pengantar homeostasis

7/17/2019 Pengantar Homeostasis

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HomeostasisHomeostasis

M. Djauhari WidjajakusumahM. Djauhari Widjajakusumah

Departmen FisiologiDepartmen Fisiologi

Fakultas Kedokteran Universitas IndonesiaFakultas Kedokteran Universitas Indonesia



Human PhysiologyHuman Physiology

o Conerns !ith theConerns !ith the spei" harateristis andspei" harateristis and

mehanisms o# the human $odymehanisms o# the human $ody that make it athat make it a

living $eingliving $eing

o %nompasses all aspets o# human $iology& it is%nompasses all aspets o# human $iology& it is

the study o# the #untion o# human $odythe study o# the #untion o# human $ody !hih!hih

is insepara$le #rom its strutureis insepara$le #rom its struture

Guyton and Hall: Textbook of Medical Physiology 11thGuyton and Hall: Textbook of Medical Physiology 11th



Cell& 'he (asi Unit o# )i#eCell& 'he (asi Unit o# )i#eo 'he $asi unit o# $oth struture and #untion in living'he $asi unit o# $oth struture and #untion in living

$eing. 'he smallest unit apa$le o# arrying out proesses$eing. 'he smallest unit apa$le o# arrying out proesses

assoiated !ith li#e.assoiated !ith li#e.o %ah type o# ell is speially adapted to per#orm one%ah type o# ell is speially adapted to per#orm one

partiular #untion.partiular #untion.

o *ll ells have ertain $asi harateristis that are alike.*ll ells have ertain $asi harateristis that are alike.

+,ygen om$ines !ith maronutrients to release energy+,ygen om$ines !ith maronutrients to release energy Cells deliver end-produts o# the hemial reations intoCells deliver end-produts o# the hemial reations into

the interstitial uids.the interstitial uids.

*lmost all ells have the a$ility to reprodue.*lmost all ells have the a$ility to reprodue.

Cells onsist o# hemial omponents /atoms0 o,ygen&Cells onsist o# hemial omponents /atoms0 o,ygen&

ar$on& hydrogen& nitrogenar$on& hydrogen& nitrogen moleules0 protein&moleules0 protein&ar$ohydrate& #at& nulei aids 1D2* geneti materials34ar$ohydrate& #at& nulei aids 1D2* geneti materials34

o +rgan is an aggregate o# many di5erent ells held together+rgan is an aggregate o# many di5erent ells held together

$y interellular supporting strutures.$y interellular supporting strutures.

Guyton and Hall: Textbook of Medical Physiology 11Guyton and Hall: Textbook of Medical Physiology 11



(asi Cell Funtions %ssential #or 6urvival(asi Cell Funtions %ssential #or 6urvival

o# the Cello# the Cell

(asi Cell Funtions %ssential #or 6urvival(asi Cell Funtions %ssential #or 6urvival

o# the Cello# the Cell

7. +$taining nutrients and o,ygen #rom the surrounding environment7. +$taining nutrients and o,ygen #rom the surrounding environment

8. Utili9ing nutrients /ar$ohydrate& #at& protein4 and o,ygen $y !ay o# 8. Utili9ing nutrients /ar$ohydrate& #at& protein4 and o,ygen $y !ay o#

per#orming various hemial reations to provide energy #or theper#orming various hemial reations to provide energy #or theells.ells.

:. %liminating C+8 and other $y produts& !astes produed during:. %liminating C+8 and other $y produts& !astes produed during

hemial reations& to the surrounding o# the ellshemial reations& to the surrounding o# the ells

;. 6ynthesi9ing protein < other omponents;. 6ynthesi9ing protein < other omponents ellular struture&ellular struture&

gro!th&gro!th&arrying out ell #untionsarrying out ell #untions

=. Controlling materials e,hange $et!een the ell and its surrounding=. Controlling materials e,hange $et!een the ell and its surrounding

environmentenvironment

>. Moving materials #rom one part o# the ell to another in arrying out>. Moving materials #rom one part o# the ell to another in arrying out ellular ativitiesellular ativities

?. (eing sensitive and responsive to hanges in the surrounding?. (eing sensitive and responsive to hanges in the surrounding


@. Aeproduing& in most ells@. Aeproduing& in most ells

7. +$taining nutrients and o,ygen #rom the surrounding environment7. +$taining nutrients and o,ygen #rom the surrounding environment

8. Utili9ing nutrients /ar$ohydrate& #at& protein4 and o,ygen $y !ay o# 8. Utili9ing nutrients /ar$ohydrate& #at& protein4 and o,ygen $y !ay o#

per#orming various hemial reations to provide energy #or theper#orming various hemial reations to provide energy #or theells.ells.

:. %liminating C+8 and other $y produts& !astes produed during:. %liminating C+8 and other $y produts& !astes produed during

hemial reations& to the surrounding o# the ellshemial reations& to the surrounding o# the ells

;. 6ynthesi9ing protein < other omponents;. 6ynthesi9ing protein < other omponents ellular struture&ellular struture&

gro!th&gro!th&arrying out ell #untionsarrying out ell #untions

=. Controlling materials e,hange $et!een the ell and its surrounding=. Controlling materials e,hange $et!een the ell and its surrounding


>. Moving materials #rom one part o# the ell to another in arrying out>. Moving materials #rom one part o# the ell to another in arrying out ellular ativitiesellular ativities

?. (eing sensitive and responsive to hanges in the surrounding?. (eing sensitive and responsive to hanges in the surrounding


@. Aeproduing& in most ells@. Aeproduing& in most ells



Interellular CommuniationInterellular Communiation

Interellular CommuniationInterellular Communiation

Cells ommuniate !ith eah otherCells ommuniate !ith eah other via cheical essenge! via cheical essenge!

• Ga" #unctionGa" #unction

Chemial messenger move #rom ell to ell !ithout enteringChemial messenger move #rom ell to ell !ithout entering

%CF%CF

• $eu!al counication$eu!al counication

2eurotransmitter released #rom nerve ells at synapti2eurotransmitter released #rom nerve ells at synapti

juntion& at aross synapti le#t on postsynapti ell juntion& at aross synapti le#t on postsynapti ell

• %ndoc!ine counication%ndoc!ine counication

Hormones reah and $ind to reeptors o# the target ellsHormones reah and $ind to reeptors o# the target ells

via the irulating $loodvia the irulating $lood

• Pa!ac!ine counicationPa!ac!ine counicationProduts o# ells di5use in the %CF to a5et neigh$oringProduts o# ells di5use in the %CF to a5et neigh$oring

ellsells

• &utoc!ine counication &utoc!ine counication

Chemial messenger sereted $y ell& $ind to reeptors onChemial messenger sereted $y ell& $ind to reeptors onthe same ell& i.e. the ell that sereted the messengerthe same ell& i.e. the ell that sereted the messenger

Cells ommuniate !ith eah otherCells ommuniate !ith eah other via cheical essenge! via cheical essenge!

• Ga" #unctionGa" #unction

Chemial messenger move #rom ell to ell !ithout enteringChemial messenger move #rom ell to ell !ithout entering

%CF%CF

• $eu!al counication$eu!al counication

2eurotransmitter released #rom nerve ells at synapti2eurotransmitter released #rom nerve ells at synapti

juntion& at aross synapti le#t on postsynapti ell juntion& at aross synapti le#t on postsynapti ell

• %ndoc!ine counication%ndoc!ine counication

Hormones reah and $ind to reeptors o# the target ellsHormones reah and $ind to reeptors o# the target ells

via the irulating $loodvia the irulating $lood

• Pa!ac!ine counicationPa!ac!ine counicationProduts o# ells di5use in the %CF to a5et neigh$oringProduts o# ells di5use in the %CF to a5et neigh$oring

ellsells

• &utoc!ine counication &utoc!ine counication

Chemial messenger sereted $y ell& $ind to reeptors onChemial messenger sereted $y ell& $ind to reeptors on

the same ell& i.e. the ell that sereted the messengerthe same ell& i.e. the ell that sereted the messenger



Intercellular communication by chemicalIntercellular communication by chemical

mediatorsmediators



(ody Fluids(ody Fluids

o =>->B o# the adult human $eing is uid.=>->B o# the adult human $eing is uid.

o 8: o# this uid is the intraellular uid /;B $!48: o# this uid is the intraellular uid /;B $!47: o# this uid is the e,traellular uid /8B $!47: o# this uid is the e,traellular uid /8B $!4

o 'laude (e!na!d'laude (e!na!d /the 7E/the 7Ethth entury Frenh physiologist40entury Frenh physiologist40

%,traellular uid is the internal environment o# the%,traellular uid is the internal environment o# the

$ody$ody )illieu inte!ieu!*)illieu inte!ieu!* that ontains - among others -that ontains - among others -the ions and nutrients needed $y the ells #or thethe ions and nutrients needed $y the ells #or the

maintenane o# the ellular li#emaintenane o# the ellular li#e hoeostasishoeostasis



Body fuid compartments. Arrows representfuid movement. Transcellular fuids, whichconstitute a very small percentage o totalbody fuids, are not shown.William F. Ganong: Review of Medical Physiology

22nd ed, 2005



%,traellular Fluid /%CF4%,traellular Fluid /%CF4

o Constantly moves throughout the $odyConstantly moves throughout the $ody

o Aapidly transported in the irulating $loodAapidly transported in the irulating $lood

/intravasular uid4/intravasular uid4

o Fluid e,hange $et!een the intravasular and theFluid e,hange $et!een the intravasular and the

tissue /interstitial4 uids $y !ay o# di5usion throughtissue /interstitial4 uids $y !ay o# di5usion through

the apillary !allsthe apillary !alls

o %CF ontents0%CF ontents0

2a& K& Ca& Cl& and $iar$onate ions2a& K& Ca& Cl& and $iar$onate ions

2utrients /+8& gluose& #atty aids& amino aids42utrients /+8& gluose& #atty aids& amino aids4

C+8& transported #rom the ells to the lungsC+8& transported #rom the ells to the lungs

+ther ellular produts+ther ellular produts



Constituents and hysical Characteristics o the !C"Constituents and hysical Characteristics o the !C"

uyton and Hall0 'e,t$ook o# Medial Physiology 77tuyton and Hall0 'e,t$ook o# Medial Physiology 77t



HomeostasisHomeostasisHomeostasisHomeostasis

•HoeoHoeo GG samesame statisstatis GG onstantonstant

•'he maintenane o#'he maintenane o# nearly onstant onditions innearly onstant onditions in

the internal environmentthe internal environment )ilieu inte!ieu!*)ilieu inte!ieu!*

•*n ative proess*n ative proess through !hih the onstanythrough !hih the onstany

o# omponents o# the immediate environment o#o# omponents o# the immediate environment o#

the ell is maintained !ithin the physiologialthe ell is maintained !ithin the physiologialrange !ithin !hih li#e an surviverange !ithin !hih li#e an survive

•2ot an unhanging or stati state it is2ot an unhanging or stati state it is a dynamia dynami

state&state& it hanges aording to the hangingit hanges aording to the hanging

needs o# the $odyneeds o# the $ody short term or long termshort term or long termadaptationsadaptations

•HoeodynaicHoeodynaic !ould $e the $etter !ord!ould $e the $etter !ord & &

dynaic steady state in the inte!nal envi!onent dynaic steady state in the inte!nal envi!onent

•HoeoHoeo GG samesame statisstatis GG onstantonstant

•'he maintenane o#'he maintenane o# nearly onstant onditions innearly onstant onditions inthe internal environmentthe internal environment )ilieu inte!ieu!*)ilieu inte!ieu!*

•*n ative proess*n ative proess through !hih the onstanythrough !hih the onstany

o# omponents o# the immediate environment o#o# omponents o# the immediate environment o#

the ell is maintained !ithin the physiologialthe ell is maintained !ithin the physiologialrange !ithin !hih li#e an surviverange !ithin !hih li#e an survive

•2ot an unhanging or stati state it is2ot an unhanging or stati state it is a dynamia dynami

state&state& it hanges aording to the hangingit hanges aording to the hanging

needs o# the $odyneeds o# the $ody short term or long termshort term or long termadaptationsadaptations

•HoeodynaicHoeodynaic !ould $e the $etter !ord!ould $e the $etter !ord & &

dynaic steady state in the inte!nal envi!onent dynaic steady state in the inte!nal envi!onent




• 'he ativities o# ells& tissues& and organs'he ativities o# ells& tissues& and organs

must $e regulated and integrated !ith eahmust $e regulated and integrated !ith eah

other in suh a !ay thatother in suh a !ay that any hange in theany hange in the

e,traellular uid initiates a reation toe,traellular uid initiates a reation to

minimi9e the hange.minimi9e the hange.

• HomeostasisHomeostasis denotes thedenotes the !elatively!elatively sta$lesta$le

onditions o# the internal environmentonditions o# the internal environment thatthat

result #rom these ompensating regulatoryresult #rom these ompensating regulatoryresponses per#ormed $yresponses per#ormed $y homeostatihomeostati

ontrol systems.ontrol systems.ander et al.0 Human Physiology0 'he Mehanism o# (odyander et al.0 Human Physiology0 'he Mehanism o# (ody

Funtion& %ighth %dition& J 'he Mra!HillFuntion& %ighth %dition& J 'he Mra!Hill

Companies& 8BB7Companies& 8BB7




• Cell survival depends onCell survival depends on maintenane o# amaintenane o# arelative sta$le internal uid environment /%CF4relative sta$le internal uid environment /%CF4 !ith !hih ells diretly make sel#-sustaining!ith !hih ells diretly make sel#-sustaininge,hangese,hanges

• 'he ells ontinue to live and #untion properly'he ells ontinue to live and #untion properlyproviding the normal ondition o# the internalproviding the normal ondition o# the internalenvironment is maintainedenvironment is maintained

• Homeostasis is essential #or eah ellLs survival&Homeostasis is essential #or eah ellLs survival&eah ell $ene"ts #rom homeostasis.eah ell $ene"ts #rom homeostasis.

• %ah ell ontri$utes its share to!ards the%ah ell ontri$utes its share to!ards themaintenane o# homeostasis.maintenane o# homeostasis.



HomeostasisHomeostasisHomeostasisHomeostasis

• The body systems# unctions are to maintain homeostasis The body systems# unctions are to maintain homeostasis$$and depend on the speciali%ed activities o the cellsand depend on the speciali%ed activities o the cells

• The internal environment actors that The internal environment actors that must bemust behomeostatically maintainedhomeostatically maintained are&are&

concentration o nutrient molecules, '( and C'(,concentration o nutrient molecules, '( and C'(,waste products, water, salt, and other electrolyteswaste products, water, salt, and other electrolytes

p)p) temperaturetemperature

volume and pressurevolume and pressure

• !ach unctional structure * organ provides its share in the!ach unctional structure * organ provides its share in the

maintenance o homeostatic conditionsmaintenance o homeostatic conditions in the internalin the internalenvironment +!C-&environment +!C-&

ungs provide '( to replenish '( being used by the cellsungs provide '( to replenish '( being used by the cells

/idneys maintain constant ion concentrations/idneys maintain constant ion concentrations

0I system provides nutrients0I system provides nutrients

• The body systems# unctions are to maintain homeostasis The body systems# unctions are to maintain homeostasis$$and depend on the speciali%ed activities o the cellsand depend on the speciali%ed activities o the cells

• The internal environment actors that The internal environment actors that must bemust behomeostatically maintainedhomeostatically maintained are&are&

concentration o nutrient molecules, '( and C'(,concentration o nutrient molecules, '( and C'(,waste products, water, salt, and other electrolyteswaste products, water, salt, and other electrolytes

p)p)

temperaturetemperature

volume and pressurevolume and pressure

• !ach unctional structure * organ provides its share in the!ach unctional structure * organ provides its share in the

maintenance o homeostatic conditionsmaintenance o homeostatic conditions in the internalin the internalenvironment +!C-&environment +!C-&

ungs provide '( to replenish '( being used by the cellsungs provide '( to replenish '( being used by the cells

/idneys maintain constant ion concentrations/idneys maintain constant ion concentrations

0I system provides nutrients0I system provides nutrients



Disruption o# Homeostati onditionDisruption o# Homeostati onditionDisruption o# Homeostati onditionDisruption o# Homeostati ondition

• +ne or more #untional systems lose their a$ility+ne or more #untional systems lose their a$ility

to ontri$ute their share o# #untionto ontri$ute their share o# #untion ells o#ells o#

the $ody su5er.the $ody su5er.

• %,treme dys#untion leads to death& !hereas%,treme dys#untion leads to death& !hereas

moderate dys#untion leads to sikness.moderate dys#untion leads to sikness.

• +ne or more #untional systems lose their a$ility+ne or more #untional systems lose their a$ility

to ontri$ute their share o# #untionto ontri$ute their share o# #untion ells o#ells o#

the $ody su5er.the $ody su5er.

• %,treme dys#untion leads to death& !hereas%,treme dys#untion leads to death& !hereas

moderate dys#untion leads to sikness.moderate dys#untion leads to sikness.



Aegulation o# (ody FuntionsAegulation o# (ody Funtions

The $e!vous +ysteThe $e!vous +yste



rovides rapid coordinationsrovides rapid coordinations o internal organo internal organsystem, and response to the e1ternal environment tosystem, and response to the e1ternal environment to

maintain the homeostatic condition.maintain the homeostatic condition. Interactions between the nervous and endocrineInteractions between the nervous and endocrine

controlling systemscontrolling systems are precisely ad2usted byare precisely ad2usted bycomple1 mechanismcomple1 mechanism the neuoendocinethe neuoendocine

egulation.egulation.

rovides rapid coordinationsrovides rapid coordinations o internal organo internal organsystem, and response to the e1ternal environment tosystem, and response to the e1ternal environment to

maintain the homeostatic condition.maintain the homeostatic condition. Interactions between the nervous and endocrineInteractions between the nervous and endocrine

controlling systemscontrolling systems are precisely ad2usted byare precisely ad2usted bycomple1 mechanismcomple1 mechanism the neuoendocinethe neuoendocine

egulation.egulation.







Composed o three ma2or partsComposed o three ma2or parts

o !he sensoy in"ut "otion!he sensoy in"ut "otion

ensory receptors detect the state o the body or theensory receptors detect the state o the body or thestate o the surroundingsstate o the surroundings

o !he cental nevous system #$%&'(integative "otion!he cental nevous system #$%&'(integative "otion

Composed o the brain, the brain stem, and the spinalComposed o the brain, the brain stem, and the spinalcord.cord.

The brain stores inormation, generate thoughts, The brain stores inormation, generate thoughts,

determines reactions in response to the sensory inputs.determines reactions in response to the sensory inputs.o !he moto out"ut "otion!he moto out"ut "otion

Transmits appropriate signals rom C3 to carry out Transmits appropriate signals rom C3 to carry outappropriate responsesappropriate responses

Composed o three ma2or partsComposed o three ma2or parts

o !he sensoy in"ut "otion!he sensoy in"ut "otion

ensory receptors detect the state o the body or theensory receptors detect the state o the body or thestate o the surroundingsstate o the surroundings

o !he cental nevous system #$%&'(integative "otion!he cental nevous system #$%&'(integative "otion

Composed o the brain, the brain stem, and the spinalComposed o the brain, the brain stem, and the spinalcord.cord.

The brain stores inormation, generate thoughts, The brain stores inormation, generate thoughts,

determines reactions in response to the sensory inputs.determines reactions in response to the sensory inputs.o !he moto out"ut "otion!he moto out"ut "otion

Transmits appropriate signals rom C3 to carry out Transmits appropriate signals rom C3 to carry outappropriate responsesappropriate responses



Vander et al.: Human Physiology: The Mechanism of Body Function, Eighth EditionVander et al.: Human Physiology: The Mechanism of Body Function, Eighth Edition

© The McGra!Hill "om#anies, $%%& © The McGra!Hill "om#anies, $%%&




The %ndoc!ine +ysteThe %ndoc!ine +yste


The %ndoc!ine +ysteThe %ndoc!ine +yste

o Hormones are transported in the %CF to allHormones are transported in the %CF to all

parts o# the $ody to help regulate ellularparts o# the $ody to help regulate ellular#untions#untions

o Complements the nervous systemComplements the nervous system

o 'he nervous system regulates mainly the'he nervous system regulates mainly the

musular and seretory ativities&musular and seretory ativities& thethe

hormonal system regulates mainly thehormonal system regulates mainly the

meta$oli #untions.meta$oli #untions.

o Hormones are transported in the %CF to allHormones are transported in the %CF to all

parts o# the $ody to help regulate ellularparts o# the $ody to help regulate ellular#untions#untions

o Complements the nervous systemComplements the nervous system

o 'he nervous system regulates mainly the'he nervous system regulates mainly the

musular and seretory ativities&musular and seretory ativities& thethe

hormonal system regulates mainly thehormonal system regulates mainly the

meta$oli #untions.meta$oli #untions.



'he Control 6ystem o# 'he (ody'he Control 6ystem o# 'he (ody'he Control 6ystem o# 'he (ody'he Control 6ystem o# 'he (ody

• Proportional ontrol system0Proportional ontrol system0

*djusting and reating*djusting and reating )giving !es"onse*)giving !es"onse* toto

hanges in thehanges in the environmentenvironment )stiuli*)stiuli* inin

proportion to the degree o# utuation o# theproportion to the degree o# utuation o# theontrolled varia$les.ontrolled varia$les.

• * omple, and integrated system.* omple, and integrated system.

6imple proportional system still has minor6imple proportional system still has minor

errors that an $e orreted $y an integralerrors that an $e orreted $y an integralontrol system.ontrol system.

• Proportional ontrol system0Proportional ontrol system0

*djusting and reating*djusting and reating )giving !es"onse*)giving !es"onse* toto

hanges in thehanges in the environmentenvironment )stiuli*)stiuli* inin

proportion to the degree o# utuation o# theproportion to the degree o# utuation o# theontrolled varia$les.ontrolled varia$les.

• * omple, and integrated system.* omple, and integrated system.

6imple proportional system still has minor6imple proportional system still has minor

errors that an $e orreted $y an integralerrors that an $e orreted $y an integralontrol system.ontrol system.



'he Control 6ystem o# 'he (ody'he Control 6ystem o# 'he (ody'he Control 6ystem o# 'he (ody'he Control 6ystem o# 'he (ody

• ,nt!acellula! cont!ol syste,nt!acellula! cont!ol syste eneti ontrol system& ontrols intraellulareneti ontrol system& ontrols intraellular

#untions#untions

• -!gan level cont!ol syste )int!insic local cont!ol-!gan level cont!ol syste )int!insic local cont!ol

syste*syste* Controls the #untions o# parts o# the organControls the #untions o# parts o# the organ

• ,nte! o!gan cont!ol syste )ext!insic cont!ol syste*,nte! o!gan cont!ol syste )ext!insic cont!ol syste* +perates throughout the entire $ody to ontrol+perates throughout the entire $ody to ontrol

the interrelationships among organsthe interrelationships among organs'he respiratory system regulates the'he respiratory system regulates the

onentration o# C+8& in assoiation !ith theonentration o# C+8& in assoiation !ith thenervous systemnervous system

'he liver and panreas regulate the'he liver and panreas regulate the

onentration o# $lood gluoseonentration o# $lood gluose

• ,nt!acellula! cont!ol syste,nt!acellula! cont!ol syste eneti ontrol system& ontrols intraellulareneti ontrol system& ontrols intraellular

#untions#untions

• -!gan level cont!ol syste )int!insic local cont!ol-!gan level cont!ol syste )int!insic local cont!ol

syste*syste* Controls the #untions o# parts o# the organControls the #untions o# parts o# the organ

• ,nte! o!gan cont!ol syste )ext!insic cont!ol syste*,nte! o!gan cont!ol syste )ext!insic cont!ol syste* +perates throughout the entire $ody to ontrol+perates throughout the entire $ody to ontrol

the interrelationships among organsthe interrelationships among organs'he respiratory system regulates the'he respiratory system regulates the

onentration o# C+8& in assoiation !ith theonentration o# C+8& in assoiation !ith thenervous systemnervous system

'he liver and panreas regulate the'he liver and panreas regulate the

onentration o# $lood gluoseonentration o# $lood gluose



Charateristis o# Control 6ystem Charateristis o# Control 6ystem

Feed$ak mehanismsFeed$ak mehanisms

/eedback syste/eedback syste

Feed$ak0 responses made a#ter a hange has $eenFeed$ak0 responses made a#ter a hange has $een

deteteddeteted

Feed$ak system generally operate on the prinipleFeed$ak system generally operate on the priniple

o# o# negative feed back:negative feed back:

$egative feedback syste$egative feedback systeIntegrative system that measures and omparesIntegrative system that measures and ompares

the input andthe input and output& and gives responseoutput& and gives response to anyto any

disrepany to maintain adisrepany to maintain a $iologial system in a$iologial system in a

steady statesteady state

$egative feedback echanis$egative feedback echanis

* series o# hanges that return the ontrolled* series o# hanges that return the ontrolled

varia$le to!ard avaria$le to!ard a ertain mean value& thusertain mean value& thus

maintaining homeostasismaintaining homeostasis

Most ontrol systems o# the $ody at $y a proessMost ontrol systems o# the $ody at $y a proess

/eedback syste/eedback syste

Feed$ak0 responses made a#ter a hange has $eenFeed$ak0 responses made a#ter a hange has $een

deteteddeteted

Feed$ak system generally operate on the prinipleFeed$ak system generally operate on the priniple

o# o# negative feed back:negative feed back:

$egative feedback syste$egative feedback systeIntegrative system that measures and omparesIntegrative system that measures and ompares

the input andthe input and output& and gives responseoutput& and gives response to anyto any

disrepany to maintain adisrepany to maintain a $iologial system in a$iologial system in a

steady statesteady state

$egative feedback echanis$egative feedback echanis

* series o# hanges that return the ontrolled* series o# hanges that return the ontrolled

varia$le to!ard avaria$le to!ard a ertain mean value& thusertain mean value& thus

maintaining homeostasismaintaining homeostasis

Most ontrol systems o# the $ody at $y a proessMost ontrol systems o# the $ody at $y a proess



2egative-#eed$ak system2egative-#eed$ak system

An increase or decrease in the variable being regulatedAn increase or decrease in the variable being regulated

brings about responses thatbrings about responses that tend to move the variabletend to move the variable

in the direction opposite +4negative5 to- the direction oin the direction opposite +4negative5 to- the direction o

the original change.the original change. The response returns the controlled The response returns the controlled

variable bac6 to its normal value,variable bac6 to its normal value, the response isthe response is

7against# the change7against# the change

• thethe deceasedecease in body temperature leads to responsesin body temperature leads to responses

that tend tothat tend to inceaseincease the body temperature 8 that is,the body temperature 8 that is,

move it toward its original value.move it toward its original value.

• thethe inceaseincease in !C" concentration o C9(in !C" concentration o C9( #initiating#initiatingstimulus'stimulus' leads to responses that tend toleads to responses that tend to increaseincrease

pulmonary ventilationpulmonary ventilation lungs e1pire greaterlungs e1pire greater

amounts o C'( rom the bodyamounts o C'( rom the body decreases bac6decreases bac6

!C" :C9(; +!C" :C9(; +negative es"onse to the initiatingnegative es"onse to the initiating

stimulus'stimulus'



%laine 2. Marie$& Katja Hoehn0 Human *natomy <%laine 2. Marie$& Katja Hoehn0 Human *natomy <Physiology ?Physiology ?thth ed& 8BB>ed& 8BB>



%laine 2. Marie$& Katja Hoehn0 Human%laine 2. Marie$& Katja Hoehn0 Human*natomy < Physiology ?*natomy < Physiology ?thth ed& 8BB>ed& 8BB>



Vander et al.: Human Physiology: TheVander et al.: Human Physiology: The

Mechanism of Body Function, Eighth Edition, ©Mechanism of Body Function, Eighth Edition, ©

The McGra!HillThe McGra!Hill

"om#anies, $%%&"om#anies, $%%&



Vander et al.: Human Physiology: The Mechanism of Body Function, Eighth Edition,Vander et al.: Human Physiology: The Mechanism of Body Function, Eighth Edition,



The homeostatic control system maintains aThe homeostatic control system maintains a

relatively constant body temperature whenrelatively constant body temperature when

room temperature decreases.room temperature decreases.

The “begin” sign indicates where to start.The “begin” sign indicates where to start.

The arrows next to each term within theThe arrows next to each term within theboxes denote increases or decreases.boxes denote increases or decreases.

The arrows connecting any two boxes in theThe arrows connecting any two boxes in the

figure denote cause and effect; that is, anfigure denote cause and effect; that is, an

arrow can be read as “causes” or “leads to.”arrow can be read as “causes” or “leads to.”

In general, one should add the wordsIn general, one should add the words

“tends to” in thinking about these “tends to” in thinking about thesecauseandeffect relationships. !or example,causeandeffect relationships. !or example,

decreased room temperature tends to causedecreased room temperature tends to cause

an increase in heat loss from the body, andan increase in heat loss from the body, and

curling up tends to cause a decrease in heatcurling up tends to cause a decrease in heat

loss from the body.loss from the body.

"ualifying the relationship in this way is"ualifying the relationship in this way isnecessary because variables like heatnecessary because variables like heat

production and heat loss are under theproduction and heat loss are under the

influence of many factors, some of whichinfluence of many factors, some of which

oppose each other.oppose each other.

Vander et al.: Human Physiology: The Mechanism of BodyVander et al.: Human Physiology: The Mechanism of Body

Function, Eighth Edition, © The McGra!HillFunction, Eighth Edition, © The McGra!Hill




Vander et al.: Human Physiology: The MechanismVander et al.: Human Physiology: The Mechanism

of Body Function, Eighth Edition, © Theof Body Function, Eighth Edition, © The

McGra!HillMcGra!Hill"om#anies, $%%&"om#anies, $%%&



anongLs Aevie! o# MedialanongLs Aevie! o# Medial

Physiology 8:Physiology 8:rdrd ed& 8BBEed& 8BBE






Feed$ak mehanismsFeed$ak mehanisms


Feed$ak mehanismsFeed$ak mehanismsPositive /eedback:Positive /eedback:

•*n initial distur$ane in a system sets o5 a train o# events*n initial distur$ane in a system sets o5 a train o# eventsthat inrease the distur$ane even #urther.that inrease the distur$ane even #urther.

•Positive #eed$ak does not #avor sta$ility and o#tenPositive #eed$ak does not #avor sta$ility and o#tena$ruptly displaes a system a!ay #rom its normal seta$ruptly displaes a system a!ay #rom its normal setpoint.point.

•'he greater the initiating stimulus& the more the'he greater the initiating stimulus& the more theontrolling system is ativated.ontrolling system is ativated.

•Does not happen very o#ten in $iologial system& does notDoes not happen very o#ten in $iologial system& does notlead to sta$ility& $ut to insta$ility and o#ten to death.lead to sta$ility& $ut to insta$ility and o#ten to death.

•Kno!n asKno!n as vicious ci!clevicious ci!cle

•* mild degree o# positive #eed$ak an $e overome $y* mild degree o# positive #eed$ak an $e overome $ynegative #eed$ak ontrolnegative #eed$ak ontrol vicious ci!clevicious ci!cle #ails to develop#ails to develop

• In ertain irumstanes& positive #eed$ak ours to $eIn ertain irumstanes& positive #eed$ak ours to $euse#uluse#ul Child$irthChild$irth

Desending o# the $a$yDesending o# the $a$y ervi, strethedervi, strethed signalssignals#rom the ervi,#rom the ervi, uterine ontrationsuterine ontrations moremorestrethed ervi,strethed ervi, more intense signalsmore intense signals moremorepo!er#ul uterine ontrationspo!er#ul uterine ontrations $irth o# the $a$y$irth o# the $a$y

Positive /eedback:Positive /eedback:

•*n initial distur$ane in a system sets o5 a train o# events*n initial distur$ane in a system sets o5 a train o# eventsthat inrease the distur$ane even #urther.that inrease the distur$ane even #urther.

•Positive #eed$ak does not #avor sta$ility and o#tenPositive #eed$ak does not #avor sta$ility and o#tena$ruptly displaes a system a!ay #rom its normal seta$ruptly displaes a system a!ay #rom its normal setpoint.point.

•'he greater the initiating stimulus& the more the'he greater the initiating stimulus& the more theontrolling system is ativated.ontrolling system is ativated.

•Does not happen very o#ten in $iologial system& does notDoes not happen very o#ten in $iologial system& does notlead to sta$ility& $ut to insta$ility and o#ten to death.lead to sta$ility& $ut to insta$ility and o#ten to death.

•Kno!n asKno!n as vicious ci!clevicious ci!cle

•* mild degree o# positive #eed$ak an $e overome $y* mild degree o# positive #eed$ak an $e overome $ynegative #eed$ak ontrolnegative #eed$ak ontrol vicious ci!clevicious ci!cle #ails to develop#ails to develop

•In ertain irumstanes& positive #eed$ak ours to $eIn ertain irumstanes& positive #eed$ak ours to $euse#uluse#ul Child$irthChild$irth

Desending o# the $a$yDesending o# the $a$y ervi, strethedervi, strethed signalssignals#rom the ervi,#rom the ervi, uterine ontrationsuterine ontrations moremorestrethed ervi,strethed ervi, more intense signalsmore intense signals moremorepo!er#ul uterine ontrationspo!er#ul uterine ontrations $irth o# the $a$y$irth o# the $a$y


Charateristis o# Control 6ystem C arater st s o Contro 6ystem



Charateristis o# Control 6ystem Charateristis o# Control 6ystem Feed$ak mehanismsFeed$ak mehanisms

Charateristis o# Control 6ystem C arater st s o Contro 6ystem Feed$ak mehanismsFeed$ak mehanisms

Positive Feed$ak0Positive Feed$ak0Positive Feed$ak0Positive Feed$ak0

!strogens!strogens

IncreasedIncreased o)ytocino)ytocin receptorsreceptors

<terine distention <terine distention PostaglandinPostaglandin

<terine contractions<terine contractions

=ilatation o cervi1 and distention o vagina=ilatation o cervi1 and distention o vagina

timuli rom cervi1 and vaginatimuli rom cervi1 and vagina

Increased secretion o o1ytocinIncreased secretion o o1ytocin

i i l



iious yleiious yleiious yleiious yleI# one or more #untional systems lose their a$ility to #untion properlyI# one or more #untional systems lose their a$ility to #untion properly

the optimal ondition o# the internal environment an not $e maintainedthe optimal ondition o# the internal environment an not $e maintained

drives the $ody a!ay #rom normal homeostasisdrives the $ody a!ay #rom normal homeostasis

vicious cyclevicious cycle

homeostati #ailurehomeostati #ailure

ells o# the $ody su5erells o# the $ody su5er

pathophysiologi onditionpathophysiologi ondition

may lead to death.may lead to death.

I# one or more #untional systems lose their a$ility to #untion properlyI# one or more #untional systems lose their a$ility to #untion properly

the optimal ondition o# the internal environment an not $e maintainedthe optimal ondition o# the internal environment an not $e maintained

drives the $ody a!ay #rom normal homeostasisdrives the $ody a!ay #rom normal homeostasis

vicious cyclevicious cycle

homeostati #ailurehomeostati #ailure

ells o# the $ody su5erells o# the $ody su5er

pathophysiologi onditionpathophysiologi ondition

may lead to death.may lead to death.



Guyton and *all: !e)t+oo of Medical Physiology --th ed. 200Guyton and *all: !e)t+oo of Medical Physiology --th ed. 200



Vander et al.: Human Physiology: The Mechanism ofVander et al.: Human Physiology: The Mechanism of

Body Function, Eighth Edition, © The McGra!HillBody Function, Eighth Edition, © The McGra!Hill


*d t ti*d t ti

*d t ti*daptation



*daptation*daptation*daptation*daptation

• iving systems are constantly ad2usting and reactingiving systems are constantly ad2usting and reacting

#/es"onses/'#/es"onses/' to changesto changes #/stimuli/ '#/stimuli/ ' in the environmentin the environment

• Immediate response&Immediate response&

ainul stimulusainul stimulus increased blood pressureincreased blood pressure

!1ercise!1ercise increased blood pressureincreased blood pressure immediateimmediate

adaptation to supply the e1ercising muscles +# the newadaptation to supply the e1ercising muscles +# the new

circumstances#- with blood, limited by muscle soreness andcircumstances#- with blood, limited by muscle soreness andatigueatigue

• >esponse to long?lasting environment changes>esponse to long?lasting environment changes

Basic biochemistry changes in 7trained muscles#&Basic biochemistry changes in 7trained muscles#&

o Increased number o open capillaries supplying theIncreased number o open capillaries supplying themusclemuscle

o Increased blood supply, contractile proteins, andIncreased blood supply, contractile proteins, and

o1ygen?storing protein +myoglobin-o1ygen?storing protein +myoglobin-

Adaptation to the new environment, muscle hypertrophy,Adaptation to the new environment, muscle hypertrophy,

increase in si%e o the individual muscle cellsincrease in si%e o the individual muscle cells

• iving systems are constantly ad2usting and reactingiving systems are constantly ad2usting and reacting

#/es"onses/'#/es"onses/' to changesto changes #/stimuli/ '#/stimuli/ ' in the environmentin the environment

• Immediate response&Immediate response&

ainul stimulusainul stimulus increased blood pressureincreased blood pressure

!1ercise!1ercise increased blood pressureincreased blood pressure immediateimmediate

adaptation to supply the e1ercising muscles +# the newadaptation to supply the e1ercising muscles +# the new

circumstances#- with blood, limited by muscle soreness andcircumstances#- with blood, limited by muscle soreness andatigueatigue

• >esponse to long?lasting environment changes>esponse to long?lasting environment changes

Basic biochemistry changes in 7trained muscles#&Basic biochemistry changes in 7trained muscles#&

o Increased number o open capillaries supplying theIncreased number o open capillaries supplying themusclemuscle

o Increased blood supply, contractile proteins, andIncreased blood supply, contractile proteins, and

o1ygen?storing protein +myoglobin-o1ygen?storing protein +myoglobin-

Adaptation to the new environment, muscle hypertrophy,Adaptation to the new environment, muscle hypertrophy,

increase in si%e o the individual muscle cellsincrease in si%e o the individual muscle cells

Patient's clinical condition



"linical signs ( sym#toms

History ( #rognosis of the disease

Histo#athological changes

(Pathology Anatomy)

(Clinical Pathology)

)*normal function

(Pathophysiology) PathogenesisPathogenesis

Feed*ac+ mechanism

failure

Trauma,

stimuli

ormal -tructure

(Anatomy,

Histology)

ormal Function Trauma,

stimuli

Feed*ac+ mechanism

-hort Term )da#tation

ong Term )da#tation

Homeostasis

Physiology

Biochemistry



Than6 you Than6 you



uyton and Hall0 'e,t$ook o# Medial Physiology 77th ed. 8BB>uyton and Hall0 'e,t$ook o# Medial Physiology 77th ed. 8BB>

pengantar homeostasis

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