Why do organisms need a transport system? In large organisms, the distance over which oxygen, carbon dioxide, nutrients and wastes have to move is too.

Why do organisms Why do organisms need a transport system?need a transport system?

• In large organisms, the distance over In large organisms, the distance over which oxygen, carbon dioxide, which oxygen, carbon dioxide, nutrients and wastes have to move is nutrients and wastes have to move is too too L-O-N-GL-O-N-G for food absorption and for food absorption and gaseous exchange to occur efficientlygaseous exchange to occur efficiently

Transport Systems in Transport Systems in HumansHumans

Circulatory SystemCirculatory SystemLymphatic SystemLymphatic System

Circulatory Circulatory SystemSystem

Human Circulatory Human Circulatory SystemSystem

BLOODBLOOD

BLOOD VESSELSBLOOD VESSELS HEARTHEART

BloodBlood

• Blood is a Blood is a LIQUID TISSUELIQUID TISSUE consisting consisting of blood cells which float in a liquidof blood cells which float in a liquid

• Blood acts as a Blood acts as a TRANSPORT TRANSPORT MEDIUMMEDIUM to carry various to carry various substances in the forms of substances in the forms of solution and suspensionsolution and suspension

BloodBlood• The various The various

components in components in blood can be blood can be separated by a separated by a machine called a machine called a CENTRIFUGECENTRIFUGE

• After After centrifugation, centrifugation, blood is divided blood is divided into two portionsinto two portions

BloodBlood

PlasmaPlasma

(55% by (55% by volume)volume)

(straw (straw colour)colour)Blood CellsBlood Cells

(45% by volume)(45% by volume)

(red colour)(red colour)

What is blood made up of?What is blood made up of?

BLOOD CELLSBLOOD CELLS

250 000/mm250 000/mm33 7 000/mm7 000/mm33 5 000 000/mm5 000 000/mm33

Blood CellsBlood Cells

Red Blood CellRed Blood Cell

PlateletPlatelet

White Blood CellWhite Blood Cell

Where are blood cells Where are blood cells made?made?

Red Blood Cells Red Blood Cells (Erythrocytes(Erythrocytes )

Red Blood CellsRed Blood Cells

• RBC’s are formed in RBC’s are formed in BONE MARROWBONE MARROW

• They have a short life-span: They have a short life-span: about 120 days onlyabout 120 days only

• Old RBC’s are destroyed in the Old RBC’s are destroyed in the liver and the spleenliver and the spleen

• Matured RBC’s in mammals do Matured RBC’s in mammals do not possess a nucleusnot possess a nucleus

Red Blood CellsRed Blood Cells

• They are shaped like They are shaped like biconcave biconcave discsdiscs in order to provide a large in order to provide a large surface area for diffusion of gasessurface area for diffusion of gases

• Their red colour comes from Their red colour comes from haemoglobin haemoglobin which is responsible which is responsible for carrying oxygen from the for carrying oxygen from the lungs to all parts of the bodylungs to all parts of the body

Transport of Oxygen Transport of Oxygen

Transport of OxygenTransport of Oxygen

Transport of OxygenTransport of Oxygen

Transport of OxygenTransport of Oxygen

HaemoglobinHaemoglobin(Purplish Red)(Purplish Red)

++ OxygenOxygen In LungsIn Lungs

In TissuesIn Tissues

OxyhaemoglobinOxyhaemoglobin(Bright Red)(Bright Red)

Transport of Carbon Transport of Carbon DioxideDioxide

• Most of the carbon dioxide is carried Most of the carbon dioxide is carried in the blood in the form of in the blood in the form of hydrogencarbonate ions (HCOhydrogencarbonate ions (HCO33

--). An ). An enzyme inside the RBC helps to enzyme inside the RBC helps to convert the COconvert the CO22 into HCO into HCO33

-- and vice and vice versa versa

Investigation #1:Investigation #1: To investigate the effects of To investigate the effects of

oxygen and carbon dioxide oxygen and carbon dioxide on chicken’s blood on chicken’s blood

ProcedureProcedure

White Blood Cells White Blood Cells (Leukocytes) (Leukocytes)

• Irregularly-shapedIrregularly-shaped• Possess nucleusPossess nucleus• Kill Kill pathogenspathogens• Number of WBC’s Number of WBC’s

in body can varyin body can vary• Different WBC’s Different WBC’s

have different have different lifespans: ranging lifespans: ranging from 10 hours to from 10 hours to over 1 yearover 1 year

White Blood CellsWhite Blood Cells

1) Phagocytes1) Phagocytes• They are made in the bone They are made in the bone

marrowmarrow• They have a They have a lobedlobed nucleus nucleus • They can move like an They can move like an AmoebaAmoeba

out of blood capillaries to out of blood capillaries to engulf engulf germs and dead cellsgerms and dead cells

PhagocytesPhagocytes

BacteriaBacteria

PhagocytePhagocyte

White Blood CellsWhite Blood Cells

2) Lymphocytes 2) Lymphocytes • They have a large nucleusThey have a large nucleus• They are made in the bone marrow They are made in the bone marrow

and then migrate to and then migrate to lymph nodeslymph nodes• Some lymphocytes produce Some lymphocytes produce

antibodiesantibodies; others kill invading cells ; others kill invading cells directly directly

• They also produce antitoxins to They also produce antitoxins to neutralize toxins produced by germsneutralize toxins produced by germs

When the lymphocyte encounters a matching When the lymphocyte encounters a matching antigen, the antibody interlocks with antigen, the antibody interlocks with the antigen and marks it for the antigen and marks it for

destructiondestruction

LeukaemiaLeukaemia

• Leukaemia is a cancer of the tissues Leukaemia is a cancer of the tissues which produce blood which produce blood

• Large numbers of abnormal white cells Large numbers of abnormal white cells are produced, which are unable to carry are produced, which are unable to carry out their normal function of fighting out their normal function of fighting infectioninfection

• The abnormal cells also displace the The abnormal cells also displace the normal production of red cells and normal production of red cells and platelets platelets

• Can be treated with chemotherapy, Can be treated with chemotherapy, radiotherapy or bone marrow transplantradiotherapy or bone marrow transplant

Platelets (Thrombocytes)Platelets (Thrombocytes) • Tiny fragments Tiny fragments

formed from formed from specialized cells in specialized cells in the bone marrowthe bone marrow

• They have no They have no nucleusnucleus

• They have a short They have a short life span: less than life span: less than 10 days10 days

• They are involved They are involved in the process of in the process of blood clottingblood clotting

PlateletsPlatelets

After the clot is formed, bleeding is stopped. After the clot is formed, bleeding is stopped.

The clot hardens to form a scab and the wound gradually healsThe clot hardens to form a scab and the wound gradually heals

Blood ClottingBlood ClottingRBC’s trappedRBC’s trappedin a network of in a network of fibrin threadsfibrin threads

Platelet plugPlatelet plug

Blood vessel Blood vessel constricts to constricts to slow down slow down blood lossblood loss

Blood ClottingBlood Clotting

A Comparison of RBC’s, WBC’s and A Comparison of RBC’s, WBC’s and PlateletsPlatelets

Bone Bone marrow marrow

Bone marrow,Bone marrow,

lymph nodeslymph nodes

Bone marrowBone marrow

5 000 000/mm5 000 000/mm33 7 000/mm7 000/mm33 250,000/mm250,000/mm33

88m diameterm diameterLym:8-10Lym:8-10mm

Phag:12Phag:12mm

Tiny cellTiny cell

fragmentsfragmentsBiconcaveBiconcave

disc-shapeddisc-shapedIrregularIrregular IrregularIrregular

No nucleusNo nucleus

HaemogloblinHaemogloblin

NucleusNucleus

No haemoglobinNo haemoglobin

No nucleusNo nucleus

No haemoglobinNo haemoglobin

Red blood cellsRed blood cellsWhite blood cellsWhite blood cells PlateletsPlatelets

Site of productionSite of production

NumberNumber

SizeSize

ShapeShape

StructureStructure

FunctionFunction Transport of Transport of oxygenoxygen

Body Body defencedefence

Blood clottingBlood clotting

PLASMAPLASMA

Dissolved Dissolved SubstancesSubstances

(10%)(10%)

WaterWater(90%)(90%)

Plasma – Dissolved Plasma – Dissolved SubstancesSubstances

• Plasma proteins – antibodies, Plasma proteins – antibodies, fibrinogenfibrinogen

• LipidsLipids• GlucoseGlucose• Amino acidsAmino acids• Hormones – coordinate body activitiesHormones – coordinate body activities• Mineral saltsMineral salts• UreaUrea• Carbon dioxideCarbon dioxide

NutrientsNutrients

WastesWastes

Investigation #2:Investigation #2: Detecting the presence Detecting the presence

of glucose in a blood of glucose in a blood samplesample

ProcedureProcedure

Functions of BloodFunctions of Blood

Transportation of:Transportation of:

1. Oxygen – in the form of oxyhaemoglobin1. Oxygen – in the form of oxyhaemoglobin

2. Carbon dioxide – in the form of HCO2. Carbon dioxide – in the form of HCO33--

3. Food – from ileum to all parts of body3. Food – from ileum to all parts of body

4. Urea – from liver to kidneys4. Urea – from liver to kidneys

5. Hormones – from endocrine glands5. Hormones – from endocrine glands

6. Antibodies – to all parts of body6. Antibodies – to all parts of body

7. Heat – to keep uniform temperature7. Heat – to keep uniform temperature

Functions of BloodFunctions of Blood

Defence against infection:Defence against infection:

1. Phagocytes engulf germs1. Phagocytes engulf germs

2. Lymphocytes produce antibodies to 2. Lymphocytes produce antibodies to destroy germs or antitoxins to destroy germs or antitoxins to neutralize toxinsneutralize toxins

3. Blood clotting prevents excess blood3. Blood clotting prevents excess blood loss and entrance of bacterialoss and entrance of bacteria

Blood VesselsBlood Vessels

A system of tubes for distributing A system of tubes for distributing blood around the body:blood around the body:

• ArteryArtery – carry blood – carry blood AWAYAWAY from the from the heartheart

• VeinVein – carry blood – carry blood TOWARDSTOWARDS the heart the heart• CapillaryCapillary – narrow vessel connecting – narrow vessel connecting

arteries and veinsarteries and veins

* Arteries branch into smaller vessels * Arteries branch into smaller vessels called called arteriolesarterioles

* Small vessels called * Small vessels called venulesvenules join into join into veinsveins

ArteriesArteries

ArteriolesArterioles

With pulseWith pulse No pulseNo pulse

88

1616

Blo

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pre

ssu

reB

lood

pre

ssu

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(kP

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(kP

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CapillariesCapillaries

VenulesVenules

VeinsVeins

Changes in blood pressure Changes in blood pressure in different types of blood in different types of blood

vesselsvessels

ArteriesArteries• Carry blood Carry blood AWAYAWAY

from the heart from the heart• Contain oxygenated Contain oxygenated

blood (exception: blood (exception: pulmonary artery)pulmonary artery)

• Thick walls of Thick walls of musclesmuscles

• Elastic fibres allow Elastic fibres allow arterial wall to arterial wall to withstand pressurewithstand pressure

• Lumen is small and Lumen is small and appeared to be roundappeared to be round

• No valvesNo valves • Need to withstand Need to withstand

high pressure high pressure

• The muscles around The muscles around the artery can the artery can contract or relax to contract or relax to allow the vessel to allow the vessel to constrict or dilateconstrict or dilate

ArteriesArteries

VeinsVeins

• Carry blood Carry blood TOWARDS TOWARDS the heartthe heart

• Contain deoxygenated Contain deoxygenated blood (exception: blood (exception: pulmonary vein)pulmonary vein)

• Thinner walls compared Thinner walls compared to those of arteries to those of arteries

• Walls are less elastic Walls are less elastic and muscularand muscular

• Lumen is larger and Lumen is larger and appeared flattenedappeared flattened

• Contain valves that Contain valves that are surrounded by are surrounded by skeletal musclesskeletal muscles

• Pressure of blood is Pressure of blood is lowlow

VeinsVeins