This document provides an overview of the three stage process of urine formation and excretion by the kidneys. It discusses: 1) Filtration - where blood is filtered through tiny capillaries in the kidneys, removing water, salts, and waste to form an early urine. 2) Reabsorption - where many valuable nutrients are reabsorbed by the body, while waste remains in the urine. 3) Secretion - where further water and salt regulation occurs as urine passes through delicate kidney structures before leaving. The finished urine is then carried from the kidneys by the ureters to the bladder for later excretion through the urethra.

1. CLASS ASSINGMENT :PROCESS OFURINE FORMATIONAND EXCREATION.
Urine is one of the body waste products. Its primarily compost of water and urea .Urea is special
nitrogenous waste compound that the body must remove.
Urine occure in 3 stages :
 Filtration
 Reabsorption
 Secration
1.Filtration[Glomerular]
Stage 1.The kindeyisbodiesbloobfiltrationsytem.Bloodvessels visitsthe kidneyandenteraspecial
ballsof capillariescalledglomerulars.
The glomerulasisa nesthedwithinaregionof kidneycalledthe Bowman’scapsule.Thisiswhere
filtrationoccurs.
As bloodispushedthroughthe tinycapillarie,thehighpressure forcessome thingstopassthroughthe
capillarywalls.Thewall actasa sieve orfilters.
Water,sugar ,salt,aminoacid, nitrogenouswaste andothertinythingsentersthe kidneyasa sabstance
calledfilteratecellsandlarge bloodproteinsthatcannot fitthroughremaininthe bloodvessels.The
filterationenteringthe kidneyislike pre-urine.
2.Reabsorption.
Stage 2:The filterationentersthe kidneyinthe proximal tubule .Thisregionof the kidneyisspecial
because manythingscan be removedfromfilterate.Thisvaluablethingare recollectedorreabsorbedby
the body.
Glucose,certainsalts,vitamins,hormones,aminoacidsare restoredtothe bodyandwill be includedin
urine.Some timesif the bodyhastoomuch of somethingthenthe extrasugerorsalt will stayinthe
filterate egindiabetiswithhighlevel of bloodglucose mayhave glucose inthere urine since itcannotbe
reabsorbed.
The filtrationafterreabsorptionislike pre-urine.
3.Secreation.
Stage3;The filtrate isthenpassesthroughareallyneatstructure calledthe loopof henle where itgains
and looseswaterandsalt.
As itleanksthe loopof henle ,itentersthe distal tubule where the secretionoccurs.
B..EXCREATION OFURINE

2. Urine leavesthe kidneyinthe tube orthe hilus,anotch that occurs at the centre of the concave
edge.Bloodvesselsandnervesenytersandleavesthe kidneyatthe hillus,withinthe kidneynephrons
clearthe bloodof waste,creaturine anddilute urine toa tube calledureter,whichcariesthe urine to
the blood.The urinarybladderthenemptiesurine intothe urethra,ductleavingtooutside the body.A
sphintermuscle controlsthe flow of urine betweenthe urinarybladderandurethra .