9.4 The Search for Better Health HSC Biology

5/22/2018 9.4 The Search for Better Health HSC Biology

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HSC - Stage 6 2 Unit Biology

9.4 The Search for Better Health:

1. What is a healthy organism?

Discuss the difficulties in defining the terms health and disease:

Health is difficult to define as health has many components, such as physical,

mental, and social, some of which ae !ey su"#ecti!e

$isease is also difficult to define, as it also has many components% Because it is

desci"ing a state of impaied functioning, it depends on an oganisms nomal

le!el of functioning, and what they e&pect thei 'uality of life to "e%

$efinitions(

Health:) state of complete physical, mental and social health, and not meely

the a"sence of disease o infimity%

Disease:) state of impaied functioning of an oganism, including impaied

physical, social and mental functioning%

Outline how the function of genes, mitosis, cell differentiation and

specialisation assist in the maintenance of health:

Genes:

*enes contol the poduction of poteins in the "ody +needed fo pope

functioning and so healthy genes ensue the coect poteins ae made%

hough poduction of poteins +especially en.ymes, genes ensue the coect

cell pocesses occu, maintaining meta"olism and homeostasis%

Mitosis:

/itosis is the pocess that ena"les genetic mateial to "e copied e&actly,

ensuing the genes ae coect and a"le to maintain health in thei own way

/itosis is also the pocess that oganisms use to gow, and maintain and epai

"ody cells, maintaining health

ell Differentiation an! S"ecialisation:

hese 2 pocesses esult in cells which ae specialised fo specific functions in

the "ody, such as ed "lood cells, etc%


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ogethe, all the specialised "ody cells wo0 togethe in a coodinated way to

maintain the health and pope functioning of the oganism%

Use available evidence to analyse the links between gene expression and

maintenance and repair of body tissues:

) healthy oganism is the esult of(

he coect functioning of genes

he poduction of pefect copies of genetic mateial "y mitosis

he e&pession of genes in cell specialisation and diffeentiation

he "odys cells ae always "eing eplaced all the time, so the coect specialised

cells must "e poduced to eplace them%

his is done though mitosis, followed "y gene e&pession%

Healthy cells ha!e thei cell cycle egulated "y poteins that ae poduced "y

diffeent types of genes

D#$ re"air genesensue that the $1) is accuately copied

2 genes that egulate the cell cycle ae(

%roto&oncogenes:hese poduce poteins that stimulate di!ision

T'mo'r s'""ressor genes: hese poduce poteins that stop di!ision

n healthy cells, these two ae "alanced n unhealthy cells(

/utated poto-oncogenes ae called oncogenes and cause uncontolled cell

di!ision +cances

/utated tumou suppesso genes lose thei a"ility to contol cell di!ision%

he ate of cell di!ision inceases and uncontolled gowth occus this also

leads to cances%


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(. )*er +,,, years ago the hinese an! He-res ere a!*ocating

cleanliness in foo!/ ater an! "ersonal hygiene:

Distinguish between infectious and noninfectious disease:

nfectious $isease(

Caused "y an in!asion of the "ody "y 3)H4*51S%

) "athogenis an infectious agent that causes disease

he disease can "e tansfeed fom one oganism to anothe

3athogens can "e micoscopic o macoscopic

5%g% !iuses +influen.a, "acteia +tonsillitis, poto.oans +malaia, pions

+C$, fungi +tinea%

1on-infectious $isease(

n!ol!es no pathogens

hee is no tansfe of the disease fom one oganism to anothe

5g(

0nherite!+genetic disease( $owns Syndome, haemophilia

#'tritionaldisease( scu!y, "ei"ei, 0washio0o

n*ironmentaldisease( s0in cance, as"estosis

!xplain why cleanliness in food, water and personal hygiene practices

assist in control of disease:

"leanliness in #ood:

Contaminated food is a souce of pathogens +such as salmonella, and can

!ey eadily spead diseases

But mico"es in food only "ecome a health is0 when they ae allowed to

multiply and each lage num"es

/oden methods to educe the num"es of mico"es in food include(

Heating( 5%g% coo0ing food to 0ill mico"es, pasteuisation

Cooling( 7efigeation of foods slows down the gowth of mico"es

$ying:$ehydating foods, such as fuit o !egeta"les, and smo0ing meat,

0ills mico"es, ma0ing them last longe


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)ll these methods ae used to educe the num"e of mico"es and to contol

the spead of disease

"leanliness in $ater:

8ac0 of clean wate, such as in de!eloping counties with no wate

puification o sewage systems, is a lage facto in speading disease%

he ma#o cause of disease ae the pathogens that oiginate fom faeces

9ate will always contain mico"es, "ut educing the num"es though

teatment contols the spead of disease

eatment of wate, in pocesses such chloination, educes the is0 of disease

%ersonal &ygiene(

3esonal hygiene is the pocess of 0eeping ou "odies clean in ode tomaintain health%

Sanitation efes to the maintenance of conditions that pomote health,

including emo!al of wastes

7educing pathogen num"es in moden times in!ol!es(

Steili.ation( his is the complete emo!al of all taces of mico"es% his

is e'uied in situations whee pathogens ae paticulaly dangeous, eg

sugical ooms%

$isinfecting( his in!ol!es educing mico"es to a safe le!el, such as

washing clothes o dishes with disinfectant%

'dentify the conditions under which an organism is described as a

pathogen:

4ganisms ae called pathogens when they cause disease%

f an pathogen is to cause disease, it must(

Ha!e virulence( that is, "e pesent in sufficient num"es to cause the disease

5nte the host though a cetain pat of the "ody o su!i!e on the "ody

without "eing destoyed "y the "odys natual defences

5scape fom one host to anothe

Su!i!e tansmission fom one host to anothe


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Describe ways in which drinking water can be treated and use available

evidence to explain how these methods reduce the risk of infection from

pathogens:

9ates fom lage undistu"ed catchment aeas need little teatment, as the

pocess of sedimentation ta0es place natually +li0e in a dam

Howe!e, wate fom i!es that lead fom industial sites, fams, o waste aeas

e'uies e&tensi!e teatment%

he teatment of wate usually has : stages%

3imay eatment(

Screeningout lage de"is using "as and sceens

Degritting the emo!al of lage git paticles

2locc'lation mi&ing of the wate with chemicals to fom suspended

paticles that contain many microbes

Se!imentationof suspended microbefullpaticles to the "ottom of tan0s

Sl'!ge "rocessing collection and pocessing of sediment fom tan0s

Seconday eatment(

2iltration this emo!es nealy all the emaining mico"es and othe paticles

"y passing the wate though sand "eds o chacoal%

etiay eatment(

hlorination adding chloine to the wate 0ills of the emaining hamful

mico"es

4the chemicals ae added hee, such as fluoides, depending on the location


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+. D'ring the secon! half of the nineteenth cent'ry/ the or3 of %aste'r

an! och an! other scientists stim'late! the search for micro-es as the

ca'se of !isease:

Describe the contribution of %asteur and (och to our understanding of

infectious diseases:

Until the mid ;


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he 2? that wee inoculated su!i!ed, while the othe 2? died

3asteu and =ementation(

3asteu e&amined samples of fementing wines unde the micoscope

He o"se!ed A5)SS, which wee con!eting the sugas to alcohol

He also o"se!ed B)C57), which wee con!eting sugas to lactic

acid%

he "acteia wee also o"se!ed in sou mil0 and wee the cause of food

spoilage%

3asteu showed that heating the wine o mil0 to ??C fo a few minutes

0ills the mico"es that spoil them% his pocess is called pasteuisation

o-ert och 6174+ 191,:

och also studied the antha& disease

)ntha& is a "acteial disease that affects "oth sheep and humans

he pocess of his in!estigation was(

;% He o"tained infected matte fom a sheep suffeing fom antha&

2% He placed it on a slide, o"se!ed it unde a micoscope and saw acti!e od-

shaped cells and inacti!e, domant spoes

:% He esta"lished that the "lood of animals with the disease always containedthese mico-oganisms, while the "lood of healthy animals did not

D% He found that if "lood fom an infected animal was in#ected into a healthy

animal, it would cause disease%

?% He gew cultues of the od-shaped "acteia to infect mice they

de!eloped the disease% his po!ed that it was the "acteia, and not any

othe "lood component that caused disease%

ochs 3ostulates +fo esta"lishing a cetain mico"e causes a disease(

he mico-oganism must "e pesent in e!ey oganism with the disease

he mico-oganism must "e isolated fom the host and cultued

) potential host, when inoculated with the cultued mico-oganism, must

de!elop the same symptoms as the oiginal host


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he mico-oganism must "e a"le to "e isolated fom the second host and

"e identified as the same species as the oiginal cultue%

Distinguish between prions, viruses, bacteria, proto)oans, fungi and macro

parasites and name one example of a disease caused by each type of

pathogen:

3741S(

hey ae non-cellula infectious agents that cause disease in mammals

)e a"nomal poteins that ae alteed fom nomal shape +no $1) o 71)

hey can also con!et nomal poteins to a"nomal poteins

Can "e passed fom one animal to anothe +usually "y "ain o spinal tissue

5*( Bo!ine spongifom encephalopathy, Ceut.feld aco"s disease%

>7US5S(

1on-cellula pathogens, simply a potein coat aound genetic mateial

)e found in eu0ayotic and pocayotic cells

Can only epoduce inside othe cells +host cells, 0illing them%

1o cue fo !ial diseases !accinations can educe pe!alence

5*( )$S, smallpo&, influen.a

B)C57)(

Unicellula, pocayotic cells% Cell wall suounding cell%

1o mem"ane "ound oganelles

4nly some ae pathogenic and cause diseaseE many ae useful

/ost li!e feely, "ut some ae paasites

5*( etanus, pneumonia, antha&

3744F4)1S(

Unicellula eucayotic, animal-li0e oganismsE no cell wall

=ee-li!ing, o paasitic%

5*( Sleeping sic0ness, giadiasis, amoe"ic dysentey

=U1*(

5ucayotic oganismsE ha!e a cell wall made of chitin +not cellulose


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Some ae unicellula +eg yeast, most ae multicellula

hey play an impotant ole in decomposition of oganic molecules, togethe

with "acteia

5*( 7ingwom, tinea

/)C743)7)S5S(

8age disease causing oganisms that can "e seen with the na0ed eye

5&tenal paasites ae called ectopaasites, intenal ae called endopaasites

5*( 7ingwom, tic0s, fleas, oundwoms

'dentify the role of antibiotics in the management of infectious diseases:

)nti"iotics ae su"stances that ae capa"le of destoying o inhi"iting the gowth

of "acteia that cause disease%

hey ae chemicals that act selecti!elyE they attac0 the "acteia "ut not the host

)nti"iotics wo0 at the cellula le!elE they destoy the cells of the "acteia

Howad =loey and )le&ande =leming disco!eed the fist anti"iotic( penicillin

Some anti"iotics affect the stuctue of the "acteia penicillin destoys cell walls

and amphoteicin destoys cell mem"anes

Boad-spectum anti"iotics affect a wide ange of "acteia, naow-spectum act

on only one o two%

*race the historical development of our understanding of the cause and

prevention of malaria:

D BC( *ee0s thought that the symptoms of malaia wee caused "y eithe

"eathing in mash !apous o "ites of insects that li!e in mashes

;GG@( 5a*erano"se!ed mico-oganisms in fesh "lood fom malaial patients

and suggested that malaia was caused "y this mico-oganisms

;GG6( Golgio"se!ed ase&ual epoduction of mico"e in "lood of patients ;G


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5aly 2@th( eatments of malaia wee de!eloped, including anti-malaial dugs

such as 'uinine% 5ffots to stop the spead of malaia include using $$ to 0ill the

disease !ecto the mos'uito%

oday( 7esistance to 'uinine and othe dugs "y the 3lasmodium, as well as $$esistance "y the mos'uitoes has "ecome a po"lem% $e!elopment of a malaial

!accine is the main diection eseach is going%

Describe one named infectious disease in terms of its: - "ause .-

*ransmission /- &ost 0esponse 1- 2a3or 4ymptoms 5- *reatment 6-

%revention 7- "ontrol:

Disease:/alaia

a'se:D species of the poto.oan,%lasmodium

Transmission:he+nophelesmos'uitoes ae the hosts that tansmit the disease

to humans duing the "lood-suc0ing pocess%

Sym"toms: he diffeent stages in the life cycle of the poto.oan cause the

diffeent symptoms of the disease(

9hen the pathogen fist entes the "lood, it ta!els to the 8>57 C588S,

whee it hides fom the immune system% hee, it multiplies apidly, poducing

do.ens of cells called meo.oites

he meo.oites then ta!el "ac0 into the "lood, whee they infect 75$

B844$ C588S, again, multiplying ase&ually poducing many cells%

he meo.oites "ust out of the ed "lood cells e!ey DG-2 hous, and as they

elease to&ins in this pocess, this causes the symptoms%

he to&ins cause ecuing attac0s of shi!eing, fe!e, headaches, nausea,

sweating and lethagy% he destuction of many ed "lood cells causes

anaemia%

Host es"onse:)t each stage of the paasites life cycle, it poduces a diffeent

set of antigens +they stimulate the immune esponse% he host poduces

anti"odies to fight the pathogens, "ut the antigens continually change, so the

immune esponse is not effecti!e% he meo.oites in the li!e escape detection


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Treatment: 1atual esistance can de!elop, "ut only !ey slowly% eatment of

suffees includes using anti-malaial dugs such as 'uinine +effecti!e against

paasites in ed "lood cells, and pima'uine phosphate +wo0s in "oth "lood and

li!e cells% Some stains of plasmodium ae esistant howe!e% %re*ention:3otecti!e clothing, insect epellent, mos'uito nets%

ontrol:)ims to 0eep incidence of disease to a minimum in population% $ugs to

destoy !ecto, and paasite% $estoying !ectos ha"itat% >accines against

plasmodium% *enetic engineeing of mos'uitoes to esist paasite%

Discuss problems relating to antibiotic resistance ICase StudyJ(

2 Stains of dug-esistant "acteia(

4treptococcus %neumoniaand 4taphylococcus +ureus8

hey cause meningitis and pneumonia

hey cannot "e teated with common anti"ioticsE they ae esistant

4ne stain of 48 +ureus has added a new gene, ena"ling it to spead though s0in

contact and e!en infect healthy people%

he supe-"ugs ae moe common o!eseas than in )ustalia

hey ae "lamed fo thousands of meningitis and othe infections e!ey yea%

3esent tends suggest that "y mid 2@@D, a"out D@K of 48 %neumonia"acteium

will "e esistant to the two most common anti"iotics +penicillin and

eythomycin%

o o!ecome these po"lems, steps must "e ta0en to limit the use of anti"iotics as

the geate the use, the geate the is0 of a mutation gi!ing "acteia esistance%


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4. )ften e recognise an infection -y the sym"toms it ca'ses. The imm'ne

res"onse is not so o-*io's 'ntil e reco*er:

'dentify defence barriers to prevent entry of pathogens in humans such as

skin, mucous membranes, cilia, chemical barriers, and other bodily

secretions:

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3esent fom "ith%

hese physical "aies, e%g% s0in, potect the "ody at possi"le enty points

he potection po!ided is non-specific it potects against all mico"es

S3in:

=oms a tough oute "aie that suounds the "ody

4ute layes contain 57)1, which mico"es cannot penetate, unless the

s0in is "o0en e%g% a cut

S0in has its own population of hamless "acteia% hese 0eep the num"es of

in!ading pathogens low stops them multiplying +competition

Se"aceous glands +oil glands secete se"um +oil% he lipids in the se"um ae

"o0en down "y the s0ins "acteia into acids which inhi"it "acteial and

fungal gowth

f the s0in is "o0en, a seal +clot is 'uic0ly fomed "y the "lood-clotting

mechanism to pe!ent pathogen enty%

M'co's Mem-ranes:

he digesti!e, espiatoy, epoducti!e and uinay tacts ae lined with thic0

mucus it is stic0y and taps dust paticles and pathogens%

/ucus also contains an anti"ody g) which eacts with potential pathogens

=luids such as sali!a, teas and nasal secetions wash o!e mucus mem"anes

and contain lyso)yme this "ea0s down "acteia cell walls%

ilia:

Cilia ae minute hais that po#ect fom cells lining the nose, tachea and

"onchial tu"es


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Cilia "eat and sweep mucus +containing dust and pathogens towads the nose

o thoat opening whee it is coughed out o swallowed

hemical Barriers:

hese ceate conditions which ma0es the sufaces inhospita"le fo the

potential pathogens%

5%*% n the digesti!e system(

he acidic en!ionment in the stomach

he al0aline en!ionment in the small intestine

)ther Bo!ily Secretions:

3opulations of hamless "acteia in the !agina act on dead "ody cells to ceate

acidic conditions these pe!ent "acteial and fungal gowth Uine is steile and acidic it flushes out the uetes, "ladde and uetha,

pe!enting mico"ial gowth%

'dentify antigens as molecules that trigger the immune response:

)n antigen is a molecule that tigges the immune esponse

/oe specifically, antigens cause the fomations of anti"odies%

)ntigen)1"ody-*51eating su"stance

t may "e pat of a pathogen o e!en a to&ic molecule

.G. he glyco-potein spi0es on the suface of the influen.a !ius act as

antigens, tiggeing the immune esponse% he !enom of poisonous sna0es also

contains antigens%

!xplain why organ transplants trigger an immune response:

)ll an indi!iduals cells ae ecognised "y the immune system as "elonging to the

"ody the "ody ecognises it as self

)ny othe su"stances ae ecognised as non-self foeign% ) tansplanted ogan contains su"stances which the immune system ecognises as

"eing foeign% hese su"stance acts as )1*51S%

his stimulates the "ody to ma0e anti"odies and othe su"stances which attac0

and can possi"ly destoy the ogan


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'dentify defence adaptations, including:

'nflammation response:

%hagocytosis:

9ymph system:

"ell death to seal off pathogen:

S5C41$ 815 4= $5=51C5

his second line of the immune system is also non-specific +li0e the fist line of

defence% t is pesent fom "ith%

his means that it will ecognise any antigen and ma0e no distinction "etween

them% he immune esponse will "e the same egadless of the natue of the

antigen%

0nflammation es"onse:

9hen "ody tissue is damaged, whethe physically, o "y mico"es, the

inflammation esponse "egins

t is chaacteised "y D symptoms pain, edness, heat and swelling

he in#ued cells elease chemo0ines which stimulate basophils and mast cellsto elease the chemicals HS)/15 and 374S4*8)1$1%

hese two chemicals cause the "lood !essels aound the aea to dilate and

incease thei pemea"ility

t has :stages(

;% Blood !essels aound the damaged aea !ilate and incease thei

pemea"ility +due to histamine and postaglandin this inceases "lood

flow to the aea%

2% he inceased "lood flow "ings heat and fl'i!s, which ma0e the

en!ionment inhospita"le to the mico"es% )lso, the inceased "lood flow

"ings 3H)*4CA5S these cells engulf foeign "odies%

:% issues "egin to epai afte the theat is emo!ed% 1ew tissue is ceated,

with the s0in epaiing fist, to pe!ent moe infectious agents enteing%


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he : "eneficial functions of inflammation ae(

t destoys the cause of infection and emo!es it fom the "ody

t limits the cause of infection to a small aea

7eplaces o epais tissue damaged "y infection

%hagocytosis:

3hagocytosis is the engulfing and destuction of foeign "odies "yphagocytes

3hagocytes ae white "lood cells +leucocytes that can engulf foeign "odies

thee ae two 0inds( /)C743H)*5S and 15U743H8S

3hagocytes can change shape and suound the foeign "odies% )fte it is

engulfed, the foeign "ody is destoyed "y com"ining it with en.ymes%

5ym"h System:

he lymphatic system is a system of !essels that "egins nea the capillaies,

un paallel to the !eins and e!entually empty into the !eins "efoe they each

the heat%

he lymph !essels contain a fluid called 8A/3H, which is "lood without ed

"lood cells, platelets and lage plasma poteins

he !essels collect into lymph nodes these nodes ae stoage stuctues fo

lymphocytes and macophages% he lymph system contains ogans which ae !ey impotant in the immune

system, such as the "one maow +whee white "lood cells ae fomed, and

whee B cells matue and the thymus gland +whee cells matue%

ell Death to Seal )ff %athogen:

9hen the "ody is una"le to neutalise an antigen, it seals off the pathogens in

a cyst o within a goup of cells

hese cells die so the pathogen can no longe su!i!e

his cluste of cells, also called a ganuloma, is made of a coe of dead tissue,

suounded "y layes of macophages, then lymphocytes, then fi"o"lasts,

which poduce a tough oute wall%

hese stuctues ae poduced in diseases such as tu"eculosis and leposy

$nti&Micro-ial %roteins I5&taJ(


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15=5741S ae a goup of poteins poduced "y cells in!aded "y !iuses

hey cause suounding cells to fom thei own anti-!ial chemicals,

pe!enting the spead of the !ius I)cts 418A on !iusesJ%

he C4/385/51 SAS5/ is a goup of 2@ poteins that act in a

cascade of eactions to destoy pathogens%

his means that the fist potein causes the poduction of the second, and the

second the thid, and so on%

he final potein em"eds itself in the pathogens cell wall +o mem"ane

causing it to die "y lysis +cell-"usting%

4how how a named disease results from an imbalance of microflora in

humans:

/icofloa ae mico-oganisms that li!e on o in the "ody, and usually do not

cause disease%

hey ae often pat of the fist line of defence the hamless "acteia that secete

acids to destoy pathogens ae an e&ample%

an!i!iasis,o thush, is a disease caused "y an im"alance in the num"es of

the fungus, Candida al"icans%

he disease can happen in the mouth, the espiatoy tact, the gastointestinaltact, and the female epoducti!e tact%

he fungus is usually 0ept in chec0 fom competition fom othe mico"es such as

"acteia li!ing in the same aea

he ta0ing of cetain medications, such as wide-spectum anti"iotics +which can

0ill "eneficial "acteia , o contacepti!e pills, can upset the "alance of

micofloa in the "ody, which can esult in a incease in the num"es of the

Candida fungus, leading to thush%


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8. Mac2arlane B'rnet;s or3 in the mi!!le of the tentieth cent'ry

contri-'te! to a -etter 'n!erstan!ing of the imm'ne res"onse an! the

effecti*eness of imm'nisation "rograms:

'dentify the components of the immune response:

+ntibodies:

"ells:

* "ells:

H7$ 815 4= $5=51C5

his is ac;uiredimmunity ospecific immunity +he specific immune esponse

his immunity is 14 pesent at "ith it is gained though e&posue to infection

he specific immune esponse acts only against s"ecificmico"es o su"stances

hat is, it only acts against cetain antigens

t has a /5/47A( this means that the cells can ecognise antigens fom pe!ious

infections, and so can act faste and moe efficiently in the second e&posue%

)nti"odies(

)e poduced "y the "ody in esponse to the pesence of specific antigens

hey ae made "y 38)S/) B-C588S

hey ae made of poteins called //U14*84BU81 in a A shape%

)nti"odies ciculate in "lood +in the plasma and com"ine with antigens to

destoy them%

)ll anti"odies ha!e 2 L"inding sitesM these "ind to the antigens%

)nti"odies inacti!ateNdestoy antigens in D ways(

1eutalisation( hey can stic0 to the "inding sites of !iuses, o disa"le

"acteial to&ins "y coating them% hese ae then engulfed "y phagocytes% )gglutination( )nti"odies clump togethe solid antigens such as "acteia,

com"ining many "acteia into a solid mass% his mass is then engulfed%

3ecipitation( Solu"le antigens ae stuc0 togethe "y multiple anti"odies,

and ae pecipitated out of the solute +plasma% 3hagocytosis follow%


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Complement )cti!ation( he anti"odies can stic0 to the sufaces of

"acteial cells, acting as tags fo destuction "y complement poteins%

B-Cells(

)e a type of 8A/3H4CA5%

8ymphocytes ae white-"lood cells that act only against specific antigens

B-Cells ae lymphocytes that matued in the "one maow

B-CellBone maow

hese cells contol the specific immune esponse only in the B844$

hus, B-Cells gi!e h'moral+"lood o anti-o!y&me!iate!immunity

B-Cells usually ae found inacti!ated in the "lood and lymph, "ut ae acti!ated

"y the pesence of antigens

hee is only 415 B-Cell fo 415 antigen%

4nce this 415 B-Cell is acti!ated, it clones itself, and then diffeentiates into(

%lasma B&ells( hese cells ceate the anti"odies% )fte the infection is

gone, these cells e!entually die off%

Memory B-ells( hese cells ae fomed in small num"es in the oiginal

infection, "ut do not die off% hey stay "ehind to ecognise the antigen if it

appeas again, hence ha!ing memoy%

B-Cells wo0 mainly in the "lood and intestitial fluids%

-Cells(

)e also lymphocytes +he and B-Cells ae the only lymphocytes

-Cells ae lymphocytes that matue in the thymus gland

T-CellThymus gland

hese cells contol the specific immune esponse in infected C588S

hus, -Cells po!ide cell&me!iate! immunity%

)fte the -Cells ae acti!ated "y antigens, they diffeentiate into D types,

which ae e&plained in moe detail lateO

Hel"er T&ells( hese cells ae fo acti!ating cytoto&ic +0ille -Cells

and the B-Cells Ihis will "e e&plained lateOJ


19/33


ytoto


20/33


his is the wo0 of /ac=alane Bunett

Befoe an antigen entes the "ody, thee ae aleady many types of

lymphocytes in the "ody

he enty of an antigen causes the selection of only 415 of the types of

lymphocyte the one that has the "inding site which matches the antigen

his esults in this lymphocyte cloningitself into lage num"es of this

same lymphocyte, so it poduces the anti"ody that matches the antigen

his selection means that all the lymphocytes that ae poduced in the

esponse +all the and B Cells ae all specific 418A to that antigen

his means that, fo e&ample, the Cytoto&ic -Cells fo influen.a "acteia

cannot 0ill the pneumonia "acteia /acophages engulf and 0ill all foeign cells lymphocytes only act

against the antigens that they specifically match%

yto3ines an! 0nterle'3ins(

Cyto0ines ae a goup of S*1)881* C4/34U1$S made of poteins

o polysacchaides that ae used fo communication "etween cells

hey coodinate the functions of cells so that they can act togethe as a

whole, such as in the immune esponse

nteleu0ins ae a type of cyto0ine that ae seceted "y Helpe -Cells and

the macophages

9hen these cells secete inteleu0ins, they ae signalling, o stimulating,

the othe cells to diffeentiate, in esponse to an antigen such as a B-Cell

changing into a 3lasma B-Cell

his is the main mechanism that is used fo intecellula inteaction

ypes of -Cells(

Hel"er T&ells( hese cells stimulate the B-Cells and -Cells to diffeentiate

into thei diffeent foms% hey ecei!e the antigen fom macophages and

only stimulate the B and -Cells with the same antigen-"inding sites%


21/33


ytotoaccines can "e(

8i!e !iuses

illed o wea0ened pathogens

)ttenuated +hamless stains of a pathogen

nacti!ated to&ins


22/33


)nti"odies fom "lood of la"oatoy animals

hese !accines ae in#ected into the "ody with the intention of po!iding

immunity to the disease without gi!ing the symptoms

>accines can gi!e eithe )C>5 o 3)SS>5 immunity( $cti*e 0mm'nity: his is gained though in#ecting the antigen of the

pathogen in the !accine% his stimulates the whole immune esponse,

including anti"odies and and B /emoy Cells that ae specific to that

antigen, without the symptoms of the infection% he poduction of memoy

cells has 2 implications(

f the pathogen does ente the !accinated indi!idual, the memoy cells

initiates a 'uic0 immune esponse, so the indi!idual does not e&peience

an infection%

t po!ides long-tem potection, as memoy cells last a long time%

5%*% /easles !accine

%assi*e 0mm'nity( his in!ol!es the in#ection of anti"odies staight into the

indi!idual, in esponse to infection "y a pathogen% he anti"odies come fom

othe oganisms(

t "y-passes the whole immune esponse immediate potection

*i!es potection fom diseases the "ody has ne!e "een infected "y

1o memoy cells poduced% his means potection is only shot-tem

t may "ing the is0 of a eaction against foeign "lood poteins

5%*% etanus seum

Outline the reasons for the suppression of the immune response in organ

transplant patients:

) tansplanted ogan is ecognised as foeign tissue "y the immune system SU3375SS41 of the immune system is needed to pe!ent the "ody fom

re=ectingthe ogan

9ithout suppession, the immune system would ceate anti"odies and cytoto&ic -

Cells to ty and destoy the ogan%


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he chances of e#ection is educed "y matching the tansplant ogan tissue with

the tissue of the patient, and "y po!iding immunosuppession dugs%

he dange of this theapy is the ina"ility of the patient to fight off any infections,

since the immune system is suppessed% he "enefits of immunosuppession hasto "e "alanced against the change of life theatening infection%

!valuate the effectiveness of vaccination programs in preventing the spread

and occurrence of once common diseases, including smallpox, diphtheria

and polio:

S/)8834P(

a'se an! Sym"toms:

Caused "y the smallpo& !ius

t entes though the thoat and lungs, then undegoes a ;2-day incu"ation

Symptoms of the disease includes o"!ious !esicles on the s0in, headaches,

"ac0aches and fe!e

History:

=ist appeaed in )sia o )fica aound ;@@@@ BC

Spead aound the wold "y e&ploes, tades and cusades

7esponsi"le fo ; in ;@ of all deaths in 5uope in the ;< thCentuy

7eached )ustalia in ;G


24/33


Since the !accination pogams esulted in the complete eadication of the

disease fom the planet, it can "e said that the pogams wee e&temely

effecti!e%

$3HH57)( a'ses an! Sym"toms:

t is a "acteial infection that is spead though the ai into espiatoy

sufaces, o "y close physical contact

t gi!es thoat infections, which esults in "eathing difficulties and death

History:

;@@ yeas ago, ?@K of all those infected with diphtheia would die

8age epidemics occued in 5uope afte 99

hee ha!e "een ecent out"ea0s in )lgeia and China

>accination %rograms:

n ;


25/33


he ate of polio "egan to fall in the 2@thCentuy

>accination %rograms:

he !accination was fist intoduced in ;


26/33


. "i!emiological st'!ies in*ol*e the collection an! caref'l statistical

analysis of large @'antities of !ata. S'ch st'!ies assist the ca'sal

i!entification of non&infectio's !iseases:

'dentify and describe the main features of epidemiology using lung cancer

as an example:

"i!emiologyis the study of the factos that influence the incidence, disti"ution,

and contol of diseases within a population

=eatues of an epidemiological study that help po!e the cause of disease(

hough analysis of statistics, it must demonstate a significant lin0 "etween

the cause and the disease

hee has to "e a chonological ode of e!entsE that is, the cause must come

"efoe the disease

he study must "e done on a lage ange of su"#ects, in tems of age, se&, ace,

occupation, socioeconomic status, and geogaphical position

he esults should pesist o!e time

he cause-and-effect elationship should "e independent of othe factos

he geate the e&posue to the cause, the geate the incidence should "e of

specific disease

he study should "e epeata"le "y othe in!estigatos at different time, and

diffeentplacesR using different methods8

hee ae thee types of epidemiological studies(

$escipti!e( hese studies in!estigate(

he fe'uency of the disease

he pat of the population affected e%g% age, gende, occupation, etc

he location and time peiod of those affected

)nalytical( hese focus on finding a ca'se an! effect elationship in the

occuence of the disease(

hese studies loo0 at factos that peceded the epidemics

hey loo0 at control groups simila indi!iduals without the disease


27/33


hey e&amine factos that affect the is0 of contacting the disease

5&peimental( hese ae used to test the effecti!eness of a paticula

teatment, such as clinical tials of a new dug%

he epidemiological studies concening lung cance ae a good e&ample the

studies ange o!e many decades, stating fom the ;


28/33


5%*% Scu!y his disease is caused "y the lac0 of !itamin C in the diet% t

causes swelling of "ody pats and teeth stat to fall out%

n*ironmental Disease:

/any factos in the en!ionment can cause disease

hey include adiation, hea!y metals, pollution, etc

5%*% )sthma this disease is whee the muscles in the aiways contact and

can cause se!ee "eathing difficulties% Causes include pollution, pollen, dust

stoms, humidity, and many othe en!ionmental factos%

'dentify the cause and effect relationship of smoking and lung cancer:

) case study( 8U1* C)1C57(

Definition( Uncontolled gowth of tumous in the lungs

a'ses( hee is a o"!ious lin0 "etween smo0ing and lung cance% o"acco

smo0e contains many cacinogens such as "en.ene%

ffect( )s the tumou gows, the ai sacs in the lungs ae destoyed and

"eathing "ecomes difficult% he lungs collapse and a"scess and the patient

may "egin coughing up "lood% he cance can metastasise +spead to othe

!ital ogans and cause death%

Statistical 0nformation(

/ass poduction of cigaettes "egan in ;GG@ fee cigaettes wee gi!en

to 99 soldies

n the ;


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)lso, a gadual decease in the num"es of people smo0ing in the past 2@

yeas has "een mioed "y a decease in suffees of lung cance

+nalyse and present information about the occurrence, symptoms, cause,

treatment=management if a named noninfectious disease:

Disease:$own syndome

a'se:isomy - it is a genetic disease that is caused "y the pesence of an e&ta

chomosome in the 2;stposition%

Sym"toms: 8owe than a!eage mental a"ility, almond shaped eyes, shote

lim"s, speech impaiment, enlaged tongue and a high is0 of heat failue

)cc'rrence:)ppo&imately ; pe :: li!e "iths

TreatmentAManagement:

Childen with $own syndome will need special cae in many aeas of life,

including eating, washing and geneal hygiene

he educed mental capacity, a symptom of the disease, may "e a limiting

facto on the de!elopment on the indi!idual in espect to social de!elopment,

schooling and the wo0foce

)n impotant issue is the physical health of the patient with the disode(

3hysiotheapy may "e needed, as childen "on with $own syndome ha!ewea0ened muscles, and shote ams and legs

he inceased is0 of se!eal diseases, most nota"ly cadio!ascula failue,

is an impotant issue that must "e managed with $own syndome patients%


30/33


. 0ncrease! 'n!erstan!ing has lea! to a i!e range of strategies to

"re*ent an! control !isease:

Discuss the role of ;uarantine in preventing the spread of disease and

plants and animals into +ustralia or across regions of +ustralia:

C'arantine is the contolling of the impot o e&pot of animals, plants, and othe

poducts fo the pupose of contolling the spead of disease

he 7ole of uaantine(

3otects the health of the human, animal and plant populations of )ustalia

3e!ents the enty of foreign "estsand contagio's !iseasesinto )ustalia

uaantine laws pe!ent the enty of items consideed a is0

mpotant animals face a time in isolation to ensue no disease is pesent%

8i!ing plants ae also 'uaantined to ma0e sue they ae not caying pests o

suffeing fom any infectious disease

3lant seeds ae e&amined to chec0 that no weed seeds ae pesent

Used !ehicles and agicultual machiney ae inspected and cleaned to ensue

no soilNplant matte entes the county

!valuate the effectiveness of ;uarantine in preventing the spread of plant

and animal diseases into +ustralia or across regions of +ustralia:

Because of )ustalias stict 'uaantine laws, )ustalian plants and animals !o not

ha*esome of the seious disease found in othe counties, such as foot and mouth

disease, mad cow disease and a"ies

5%*% )nimal disease that has not enteed )ustalia 2oot an! mo'th !isease(

) highly contagious muscle-wasting disease of clo!en-hoofed animals such as

cows, sheep and goat

Symptoms include fe!e, di""ling, lethagy and "listes on mouth, tongue,

lips, hoo!es and feet

t is caused "y an ai"one !ius it is spead not only "y li!e animals "ut also

"y the cacass, and also in soil and e'uipment%


31/33


uaantine egulations has pe!ented the enty of this disease if an out"ea0

did occu, it would cost "illions of dollas in loss%

5%*% 3lant disease that has not enteed )ustalia Sorgh'm !ony mil!e(

his disease has "een pe!ented fom enteing into )ustalia

Caused "y a fungusE if it was eleased into )ustalia, it would de!astate wheat

and othe cops gown hee

he fungus inhi"its the plants a"ility to ma0e chloophyll, which esults in the

death of the plant

uaantine measues include the "anning of enty of any li!e plant mateial,

and the stict e&amination of any seeds "eing "ought in%

5%*% 3e!enting spead of disease acoss egions of )ustalia 2r'it flies uaantine measues ha!e "een implemented that fo"id the mo!ement of

fuit acoss state "odes

hese measues ae in place to contol the spead of fuit flies, which cause

se!ee damage to fuit cops such as "ananas

hee is the /editeanean fuit fly in 9esten )ustalia, and the ueensland

fuit fly, in easten )ustalia

he 1othen eitoy, South )ustalia and asmania do not ha!e these pests,

"ecause of 'uaantine measues

4!eall, 'uaantine pactices ha!e "een geatly effecti!e%

$ue to the igoous implementation of 'uaantine pactices, most diseases and

pests ha!e not "een "ought to )ustalia%

!xplain how one of the following strategies has controlled and=or prevented

disease I3esticides chosenJ(

3esticides ae used usually to 0ill the !ectos that cay the disease

)n e&ample is using pesticides to contol the malaia disease

$$ +dichloo-diphenyl-tichlooethane is the pesticide that was used to 0ill

populations of the )nopheles mos'uito, the !ecto of malaia

t was !ey effecti!e in the "eginning, and num"es of malaia suffees went

down, "ut then pesticide-esistance educed its efficacy


32/33


$$ was also used to 0ill lice on the "odies of soldies duing 99

he lice caied diseases such as typhus fe!e

he pesticide pe!ented thousands of deaths

Discuss the changing methods of dealing with plant and animal diseases,

including the shift in emphasis from treatment and control to management

or prevention of disease:

he incidence of disease has moe commonly "een met with an emphasis on

teatment and contol

/oe ecently howe!e the emphasis has shifted to the impotance and

effecti!eness of pe!enting and managing diseases instead

hese e&amples illustate this(

Smallpo&( ) widespead disease that 0illed many in the ;Gth Centuy%

eatments wee a!aila"le, "ut wee ineffecti!e many died% 3e!ention came

in the fom of !accinations, and this has contolled the disease fa moe

successfully than any teatments

Cances( hee ae cuent teatments, such as chemotheapy, adiotheapy,

and sugical emo!als% hey ae 'uite successful, especially if detected ealy%

Howe!e, they ae not ;@@K successful and can cause physical tauma to the

"ody +scas% 3e!ention campaigns +pu"lic health campaigns such as gi!ing

people ad!ice on pope s0in cae +s0in cance and 'uit-lines fo smo0ing

ha!e educed the num"es of cances%

3lant $iseases( hese include disease such as fungal oot infections, pests

such as aphids and disease causing oganisms% he usual teatment is spaying

with pesticides% Howe!e this has had a detimental effect on the en!ionment%

3e!entati!e measues ae used, especially 'uaantine measues, "iological

contol +intoducing species to contol pests and genetic engineeing

!vidence of pathogens and insect pests on plant leaves and shoots:

%athogens 0nsect %ests


33/33


- Bacteia cause spots on the suface of the

lea!es +ust on the Ban0sia lea!es

- =ungal infections ae shown "y da0

gowths on the stems +"lac0 stem ot

o on the undesides of lea!es%

- nsects +a.alea lace-"ugs feed on the

plant itself, ceating holes and damage%

- 4the insects, such as psyllids, epoduce

on the plants, and lea!e "ehind egg shells

and holes%

9.4 The Search for Better Health HSC Biology

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Transcript of 9.4 The Search for Better Health HSC Biology