Study of Frog

8/13/2019 Study of Frog

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FY.Bsc. Paper I / Term II Zoology

Chapter 3 Study of Frog

1) Rana tigrina is a member of the order

A) Lepospondyli

B) Anura

C) Apoda

D) Urodela

Answer is B

2) he frog swims in water by!

A) "owerful forward thrusts of its forelimbs#

B) "owerful ba$%ward thrusts of its forelimbs#

C) "owerful ba$%ward thrusts of its hind limbs#

D) "owerful forward thrusts of its hind limbs

Answer is C

&) he tongue of frog is

A) 'hort( protrusible and atta$hed at the front end#

1Sharps Notes

Multiple Choice Questions


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FY.Bsc. Paper I / Term II ZoologyB) 'hort( protrusible and atta$hed at the distal end#

C) Long( nonprotrusible and atta$hed at the front end#

D) Long( protrusible and atta$hed at the front end#

Answer is D*

+) During hibernation or aesti,ation frog li,es upon!

A) 'tored gly$ogen and fat#

B) 'tored glu$ose and fat#

C) 'tored star$h and fat#

D) 'tored gala$tose and fat#

Answer is A

-) .n frog( the se/ual embra$e between male and female is $alled!

A) 'pawning

B) 'warming

C) Aple/us

D) Ample/us

Answer is D

0) pening of re$tum in frog is termed as

A) Co$$y/#

B) Anus

2Sharps Notes


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FY.Bsc. Paper I / Term II ZoologyC) Cloa$a

D) Re$tum

Answer is C

) eeth in frog are

A) A$rodont

B) 3omodont

C) "olyphyodont

D) All of the abo,e

Answer is D

4) he $hief nitrogenous waste material in the urine of frog is

A) Ammonia

B) Uri$ a$id

C) Urea

D) rimethylamine

Answer is C*

5) 6hi$h of the following differentiates male frog from female frog7

A) 8/ternal nares

B) Brow spot

C) 9uptial pad

3Sharps Notes


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FY.Bsc. Paper I / Term II ZoologyD) All of the abo,e

Answer is C

1:) ;ale frog $an $roa% louder than females be$ause being

A) 'tronger

B) Larger in siidney of male frog

B) >idney of frog

C) estis of frog

D) Li,er of frog

Answer is A

12) .n frog tangore$eptors respond to

A) 3eat

B) ou$h

C) Chemi$als

D) 'mell

4Sharps Notes


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FY.Bsc. Paper I / Term II ZoologyAnswer is B

1&) 'ome frogs hibernate during the winter and a,oid the harmful effe$ting of free


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FY.Bsc. Paper I / Term II ZoologyAnswer is B

Q.. !"plain in short the ha#itat of Frog

Ans$

?rogs are non poisonous ( harmless and normally silent animals

?rogs are found near water and in or near water fresh water la%es( ponds andstreams) and in ,ery damp pla$es of land#

.t li,es in water( to %eep the s%in moist to $arry on $utaneous respiration and to

ump or slip into water to es$ape from enemies#

Q.%. &hat is the food of the frog'

Ans$

?rogs are $arni,ores#

'maller frogs eat inse$ts su$h as flies( mosuitoes( moths and dragonflies#

Larger frogs will eat larger inse$ts li%e grasshoppers and worms#

'ome large frogs will e,en eat small sna%es( mi$e( baby turtles( and e,en other

smaller frogs

;ost frogs will star,e before they eat a dead inse$t or animal#

Sharps Notes

Ans(er the Follo(ing ) % Mar*s


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FY.Bsc. Paper I / Term II ZoologyQ.3.Define portal syste+ )March %,3-

Ans$

he ,eins( whi$h start with $apillaries in the organ from where they $olle$t blood

and then end or brea% up into $apillaries in $ertain other organs( are %nown as

portal ,eins( and this system is %nown as portal syste+#

he name portal ,ein and the portal system portal is usually based upon the

name of that parti$ular organ into whi$h it finally brea%s up#

.n frog( there are two portal systems

Renal portal system )ii-3epati$ portal system

Q..&hat is a /ictitating +e+#rane') March %,3-

Ans$

/ictitating +e+#rane$

he third eyelid( a thin( transparent fold of s%in at the inner angle of the eye or

below the lower eyelid that $an be drawn a$ross the eyeball for prote$tion

without obs$uring ,ision

his membrane $loses o,er the eye whene,er the frog is in or under the water# .t

$an also fli$% a$ross the eyes when the frog is out of the water( performing a

useful fun$tion by $leansing and moistening the surfa$e of the eye#

Q.0. &hat is the 1osture of the frog (hile floating in (ater')March %,3-

Ans$

!Sharps Notes


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6hen the water of pond is ,ery deep( the frogs float on the surfa$e#

.n the floating posture( the rest of the body lies uiet( hanging obliuely with the

hind limb moderately e/tended with the nostrils abo,e the water for breathing

Q.2. !"plain Anura) March %,-

Ans$

Anura!salientiaE anurans( tailless amphibians( frogs and toadsE

An order of amphibians in whi$h the head oins dire$tly into the trun%#

he ,ertebral $olumn is short and there is no tail in the adult#

he fore limbs are stout and long( webbed#

hind limbs are usedfor umping and swimming#

he eyes are large and high on the head#

here are superfi$ial ear membranes posterior to the eyes#

All anurans lay eggs( ha,e e/ternal fertili


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Q.4. 5i6e the general characteristics of A+phi#ians

Ans$

@eneral $hara$ters of Amphibians are!

1) Amphibians are $old blooded ,ertebrates whi$h $an li,e on land and in water#

2) Amphibians show four limbs with whi$h they $an swim in water and ump or wal% on

the land( But .n apoda limbs are absent#)

&) .n Amphibians animals e/os%eleton is absent# But in apoda animals small $y$loid

s$ales are present#

+) .n Amphibians the adult animals lungs are present# @ills are absent# But .n some

urodelans the gills are present#

-) Amphibians '%in is a respiratory organ#

0) he Amphibians s%ull is di$ondyli$#

) Amphibians Ribs are absent#

4) .n Amphibians he body di,isible into head and trun% ail is present#

5) Amphibians Digesti,e system is well de,eloped# A well de,eloped li,er .s present#

1:) 8/ternal ear is absent# ;iddle and inner ears are present( the middle ear $olumella

auris .s present#

#Sharps Notes


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FY.Bsc. Paper I / Term II Zoology11) Amphibians 3eart is & $hambered with 2 auri$les and 1 ,entri$le he blood

$ontains R#B#C# hey are nu$leated# hey $ontain hemoglobin#

12) Blood ,as$ular system $ontain hepati$ and renal portal systems#

1&) Amphibians >idneys are mesonephri$# Urinary bladder is present# .t stores urine#

1+) Central ner,ous system is well de,eloped# he brain o$$upies $ompletely the

$ranial $a,ity# he brain is di,ided into fore( mid and hind brains# Brain $ontinuous

as spinal $ord#

1-) 1: pairs of $ranial ner,es will arise#

10) 'e/es are separate#

1) ;ale and female $an be indentified 'e/ual dimorphism#

14) .n Amphibians the life history a lar,astage may be present#

15) Amphibian 8ggs are telole$ithal( Clea,age is holoblasti$ uneual#

Q.7. 5i6e the syste+atic position of frog

Ans$

'ystemati$ position of frog!

"hylum! Chordata

'ubphylum! =ertebrata

Di,ision! @nathostomata

'uper$lass! etrapoda

Class! Amphibia

1$Sharps Notes
http://biozoom.blogspot.com/2010/11/larvaes-of-animals.htmlhttp://biozoom.blogspot.com/2010/11/larvaes-of-animals.html


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FY.Bsc. Paper I / Term II Zoologyrder! Anura

'uborder Diplasio$oela

?amily G Ranidae

ype! Rana igrina

Q.8. Descri#e the ha#its of frog.

Ans$

'ome of the habits of frog are des$ribed below#

- 9oco+otion$ ?rog mo,es in two ways i) by leaping on land and by swimming in

water#

)i- 9eaping!

.t umps or leaps by e/tending the hind limbs( whi$h a$t li%e springs throwing

the body up into air#

A frog may leap a distan$e of 1#- to 2 meters in a single ump#

n landing ba$% the forelimbs a$t li%e sho$% absorber#

he forelimbs also manipulate and adust the dire$tion of the ump#

)ii-S(i++ing$

he frog swims in water by powerful ba$%ward thrusts of its hind limbs whi$h

a$t li%e propellers#

During their ba$%ward stro%es( the toes are spread apart and the broad webs

push against water( mo,ing the body forward#

11Sharps Notes


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FY.Bsc. Paper I / Term II Zoology%- Feeding$

?rogs are $arni,orous and food $onsists mainly of li,ing inse$ts( worms(

mollus%s( and tadpoles#

he food is not $hewed but swallowed whole#

3- Croa*ing$

he $hara$teristi$s noise or sound made by frogs is %nown as $roa%ing#

.t is $ommonly heard in breeding season whi$h is a mating $all#

?rogs $an $roa% under the water and on land#

- :i#ernation and aesti6ation$

Body temperature of frogs flu$tuates with en,ironment#

During ad,erse en,ironmental $onditions in $old winter or dry hot summer days(

they burry in the soft damp bottom mud for prote$tion# #

hey be$ome metaboli$ally ina$ti,e and stop feeding( li,ing on gly$ogen and fat

stored in the body#

his state of dorman$y is $alled as hibernation( whi$h o$$urs in winters and

aesti,ation o$$urs in summers#

0- Ca+ouflage$

?rogs are not easily noti$eable by their enemies as they $an $hange the $olour

of their s%in to mat$h that of the en,ironment#

his type of prote$ti,e $olouration is %nown as $amouflage#

12Sharps Notes


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2- Breeding$

During rainy season( frogs emerge out of aesti,ation and immediately start

breeding whi$h lasts from Huly to 'eptember#

;ales gather in appropriate shallow waters and start $roa%ing ustly to attra$t

females for mating or $opulation#

4- !ne+ies$

'e,eral natural enemies eat adult frogs and tadpoles thus redu$ing( their

numbers#

?rogs also ser,e as hosts for different %inds of parasites#

7- !cono+ic i+portance$

.t is used for laboratory study more often than any other animal as a ,ertebrate

type#

.t is a good friend of farmers as it feeds on inse$ts harmful to $rops#

Q.,. !"plain the se"ual Di+orphis+ in frog.

Ans$

se"ual di+orphis+;is the differen$es in appearan$e between males and

females of the same spe$ies(

here are some differen$es in e/ternal $hara$ters by whi$h male and female

frogs $an be distinguished# 'u$h as

13Sharps Notes
http://www.britannica.com/EBchecked/topic/558649/specieshttp://www.britannica.com/EBchecked/topic/558649/species


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FY.Bsc. Paper I / Term II Zoology1) ;ales are smaller and dar%er in $olour than females#

2) ;ales are slimmer while females are stouter( espe$ially when they $ontain eggs#

&) ;ales $roa% loudly as they ha,e ,o$al sa$s whi$h are absent in females# he

eardrum is larger in male#

+) ;ales ha,e swollen $opulatory or nuptial pads on inner fingers ( espe$ially

de,eloped in breeding season for grasping the females during mating# 9uptial

pads are la$%ing in females#

-) .n $opulating ( frogs in ample/us( the upper one is male and the lower one is

female

Q.. Descri#e the feeding and 1hysiology of digestion in frog

Ans$

?rog is $arni,orous

.t feeds on inse$ts( worms ( $rusta$eans ( mollus%s ( small fishes ( small frogs

and tadpole#

14Sharps Notes


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"rey is $aptured by fli$%ing a$tion of tongue and swallowed whole without

masti$ation#

he food is passed down the oesophagus into the stoma$h#

;u$us helps in lubri$ating food#

- 5astric digestion$

?ood stays in stoma$h for suffi$ient time 2 to & hours)

he gastri$ $ontaining hydro$hlori$ a$id and en


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'urplus glu$ose may be either stored as gly$ogen in li,er or s%eletal mus$les( or

$on,erted to fat or in$orporated in li,ing protoplasm#

?atty a$ids and gly$erol are $on,erted into fats whi$h are deposited in adipose

tissues#

Amino a$ids forms proteins for growth and repair or undergo deamination

resulting in the formation of urea to be e/$reted by %idneys with urine#

0- !gestion!

Undigested part of food is slowly mo,ed by peristalsis into re$tum for storage

and preparation of fae$es#

At inter,als the fae$al matter passes into $loa$a and egested through $loa$al

aperture#

Q.%. Descri#e the sense organs in frog

Ans$

he sensory system in$ludes re$eptors or sense organs#

hese re$ei,e sensation or stimuli due to $hange in the e/ternal or internal

en,ironment#

?rog has fi,e senses li%e tou$h( smell( taste( sight and hearing#

- =rgans of touch or tangoreceptors$

1!Sharps Notes


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?rog has numerous $utaneous sense organs or tangore$eptors present under

epidermis of s%in#

hese are either in the form of simple networ% of ner,e endings s$attered among

$ells or as $ompa$t groups of $ells forming $orpus$les proe$ting into papillae of

epidermis#

hey are sensiti,e to ,arious types of stimuli su$h as tou$h( $hemi$als(

temperature# 3umidity( light( pain et$

%- =rgans of taste or taste #uds$

@ustatore$eptors or taste organs are in the form of taste buds present in small

papillae on the tongue and on the floor and roof of bu$$al $a,ity#

A taste bud $onsists of elongated spindle li%e re$eptor $ells or taste $ells ending

in fine hair li%e pro$esses for sampling food whi$h is ta%en in mouth#

3- =rgans of s+ell or olfactory organs$

8pithelial lining of two nasal $hambers forms the olfa$tore$eptor or the organ of

smell#

.t $ontains tall olfa$tory re$eptor $ells with tufts of fine $ilia on their outer ends and

ner,e fibres atta$hed to their inner ends#

- =rgans of sight or eyes$

"hotore$eptors or the organs of sight are the two large eyes( similar in general

stru$ture and fun$tion with those of the ,ertebrates#

8a$h eyeball is roughly spheri$al and lodged inside an orbit in the dorsolateral

side of head prote$ted by eyelids#

1"Sharps Notes


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FY.Bsc. Paper I / Term II Zoology0- =rgans of hearing or ears$

'tatoa$ousti$ organs meant for hearing and euilibrium are a pair of ears

atta$hed to s%ull posterolaterally in all ,ertebrates#

An ear of frog $onsists of only two parts( middle and internal ear #

here are no e/ternal ears#

Q.3. Discuss the #lood in frog and gi6e its function

Ans$

Blood is the $hief $ir$ulatory fluid of the body#

.t $ontains a $lear liuid $alled plasma( in whi$h are suspended ,arious types of free

$ells ( $alled blood $orpus$les#

- 1las+a$

"lasma forms nearly twothird part of blood#

.t $ontains 5:I of water in whi$h are dissol,ed mineral salts ( absorbed foods

sugars( proteins) e/$retory wastes urea) ( se$retions hormones) and other

soluble substan$es#

%- Corpuscles$

Blood $ells or $orpus$les are mainly of three types

)i-!rythrocytes or red #lood corpuscles$

1#Sharps Notes


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hese are o,al ( flattened( nu$leated and bi$on$a,e in shape hey bear the

respiratory pigment hemoglobin( whi$h ser,es as an o/ygen $arrier#

)ii- 9eucocytes or (hite #lood corpuscles$

hese are $olourless( nu$leated and mostly amoeboid $ells of at least fi,e

types#

;ost of them are phago$yti$( ingesting ba$teria and other foreign parti$les that

appear in blood# And also remo,e dead old tissue $ells#

he 6BC of frog are Lympho$ytes( mono$ytes and granulo$ytes#

)iii->hro+#ocytes or #lood platelets $

hese are small (nu$leated (spindle $ells playing an important role in $oagulation#

?un$tions of blood in ?rog!

1) he fun$tions of frog blood $ells are $arrying o/ygen and nutrients to $ells and

ta%ing waste and $arbon dio/ide away from $ells#

2) Blood $ells also heal the s%in when $ut and fight diseases that $ome into the body#

Q.. &hat is ga+etogenesis' Descri#e the sper+atogenesis in frog )April%,-

Ans$

5a+etogenesis! "ro$ess of formation and maturation of gametes sperm or o,a) is

$alled gametogenesis# .t o$$urs in gonads testes and o,aries)# he term

gametogenesis in$ludes both spermatogenesis and oogenesis# spermatogenesis or the

formation of sperms( o$$urs in the testes and oogenesis or the formation of o,a(o$$urs

in the o,aries#

2$Sharps Notes


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FY.Bsc. Paper I / Term II ZoologySper+atogenesis$ "rodu$tion of sperms( whi$h ta%es pla$e in the testes is %nown as

spermatogenesis#

Sper+atogenesis is frog$

6hen the photoperiodism is appropriate during breeding season( the gi,en $ells

undergo spermatogenesis within the testes#

During this period( the walls of the seminiferous tubules produ$e spermatogonia

whi$h go through mitoti$ di,isions and then the series of nu$lear $harges without

mitosis#

his results in the appearan$e( toward the lumen of ea$h tubule( of $lusters of

mature spermato


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FY.Bsc. Paper I / Term II Zoology Frog >.s of testis.

he mature spermato


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FY.Bsc. Paper I / Term II Zoology Frog Sper+ato?oon

Q.0. Discuss the =ogenesis in frog

Ans$

.n frog( the pro$ess of ooggenesis in,ol,es the following phases#

1) "remeioti$ or multipli$ation phase 2) @rowth phase &) ;aturation phase

-. 1re+eiotic or +ultiplication phase!

,a frog is deri,ed from the primordial germ $ells that enter into the o,ary at an

early stage of embryoni$ de,elopment#

he primordial germ $ells di,ide mitoti$ally and produ$e a large number of

oogonial $ells( whi$h di,ide through mitosis se,eral times and then stop di,iding#

'ome of these $ells grow in si


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he differentiation of the o,um also o$$urs along with the growth#

.nfrog( a young oo$yte measures about -: Jm in diameter( and the fully

de,eloped o,um in different spe$ies measures from 1::: to 2::: Jm in

diameter#

Rate of growth of oo$ytes ,aries in different animal spe$ies#

.n Rana pipiens the growth phase $ontinues for three years#

he young primary oo$ytes start growing after the tadpole metamorphoses into

a young frog#

he young frog does not lay eggs upto the age of two years#

.t lays eggs only in the third year#

8,ery year a new bat$h of oo$ytes is produ$ed by the oogonial di,isions# 8,ery

bat$h of eggs matures in three years#

he oo$ytes grow slowly for first two years( but grow rapidly in the third year#

he growth phase of the oo$ytes may be di,ided into two stages !

A) "re,itellogenesis

B) =itellogenesis#

A-1re6itellogenesis#efore yol* for+ation- $

During this period of growth( the si


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?ormation and deposition of yol%( or ,itellogenesis( o$$urs in the oo$ytes during

the se$ond period of growth#

o$ytes grow rapidly during ,itellogenesis

.n amphibian eggs( the yol% is found in the form of large o,al granules( $alled

yol% platelets#

Kol% is the reser,e food of the o,um# .n amphibians( yol% platelets $ontain two

main proteina$eous substan$es! phos,itin and lipo,itellin#

"hos,itin is a highly phosphorylated protein( and lipo,itellin $ontains proteinsand bound lipids#

3- Maturation 1hase$

he diploid primary oo$yte undergoes first meioti$ di,ision in the beginning of the

growth phase#

his result in small $ell $alled the first polar body and large $ell $alled se$ondary

oo$yte#

he se$ond phase of the meioti$ di,ision o$$urs( resulting smaller $ell $alled

se$ond polar body#

he larger $ell is now $alled the mature ,um#

.n the meantime( the first polar body may di,ide into two

hus at the end ( four $ells are produ$ed from one oo$yte#

ne haploid o,um and three haploid polar bodies#

he polar bodies soon degenerate#

2Sharps Notes


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Q.2. State the difference #et(een Sper+atogenesis and =ogenesis) April %,-

Ans$

Sper+atogenesis =ogenesis

.t o$$urs in the testes .t o$$urs in the ,aries

@rowth phase is short (so that

spermato$ytes are only twi$e the si


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FY.Bsc. Paper I / Term II ZoologyQ.4. &rite a short note on hi#ernation and Aesti6ation ) April %,; April

%,,8 ; =ct %, ; April %,%-

Ans$

:i#ernation$

3ibernation is a phenomenon of amphibians li,ing in temperate regions( where the

low ambient temperature of winter is adeuate to raise their own body temperature

suffi$iently to allow a$ti,ity#

After an animal finds or ma%es a li,ing spa$e hiberna$ulum) that prote$ts it from

winter weatherand predators( the animals metabolism slows dramati$ally( so it $an

sleepaway the winter by utili


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'e,eral spe$ies of frog are %nown to Aesti,ate# wo of the better%nown spe$ies are

the ornate horned frog (Ceratophrys ornata)from 'outh Ameri$a and the Afri$an

bullfrog (Pyxicephalus adspersus)#

6hen the dry season starts( these frogs burrow into the soil and be$ome dormant#

During the e/tended dry season( whi$h $an last se,eral months( these frogs perform a

neat tri$%! they shed se,eral inta$t layers of s%in( forming a ,irtually waterproof $o$oon

that en,elopes the entire body( lea,ing only the nostrils e/posed( whi$h allows them to

breathe# hese herpetologi$al mummies remain in their $o$oons for the duration of the

dry season# 6hen the rains return( the frogs free themsel,es of their shrouds and ma%e

their way up through the moist soil to the surfa$e#

Q.7. 5i6e the functions of the s*in in frog.) =ct%,-

Ans$

he s%in of frog has a ,ariety of fun$tions su$h as

1) he s%in pro,ides a prote$ti,e body $o,ering whi$h prote$ts the underlying

mus$les#

2) .t a$ts as a germ proof $o,ering and prote$ts the body against foreign germs#

&) he mu$us ma%es the s%in slippery whi$h prote$ts the animal by se$uring release

from the enemies#

+) he mu$ous and poison glands se$rete disagreeable and unpleasant fluid whi$h

prote$ts the animal from enemies#

2#Sharps Notes


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FY.Bsc. Paper I / Term II Zoology-) he s%in also pro,ides prote$ti,e $olouration due to dispersion of $hromatophores

under the influen$e of neurohumours se$reted by the ner,e endings# hus the

animal $an adapt a$$ording to surroundings and is well prote$ted#

0) he thin( smooth( moist and highly ,as$ular s%in is the main respiratory organ of

frog# During hibernation and aesti,ation the s%in is the only respiratory organ to

%eep the animal ali,e#

) he s%in is an effe$ient sensory organ whi$h is sensiti,e to stimulation(

temperature( humidity et$#

4) he $asting of stratum $orneum in the form of %eratin remo,es the e/$retory matter

of the body#'o the s%in is also regarded as e/$retory in fun$tion#

5) he mu$ous glands %eep the s%in moist and prote$t the animal against

asphy/iation(

1:) he frog does not drin% water# he water balan$e of the body is maintained by

absorption through the s%in#

11) he s%in in frog also helps in lo$omotion and swimming# he hind limbs are webbed

whi$h enable the animal to swim#

12) he s%in of frog is also regarded as helpful in nutrition# .t is $onsidered that the s%in

is $apable to se$rete an en


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hese are the soundresonating throat pou$h of male frogsand toads

=o$al sa$s are outpo$%etings of the floor of the mouth( or bu$$al $a,ity#

?rogs display three basi$ types of ,o$al sa$s! a single median throat sa$( paired

throat sa$s( and paired lateral sa$s# Lateral sa$s are lo$ated ust rearward of

the angle of theaw on ea$h side of the head#)

All three types( whether single or paired( open into the bu$$al $a,ity by paired

slits#

8a$h slit is lo$ated on either side of the base of the tongue#

A $allingfrogtypi$ally inflates his sa$ or sa$s prior to $alling or simultaneously

with the produ$tion of the first $all#

he sa$ is inflated with air from the lungs#

.f another $all is forth$oming and the male frog is not in the pro$ess of $alling(

air is still held in the sa$#

'ound is produ$ed by a $ontrolled rush of air through the laryn/and a$ross its

,o$al $ords#

he resulting sound ,ibrations are amplified by the resonating ualities of the

,o$al sa$ or sa$s#

frogs broad$ast sound without e/pelling air#

Air does not e/it the mouthE rather( it $y$les ba$% and forth between the bu$$al

$a,ity and lungs#

@enerally used in breeding season ( to $all the female frogs

31Sharps Notes
http://www.britannica.com/EBchecked/topic/555255/soundhttp://www.britannica.com/EBchecked/topic/220611/froghttp://www.britannica.com/EBchecked/topic/597631/toadhttp://www.britannica.com/EBchecked/topic/301800/jawhttp://www.britannica.com/EBchecked/topic/220611/froghttp://www.britannica.com/EBchecked/topic/351473/lunghttp://www.britannica.com/EBchecked/topic/351473/lunghttp://www.britannica.com/EBchecked/topic/330791/larynxhttp://www.britannica.com/EBchecked/topic/631679/vocal-cordhttp://www.britannica.com/EBchecked/topic/555255/soundhttp://www.britannica.com/EBchecked/topic/220611/froghttp://www.britannica.com/EBchecked/topic/597631/toadhttp://www.britannica.com/EBchecked/topic/301800/jawhttp://www.britannica.com/EBchecked/topic/220611/froghttp://www.britannica.com/EBchecked/topic/351473/lunghttp://www.britannica.com/EBchecked/topic/330791/larynxhttp://www.britannica.com/EBchecked/topic/631679/vocal-cord


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Cloaca$

he $loa$a is a short tube that e/tends from its union with the $audal end of the

large intestine to the e/terior#

.t is a $ommon $hamber that re$ei,es fe$es( urine( and gametes and releases

them to the e/terior through the $loa$al aperture#

;ale $loa$a ser,es as a temporary reser,oir for sperm prior to fertili


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'i


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- >run*$

3ead is broadly oined behind with the flat o,oid trun%#

.ts ba$% is raised in the middle in a $hara$teristi$s sa$ral prominen$e of hump#

At the posterior end of trun% is a small $ir$ular $loa$al aperture or ,ent for the

dis$harge of fae$al and urinary wastes as well as reprodu$ti,e produ$ts#

0- 9i+#s$

Laterally( the trun% bears two pairs of limbs or appendages#

he short forelimbs arise anteriorly from trun% ust behind the head#

8a$h forelimb $onsists of the upper arm bra$hium) ( forearm antebra$hium)(

wrist $arpus) and hand manus) bearing four digits without web#

humb or polle/ is ,estigial#

he mu$h elongated and powerful hind limbs or legs arise $lose together

posteriorly from trun%#

8a$h hind limbs $onsist of thigh( shan% $rus)( mu$h legthened an%le larsus)

and large foot pes) ha,ing fi,e slender $lawless toes $onne$ted by broad thin

webs of s%in#

34Sharps Notes


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Alimentary $anal of frog is a long and $oiled tube of ,arying diameter e/tending

between mouth and $loa$a#

.t $onsists of bu$$al $a,ity ( pharyn/( esophagus ( stoma$h ( small intestine (

large intestine and $loa$a#

)i-Mouth!

Alimentary $anal begins at the mouth opening#

.t is a wide gap( e/tending from one side of the snout to the other#

.t is bounded by two bony aws $o,ered by immo,able lips#

Upper aw is fi/ed while the lower aw $an mo,e up and down to $lose or open

the mouth#

)ii-Buccal Ca6ity$

;outh opens into a large( wide and shallow oral or bu$$al $a,ity#

.ts $iliated $olumnar epithelial lining $ontains mu$ous glands whi$h se$retes

mu$us for lubri$ating food#

here are no sali,ary glands in frog#

)a->eeth$

he lower aw la$%s the teeth( but small $oni$al and ba$%wardly pointed teeth

o$$ur in a row on either side on the prema/illae and ma/illae bones of the upper

aw#

eeth are not meant for $hewingE they ust hold the prey in their mouth and

pre,ent it from es$aping#

3Sharps Notes


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eeth are similar( not set in a so$%et( but ea$h atta$hed to the aw bone#

.n life( teeth of frog are repla$ed se,eral times by the growth of new teeth when

worn out or lost#

)#->ongue!

n the floor of mouth $a,ity lies a large( mus$ular sti$%y protrusible tongue#

.ts anterior end is atta$hed end is atta$hed to the inner border of lower aw#

.ts posterior end is free and bifid whi$h $an be fli$%ed out and retra$ted suddenly

after $apturing the prey with its slimy surfa$e#

)c-


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.n the roof on either lateral side is a wide eusta$hian aperture whi$h opens into

the middle ear#

- =esophagus$

esophagus is a short( wide mus$ular and highly distensible tube#

.t $ontains mu$ous glands#

Longitudinal folding of the oesophagus allows its e/pansion during the passage

of food into the stoma$h#

0- Sto+ach$

'toma$h lies on the left side in the body $a,ity( atta$hed to the dorsal body wall

by a mesentery $alled mesogaster#

.t is a large( broad and slightly $ur,ed bag or tube with thi$% mus$ular walls#

.ts large broader anterior part is $alled as $ardia$ stoma$h( while the short

narrower posterior part is $alled as pylori$ stoma$h#

he inner surfa$e of the stoma$h has se,eral prominent longitudinal folds whi$h

allow its distension when food is re$ei,ed#

.ts mu$ous epithelium $ontains multi$ellular gastri$ gland( se$reting the

en


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FY.Bsc. Paper I / Term II Zoology2- S+all intestine$

'mall intestine is a long( $oiled and narrow tube( atta$hed mid dorsally to body

wall#

.t is made up of two parts a) a small anterior duodenum and b) longer

posterior ileum#

)a- Duodenu+$

.t runs a head parallel to stoma$h forming a U shape#

.t re$ei,es a $ommon hepatopan$reati$ du$t from li,er and pan$reas bringing

bile and pan$reati$ ui$e#

)#-


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Cloa$a opens to outside by the ,ent or $loa$al aperture( lying at the hind of the

body#

Digesti6e Syste+ of Frog

4$Sharps Notes


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Q.%%. Discuss the Male reproducti6e syste+ of frog

Ans$

;ale reprodu$ti,e of frog $onsists of two testes atta$hed to %idneys ( se,eral

,asa efferentia and two urinogenital du$ts#

Copulatory organs are la$%ing

- >estes $

A testis is an elongated or o,oid( light Gyellow body atta$hed to the antero

,entral surfa$e of ea$h %idney by a double fold of peritoneum $alled

mesor$hium#

9ear the anterior end of the testis( se,eral bran$hed fingerli%e fat bodies arise

whi$h pro,ide reser,e food used to nourish de,eloping spermato


42/66


%- @asa efferentia$

All the seminiferous tubules in a testes are $onne$ted to form 1: to 12 narrow

tubes( the ,asa efferentia#

hese lea,e from the inner margin of testis( run through mesor$hium and enter

the inner margin of the %idney to open into the Bidder*s $anal#

he Bidder*s $anal is then $onne$ted to the ureter through $olle$ting tubules of

%idney#

hus ,asa efferentia $ondu$t mature spermato


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Mature sper+ of Frog

Q.%3. Descri#e the Fe+ale eproducti6e syste+ in frog

Ans$

43Sharps Notes


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FY.Bsc. Paper I / Term II Zoology?emale reprodu$ti,e system of frog $onsist of two o,aries and two o,idu$ts

- =6aries$

8a$h o,ary is atta$hed to the dorsal abdominal wall( near %idney( supported by a

peritoneal fold $alled meso,arium#

.t is a large( irregularly folded( multilobed( hollow sa$ grayish or bla$%ish in

$olour#

.n breeding season( the two o,aries be$ome greatly enlarged#

8a$h o,ary $ontains innumerable dar% round o,a in different stages of

de,elopment#

,a arise from germinal epithelial lining by oogenesis#

6hen ripe the o,a are shed by rupture of o,arian wall into the body $a,ity from

there are mo,ed by $ilia of peritoneum into the ostia of o,idu$ts#

%- =6iducts$

he two o,idu$ts are long and mu$h $oiled white glandular tubes not $onne$ted

dire$tly to the o,aries#

heir anterior ends form $iliated funnel G li%e opening( the stia#

hese are pla$ed anteriorly in the body $a,ity at the base of the lungs one on

either side of oesophagus#

Cilia present on the inner wall of o,idu$ts mo,e the eggs posteriorly while glands

se$rete an albuminous $oat around ea$h egg during its passage#

44Sharps Notes


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he posterior ends of o,idu$ts open dorsally into $loa$a separately on papillae

ust in front of the ureters#

Hust before entering $loa$a( ea$h o,idu$t forms a thin G walled enlargement( the

o,isa$#

he eggs are $olle$ted inside the o,isa$ before being laid#

An unfertili


46/66


Q.%. Descri#e the Central /er6ous Syste+ of frog. )April %,-

Ans$

he ner,ous system of frog is $omposed of & main sub di,isions#

A) Central ner,ous system $onsisting of brain and spinal $ord#

B) "eripheral ner,ous system $onsisting of $ranial and spinal ner,es#

C) 'ympatheti$ ner,ous system $onsisting of sympatheti$ ner,es and ganglia#

A- Central ner6ous syste+#

- Brain$

4Sharps Notes


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Brain is a white $oloured ( elongated and somewhat flattened stru$ture ( lying

well prote$ted inside the $ranium of s%ull#

.t is surrounded by two $onne$ti,e tissue membranes( $alled meninges#

he inner or piamater is deli$ate( pigmented( ,as$ular and $losely applied to

brain#

he outer durameter is tough( fibrous and lines the $ranial $a,ity#

he narrow spa$e between the membranes and the inner $a,ities of brain are

filled with a $lear( watery and lymphati$ $erebrospinal fluid whi$h prote$ts andnourishes brain#

he inner $a,ities of brain( $alled ,entri$les are $ontinuous with one another#

Brain has well de,eloped $erebrum and opti$ lobes#

Brain is further di,ided into & main parts#

i- Fore#rain! .t in$ludes two olfa$tory lobes( two $erebral hemisphere and a

dien$ephalon#

)a-=lfactory lo#es!

here are two anterior most( small and spheri$al lobes ea$h sending a small

olfa$tory ner,e to the nasal $hamber of its side#

he two lobes are united but ea$h $ontains a separate small $a,ity( the olfa$tory

,entri$le or rhino$oel#

lfa$tory lobes are $on$erned with sense of smell whi$h is poor in frog#

)#-Cere#ral he+isphere$

4!Sharps Notes


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.n tadpole a small spheri$al pineal body is atta$hed to the stal%#

But( it is deta$hed and $omes to lie outside s%ull in adult frog#

=entral surfa$e of din$ephalon bears the M shaped opti$ $hiasma formed by the

two opti$ ner,es $rossing ea$h other#

Hust posterior to opti$ $hiasma is a large median bilobed proe$tion( the

infundibulum( whi$h bears a flattened o,al pituitary body or hypophysis#

Dien$ephalon is $on$erned with ,ision and balan$e#

ii- Mid#rain$

.t is the broadest part of the brain $ontaining a narrow $anal( the iter or auedu$t

of 'yl,ius( whi$h is $ontinuous with ... ,entri$le in front and .= ,entri$le behind#

;idbrain bears dorsolaterally two large rounded opti$ lobes ( $alled $orpora

bigemina#

heir $anals $alled opto$oels( open into iter#

wo thi$% longitudinal bands of ner,e fibres ( $alled $rura $erebri( run

longitudinally beneath opti$ lobes $onne$ting dien$ephalon and medulla #

he opti$ lobes inhibit spinal $ord refle/es( and ea$h $ontrols the opposite side

of body#

iii- :ind#rain$

he posterior part of brain in$ludes $erebellum and medulla oblongata#

)a- Cere#ellu+$

4#Sharps Notes


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.t is poorly de,eloped narrow trans,erse solid ridge or band( pla$ed dorsally

behind the opti$ lobes#

.t $ontrols euilibrium and mus$ular $oordination whi$h are of little importan$e

in frog#

)#- Medulla o#longata$

.t is the last small $oni$al part whi$h is $ontinuous with spinal $ord without

distin$tion#

.ts triangular $a,ity( $alled .= ,entri$le or meta$oel( is $ontinuous anteriorly withiter and posteriorly with the $entral $a,ity of spinal $ord#

he thin and highly ,as$ular dorsal roof of meta$oel forms the posterior $horoid

ple/us#

;edulla $ontrols important in,oluntary fun$tions su$h as heart beat( metabolism(

respiration( et$#

%- Spinal Cord$

he spinal $ord e/tends posteriorly from medulla oblongata through foramen

magnum and lies prote$ted within the neural $anal of ,ertebral $olumn#

.t is a short( thi$%( $ylindri$al( somewhat flattened and white in $olour #

Li%e brain( spinal $ord is also surrounded by the two meninges( piamater and

durameter( $ontaining prote$ti,e and nourishing $erebrospinal fluid#

"osteriorly it terminates into a fine ( non ner,ous filament ( filum terminale( in

the urostyle #

5$Sharps Notes


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'pinal $ord shows swelling in two pla$es G bra$hial enlargement between

forelimbs and s$iati$ or lumbar swelling anterior to filum terminale #

hroughout its length run two longitudinal groo,es( the mid dorsal $alled dorsal

fissure and the mid ,entral $alled ,entral fissure#

.t en$loses a narrow $entral $anal whi$h is a $ontinuation of the ,entri$les of

brain#

'pinal $ord is made up of outer white matter $omposed of ner,e fibres and inner

grey matter( largely of ner,e $ells#

'pinal $ord is mainly $on$erned with the refle/ a$tion#

Frog structure of Brain A Dorsal @ie( ; B @entral @ie(; C 9ongitudinal

hori?ontal section sho(ing @entricles.

51Sharps Notes


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Q.%0. Discuss the structure and (or*ing of heart in frog.

Ans$

?rog has a $losed $ir$ulatory system#

.t in$ludes heart( arterial system( ,enous system and blood#

.ts $hief fun$tion is to transport all ne$essary liuids and gaseous material to the

li,ing tissues and to bring away from them the liuid and gaseous wastes of

metabolism to organ of elimination#

- :eart$

he mus$ular heart is the $entral pumping station dri,ing blood through the $losed

$ir$ulatory system#

i- !"ternal features$

he heart lies mid ,entrally inside the anterior trun% region prote$ted by the pe$toral

girdle #

.t is reddish in $olour and somewhat $oni$al or triangular in shape with the broad base

dire$ted anteriorly and the narrow ape/( posteriorly#

)a- 1ericardiu+$

he heart lies en$losed by a thin( transparent( two G layered sa$( theperi$ardium#

hen outer wall of peri$ardium( parietal peri$ardium and inner wall of whi$h

$losely in,ests the heart( $alled ,is$eral peri$ardium#

52Sharps Notes


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he narrow $a,ity between two peri$ardial layers $ontains a watery peri$ardial

fluid whi$h prote$ts the heart from fri$tion or me$hani$al sho$%s# >eeps it moist

and permits its mo,ement#

)#- Cha+#ers of heart$

?rog*s heart is a three $hambered stru$tures( made up of two anterior dar%

$oloured atria or auri$les( right and left( and a single posterior $oni$al and pin%

$oloured ,entri$le#

he two auri$les are e/ternally isolated by a ,ery faint longitudinal inter auri$ular

groo,e#

he two auri$les are $learly mar%ed off from ,entri$les by a narrow trans,erse

auri$ulo,entri$ular groo,e or $oronary sul$us#

Additional two $hambers of heart are sinus ,enous and trun$us arteriosus#

'inus ,enosus is a dar% G $oloured ( thin walled and triangular $hamber atta$hed

dorsally to heart#

run$us arteriosus arising anteriorly from the right ,entral side of ,entri$le( it is a

tubular $hamber#

.t bifur$ates anteriorly into two bran$hes or trun%s ( ea$h further brea%s into three

ar$hes $arotid( systemi$ and pulmo$utaneous#

53Sharps Notes


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ii-


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Both auri$les open into single ,entri$le by a $ommon large auri$ulo,entri$ular

aperture guarded by two pairs of flap Gli%e ,entri$ular ,al,es#

)#- @entricle$

he ,entri$le has thi$% mus$ular and spongy wall#

.ts inner surfa$e has irregular strands or ridges( the $olumnae $arneae or

trabe$ulae( with depressions $alled fissures#

he flaps of auri$ulo,entri$ular ,al,es are $onne$ted to the wall of ,entri$le by

thread Gli%e $hordate tendineae#

)c- >runcus arteriosus$

he opening of ,entri$le into trun$us arteriosus is guarded by & semilunar

,al,es(whi$h pre,ents ba$% flow of blood from trun$us into ,entri$le#

he spirally twisted $a,ity of trunn$us arteriosus is di,ided uneually by another

set of & semilunar ,al,es into a long basal thi$% walled $onus arteriosus or

pylangium and a short distal thin G walled bulbous aorta or synangium#

A large twisted longitudinal spiral ,al,es further di,ides the $a,ity of $onus or

pylangium into a left dorsal $a,um pulmo$utaneum and a right ,entral $a,um

aorti$um#

he spiral ,al,e is atta$hed dorsally while its ,entral edge is free#

he $ommon opening of the two pulmo$utaneous ar$hes lies in $a,um

pulmo$utaneous ( while separate openings of $arotid and systemati$ arhes lie in

synangium#

All these opening are guarded by ,al,es#

55Sharps Notes


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he distal right and left bran$hes or trun%s appear e/ternally to be single

,essels but internally( ea$h is made of & $hannesl whi$h e,entually form three

separate ar$hes on either side#

&or*ing of heart$

3eart beats $ontinuously during life#

Contra$tion of heart is $alled systole( while its rela/ation is $alled diastole#

Different $hambers of heart $ontra$t in a regular seuen$e and the ,al,es

present ( pre,ent the ba$% flow of blood#

6hen the sinus ,enosus $ontra$ts( its nono/ygenated ,enous blood is for$ed

into the right auri$le through sinuauri$ular aperture#

5Sharps Notes


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6hile the o/ygenated blood from the lungs is poured into left auri$le through

$ommon pulmonary ,ein#

he two auri$les now $ontra$t almost simultaneously for$ing their blood into

,entri$le through the single auri$ulo,entri$ular aperture#

Q.%2. Discuss the Arterial syste+ in frog.

Ans$

Aortic arches$

Arteries $arry blood away from the heart#

he arterial system in frog begins with the trun$us arteriosus#

run$us arteriosus arteries is further di,ided into three maor ,essels

Called i) Common $arotid to head( ii) systemi$ to body and ,is$era( and iii)

pulmo$utaneous to lung and s%in#

-Co++on carotid arch $

.t is a short ,essel running forward and outward#

.t further di,ides into e/ternal and internal $arotids

)a-!"ternal carotid$

5!Sharps Notes


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Also $alled lingual ( it is the smaller inner bran$h $arrying blood to the tongue

and ada$ent parts#

)#-


59/66

FY.Bsc. Paper I / Term II Zoology)c- Su#cla6ian$ .t is a large artery supplying the shoulder region and e/tending

into the forelimbs as bran$hial artery#

Dorsal aorta$

.t is formed by the union of both the systemi$ ar$hes#

.t runs posteriorly lying middorsally( beneath the ,ertebral $olumn

.t gi,es off the following arteries#

)a- Coeliaco+esenteric!

.t is a single large artery( arising from the un$tion of the two systemi$ ar$hes#

.t has two main bran$hes! he $oelia$ to stoma$h( pan$reas and li,erE and the

anterior mesenteri$ to spleen and intestine#

)#-5onadial$A pair of short arteries to gonads( $alled spermati$ in male and

o,arian in female frog#

)c- enal$ 6hile passing between the two %idneys( dorsal aorta sends off -0 pairs

of small renal arteries in a series into both the %idneys#

)d- 1osterior +esenteric$.t arises from the posterior end of dorsal aorta ( or

sometimes from anterior mesenteri$ #.t goes to large intestine or re$tum#

)e-Co++on iliacs$he dorsal aorta bifur$ates posteriorly into two $ommon ilia$s (

ea$h supplying an epigastri$ to ,entral body wall ( re$to,esi$ular to re$tum and

urinary bladder( femoral to hip and upper thigh ( and s$iati$ to lower leg#

3- 1ul+ocutaneous arch$

5#Sharps Notes


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.t di,ided into two main arteries( pulmonary to the lung and $utaneous to s%in of

dorsal and lateral sides and ,arious other stru$tures #

f these auri$ularis supply blood to tympanum( thymus gland( lower aw(

pharyn/ and hyoid et$#

6hile dorsalis supplies the s%in of dorsal side and lateralis supplies the s%in of

lateral sides of the body#

$Sharps Notes


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62/66

FY.Bsc. Paper I / Term II Zoology Arterial syste+ in Frog

Q.%4. Discuss the @enous syste+ in frog

Ans$

he ,enous system in$ludes ,eins or those blood ,essels in whi$h blood of body

returns to the heart#

.n frog it $an be studied in four parts!

1) "ulmonary ,eins 2) $a,al ,eins &) renal portal ,eins and +)hepati$ portal ,eins

- 1ul+onary 6eins!

/ygenated blood from two lungs is $olle$ted by right and left pulmonary ,eins

whi$h unite to form a $ommon pulmonary ,ein opening dire$tly into the left

auri$le on the dorsal side#

%-Ca6al 6eins!

Deo/ygenated blood from rest of the body tra,els towards heart in three large

,essels ( two anterior ,enae $a,ae and single posterior ,ena $a,a ( all the three

opening into sinus ,enosus#

)a-Anterior @enae ca6ae or preca6als$

he right and left pre$a,als or anterior ,enae $a,ae $olle$t ,enous blood fromthe anterior part of body#

8a$h pre$a,al is formed by the union of & maor ,eins whi$h meet

simultaneously

2Sharps Notes


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FY.Bsc. Paper I / Term II Zoology)i- !"ternal ugular! .t is formed by the slender and sinuous lingual from tongue

and mandibular from outer margin of lower aw#

)ii-


64/66


n entering the abdominal $a,ity the femoral di,ides into a dorsal renal portal

and ,entral pel,i$ ,ein#

he renal postal unites with the s$iati$ of its side and while running along there

outer border of %idney of its side it re$ei,es alone from lumbar region by a dorso

lumbar ,ein#

Renal postal ,ein enters the %idney by se,eral bran$hes whi$h brea% up into

$apillaries#

- :epatic portal syste+$

A large hepati$ portal ,ein is formed by the $onfluen$e of se,eral bran$hes from

stoma$h ( intestine( spleen and pan$reas#

.t $arries blood of alimentary $anal laden with the digested foodstuff to li,er

where it brea%s up into $apillaries#

the pel,i$ ,eins of both sides unite to form a median ,entral or anterior

abdominal ,ein#

.t re$ei,es blood form urinary bladder and ,entral abdominal wall and runs

forwards to enter li,er into whi$h it brea%s up into $apillaries#

Before entering li,er the anterior abdominal and hepati$ postal ,eins are

$onne$ted by small loop#

4Sharps Notes


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@enous syste+ of frog

5Sharps Notes


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Study of Frog

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