excretion & osmoregulation

7/24/2019 Excretion & Osmoregulation

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Excretion &

OsmoregulationCHETAN K.



What is Excretion

Excretion is the removal of metabolic waste from the cells

etabolic waste is the unwante! material that is forme!as a result of the bo!ies metabolism. That is the largenumber of chemical reactions that occur in the cells"tissues an! organs.

The waste #ro!ucts of metabolism are fre$uentl% toxican! so must be remove! from the bo!%.

Ki!ne% #la%s im#ortant role in excretion #rocess in allvertebrates.

While sin also hel#s in excretion of urea" inorganic salts &

water through sweat glan!s.



'unctions of Ki!ne%

Elimination on nitro.waste

aintain H(O level

ie.

osmoregulation

aintainconcent

ie

iso*to



o!es of excretion #rocess..

Excretion carrie! out in !i+erent manner in !i+erentanimals vi,.

-etoxicatation

Ammonia to urea

Ammonia to uric aci!

-eamination

Amino aci! to ammonia



o!es of

Excretions

/ricotelis

m

Ammono

telism

ureotelism



Ammonotelism

0henomenon of formation of excretor% #ro!uct inform of ammonia is calle! as ammonotelism.

Organisms which show this activit% are1ammonotelic2.

Ammonia is highl% soluble in water & highl% toxic innature

3t can be excrete! b% sim#le !i+usion so itsconcentration in bo!% is e#t ver% low.

As it is harmful for bo!% tissues hence nee! toremove as soon as forme!.



Ammonotelicanimals

'or elimination of ammonia large $uantit%of water is re$uire!.

-ue to this reason ammonotelism is seenin a$uatic animals" bon% sh" ta!#ole larva.

4uch animals ammonia !i+use through thesin an! gills an! i!ne%.



/reotelism Excretion of nitrogenious waste in form of

urea is uricotelism. 3n this urea formation re$uire ex#en!iture

of energ% an! forme! in liver b% ornithinec%cle.

/rea can store in water in its !issolve!form urine

o!rate amount of water is re$uire ie 56ml for 7 gm

Animals have this excretor% s%stems are

Turtles

ammals

Ornithine

Arginine

Urea

H2O



/ricotelism

Elimination of nitrogenous waste in form of uric aci!. 4%nthesis of uric aci! re$uire more energ%. 3t taes

#lace b% inosinic #athwa%.

/ric aci! is eliminate! in form of soli! #allets or thic#aste which re$uire ver% less amount of water

76 ml for 7 gm hence useful for !esert animals

Animals #ossess this excretion s%stem are 4nails

8e#tiles

9i,ar!s



Human Excretor% s%stem

Human Excretor% 4%stem consist offollowing organs

A #air of i!ne%"

A #air of ureters"

A single un#aire! urinar% bla!!er"

A urethra in males : vestibule in

females.



'unction of the Excretor% 4%stem

The human excretor% s%stem functions to remove waste from thehuman bo!%.

-uring this #rocess animals get ri! of nitrogenous waste #ro!ucts ofmetabolism" inclu!ing ammonia" urea" an! uric aci!.

Although excretor% s%stems are !iverse" nearl% all #ro!uce urine in a#rocess that involves several ste#s.

Ki!ne%s

/rethras

/rinar% bla!!er

/rethra

Organs ofthe Excretor%

4%stem

Organs ofthe Excretor%

4%stem



7. 'iltration:

The excretor% tubule collects ltrate from the bloo!.

Water an! solutes are force! b% bloo! #ressureacross the selectivel% #ermeable membranes of acluster of ca#illaries an! into the excretor% tubule.

(. 8eabsor#tion:

The trans#ort e#ithelium reclaims valuablesubstances from the ltrate an! returns them.

;. 4ecretion:

Other substances are extracte! from bo!% <ui!san! a!!e! to the contents of the excretor% tube.

=. Excretion:

The ltrate leaves the s%stem an! the bo!%.

Function of the Excretory System

Structure of the Excretory



Structure of the ExcretorySystem

This s%stem consists of s#eciali,e! structures an! ca#illar%networs that assist in the excretor% #rocess.

The human excretor% s%stem inclu!es the i!ne% an! its

functional unit" the ne#hron. The excretor% activit% of the i!ne% is change! b% s#eciali,e!

hormones that regulate the amount of absor#tion within thene#hron.

Excretory System

>la!!er Ki!ne%s

/rethra/reters

eatus



Kidney



The i!ne%s are two bean*sha#e! organs ablong" three*inches wi!e an! one*inch thic lobac on each si!e of %our s#ine.

Each i!ne% is about the si,e of a st an! wto six ounces. The% are situate! above %our left i!ne% a little higher an! a little larger.

The right i!ne% is a little lower an! smallerfor the liver. The lower ribs #rotect %our i!n

3nsi!e the i!ne%s are ne#hrons. These are t

where the ltering of excess <ui!s an! !issooccurs. There are between 7 an! 7.; million each i!ne%.

>loo! enters the i!ne%s through renal artethrough renal veins.

Tubes calle! ureters carr% waste #ro!ucts froto the urinar% bla!!er for storage or for rele

-uring urination" urine is ex#elle! from the

Kidney

http://www.davita.com/kidney-disease/vocabulary/nephron/e/5502

http://www.davita.com/kidney-disease/vocabulary/nephron/e/5502



'low of /rineFlow of Urine

@lomerulus

8enal Tubules

8enal 0elvis

8enal Calices

/reters

8enal cort

8enal ca#

8enal me!

/reter

8enal vein

8enal arte

Ne#

i! l b 66 li f bl ! ! il i h



Ki!ne%s lter about 766 liters of bloo! !ail% in the averagea!ult.

0arts of the i!ne%s

• Cortex

*outer #rotective #ortion

• Medulla

*inner soft #ortion

• Hilum*a !e#ression locate! in the mi!!le ofthe concave si!e of the i!ne% wherebloo! vessels" nerves" an! the uretersenter an! exit the i!ne%s

Medulla

Hilum

The cortex is where the bloo! is ltere!.

The medulla contains the collecting !ucts which carr% ltrateBltere! substances to the #elvis.

The pelvis is a hollow cavit% where urine accumulates an! !rainsinto the ureter.



Ureters

Peristalsis a rh%thmic contraction of theureter smooth muscle which hel#s to move

the urine into the !ladder.

A tube approximately 6 to 7 inches longattached to each kidney.

a!e u# of three la%ers of tissue 4mooth muscle 'ibrous tissue ucous la%er



/rinar% >la!!er•Hollow" muscular organ thurine•4#hincter muscles hol! the#lace•Hol!s ;66 to =66 millilitersbefore em#t%ing•Walls contain e#ithelial tisstretch to allow the bla!!ertwice its ca#acit%

/rethra

0rostateglan!

/reter

/rinar%bla!!er

• The trigone is a triangulathe base of the bla!!er wureters enter an! the ureexits



/rethra

'emale/rethra

ale /rethra

•A##roximatel% 7.5

inches long•O#ens through themeatus

•A##roximatel% D inches lo

•0asses through three !i+eregions0rostate glan!embranous #ortion0enis

A tube of smooth muscle with a mucous lining thatcarries urine from the bladder to the outside of thebody.



The functional units of the i!ne% are calle! ne#hrons.

Ne#hrons are locate! in the renal cortex" exce#t for their loo#s ofHenle" which !escen! into the renal me!ulla.

"ephron



Two #arts

a. 8enal Cor#uscle

7. >owman Ca#sule

(. @lomerulus

a. Fenestrae * #ore in en!othelial walls of glomerulus.

b. Podocytes * s#eciali,e! cells.

c. Filteration slits

b. 8enal Tubule * 4eries of single la%er tubules

7. 0roximal Convolute! tubule

(. 9oo# of Henle

;. -istal Convolute! tubule

"ephron

Ki!ne%s are ma!e u# of ne#hrons. >loo! enters the ne#hron" whereim#urities are ltere! out an! em#tie! into the collecting !uct. The#urie! bloo! leaves the ne#hron through the renal vein.



"ephron



The glomerulus is a mass of thin*walle! ca#illaries.

The Bowman’s capsule is a !ouble*walle!" cu#*sha#e! structure.

The proximal tubule lea!s from the >owmanFs ca#sule to the 9oo# ofHenle.

The loop of enle is a long loo# which exten!s into the me!ulla.

The distal tubule connects the loo# of Henle to the collecting !uct.

Each ne#hron has its own bloo! su##l%

An arteriole

A venule

A networ of ca#illaries connectingthem

Each ne#hron releases <ui!s to a collecting !uct"which lea!s to the ureter.

Each i!ne% contains more than 7 million nephrons



Each i!ne% contains more than 7 million nephrons.

Blood Flow through the Kidneys

Blood enters through the renal artery Arterioles

!ach arteriole leads to a nephron "enal corpu

The #lomerulus lters <ui! from the bloo!" an! is the r#lace where urine is forme! in the i!ne%s.

>loo! <ows through the glomerulus at a constant rate.

Each glomerulus is surroun!e! b% a ca#sule nown as >owmanca#sule.

>loo! then #asses into the renal tubules where some substanceare reabsorbe! an! the remaining become urine.

$he



$heKidneys

As bloo! enters a ne#hron through the arteriole" im#urities areltere! out an! em#tie! into the collecting !uct.

The #urie! bloo! exits the ne#hron through the venule.

How is blood fltered?

#he mechanism of blood puri$cation in%ol%es two distinct

processes& 'iltration

8eabsor#tion



Filtration

0assing a li$ui! or gas through a lter to remove wastes is calle!

%ltration.

The ltration of bloo! mainl% taes #lace in the glomerulus. The #lomerulus is a small networ of ca#illaries encase! in the

the ne#hron b% a hollow" cu#*sha#e! structure calle! &owman'capsule.

'lui! from the bloo! <ows into >owmanFs ca#sule.

The materials ltere! from the bloo! inclu!e water" urea" glucos

amino aci!s" an! some vitamins. 0lasma #roteins" cells" an! #latelets remain in the bloo! because

too large to #ass through the ca#illar% walls.

Composition (nd Formation of



Composition (nd Formation ofUrine

urine formation tae #lace in three !i+erent stages

/ltraltration"

4elective 8eabsor#tion"

Tubular secretion.



/ltraltration

Taes #lace in al#ighian bo!%" its #h%sical #rocess.

@lomerulus & bowmanFs ca#sule act as ltering unit.

76*7666 G more #ermeable ca#illaries of glomerulus hel# to enter wbloo! insi!e the ltering unit

A+erent arteriole !iameter is larger than e+erent.



4elective 8eabsor#tion

This #rocess stae #lace in two ste#s

0assive trans#ort

Active trans#ort.

Water is reabsorbe! b% osmosis in 0CT" -CT" !escen!ing loo# of Henever%where exce#t acen!ing #art of it nown as" 1Obligator% absor#t

The i!ne%s maximum ca#acit% for reabsor#tion of substance is transthreshol!.

Eg. =5*5 mg of sugar in 766 ml of bloo! is normal level" but if it rise a

maximum level ie 7I6 mg #er 766 ml. then glucose a##ears in urinows as 1@lucosuria2.

R b ti



Reabsorption ost of the material remove! from the bloo! at >owmanJs ca#s

maes its wa% bac into the bloo!.

The #rocess in which li$ui! is taen bac into a vessel is calle!

reabsorption. Almost of the water that enters >owmanFs ca#sule is reab

into the bloo!.

When the ltrate !rains in the collecting !ucts" most water an!have been reabsorbe! into the bloo!.

@lomerulus

A+erent arteriole

E+erent arteriole

>owmanFs

ca#sule

@lomerula'iltration

@lomerula'iltration



8emaining material" calle! urine" is em#tie! into a collecting

/rine is #rimaril% concentrate! in the loo# of Henle.

The loo# of Henle is a section of the ne#hron tubule in whichconserve! an! the volume of urine minimi,e!.

As the i!ne% wors" #urie! bloo! is returne! to circulationis collecte! in the urinar% bla!!er.

/rine is store! here until it is release! from the bo!% throughcalle! the urethra.

b l i



Tubular secretion

3t !oes not s%nthesi,e or a!! an% material in the urine.

4ubstance which generall% secrete! are creatininean! #otassium an!

ion. 4ecretion of ion in in -CT an! collecting tubule is im#ortant to regulat

of bloo!.

4ome abnormal substance in bloo! are also secrete! in the urine.

Anti*biotics lie #enicillin io!ine com#oun!" io!o#%race are secrete! in



Com#osition of /rine

-e#en!s on foo! that in!ivi!ual eat consume on !ail% basis.

On an average 7.(*7.5 ltr of urine #ro!uce! #er !a%.

Characteristic %ellow colour is !ue to #resence of #igment

1urochrome2.

Contains

5 of water

8est of urea" uric aci!" creatinine

-ial%sis



#iny pores in the tubinsmall molecules to pas

(astes di)use out of t*uid+$lled chamber, al

blood to be returned t

-ial%sis

Air

!etector

-ial%sis

machin

'resh !ial%sis

<ui!

Com#res

Lein

Arter%

4hunt

>loo! #um#

>loo! in tubing <owsthrough !ial%sis <ui!

/se! !ial%sis <ui!

Blood is remo%ed by a tube and pumped through special tubing

that acts like nephrons.

excretion & osmoregulation

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