Science Module7th Grade

Circulatory System Structures

• Heart• Blood Vessels

– Arteries– Veins– Capillaries

• Blood

Circulatory System Function

• The overall function of the circulatory system is to transport materials throughout the body toward and away from particular target organs and tissues.

Two Pathways

• Pulmonary Circulation– Carries blood to lungs and back to the heart

• Systemic Circulation– Carries blood to body and back to the heart

Capillaries of head and arms

Capillaries of abdominal organs and legs

Inferior vena cava

Pulmonary vein

Capillaries of right lung

Superior vena cava Aorta Pulmonary artery

Capillaries of left lung

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

3 types of vessels3 types of vessels– ArteriesArteries– CapillariesCapillaries– VeinsVeins

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 pulsatingSteady pulsatingArteriolesArterioles: smaller vessels, enter tissue: smaller vessels, enter tissue

CapillariesCapillaries

– Smallest vesselSmallest vessel– MicroscopicMicroscopic– Walls one cell thickWalls one cell thick– Nutrients and gases diffuse hereNutrients and gases diffuse here

Veins:Veins:Carries blood to heart

– Carries blood that contains Carries blood that contains waste and COwaste and CO22 Exception pulmonary veinException pulmonary vein

– Blood not under much Blood not under much pressurepressure

– ValvesValves to prevent much to prevent much gravity pullgravity pull

VenulesVenules: larger than : larger than capillariescapillaries

Varicose VeinsVaricose VeinsDamaged Valves in VeinsDamaged Valves in Veins

Artery vs. VeinArtery vs. Vein

Your Heart: The Vital PumpYour Heart: The Vital Pump At REST, the heart At REST, the heart

pumps about 5 pumps about 5 QUARTS of blood a QUARTS of blood a minute.minute.

During EXTREME During EXTREME EXERTION EXERTION (exercise) it can (exercise) it can pump 40 quarts a pump 40 quarts a minute.minute.

Structure of HeartStructure of Heart

Four chambers Four chambers – Two upper (Atria)Two upper (Atria)

Right AtriaRight Atria Left AtriaLeft Atria

– Two lower Two lower (Ventricles)(Ventricles) Right VentricleRight Ventricle Left VentricleLeft Ventricle

Heart PumpingHeart Pumping

http://library.med.utah.edu/kw/pharm/hyper_heart1.html

LyricsLyrics

Pump, pump, pumps your Blood.Pump, pump, pumps your Blood. The right atrium’s where the process begins, The right atrium’s where the process begins,

where the CO2 Blood enters the heart.where the CO2 Blood enters the heart. Through the tricuspid valve, to the right ventricle, Through the tricuspid valve, to the right ventricle,

the pulmonary artery, and lungs.the pulmonary artery, and lungs. Once inside the lungs, it dumps its carbon dioxide Once inside the lungs, it dumps its carbon dioxide

and picks up its oxygen supply.and picks up its oxygen supply. Then it’s back to the heart through the pulmonary Then it’s back to the heart through the pulmonary

vein, through the atrium and left ventricle.vein, through the atrium and left ventricle. Pump, pump, pumps your Blood. Pump, pump, pumps your Blood. 

Blood Flow Through HeartBlood Flow Through Heart

Label the Following StructuresRight ventricleLeft ventricleRight atriumLeft atriumPulmonary arteriesPulmonary veinsAortaSuperior vena cavaInferior vena cavaSemi-lunar valvesBicuspid valveTricuspid valveCardiac musclePericardiumSeptum

Color in oxygenated blood red & de-oxygenated blood blue

Draw arrows showing blood flow Through the heart & adjacentBlood vessels

Indicate the location of the lungs

Heart SoundsHeart Sounds First heart sound or “lubb”First heart sound or “lubb”

– Atrioventricular valves and surrounding fluid Atrioventricular valves and surrounding fluid vibrations as valves close at beginning of ventricular vibrations as valves close at beginning of ventricular systolesystole

Second heart sound or “dupp”Second heart sound or “dupp”– Results from closure of aortic and pulmonary Results from closure of aortic and pulmonary

semilunar valves at beginning of ventricular diastole, semilunar valves at beginning of ventricular diastole, lasts longerlasts longer

Third heart sound Third heart sound (occasional)(occasional)– Caused by turbulent blood flow into ventricles and Caused by turbulent blood flow into ventricles and

detected near end of first one-third of diastoledetected near end of first one-third of diastole

The BloodThe Blood Body contains 4-6 Body contains 4-6

LL Consists of Consists of

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

and plateletsand platelets

Erythrocytes (RBC)Erythrocytes (RBC)

Transporters ofTransporters of– OxygenOxygen– Carbon DioxideCarbon Dioxide

RBC are produced in red RBC are produced in red bone marrow of bone marrow of – ribs, ribs, – humerus, humerus, – femur, femur, – sternum, and other long bonessternum, and other long bones

Leukocytes (WBC)Leukocytes (WBC)

WBC fight WBC fight infectioninfection

– Attack foreign Attack foreign substancessubstances

Less abundantLess abundant Large cellsLarge cells

PlateletsPlatelets

PLATELETS are for CLOTTING PLATELETS are for CLOTTING bloodblood

Cell fragmentsCell fragments Produced in bone marrowProduced in bone marrow Fibrin (sticky network of protein Fibrin (sticky network of protein

fibers)fibers)– Form a web trapping blood cellsForm a web trapping blood cells

Section 37-2

Blood Clotting

Break in Capillary Wall

Blood vessels injured.

Clumping of Platelets

Platelets clump at the site and release thromboplastin. Thromboplastin converts prothrombin into thrombin..

Clot Forms

Thrombin converts fibrinogen into fibrin, which causes a clot. The clot prevents further loss of blood..

Blood TypesBlood Types Massive loss of blood requires a Massive loss of blood requires a

transfusiontransfusion Four TypesFour Types

– AA– BB– ABAB– OO

Inherited from your parentsInherited from your parents

Blood TypesBlood Types

What happens when you mix What happens when you mix blood types?blood types?

Plasma contains proteins Plasma contains proteins that correspond to the shape that correspond to the shape of the different antigensof the different antigens

If you mix one type with the If you mix one type with the wrong one, you get wrong one, you get CLUMPINGCLUMPING

Type O is the universal donor Type O is the universal donor Type AB is the universal acceptorType AB is the universal acceptor

What Makes Our Blood What Makes Our Blood Type?Type?

Blood Type of Donor

A

B

AB

O

Blood Type of Recipient

A B AB O

Unsuccessful transfusion Successful transfusion

Blood Transfusions

Rh FactorRh Factor Rhesus factor (Rh), also inheritedRhesus factor (Rh), also inherited

– RhRh++ (have antigen) (have antigen)– RhRh- - (NO antigen)(NO antigen)

Can cause complications in pregnanciesCan cause complications in pregnancies– mother Rhmother Rh-- 1 1stst baby Rh baby Rh++ : blood mixes with : blood mixes with

mother; mother’s body makes anti-Rhmother; mother’s body makes anti-Rh++ antibodiesantibodies

– 22ndnd Rh Rh ++ body attacks baby body attacks baby– Now have medicine to prevent antibody Now have medicine to prevent antibody

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