Homeostasis Prepared by : Irfan Nafiz Bin Mazdi Faizal Bac
(Hons) Information Technology in Engineering MCSE : Enterprise
Devices and Apps (Microsoft)1. Homeostasis is the maintenance of a
relatively constant internal environment.Physical factor such as
body temperature and blood pressure while chemical factor are sugar
level and osmotic pressure such as partial of carbon dioxide and
oxygen2. The excretory systemPlays an important role in
homeostasisThe primary organs of the excretory system are the
kidneys.
CortexPyramidUreterPelvisRenal VeinRenal ArteryMedullaKidney
Nephron
Bowmans CapsuleRenal Tubule : Proximal convoluted tubuleLoop of
HenleDistal convoluted tubule glomerulusBowmans campsuleRenal
tubule
UltrafiltrationFormation of urine
:UltrafiltrationReabsorptionSecretion
Podocyctes/endhothelium of glomerulus form filtration
membraneHigh hydrostatic pressure : Afferent ateriole larger
diameter than efferent aterioleThe fluid enters into capsular space
= glomerular filtrateGlomerular filtrate: water, glucose , amino
acids , urea mineral salts and other small moleculesRed Blood cell
and plasma protein remain in the blood because the too large too
pass trough filtration membrane,Reabsorption
SecretionNormal ValueNormal ValueExcess the value rises above
the normal valueCorrective Mechanisms Deficiency the value drops
below the normal value Corrective MechanismsNegative Feedback
MechanismsNegative feedback
Negative feedback
Detected by osmoreseptors in hypothalamusDecrease in solute
potentialNormal plasma osmotic levelIncreased in solute
potentialDetected by osmoreseptors in hypothalamusIncreased
permeability of distal convoluted tubule and collecting duct to
waterGreater proportion of water reabsorption in renal tubulesA
small volume of concentration urine producedA large volume of
dilute urine produced smaller proportion of water reabsorption in
renal tubulesDecreased permeability of distal convoluted tubule and
collecting duct to waterAn increased in ADH released from posterior
pituitaryA decreased in ADH released from posterior pituitaryPlasma
solute potential decreasesPlasma solute potential
increasesIncreased water intakeDecreased water intakeTHE REGULATION
OF BLOOD OSMOTIC PRESSURE DROPS/RISES THE NORMAL RANGE
Haemodialysis/Kidney TransplantHaemodialysis is the process of
filtering blood by using an artificial means that replaces the
functions of a failed kidney
After mealRise in blood glucose levelSecretion of more
insulin(-cells) or less glucagon by pancreasLiver cells absorb
glucose from blood to form glycogenIncrease in glucose uptake by
body cells for respirationLiver cell break down glycogen into
glucoseDecrease in glucose uptake by body cells for respiration
Drop in blood glucose levelSecretion of less insulin or more
glucagon(-cells) by pancreasDuring fasting or after exerciseBlood
glucose level returns to normal++THE REGULATION OF GLUCOSE
LEVELThermoregulationBody tempratures increase/decrease above 37
CThermoreseptors in the hypothalamus detect the increase /decrease
in body tempratureThermoreseptors in the skin detect the
increase/decerease in external temprature
Thermoregulatory centre in the hypothalamus Effector
