (WBC - white blood Leucocytes (WBC - white blood

cells) cells) • Platelets (fragments of the cells in Platelets (fragments of the cells in

bone marrow – no nucleus)bone marrow – no nucleus)• ProteinsProteins• Nutrients - Nutrients - digestive systemdigestive system• Gases - Gases - Respitory systemRespitory system

Oxygen in the BloodOxygen in the Blood

• Hemoglobin , iron Hemoglobin , iron containing moleculecontaining molecule

• Loosely picks up Loosely picks up oxygen in the lungsoxygen in the lungs

• Releases oxygen in Releases oxygen in areas low in oxygen areas low in oxygen – body tissues– body tissues

O2

O2

O2O2

Carbon Dioxide in the BloodCarbon Dioxide in the Blood

• Hemoglobin also carries COHemoglobin also carries CO22

• COCO2 2 is a waste product of is a waste product of cellular respirationcellular respiration

• Travels to the lungs to be Travels to the lungs to be exhaledexhaled

What does blood contain?What does blood contain?

• 50% Water50% Water

• 45% Erythrocytes (RBC)45% Erythrocytes (RBC)

• 4% Plasma with Substances4% Plasma with Substances

• 1% Leukocytes (WBC) + Platelets1% Leukocytes (WBC) + Platelets

Erythrocytes (RBC)Erythrocytes (RBC)• Transporters ofTransporters of

– OxygenOxygen– Carbon dioxideCarbon dioxide

• RBCRBC– Lack a nucleusLack a nucleus– Contain hemoglobinContain hemoglobin– Disk-shapedDisk-shaped

• RBC are produced in the RBC are produced in the bone marrowbone marrow

• Lives for ~120 daysLives for ~120 days• Old RBC are destroyed in Old RBC are destroyed in

liver and spleen liver and spleen

Leukocytes (WBC)Leukocytes (WBC)

• WBC fight infectionWBC fight infection– Attack foreign Attack foreign

substancessubstances• Less abundantLess abundant• Created in bone Created in bone

marrow marrow • Some live for monthsSome live for months

– Most just a few daysMost just a few days• Several typesSeveral types• ALL contain nucleiALL contain nuclei• Difference between Difference between

red and white ? red and white ?

PlateletsPlatelets

• PLATELETS are for PLATELETS are for CLOTTING bloodCLOTTING blood

• Cell fragmentsCell fragments• Produced in bone Produced in bone

marrowmarrow• Short life span (1 week)Short life span (1 week)• Form a web trapping Form a web trapping

blood cellsblood cells

Blood Clotting

Break in Capillary Wall

Blood vessels injured.

Clumping of Platelets

Platelets clump at the site and release a protein

Clot Forms

Protein creates a net creating a clot. The clot prevents further loss of blood.

Circulatory SystemCirculatory SystemHEARTHEART

Your HeartYour Heart

• Pumps blood around Pumps blood around your body to keep your body to keep you alive!you alive!

• If your heart stops If your heart stops you will die!you will die!

Heart:Heart:Structure and FunctionStructure and Function

• Keeps blood movingKeeps blood moving• Large organ Large organ

composed of composed of – Cardiac Muscle Cardiac Muscle – Rich in Rich in

MitochondriaMitochondria

The Structures of the Heart

Right Ventricle

Right Atrium

Left Atrium

Inferior Vena CavaVein that brings oxygen-poor blood from the lower part of the body to the right atrium

Pulmonary VeinsBring oxygen-rich blood from each of the lungs to the left atrium

Superior Vena CavaLarge vein that brings oxygen-poor blood from the upper part of the body to the right atrium

AortaBrings oxygen-rich blood from the left ventricle to the rest of the body

Pulmonary ArteriesBring oxygen-poor blood to the lungs

Left Ventricle

Structure of Heart (cont)Structure of Heart (cont)• Four chambers Four chambers

– Two upper (Atria)Two upper (Atria)•Walls thinnerWalls thinner•Less MuscularLess Muscular

– Two lower Two lower (Ventricles)(Ventricles)•Walls thickerWalls thicker•More muscularMore muscular•Do more workDo more work

http://www.kscience.co.uk/animations/heart_label.swfHeart Structure Animation

Blood Flow Through the Blood Flow Through the HeartHeart

©COPY 1997 HeartPoint©COPY 1997 HeartPoint

Bloods Path Through the Bloods Path Through the HeartHeart

• Both Atria fill at same timeBoth Atria fill at same time

– Rt atrium receives oxygen poor blood from Rt atrium receives oxygen poor blood from body from vena cavasbody from vena cavas

– Left atrium receives oxygen Rich blood Left atrium receives oxygen Rich blood from lungs through four pulmonary veinsfrom lungs through four pulmonary veins

• After filled with blood atria contract, After filled with blood atria contract, pushing blood into ventriclepushing blood into ventricle

Both ventricles contractBoth ventricles contractRight ventricle contracts and pushes Right ventricle contracts and pushes

oxygen-poor blood toward lungs oxygen-poor blood toward lungs • through the pulmonary arteriesthrough the pulmonary arteries

Left ventricle contracts and forces Left ventricle contracts and forces oxygen rich blood out of heart oxygen rich blood out of heart • Through Aorta (Largest Vessel)Through Aorta (Largest Vessel)

Bloods Path Through the HeartBloods Path Through the Heart

The cardiac cycleThe cardiac cycle

http://www.kscience.co.uk/animations/blood_system.swfAnimation of blood flow

Control of Heart RateControl of Heart RateResting Heart Rate Heart Rate during exercise

58 80

Control of the HeartControl of the Heart• The Heart is controlled by nerves and hormones:The Heart is controlled by nerves and hormones:Nerves:Nerves:

– Its own nerves Its own nerves Pacemaker which keeps a Pacemaker which keeps a constant beatconstant beat

• Heart will beat even if it is disconnected from the brainHeart will beat even if it is disconnected from the brain• Can be substituted by an artificial pacemakerCan be substituted by an artificial pacemaker

- The Brain can speed-up (exercise) or slow down the heart (sleep) if needed

Control of the HeartControl of the Heart

Hormones:Hormones:

•Certain hormones such as epinephrine Certain hormones such as epinephrine (adrenalin) (adrenalin) impact how the heart impact how the heart operatesoperates

Your Heart: The Vital PumpYour Heart: The Vital Pump

• At REST, the heart At REST, the heart beats about 60-80 beats about 60-80 times per minute times per minute (~4.7L)(~4.7L)

• During EXTREME During EXTREME EXERTION (exercise) EXERTION (exercise) it can beat between it can beat between 150-200 times per 150-200 times per minute (~38L)minute (~38L)

Heart Rate DiscussionHeart Rate Discussion• Why??Why??

• Brain sends a signal to increase HR Brain sends a signal to increase HR

• Adrenal Gland secretes epinephrineAdrenal Gland secretes epinephrine

• Both work together to increase blood flow Both work together to increase blood flow around the bodyaround the body

• Increased blood frow = increase 02/glucose Increased blood frow = increase 02/glucose delivery to cells and CO2 removaldelivery to cells and CO2 removal

DISORDERSDISORDERS

• Coronary Artery Disease Coronary Artery Disease Your heart needs Oxygen too!Your heart needs Oxygen too!– Is supplied with Oxygen by coronary arteriesIs supplied with Oxygen by coronary arteries– Coronary arteries can become partially Coronary arteries can become partially

blocked by plaque (fat and cholesterol blocked by plaque (fat and cholesterol mainly)mainly)• Causes by lifestyle choice and geneticsCauses by lifestyle choice and genetics

– This block limits the amount of oxygen This block limits the amount of oxygen delivered to the heartdelivered to the heart

– Can cause Can cause tiredness, dizziness and paintiredness, dizziness and pain

Coronary Artery DiseaseCoronary Artery Disease• Can be diagnosed with an Can be diagnosed with an angiogram angiogram

whereby a fluorescent dye is injected into whereby a fluorescent dye is injected into the bloodstream.the bloodstream.

• This dye shows up on an x-ray and shows This dye shows up on an x-ray and shows where flow is disruptedwhere flow is disrupted

Disorders (cont)Disorders (cont)

• Heart AttackHeart Attack– Coronary artery(ies) become completely blocked Coronary artery(ies) become completely blocked No Oxygen can reach the heart muscleNo Oxygen can reach the heart muscle

• Heart muscle begins to die and eventually stops beatingHeart muscle begins to die and eventually stops beating

• SymptomsSymptoms– Nausea, Shortness of breath, Severe chest pain, sweating, Nausea, Shortness of breath, Severe chest pain, sweating,

dizziness, fatiguedizziness, fatigue

IMMEDIATE MEDICAL ATTENTION NECESSARYIMMEDIATE MEDICAL ATTENTION NECESSARY

Disorders (cont)Disorders (cont)• StrokeStroke

– Heart atack for the brain Heart atack for the brain

– Blood cannot reach the Blood cannot reach the brain due to a blockage in brain due to a blockage in its blood vesselsits blood vessels

– Brain cells die due to lack Brain cells die due to lack of oxygenof oxygen

– Can lead to paralysis, Can lead to paralysis, • loss of ability to speakloss of ability to speak• deathdeath

Current PREVENTION Current PREVENTION RecommendationsRecommendations

• Regular exerciseRegular exercise• Weight control Weight control • Well balanced dietWell balanced diet• Do not smokeDo not smoke• Diet low in Diet low in

saturated fatsaturated fat

http://www.pbs.org/wgbh/nova/eheart/transplantwave.htmlHeart Transplant Interactive Activity