Biology notes for Level 1 students 2021 PDF

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REGULATION OF INTERNAL ENVIRONMENTAn organism is affected by changes in its internal environment that is conditions within its own body. Every organism has self-regulatory mechanisms which help to maintain its internal environment within the ranges needed for normal metabolism. The maintenance of a ...

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REGULATI ON OFI NTERNALENVI RONMENT Anor gani sm i saffect edbychangesi ni t si nt er nalenvi r onmentt hati scondi t i ons wi t hi ni t sownbody .Ever yor gani sm hasse l f r egul at orymechani smswhi chhe l pt o mai nt ai ni t si nt er nalenvi r onmentwi t hi nt her angesneededf ornor malme t abol i sm. Themai nt enanceofaf ai r l ycons t ants t at eoft hei nt er nalenvi r onmenti sknown ashomeos t asi s. I nani mal s,t heki dney ,l i v er ,ski n,br ai nandhor mones( subst ancessecr et edby endocr i negl ands)hel pi nmai nt ai ni ngconst anti nt er nalenvi r onmentwhi l ei npl ant s auxi ns( e. g.gi bber e l l i nsandcyt oki ni n)al sohel pi nmai nt ai ni ngc onst anti nt er nal envi r onment . NOTE:Thes t r uct ur eoft heki dneyhasbeent r eat edundert heexcr e t or ysyst em of mammal . Funct i onsoft heki dneys Theki dneysper f or m somef unct i onsl i keexcr e t i on,osmor egul at i onaci dbase bal anceoft hebodybutt hemaj orf unct i onsar eexcr e t i onandosmor egul at i on. a)Excr et i on: -t heki dneysar er esponsi bl ei nr emovi ngwast epr oduct sf r om t hebodyt o t heenvi r onment . ( seeSS2not eonmec hani s m ofexcr e t i on) . b)Osmor egul at i on: -t hi si sapr ocessbywhi chanor gani sm r egul at est hebal anceoft he r at i oofwat ert osal t si ni t sbodyflui ds.Theki dneysr egul at et heosmot i c concent r at i onofbl oodpl asmaandi ndoi ngsokeept heenvi r onment alcondi t i onsof eac hi ndi vi dualc el loft hebodyf ai r l yc onst ant .Thi si sdonei nt woways: i )Whent heosmot i cconcent r at i onoft hebl oodpl asmai shi ghert hant hatoft hecel l cont ent si . e .whensubs t ancesl i kesugar ,mi ner alsal t s ,ami noaci dsandot herpl asma sol ut ear epr esenti nl ar geamount s .Theki dneysr educet heconcent r at i onby ext r act i ngsomeoft hesesubst ancesf r om t hebl oodandexcr et et hem. i i )Whent heosmot i cconcent r at i onoft hebl oodpl asmai sl owert hant hatoft hec el l cont ent si . e .t hepl asmasol ut e sar epr esenti nsmal lamount .Theki dneysext r act mor ewat eri ns t eadoft hepl asmasol ut et her e byi ncr easi ngt heosmot i cconcent r at i on oft hebl oodpl asma. c)Mai nt enanceofaci dbasebal ance:t heaci dbasebal ancei nt hebodyi sal so mai nt ai nedbyt heki dneys.Whent hebodyflui dsbecomeaci di c,mor eaci di sexcr et ed byt heki dneyswi t ht heur i ne.Theki dneyspr eventt heexcessi v el ossofbasesatt he samet i me.Whent heconcent r at i onofabasebecomeshi gher ,mor esal t swi l lbe excr et edwi t ht heur i ne . 1

Di seasesoft heki dneys,effec t sandr emedy

Ce r t ai nscondi t i onst hatcanaffectt hef unct i oni ngoft heki dneysi ncl ude di seases,dr ugs,changesi nnor malhabi torphysi cali nj uryandt emper at ur e .Someof t hedi seasesoft heki dneysi ncl udegl omer ul arnephr i t i sorbr i ght ’ sdi sease,ki dney s t onesorr enalcal cul i ,di ur esi sandoedemaordr opsy . a)Gl omer ul arnephr i t i s( Br i ght ’ sdi sease)i sacondi t i oni nwhi c ht hebl oodvesse l s ( gl omer ul us)i nBowman’ scapsul ebecomei nflamedandpor ous.Thi si nflammat i on makest hebl oodv essel snott ocar r youtt hef unct i onoful t r afil t r at i onc ompl e t e l y .I t canbecausedbybact er i ali nf ect i on. Effect s 1) i nflammat i onoft heki dneys 2) ami noaci dsar epr esenti nur i ne 3) weaknessoft hebody 4) f everandpai ns Remedy 1) Useofdi al ysi s 2) Ki dneyt r anspl ant 3) Useofant i bi ot i cs b)Ki dneyst ones( r enalcal cul i ) :i ti scausedbysomedi seasegr owt hswi t hi nt het ubul es orbydeposi t i onofhar dmassesofcal ci um ormi ner al s.Thi smayal soocc urwhent he i nt akeofwat eri sl ow,t hesal ti nt akei shi ghort heur i nei sabnor mal l yaci di cor al kal i ne.Ki dneyst onesar et henar r owi ngoft heki dneyt ubul esbyc er t ai nsubs t ances t hatbl ockt het ubul es. Effect s 1)Obs t r uct st hepassageofur i ne 2)Pai ni se xper i encedonpassi ngoutur i ne 3)Sever eabdomi nalpai ni sexper i e nced 4)I tcancausehi ghbl oodpr essur e,f eve r ,c hi l l sandbl oodi nur i ne.

Remedy ( 1)Sur gerycal l ednephr ect omycanbeper f or medormi cr osur gery . ( 2)Pat i ent snott ot akeexcessi v ecal ci um andpr ot ei n. ( 3)Takesal otofwat er .

c)Di ur esi s:i sac ondi t i oni nwhi cht hece l l soft heki dneyt ubul esar enotr eabsor bi ng wat erf r om t hegl omer ul arfil t r at e .Thi scausesal ar geamountofwat ert obepassed outi nt heur i ne.I tcanal soocc urf r om apat i entsuffer i ngf r om di abe t esi nspi dus. Di abet esi nspi dusi sac ondi t i oni nwhi cht hepr oduct i onofADH i sr educedorl ow.The pat i entpr oducesal otofur i neofabout520l i t r esaday . Effect s 1)Leadst oexcr e t i onofl ar geamountofur i ne 2)Leadst ol ossofwe i ght 3)Leadst oemaci at i onandhi ght hi r s tf oral otofwat er . Remedy 1)Sur gi caloper at i on 2)Dr ugssuc hasdi ur e t i corv asapr essi onnasalspr ayi ngt ogetr i dofexcesswat eri n t hebody . d)Dr opsyoroedema:i sac ondi t i oni nwhi cht hece l l sofbowman’ scapsul esar e unabl et oabsor bwat erf r om t hebl oodi nt het ubul es.Al otofwat eri sr et ai nedi nt he bl oodort i ssue. Effect s 1) Swel l i ngi nf acesandankl es 2) Causessl uggi shness 3) Leadst oabdomi nalpai ns 4) Weaknessorf at i guer esul t s Remedy 1)Seekmedi calt r eat mentbys peci al i s tdoc t or . 2)Reduc t i oni nt hei nt akeofwat erandsal t 3)Ki dneyt r anspl antcanbeper f or medi ft hec ondi t i oni sc r i t i cal . St r uct ur eoft hel i v er Thel i v eri sal ar ger eddi shbr ownor ganwi t ht wol ar gel obesandt hr eesmal l er ones.I tl i esj ustbel ow t hedi aphr agm t ot her i ghtsi de,par t l yover l appi ngt he s t omac h. Leadi ngf r om t hel i vert ot hesmal li nt est i nei st hebi l eductt owhi cht hegal l bl adderi sat t ached.I ti sasof tor ganwi t har i chande xt e nsi vebl oodsuppl y .The or gansassoci at edwi t ht hel i v erar ei nt e st i ne,di aphr agm,st omach,g al lbl adder ,spl een andt hepancr eas.I ti st hel ar gestgl andi nt hebody . Dr aw t hedi agr am oft heposi t i onoft hel i verr el at i vet ot heal i ment ar ycanal .

Funct i onsoft hel i ver Thel i v erhasmanyf unc t i onsi nc l udi nghomeost asi s.Thesef unct i onsar e:1) Car bohydr at emet abol i sm:t hel i verc ont r ol st hebl oodgl ucosel eve landkeepsi twi t hi n nor mall i mi t sbyt hef ol l owi ngpr ocess es. a)Thel i v erc onv er t sanyexcessgl ucosei nt hebl oodt hatr eac hesi taf t eramealt o gl ycogenwhi c hi ss t i mul at edbyt hehor monei nsul i n.Thi sgl ycogeni ss t or edi nt he l i v er . b)Whent hebl oodgl ucosel ev elf al l sbel ow nor mal ,t hel i verconv er tgl ycogeni nt o gl ucoseandt hi spr ocessi ss t i mul at e dbyt hehor moneknownasgl ucagon. 2)Pr ot ei nme t abol i sm:t hel i v erbr eaksdowne xcessami noaci dswhi c hcannotbest or ed i nt oni t r ogencont ai ni ngami nopar t swhi c hi tconver tf ur t hert our eaf orexcr e t i onby t heki dneyandcar boncompoundswhi c hi tconver t si nt ogl ucose,gl ycogenorf at s. Thi spr ocessi sknownasdeami nat i on.I tal somanuf act ur espl asmapr ot e i nsf r om di et ar yami noaci ds.Thesepr ot ei nsar eal bumi ns,gl obul i nsandfibr i nogen. 3)Li pi dme t abol i s m:t hel i v erbr eaksdownl i pi dst opr oducegl ucoseandot her subs t ancesi fneededbyt hebody .I tal soconv er t sexc essgl ucoset of at sf ors t or age. 4)Bi l epr oduct i on:t hel i v ermakesbi l ewhi chi ss t or edi nt hegal lbl adderandsecr e t ed i nt ot heduodenum whenneeded. 5)St or ageofvi t ami nsandmi ner al s:t hel i verst or est hef at sol ubl evi t ami nsaswe l las t hewat er sol ubl evi t ami n.I tst or esmi ner al sl i kei r ons,z i nc,copperand pot assi um. 6)St or ageofbl ood:t hel i vercanst or eupt o1500cm³oft hebl oodand canr egul at et hevol umeofbl oodi ngener alci r cul at i on. 7)For mat i onandbr eakdown ofr edbl oodce l l s:i nt hef oe t us,t hel i verpr oducesr edbl oodcel l si nadul t ;t hel i v er ands pl eenbr eakdownwor noutr edbl oodcel l . 8)I nact i vat i onofhor mones:t hel i veri nact i vat est hebody’ shor monest husendi ng t hei rper i odofac t i vi t y .Theact i vi t i esofcer t ai nhor monesl i ket est ost er onear er api dl y dest r oyed. 9)De t oxi ficat i on:t hel i verconver t smanyt oxi candbi ol ogi calact i vef or ei gnsubst ances l i kepoi sonoussubs t ances ,dr ugs ,medi ci nes,f oodpr eser vat i v esandaddi t i ves , pol l ut ant sofai randwat eri nt ohar ml essori nact i vef or mswhi char eexcr e t edf r om t he body . 10)Pr oduct i onofheat :t heme t abol i cac t i vi t i esoft hel i v erpr oduceheatasabypr oduct .Thi si sdi s t r i but edt hr oughoutt hebodybyt hebl oodci r cul at i onandhel pst o keept hebodywar m. Di seasesoft hel i verandbi l educt ,e ffect s ,r emedy . I mpor t antdi s easesoft hel i verandbi l educt si nc l udehepat i t i s,di abe t es mel l i t us,canceroft hel i v er( car ci noma) ,gal ls t ones,ci r r hosi s,amoebi cl i verabscess, j aundi cee t c .

a)Hepat i t i s:i ti st hei nflammat i onoft hel i veranddes t r uct i onoft hel i vercel l s.I tmaybe causedbyavar i e t yofagent ssuchasi nf ec t i onsbyvi r us,t oxi cmat er i al ,dr ugsand poi sons.Ther ear et hr eet ypesofhepat i t i si . e.vi r alhepat i t i swhi chi soft wot ypes name l yi nf ect i vehepat i t i scausedbyvi r usTypeAandser um hepat i t i scausedbyvi r us TypeB,wei l ’ sdi sease( l ept os pi r osi s)andhepat i t i sduet odr ugsandpoi sons(ar seni c, bemeneandci nc hophen) .

Effect s Themostcommonoft hi shepat i t i si sacut ei nf ect i v ehepat i t i s.I t seffect sar eas f ol l ows: i ) Lossofappe t i t i s,enl ar ge dandt e nderl i ver . i i )Sev er eheadac heandnausea i i i )Theur i nebecomesdar kaf t eraf ew days,owi ngt ot hepr esenceofbi l e. i v)Thec onj unct i vaoft heeyeandt hes ki nbecomesye l l ow. v)Gener alweaknessoft hebody vi )Hi ghbl oodpr essur e. Remedy i )Dr ugsmustbet akenl i keant i hi st ami nedr ugscanbeusedt opr ev enti t chi ngi f pr esent . i i )Pat i ent sshoul dbepl acedonspeci aldi e t sl i kehi ghpr ot ei nf oods,pl ent ygl ucoseand flui dbutf at sshoul dbeexc l udedal coholmustbeavoi dedf orseve r almont hsaf t er r ecover y . b)Di abe t esmel l i t us:i sadefici encyofi nsul i npr oduct i onwhi chmakest hebodycel l s unabl et oabsor bgl ucose,henceexcessgl ucosecannotbeconver t edt ogl ycogen.The gl ucosei spass edoutwi t ht heur i ne. Effect s i )Cont i nuousde hydr at i on i i )Causesmuscul arweakness i i i )Leadt obl ur r edvi si on. i )Lossofwei ght Remedy i )Dr ugssuchasDi abi neset obet aken. i i )Regul ardosesofi nsul i ni nj ect i onshoul dbet akeni nt r av enousl yt hr oughoutl i f e. i i i )Car bohydr at er i chf oodmustbeav oi ded.

c) Canceroft hel i ver ( car ci noma) : i ti sanuncont r ol l abl egr owt hoft hel i vercel l swhi ch sendsoutl ongpr ocessest hatar el i ket hel i mbsoft hecr ab. Thece l l soft hi sgr owt hdo notr et ai nt henor malf unct i onoft het i ssuei nwhi c ht heyar i se Effect s i ) Ge ner alweaknessoft hebody i i ) Thi scanl eadt odeat h. i i i )Ti r edness oft hebody , sl i ghtf ev er ,accumul at i onofflui di nt heabdomen. Remedy i ) Sur gi calr emovalcanbedonei fde t ect edear l yi nl i f e. i i ) Canbedes t r oyedbyt heuseofr adi at i onorc hemot her apy .Theshor t l i ved r adi oact i vemat er i al scanbepl ant edi nt er nal l yr oundt hegr owt har ea. i i i ) Li vert r anspl ant maybecar r i edout . d)Gal ls t ones:t hesear egr owt hi nt hegal lbl adderduet ot hepr oduct i onofabnor mal bi l ebyt hel i v er .I tmayaffectt hebi l educ t s.Mos tofgal ls t onesar ecomposedof c hol est er ol . Effect s i )I tbl oc kst heduct smaki ngi ti mpossi bl ef ort hegal lbl addert of unct i onpr oper l y . i i ) I tcausesobst r uct i vej aundi cebybl oc ki ngt hecommonbi l educ t . i i i )I nabi l i t yt odi ges tf at sandoi lpr oper l y .

Remedy i )Sur gi caloper at i oni snecessar ybuti fobs t r uct i v ej aundi cei spr esent , vi t ami nK i sgi venbef or et heoper at i ont opr esenthaemor r hage. i i ) Takenofdr ugs i i i )Takenofor alf eedi ngonabi l eaci dt odi ssol vet hes t one. E)Ci r r hosi s:i st hehar deni ngoft hel i vercausedbyvi r almi cr obesort oxi cs ubs t ances l i keal coholanddi e t ar ydefici ency .Hepat i t i scanal socauset hi sdi sease.Excessi ve dr i nki ngofal coholoverapr ol ongedper i odcanal socauset hedi sease.Thi si sa ser i ousl i verdi s easei nwhi c ht hedamagedl i verc el l sbecomer epl acedbyusel ess fibr oust i ssue. Effect s i ) Ge ner alweaknessoft hebody

i i ) Lossofappe t i t e i i i )Leadst odeat h i v)Hi ghbl oodpr essur e.

Remedy i ) Av oi dal coholdr i nk i i ) Sur ger ymaybedone i i i )Li vert r anspl ant F)Amoe bi cl i verabsc ess:t hepar asi t i camoebaknownasEnt amoebahi s t ol yt i cacauses t hei nf ect i on.Thepar asi t eent er st hel i v erf r om t hel ar gei nt est i net hr ought hehepat i cpor t alv ei n.I tpr oducesanenzymet hatdest r oysl i vert i ssuesandcausesanabsc esst o f or m.

Effect s i ) Causese nl ar gedandt e nderl i ver i i ) Causespus. Remedy i )Dr ai nageoft hepus i i )Useofant i amoebi cdr ugst oge tr i doft hepar asi t i ci nf ect i on. G)Jaundi ce:i ti scausedbyani ncr easei nt hebl oodbi l i r ubi nl ev elorbi l epi gment s. Thi sgi v esay el l ow col our at i ont ot hes ki nandwhi t eoft heey es.Jaundi cemaybedue t ot hr eemai ncauses: i )Excessi vebr eakdownofr edbl oodc el l s:i tcanoc curdur i ngamal ar i ali nf ect i oni n newbor nbabi esori nsi ckl ece l lanaemi a.Cer t ai npoi sonscancauseexcessi ve br eakdownofr edbl oodc el l s. I nt hi scase,t hest ool sar edar kduet ot heexcr e t i onofl ar geamount sofbi l epi gment t hr ought hebi l educ t . i i ) Obst r uc t i onoft hebi l educ t sduet ot hebl ockageoft hebi l educ t sbygal l st ones. Thesest onespr eventbi l ef r om empt yi ngi nt ot hei nt est i ne .Asar esul t ,t hebl oodl ev el oft hebi l epi gmentbecomesr ai sed.Thes t ool sar epal eandcont ai nundi gest edf at s whi l et heur i nei sdar kye l l ow orbr own. I i i ) Di seasesoft hel i v erdamagel i verc el l s t hatt hei rabi l i t yt oext r actbi l i r ubi nf r om t hebl oodbi l i r ubi nl ev eli sr ai sed.Thi scan al socauseJauundi ce.

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