Appendicular skeleton by: Mr. Claver Digamon

1. APPENDICULARAPPENDICULAR
SKELETONSKELETON
ENDOSKELETON OFENDOSKELETON OF
VERTEBRATESVERTEBRATES

2. The Appendicular SkeletonThe Appendicular Skeleton
 TheThe appendicularappendicular
skeletonskeleton includes:includes:
 Pectoral girdlePectoral girdle
 Pelvic girdlePelvic girdle
 Upper extremitiesUpper extremities
 Lower extremitiesLower extremities
 TheThe appendicularappendicular
skeletonskeleton functionsfunctions
primarily to facilitateprimarily to facilitate
movementmovement

3. Fig. 9.4

4. Tetrapod LimbTetrapod Limb
 Typical 4 limbsTypical 4 limbs
 Primarily a modification of the RhipidistianPrimarily a modification of the Rhipidistian
finfin
wings
paddles
Lost 2
Lost 4
Modified elements

5.  Recall: VRecall: Vpp = V= Vgg + V+ Vee + V+ Vgxegxe
 V = variationV = variation
 p = phenotypicp = phenotypic
 g = genotypicg = genotypic
 e = environmentale = environmental
Morphology
(anatomy)
Behavior
& Performance
Resource use
(ecology)
Fitness

6. Three main componentsThree main components
 With respect to the pectoral andWith respect to the pectoral and
pelvic girdles:pelvic girdles:
• Serially homologous –Serially homologous –
1.1. Propodium (= stylopodium) – upperPropodium (= stylopodium) – upper
arm, upper legarm, upper leg
2.2. Epipodium (= zeugopodium) –Epipodium (= zeugopodium) –
forearm, shinforearm, shin
3.3. Autopodium – manus or pes (digits,Autopodium – manus or pes (digits,
and wrist and palm, or ankle and soleand wrist and palm, or ankle and sole

7.  MesopodiumMesopodium
 MetapodiumMetapodium
 PhalangesPhalanges

9. Fig. 9.12

12. Focus 9.2

13. Pectoral (Shoulder) GirdlePectoral (Shoulder) Girdle• TheThe pectoralpectoral oror
shoulder girdleshoulder girdle
attaches the bones ofattaches the bones of
the upper limbs to thethe upper limbs to the
axial skeletonaxial skeleton
 Consists ofConsists of scapulascapula &&
clavicleclavicle
 ClavicleClavicle articulatesarticulates
withwith sternumsternum
((sternoclavicular jointsternoclavicular joint))
 ClavicleClavicle articulatesarticulates
withwith scapulascapula
((acromioclavicularacromioclavicular
jointjoint))
 ScapulaScapula held in placeheld in place
by muscle onlyby muscle only
 Upper limb attachedUpper limb attached
toto pectoral girdlepectoral girdle atat

14. Clavicle (Collarbone)Clavicle (Collarbone)
 S-shaped bone with two curvesS-shaped bone with two curves
 Extends fromExtends from sternumsternum toto scapulascapula above 1st ribabove 1st rib
 Sternal & acromial extremitiesSternal & acromial extremities
 One of the most commonly fractured bones in theOne of the most commonly fractured bones in the
human bodyhuman body
 Fracture site is junction of curvesFracture site is junction of curves


15. Anterior Surface of ScapulaAnterior Surface of Scapula
 Articulates with theArticulates with the clavicleclavicle and theand the
humerushumerus
 Subscapular fossaSubscapular fossa filled with musclefilled with muscle
 Coracoid processCoracoid process for muscle attachmentfor muscle attachment

16. Posterior Surface of ScapulaPosterior Surface of Scapula
 Triangular flat bone found in upper backTriangular flat bone found in upper back
regionregion
 Scapular spineScapular spine ends asends as acromion processacromion process
 Glenoid cavityGlenoid cavity forms shoulder joint with headforms shoulder joint with head
ofof humerushumerus

17. UpperUpper
ExtremityExtremity Upper extremity consists of 30Upper extremity consists of 30
bonesbones
 HumerusHumerus within the armwithin the arm
 UlnaUlna && radiusradius within the forearmwithin the forearm
 CarpalCarpal bones within the wristbones within the wrist
 MetacarpalMetacarpal bones within the palmbones within the palm
 PhalangesPhalanges in the fingersin the fingers
 JointsJoints
 ShoulderShoulder ((glenohumeralglenohumeral),), elbowelbow,, wristwrist,,
metacarpophalangealmetacarpophalangeal,, interphalangealinterphalangeal
 Shoulder dislocationShoulder dislocation is separation of theis separation of the
humerushumerus from thefrom the glenoid cavityglenoid cavity of theof the
scapulascapula

18. Shoulder DislocationShoulder Dislocation
 Head of humerus slips out of glenoid cavityHead of humerus slips out of glenoid cavity
 Closed reductionClosed reduction is term for slipping humerus backis term for slipping humerus back
into place without surgeryinto place without surgery


19. Humerus: ProximalHumerus: Proximal
EndEnd Largest and longest bone of upperLargest and longest bone of upper
extremity, part of shoulder joint,extremity, part of shoulder joint,
articulates witharticulates with scapulascapula
 HeadHead
 GreaterGreater && lesserlesser tuberclestubercles
for muscle attachmentsfor muscle attachments
 IntertubercularIntertubercular
sulcussulcus oror bicipitalbicipital
groovegroove
 ShaftShaft oror bodybody

20. Humerus: Distal EndHumerus: Distal End
 Forms elbow joint withForms elbow joint with ulnaulna
andand radiusradius
 CapitulumCapitulum
 articulates with head ofarticulates with head of radiusradius
 TrochleaTrochlea
 articulation witharticulation with ulnaulna
 Olecranon fossaOlecranon fossa
 posterior depression forposterior depression for
olecranon processolecranon process ofof ulnaulna
 MedialMedial && laterallateral epicondylesepicondyles
 attachment of forearm musclesattachment of forearm muscles

21. Ulna & Radius: ProximalUlna & Radius: Proximal
EndEnd UlnaUlna (on little finger side)(on little finger side)
 Trochlear notchTrochlear notch articulates witharticulates with
humerushumerus && radial notchradial notch withwith radiusradius
 Olecranon processOlecranon process forms point of elbowforms point of elbow
 RadiusRadius (on thumb side)(on thumb side)
 Head articulates withHead articulates with capitulumcapitulum ofof
humerushumerus && radial notchradial notch ofof ulnaulna
 TuberosityTuberosity for muscle attachmentfor muscle attachment

22. Ulna & Radius: ProximalUlna & Radius: Proximal
EndEnd
 RadiusRadius (on thumb(on thumb
side)side)
 HeadHead articulates witharticulates with
capitulumcapitulum ofof humerushumerus &&
radial notchradial notch ofof ulnaulna
 TuberosityTuberosity for musclefor muscle
attachmentattachment
 Ulnar notchUlnar notch articulatesarticulates
with ulnawith ulna

23. Elbow JointElbow Joint
 Articulation ofArticulation of humerushumerus withwith ulnaulna andand radiusradius
 UlnaUlna articulates witharticulates with trochleatrochlea ofof humerushumerus
 RadiusRadius articulates witharticulates with capitulumcapitulum ofof humerushumerus
 InterosseousInterosseous membrane betweenmembrane between ulnaulna && radiusradius
provides site for muscle attachmentprovides site for muscle attachment

24. Ulna and Radius: Distal EndUlna and Radius: Distal End
 UlnaUlna
 Styloid processStyloid process
providesprovides
attachment forattachment for
ulnar collateralulnar collateral
ligamentligament
 Head separatedHead separated
from wrist jointfrom wrist joint
byby fibrocartilagefibrocartilage
discdisc
 RadiusRadius
 Forms wrist jointForms wrist joint
withwith scaphoidscaphoid,,
lunatelunate &&
triquetrumtriquetrum
 FormsForms distaldistal
radioulnar jointradioulnar joint
with head ofwith head of ulnaulna

25. 8 Carpal Bones (Wrist)8 Carpal Bones (Wrist)
 Proximal row -Proximal row -
lateral to mediallateral to medial
 ScaphoidScaphoid: boat: boat
shapedshaped
 LunateLunate: moon: moon
shapedshaped
 TriquetrumTriquetrum: 3: 3
cornerscorners
 PisiformPisiform: pea: pea
shapedshaped
 Distal row -Distal row -
lateral to mediallateral to medial
 TrapeziumTrapezium: four: four
sidedsided
 TrapezoidTrapezoid: four: four
sidedsided
 CapitateCapitate: large: large
Scared Lovers Try Positions
That They Can’t Handle

26. Metacarpals and PhalangesMetacarpals and Phalanges MetacarpalsMetacarpals
 5 total: #15 total: #1
proximal to thumbproximal to thumb
 basebase,, shaftshaft,, headhead
 knucklesknuckles
((metacarpophalangmetacarpophalang
ealeal joints)joints)
 PhalangesPhalanges
(Digits)(Digits)
 14 total: each is14 total: each is
calledcalled phalanxphalanx
 proximalproximal,, middlemiddle,,
distaldistal on eachon each
finger, exceptfinger, except
thumbthumb
 basebase,, shaftshaft,, headhead

27. Pelvic Girdle and HipPelvic Girdle and Hip
BonesBones
 Pelvic girdlePelvic girdle = two hip bones united at= two hip bones united at pubic symphysispubic symphysis
 articulate posteriorly witharticulate posteriorly with sacrumsacrum atat sacroiliac jointssacroiliac joints
 Each hip bone (Each hip bone (os coxaos coxa) =) = iliumilium,, pubispubis, and, and ischiumischium
 fuse after birth atfuse after birth at acetabulumacetabulum
 Bony pelvis = 2 hip bones,Bony pelvis = 2 hip bones, sacrumsacrum andand coccyxcoccyx

28. IliumIlium
 Iliac crestIliac crest andand iliac spinesiliac spines for muscle attachmentfor muscle attachment
 Iliac fossaIliac fossa for muscle attachmentfor muscle attachment
 Gluteal linesGluteal lines indicating muscle attachmentindicating muscle attachment
 Sacroiliac jointSacroiliac joint atat auricular surfaceauricular surface && iliac tuberosityiliac tuberosity
 GreaterGreater sciatic notchsciatic notch forfor sciatic nervesciatic nerve

29. IschiumIschium
and Pubisand Pubis
 IschiumIschium
 Ischial spineIschial spine &&
tuberositytuberosity
 Lesser sciaticLesser sciatic
notchnotch
 RamusRamus
 PubisPubis
 BodyBody
 SuperiorSuperior && inferiorinferior
ramusramus
 Pubic symphysisPubic symphysis isis
pad ofpad of
fibrocartilagefibrocartilage
between 2between 2 pubicpubic
bonesbones

30. Female PelvisFemale Pelvis
Male PelvisMale Pelvis
 Many differencesMany differences
between the twobetween the two
 In particular,In particular,
pubic archpubic arch inin
males is usuallymales is usually
less than 90˚,less than 90˚,
whereas inwhereas in
females it isfemales it is
usually greaterusually greater
than 90˚than 90˚

31. Lower ExtremityLower Extremity
 Each lower limb = 30Each lower limb = 30
bonesbones
 femurfemur andand patellapatella within thewithin the
thighthigh
 tibiatibia && fibulafibula within the legwithin the leg
 tarsaltarsal bones in the footbones in the foot
 metatarsalsmetatarsals within the forefootwithin the forefoot
 phalangesphalanges in the toesin the toes
 JointsJoints
 hip, knee, anklehip, knee, ankle
 proximalproximal && distaldistal tibiofibulartibiofibular
 metatarsophalangealmetatarsophalangeal

32. FemurFemur
 TheThe femurfemur or thighboneor thighbone
is the largest, heaviest,is the largest, heaviest,
and strongest bone ofand strongest bone of
the bodythe body
 It articulates with theIt articulates with the
hip bonehip bone and theand the tibiatibia
 HeadHead articulates witharticulates with
acetabulumacetabulum
 MedialMedial && laterallateral condylescondyles
articulate witharticulate with tibiatibia
 Neck is commonNeck is common
fracture sitefracture site
 Muscle attachments atMuscle attachments at
greatergreater && lesserlesser
trochanterstrochanters,, linealinea

33. FemurFemur
 Fovea capitisFovea capitis in thein the
center of the headcenter of the head
 Medial epicondylesMedial epicondyles
above the condylesabove the condyles
 Intercondylar fossaIntercondylar fossa
between the condylesbetween the condyles

34. PatellaPatella
 TriangulaTriangula
rr
sesamoidsesamoid
bonebone
 Apex &Apex &
basebase
 ArticularArticular
facetsfacets forfor
thethe femurfemur
 IncreasesIncreases

35. Tibia andTibia and
FibulaFibula Tibia (Shinbone)Tibia (Shinbone)
 Medial & largerMedial & larger
bone of legbone of leg
 Weight-bearingWeight-bearing
bonebone
 HeadHead
 LateralLateral && medialmedial
condylescondyles
 IntercondylarIntercondylar
eminenceeminence
 Tibial tuberosityTibial tuberosity
forfor patellarpatellar

36. Tibia andTibia and
FibulaFibula
FibulaFibula
 Parallel andParallel and
lateral to thelateral to the
tibiatibia
 Smaller than theSmaller than the
tibiatibia
 Not weightNot weight
bearingbearing
 Not part of theNot part of the
knee jointknee joint
 MuscleMuscle
attachmentsattachments
onlyonly

37. Tarsals, Metatarsals, andTarsals, Metatarsals, and
PhalangesPhalanges SevenSeven tarsaltarsal bonesbones
constitute theconstitute the ankleankle
(tarsus)(tarsus) and share theand share the
weight associated withweight associated with
walkingwalking
 FiveFive metatarsalmetatarsal bonesbones
are contained in theare contained in the
footfoot
 Fractures of theFractures of the
metatarsalsmetatarsals areare
common amongcommon among
dancers, especiallydancers, especially
ballet dancers, and alsoballet dancers, and also
among martial artistsamong martial artists

38. TarsusTarsus
(Ankle)(Ankle) ProximalProximal
region of footregion of foot
(contains 7(contains 7
tarsal bones)tarsal bones)
 TalusTalus = ankle= ankle
bone (articulatesbone (articulates
withwith tibiatibia &&
fibulafibula))
 CalcaneusCalcaneus = heel= heel
bonebone
 CuboidCuboid,,
navicularnavicular & 3& 3
cuneiformscuneiforms
 MetatarsalMetatarsal
fractures occurfractures occur
when you dropwhen you drop
something heavysomething heavy
on your footon your foot

39. Metatarsus and PhalangesMetatarsus and Phalanges
 MetatarsalsMetatarsals
 Midregion of the footMidregion of the foot
 5 metatarsals (#1 is most5 metatarsals (#1 is most
medial)medial)
 Each withEach with basebase,, shaftshaft andand headhead
 PhalangesPhalanges
 Distal portion of the footDistal portion of the foot
 Similar in number andSimilar in number and
arrangement to the handarrangement to the hand
 Big toe isBig toe is halluxhallux

40. Arches of the FootArches of the Foot FunctionFunction
 distribute body weight over footdistribute body weight over foot
 yield & spring back when weight is liftedyield & spring back when weight is lifted
 Longitudinal arches along each side of footLongitudinal arches along each side of foot
 Transverse arch across midfoot regionTransverse arch across midfoot region
 navicular, cuneiforms & bases of metatarsalsnavicular, cuneiforms & bases of metatarsals

41. HOMOLOGY OFHOMOLOGY OF
APPENDICULAR BONESAPPENDICULAR BONES
 FORELIMBFORELIMB
1.1. HumerusHumerus
2.2. RadiusRadius
3.3. UlnaUlna
4.4. CarpalsCarpals
5.5. MetacarpalsMetacarpals
6.6. PhallangesPhallanges
 HINDLIMBHINDLIMB
1.1. FemurFemur
2.2. TibiaTibia
3.3. FibulaFibula
4.4. TarsalsTarsals
5.5. MetatarsalsMetatarsals
6.6. PhallangesPhallanges

42. HOMOLOGY OF GIRDLESHOMOLOGY OF GIRDLES
PECTORAL GIRDLEPECTORAL GIRDLE
1.1. ScapulaScapula
* coracoid* coracoid
processprocess
2. Clavicle2. Clavicle
 PELVIC GIRDLEPELVIC GIRDLE
1.1. IliaIlia
2. Ischia2. Ischia
3. Pubis3. Pubis

43. I. GIRDLESI. GIRDLES
A.A. PECTORAL GIRDLEPECTORAL GIRDLE
- COMPOSITION:- COMPOSITION:
1. Replacement Bones1. Replacement Bones
a. coracoida. coracoid
b. Scapulab. Scapula
c. Suprascapulac. Suprascapula
2. Dermal Bones – 4 bones of more2. Dermal Bones – 4 bones of more
a. claviclea. clavicle
b. large cleithriumb. large cleithrium
c. small supracleitriumc. small supracleitrium
d. post temporald. post temporal
e. post cleithria (ganoid fishes)e. post cleithria (ganoid fishes)

44. VARIATION OF PECTORALVARIATION OF PECTORAL
GIRDLEGIRDLE
1.1. CHONDRICHTHYESCHONDRICHTHYES
- ventral coracoid- ventral coracoid
- scapula- scapula
- suprascapula- suprascapula
2. OSTEICHTHYES2. OSTEICHTHYES
- suprascapula is absent- suprascapula is absent
- coracoid +scapula=coracoscapula- coracoid +scapula=coracoscapula

45. 3. TETRAPODS3. TETRAPODS
A.A. AMPHIBIANSAMPHIBIANS
- girdle retained in dermal bones- girdle retained in dermal bones
-components:-components:
a. 2 coracoida. 2 coracoid c. 2 suprascapulac. 2 suprascapula
b. 2 scapulab. 2 scapula d. 1 epicoracoidd. 1 epicoracoid
B. REPTILESB. REPTILES
- coracoids are fused to form one bone- coracoids are fused to form one bone
PROCORACOIDPROCORACOID

46. c. AVESc. AVES
- components:- components:
a. furculaa. furcula
-2 clavicles-2 clavicles
-1 interclavicle-1 interclavicle
b.2 scapulab.2 scapula
c. 2 precoracoidc. 2 precoracoid
D. MAMMALSD. MAMMALS
- components:- components:
a. 2 claviclesa. 2 clavicles
b. 2 scapula (shoulder blade)b. 2 scapula (shoulder blade)
- coracoid process- coracoid process
- acromial process- acromial process
- glenoid fossa- glenoid fossa

47. II. PELVIC GIRDLESII. PELVIC GIRDLES
VARIATION OF PELVIC GIRDLESVARIATION OF PELVIC GIRDLES
1.1. FISHESFISHES
- fusion of ishium and pubis forming- fusion of ishium and pubis forming
ISHIIO-PUBIC PLATEISHIIO-PUBIC PLATE
- (median pubic symphysis)- (median pubic symphysis)
2. AMPHIBIANS2. AMPHIBIANS
- 2 Ilia- 2 Ilia
- 1 sichium (ischiac sysmphysis)- 1 sichium (ischiac sysmphysis)
- 1 pubis (pubic symphysis)- 1 pubis (pubic symphysis)

48. 3. REPTILES3. REPTILES
- 2 Ilia- 2 Ilia
- sacral rib – fused with the carapace- sacral rib – fused with the carapace
- 2 ishia- 2 ishia
- 2 pubis- 2 pubis
4. AVES4. AVES
- 2 Ilia (concave and convex area)- 2 Ilia (concave and convex area)
- 2 pubis- 2 pubis
- 2 ischia- 2 ischia
- 2 foramens- 2 foramens
a. obturator foramena. obturator foramen
b. ilio-ischiac foramenb. ilio-ischiac foramen
––fused to synsacrumfused to synsacrum

49. 5. MAMMALS5. MAMMALS
- 2 Ilia- 2 Ilia
- 2 ischia- 2 ischia
- 2 pubis- 2 pubis
(os coxae, innominate bone, pelvic(os coxae, innominate bone, pelvic
bone)bone)

50. III. LIMBSIII. LIMBS
VARIATION OF FORELIMBSVARIATION OF FORELIMBS
1.1. AMPHIBIANSAMPHIBIANS
- 2 humerus- 2 humerus
- 2 radio-ulna (fused)- 2 radio-ulna (fused)
- 2 rows of carpals- 2 rows of carpals
a. proximal rowa. proximal row
* radiale, ulnare,centrale* radiale, ulnare,centrale
b. distal rowb. distal row
* 3 ordinary fused carpals* 3 ordinary fused carpals
- phalanges : 2: 3: 3:2- phalanges : 2: 3: 3:2

51. 2. REPTILES2. REPTILES
- different size and shape, diameter- different size and shape, diameter
- addition – increase in number- addition – increase in number
- fusion - reduction in size- fusion - reduction in size
3. AVES - modified for flight3. AVES - modified for flight
- 2 Humerus- 2 Humerus
- 2 radius- 2 radius
- 2 ulna- 2 ulna
- 2 carpometacarpus- 2 carpometacarpus
- phalanges: 1:3:2- phalanges: 1:3:2

52. 4. MAMMALS4. MAMMALS
 2 humerus2 humerus
 2 radius2 radius
 2 ulna2 ulna
 8 carpals8 carpals
a. proximal rowa. proximal row
* scaphoid* scaphoid * triquetral* triquetral
* lunate* lunate * pisiform* pisiform
b. distal rowb. distal row
*trapezium*trapezium *capitate*capitate
* trapezoid* trapezoid * hamate* hamate
* Phalanges : 2:3:3:3:3* Phalanges : 2:3:3:3:3

53. II. HINDLIMBII. HINDLIMB
 FEMUR – THIGHFEMUR – THIGH
 TIBIA AND FIBULA – SHANKTIBIA AND FIBULA – SHANK
 TARSALS - ANKLETARSALS - ANKLE
 METATARSALS – SOLEMETATARSALS – SOLE
 PHALANGES – DIGITS /TOESPHALANGES – DIGITS /TOES

54. VARIATION OF HINDLIMBVARIATION OF HINDLIMB
1.1. AMPHIBIANSAMPHIBIANS
- 2 Femur- 2 Femur
- 2 tibio-fibula- 2 tibio-fibula
- 2 proximal tarsals- 2 proximal tarsals
* astragalus *calcaneum* astragalus *calcaneum
- 2 ordinary tarsals – fused- 2 ordinary tarsals – fused
- 5 metatarsals- 5 metatarsals
- phalanges : 1 :3:4:4:3- phalanges : 1 :3:4:4:3

57. 2. REPTILES2. REPTILES
- in sphenodons and lizards- tarsal- in sphenodons and lizards- tarsal
bones are fused formingbones are fused forming
ASTRAGALOCALCANEUMASTRAGALOCALCANEUM
3.AVES3.AVES
- TIBIOTARSUS- TIBIOTARSUS
- TARSOMETATARSUS- TARSOMETATARSUS
- METATARSALS- METATARSALS
- 4 DIGITS WITH CLAWS, KNEE CAP- 4 DIGITS WITH CLAWS, KNEE CAP

60. 3. MAMMALS3. MAMMALS
- 2 FEMUR- 2 FEMUR
- 2 TIBIA- 2 TIBIA
- 2 FIBULA- 2 FIBULA
- 7 TARSALS- 7 TARSALS
A. PROXIMALA. PROXIMAL
- calcaneum,talus,navicular- calcaneum,talus,navicular
B. DISTALB. DISTAL
- 3 cunieforms, 1 cuboid- 3 cunieforms, 1 cuboid
- 5 metatarsals- 5 metatarsals
- phalanges: 2:3:3:3:3- phalanges: 2:3:3:3:3

63. ADAPTATION OF MANUSADAPTATION OF MANUS
1.1. WRISTWRIST
2.2. PALMPALM
3.3. DIGITSDIGITS
• FUNCTIONS:FUNCTIONS:
• For graspingFor grasping
• For swift-footednessFor swift-footedness
• DigitigradeDigitigrade * unguligrade* unguligrade
• PlantigradePlantigrade

65.  For flight – wingsFor flight – wings
 For swimming – flippers for life in theFor swimming – flippers for life in the
oceanocean
 FINSFINS
- stabilizers- stabilizers
- steering device for undulation- steering device for undulation

66. TYPES OF FINSTYPES OF FINS
1.1. PAIRED FINSPAIRED FINS
1.A BONY FISH1.A BONY FISH
A. PECTORAL FINS –coracoscapulaA. PECTORAL FINS –coracoscapula
B. PELVIC FINS - ischio-pubic plateB. PELVIC FINS - ischio-pubic plate
1.B. CARTILAGINOUS FIS1.B. CARTILAGINOUS FIS
A. PECTORAL FINSA. PECTORAL FINS
–– coracoid,scapula, suprascapulacoracoid,scapula, suprascapula
B. PELVIC FINS - ischio-pubic plateB. PELVIC FINS - ischio-pubic plate

67. 2. UNPAIRED FINS2. UNPAIRED FINS
A. ANAL FINSA. ANAL FINS
B.CAUDAL FINSB.CAUDAL FINS
C. MEDIAN DORSAL FINSC. MEDIAN DORSAL FINS
A. ANTERIOR DORSAL FINA. ANTERIOR DORSAL FIN
B. POSTERIOR DORSAL FINB. POSTERIOR DORSAL FIN

68. DIVERSITIES IN SKELETALDIVERSITIES IN SKELETAL
STRUCTURES OF PAIRED FINSSTRUCTURES OF PAIRED FINS
1.1. SPINY FINSSPINY FINS
2.2. LOBED FINSLOBED FINS
3.3. FINFOLD FINSFINFOLD FINS
4.4. FIN SPINEFIN SPINE
VARIATION OF MEDIAN FINSVARIATION OF MEDIAN FINS
1.1. HETEROCERCAL -unidenticalHETEROCERCAL -unidentical
2.2. HOMOCERCALHOMOCERCAL - identical- identical
3.3. DIPHYCERCALDIPHYCERCAL - symmetrical- symmetrical
4.4. HYPOCERCALHYPOCERCAL - directed downward- directed downward

71. THEORIES OF THETHEORIES OF THE
ORIGIN OF FINSORIGIN OF FINS
1.1. FIN FOLD HYPOTHESISFIN FOLD HYPOTHESIS
––paired fins are derived from a pair of continuouspaired fins are derived from a pair of continuous
fleshy folds of the lateral body wall analogous to thefleshy folds of the lateral body wall analogous to the
metapleural folds of amphioxusmetapleural folds of amphioxus
2. GILL ARCH HYPOTHESIS (Gegenbaur)2. GILL ARCH HYPOTHESIS (Gegenbaur)
- pectoral and pelvic fins are modified gill arches and- pectoral and pelvic fins are modified gill arches and
the skeleton within the fin is an expansion of gill raysthe skeleton within the fin is an expansion of gill rays
3. FIN SPINE HYPOTHESIS (Gregory and Raven)3. FIN SPINE HYPOTHESIS (Gregory and Raven)
-in early acanthodians, pectoral and pelvic appendages-in early acanthodians, pectoral and pelvic appendages
were the largest of the series of lateral hollow spinywere the largest of the series of lateral hollow spiny
appendagesappendages
-lateral extension of the trunk-lateral extension of the trunk

72. LOCOMOTION OF LIMBLESSLOCOMOTION OF LIMBLESS
VERTEBRATESVERTEBRATES
1.1. SERPENTINE OR LATERAL UNDULATIONSERPENTINE OR LATERAL UNDULATION
– movement forming irregular loops– movement forming irregular loops
2.2. CONCERTIVE OR RECTILINEARCONCERTIVE OR RECTILINEAR
- move from place to place by- move from place to place by
gliding using the cervical ribsgliding using the cervical ribs
3. SIDESWINDING3. SIDESWINDING
- occupy territory or sandy dessert- occupy territory or sandy dessert
- rattlesnakes- rattlesnakes