skeletal system the skeleton is a framework of structures, made of bones and cartilage that support...

Skeletal SystemSkeletal System

- The skeleton is a The skeleton is a framework of structures, framework of structures, made of bones and cartilage made of bones and cartilage that support and protect the that support and protect the body.body.

Axial SkeletonAxial Skeleton

- includes the skull, includes the skull, vertebrae, ribs, and vertebrae, ribs, and

sternum.sternum.

Skull

Cervical

Axis Thoracic

Lumbar

Atlas

Coccygeal

Sacral

Axial SkeletonAxial Skeleton

Ribs

SkullSkull

- many plates of bone many plates of bone fused together.fused together.

SkullSkull

The soft spot on top of the The soft spot on top of the skull is called a skull is called a fontanelfontanel.

VertebraeVertebraeHave five distinct regions:Have five distinct regions:

1.1. CervicalCervical

2.2. ThoracicThoracic

3.3. LumbarLumbar

4.4. SacralSacral

5.5. CoccygealCoccygeal

CervicalCervical• vertebrae of the neck regionvertebrae of the neck region

CervicalCervicalAtlasAtlas

the first cervical vertebra the first cervical vertebra

called “C1”called “C1”

CervicalCervicalAtlasAtlas

CervicalCervicalAtlasAtlas

Forms the joint that lets you nodForms the joint that lets you nod

““yes”yes”

CervicalCervical

AxisAxis

the second cervical vertebra the second cervical vertebra

called “C2”called “C2”

CervicalCervical

AxisAxis

CervicalCervical

AxisAxis

Forms the joint that lets you nod Forms the joint that lets you nod “no”“no”

CervicalCervical• How many does a cow have?How many does a cow have?

• What about a horse?What about a horse?

• How about a dog?How about a dog?

• And a cat?And a cat?

• Any guesses on a giraffe?Any guesses on a giraffe?

CervicalCervical

There are There are sevenseven cervical vertebrae cervical vertebrae in all mammals in all mammals

Even the giraffe!Even the giraffe!

CervicalCervical

1 23

45

67

ThoracicThoracic

- vertebrae of the body region- vertebrae of the body region

ThoracicThoracic- always have a rib attached and - always have a rib attached and

a spine on top.a spine on top.

ThoracicThoracic

““True ribs”: True ribs”:

directly attach to sternum with directly attach to sternum with cartilagecartilage

ThoracicThoracic

““True ribs”: True ribs”:

ThoracicThoracic

““False ribs”:False ribs”:

connect to each other with connect to each other with cartilage, not the sternumcartilage, not the sternum

ThoracicThoracic

““False ribs”:False ribs”:

ThoracicThoracic

““Floating ribs”:Floating ribs”:

seen in the dog seen in the dog

have cartilage on the tips but do not have cartilage on the tips but do not attach to anything.attach to anything.

ThoracicThoracic

““Floating ribs”:Floating ribs”:

LumbarLumbar

vertebrae of the lower backvertebrae of the lower back

LumbarLumbar

Carnivores generally tend to have more

perhaps to lend greater flexibility

LumbarLumbar

Herbivores need to have a short, strong back to support large digestive and reproductive

organs

SacralSacral

vertebrae of the pelvic regionvertebrae of the pelvic region

SacralSacral

Fused together on the ventral side.

SacralSacral

Herbivores generally tend to have more to add strength and support

to the back.

Carnivores tend to have less for flexibility.

CoccygealCoccygeal

vertebrae of the tail regionvertebrae of the tail region

CoccygealCoccygeal

Used for balance.

Become smaller at the

end of the tail

Appendicular SkeletonAppendicular Skeleton

the fore and hind limbsthe fore and hind limbs

Appendicular Skeleton

Scapula

UlnaRadiusCarpals

Humerus

MetacarpalsPhalanges

Olecranon

Forelimb

Sesamoids

Pelvis

TarsalsTibia

Metatarsals

FibulaFemur

SesamoidsPhalanges

Appendicular SkeletonHind limb

Patella

ForelimbForelimbScapulaScapula

““shoulder blade” attached with muscleshoulder blade” attached with muscle

Clavicle Clavicle ForelimbForelimb

the cat is the only domestic animal with a clavicle!

HumerusHumerus

forms the upper arm

ForelimbForelimb

Ulna Ulna forms the elbow joint

ForelimbForelimb

Ulna Ulna

fused with the radius in herbivores

ForelimbForelimb

RadiusRadiusforms the forearm

ForelimbForelimb

CarpusCarpuscommonly called the “knee” in horsescommonly called the “knee” in horses

ForelimbForelimb

CarpusCarpus

the “wrist” in dogs and humans

ForelimbForelimb

MetacarpalsMetacarpalscommonly called the cannon region of the

forelimb

ForelimbForelimb

MetacarpalsMetacarpals

Humans:Humans:

55

Number depends on species:Number depends on species:

MetacarpalsMetacarpals

Number depends on species:Number depends on species:

Horses:Horses:

1 plus 2 accessory metacarpals 1 plus 2 accessory metacarpals

called “splint bones”called “splint bones”

MetacarpalsMetacarpals

Splint Bones(II or IV Metacarpals)

Cannon Bone(III Metacarpals)

MetacarpalsMetacarpals

Dogs and cats: Dogs and cats:

4 plus the dewclaw4 plus the dewclaw

Number depends on species:Number depends on species:

MetacarpalsMetacarpals

Cattle: Cattle:

1 that splits at bottom into a cloven hoof 1 that splits at bottom into a cloven hoof and 2 dewclawsand 2 dewclaws

Number depends on species:Number depends on species:

MetacarpalsMetacarpals

Pigs: Pigs:

4 4

(2 toes and 2 dewclaws)(2 toes and 2 dewclaws)

Number depends on species:

PhalanxPhalanxProximal phalanx (P1) Proximal phalanx (P1)

(bones of the finger, hoof, and claw)(bones of the finger, hoof, and claw)

Intermediate phalanx (P2)Intermediate phalanx (P2)

Distal phalanx (P3)Distal phalanx (P3)(the coffin bone in horses)(the coffin bone in horses)

PhalanxPhalanx

P1P2

P3

PhalanxPhalanx

P1

P2P3

SesamoidsSesamoidsProximal sesamoidsProximal sesamoids

(tucked in behind P1)(tucked in behind P1)

Distal sesamoidDistal sesamoid(tucked in underneath P3)(tucked in underneath P3)

called the navicular bone in horsescalled the navicular bone in horses

SesamoidsSesamoids

Proximal

Distal

SesamoidsSesamoids

Navicular Bone

Hind LimbHind Limb

PelvisPelvis

Hind LimbHind LimbPelvisPelvis

Tuber coxaeTuber coxae

part of pelvis that forms the part of pelvis that forms the

““point of hip”point of hip”

Hind LimbHind LimbPelvisPelvis

Ischiatic tuberosityIschiatic tuberosity

part of pelvis that forms the part of pelvis that forms the

““seat bones”seat bones”

PelvisPelvisTuber coxaeTuber coxae

Ischiatic tuberosityIschiatic tuberosity

FemurFemur

Hind LimbHind Limb

PatellaPatella

Hind LimbHind Limb

PatellaPatella

-- forms the “stifle” joint in horsesforms the “stifle” joint in horses

- sometimes called the “knee” in dogs sometimes called the “knee” in dogs

- equivalent to the human kneeequivalent to the human knee

Hind LimbHind Limb

Patella

Patella

TibiaTibia

main bone of the gaskin of the horsemain bone of the gaskin of the horse

Hind LimbHind Limb

FibulaFibula

fused with the tibia & considered fused with the tibia & considered vestigial in herbivoresvestigial in herbivores

Hind LimbHind Limb

TarsusTarsus

commonly called the “hock”commonly called the “hock”

Hind LimbHind Limb

TarsusTarsus

equivalent to the human “ankle”equivalent to the human “ankle”

Hind LimbHind Limb

MetatarsalMetatarsal

cannon region in the hind limb.cannon region in the hind limb.

Hind LimbHind Limb

MetatarsalMetatarsal

Number depends on speciesNumber depends on species

Hind LimbHind Limb

Short BoneShort Bone

cube shaped cube shaped

i.e. carpus and tarsusi.e. carpus and tarsus

Classification of BonesClassification of Bones

Flat BoneFlat Bone

plate of boneplate of bone

i.e. scapula, rib, skulli.e. scapula, rib, skull

Classification of BonesClassification of Bones

Irregular BoneIrregular Bone

complex shaped

i.e. vertebrae

Classification of BonesClassification of Bones

SesamoidSesamoid

small, seed-shaped bonesmall, seed-shaped bone

i.e. proximal and distal sesamoids, i.e. proximal and distal sesamoids, patellapatella

Classification of BonesClassification of Bones

Long BoneLong Bone

bone is longer that it is widebone is longer that it is wide

i.e. femur, tibia, humerus, etc.i.e. femur, tibia, humerus, etc.

Classification of BonesClassification of Bones

Bone AnatomyBone AnatomyDiaphysisDiaphysis

body of a long bonebody of a long bone

Bone AnatomyBone AnatomyEpiphysisEpiphysis

enlarged ends of long bonesenlarged ends of long bones

Bone AnatomyBone AnatomyMetaphysisMetaphysis

joining point of diaphysis and joining point of diaphysis and epiphysisepiphysis

Bone AnatomyBone AnatomyPeriosteumPeriosteum

thin outer protective layer of bonethin outer protective layer of bone

Bone AnatomyBone AnatomyMedullary CavityMedullary Cavity

space within bone filled with space within bone filled with marrowmarrow

Bone AnatomyBone AnatomyEndosteumEndosteum

thin inner protective layer lining thin inner protective layer lining the medullary cavitythe medullary cavity

Bone AnatomyBone AnatomyMarrowMarrow

Bone GrowthBone Growth

Occurs in the epiphysis of Occurs in the epiphysis of

long bones.long bones.

Bone GrowthBone Growth

Epiphyseal growth plates produce Epiphyseal growth plates produce cartilage, which gradually turns cartilage, which gradually turns into bone via a process called into bone via a process called

ossificationossification

FracturesFractures

Major CategoriesMajor Categories

SimpleSimple

bone does not break skinbone does not break skin

FracturesFractures

Major CategoriesMajor Categories

CompoundCompound

bone breaks through skin, much bone breaks through skin, much more seriousmore serious

FracturesFractures

Major CategoriesMajor Categories

CompleteComplete

fracture goes completely across the fracture goes completely across the bonebone

FracturesFractures

Major CategoriesMajor Categories

IncompleteIncomplete

fracture does not go completely fracture does not go completely across boneacross bone

Classifying FracturesClassifying FracturesFissure FractureFissure Fracture

incomplete break, along the long axis of the bone

Classifying FracturesClassifying Fractures

Greenstick FractureGreenstick Fractureincomplete break on one side of a incomplete break on one side of a

bone, usually due to bone, usually due to

a bending forcea bending force

Classifying FracturesClassifying Fractures

Transverse FractureTransverse Fracturebreak across the bonebreak across the bone

Classifying FracturesClassifying Fractures

Comminuted FractureComminuted Fracturebone shatters into many piecesbone shatters into many pieces

Healing FracturesHealing Fractures

Bone cells lay down a material Bone cells lay down a material called called fibrocartilagefibrocartilage, which , which

gradually turns into bone in a gradually turns into bone in a process called process called ossificationossification..