SKELETAL SKELETAL SYSTEMSYSTEM

Celeste Roderno- Celeste Roderno- DesingañoDesingaño

Skeletal SystemSkeletal System

Composed of all bones which support Composed of all bones which support the whole bodythe whole body

Our body is made up of 206 bonesOur body is made up of 206 bones

Division of the Skeletal Division of the Skeletal SystemSystem

Axial SkeletonAxial Skeleton SkullSkull BackboneBackbone Rib BasketRib Basket

Appendicular SkeletonAppendicular Skeleton Pelvic GirdlePelvic Girdle Pectoral GirdlePectoral Girdle AppendagesAppendages

Skeleton Region Types of Bone Number of Bones

AXIAL

Skull Cranial BoneFacial BoneMandibleEar BoneHyoid Bone

813161

Vertebral Column Cervical VertebraeThoracic VertebraeLumbar vertebraeSacrumCoccyx

712511

Thoracic Cage Rib bonesSternum

241

APPENDICULAR

Pectoral girdle ClavicleScapula

22

Arms HumerusRadiusUlnaCarpal BonesMetacarpal BonesFingers/ Phalanges

222161028

Legs FemurFibulaTibiaTarsal BonesMetatarsal BonesToes/ Phalanges

222141028

Pelvic Girdle Coxal 4

Total 206

JointsJoints joint, or articulation, is the place where two bones come joint, or articulation, is the place where two bones come

together. There are three types of joints classified by the together. There are three types of joints classified by the amount of movement they allow:amount of movement they allow: 1. Synarthroses (movable)1. Synarthroses (movable)

the bones are in very close contact and are the bones are in very close contact and are separated only by a thin layer of fibrous connective separated only by a thin layer of fibrous connective tissue. tissue.

Ex: the suture in the skull between skull bonesEx: the suture in the skull between skull bones

2. Amphiarthroses (slightly movable)2. Amphiarthroses (slightly movable) This type of joint is characterized by bones that are This type of joint is characterized by bones that are

connected by hyaline cartilage (fibro cartilage). connected by hyaline cartilage (fibro cartilage). Ex: The ribs that connect to the sternum Ex: The ribs that connect to the sternum

3. Diarthrosis (freely movable)3. Diarthrosis (freely movable) Most of the joints in the adult human body are Most of the joints in the adult human body are

freely movable jointsfreely movable joints There are six types of diarthroses jointsThere are six types of diarthroses joints

Types of Diarthrosis JointTypes of Diarthrosis Joint

Ball-and-SocketBall-and-Socket

The ball-shaped The ball-shaped end of one bone end of one bone fits into a cup fits into a cup shaped socket on shaped socket on the other bone the other bone allowing the widest allowing the widest range of motion range of motion including rotation.including rotation.

Example: shoulder Example: shoulder and hip.and hip.

Types of Diarthrosis JointTypes of Diarthrosis JointCondyloid Condyloid Oval shaped condyle Oval shaped condyle

fits into elliptical cavity fits into elliptical cavity of another allowing of another allowing angular motion but not angular motion but not rotation.rotation.

Ex: Joint between Ex: Joint between metacarpals (bones in metacarpals (bones in the palm of the hand) the palm of the hand) and phalanges and phalanges (fingers) and between (fingers) and between the metatarsals (foot the metatarsals (foot bones excluding heel) bones excluding heel) and phalanges (toes).and phalanges (toes).

Types of Diarthrosis JointTypes of Diarthrosis JointSaddleSaddle This type of joint This type of joint

occurs when the occurs when the touching surfaces of touching surfaces of two bones have both two bones have both concave and convex concave and convex regions with the regions with the shapes of the two shapes of the two bones complementing bones complementing one other and allowing one other and allowing a wide range of a wide range of movement.movement.

Ex: The only saddle Ex: The only saddle joint in the body is in joint in the body is in the thumb.the thumb.

Types of Diarthrosis JointTypes of Diarthrosis Joint PivotPivot Rounded or Rounded or

conical conical surfaces of surfaces of one bone fit one bone fit into a ring of into a ring of one or tendon one or tendon allowing allowing rotation.rotation.

Ex: joint Ex: joint between the between the axis and atlas axis and atlas in the neck.in the neck.

Types of Diarthrosis JointTypes of Diarthrosis JointHinge Hinge A convex A convex

projection on projection on one bone fits one bone fits into a concave into a concave depression in depression in another another permitting only permitting only flexion and flexion and extension extension

Ex: elbow Ex: elbow joints.joints.

Types of Diarthrosis JointTypes of Diarthrosis JointGlidingGliding Flat or slightly Flat or slightly

flat surfaces flat surfaces move against move against each other each other allowing allowing sliding or sliding or twisting twisting without any without any circular circular movement. movement.

Ex: Joint Ex: Joint between between carpals in the carpals in the wrist and the wrist and the tarsals in the tarsals in the ankle.ankle.