1

Skeletal System

Approximate 206 bones67% Mineral33% Organic Matter

MineralsCalciumPhosphorusSodiumPotassiumCitrateMagnesiumChorine

Skeletal System Functions

Support. Bone is hard and rigid; cartilage is flexible yet strong. Cartilage in nose, external ear, thoracic cage and trachea. Ligaments- bone to boneProtection. Skull around brain; ribs, sternum, vertebrae protect organs of thoracic cavityMovement. Produced by muscles on bones, via tendons. Ligaments allow some movement between bones but prevent excessive movementStorage. Ca and P. Stored then released as needed. Fat stored in marrow cavitiesBlood cell production. Bone marrow that gives rise to blood cells and platelets

Divisions of the Skeletal System

Axial skeleton-80*Bones of Longitudinal

axisRibsBreastboneHyoidSkullSpine

2

Appendicular Skeleton

Bones of the appendagesUpper & Lower extremities (limbs)Bones of the girdles

-Connect to axial skeletonAbout 126 bones

Bone Shapes

Long

Ex. Upper and lower limbs

Short

Ex. Carpals and tarsalsFlat

Ex. Ribs, sternum, skull, scapulae

Irregular

Ex. Vertebrae, facial

Chapter 8Joints of the Skeletal System

• Articulations• Functional junctions between bones• Bind parts of skeletal system together• Make bone growth possible• Permit parts of the skeleton to change shape during childbirth• Enable body to move in response to skeletal muscle contraction

3

Classification of Joints

• Fibrous Joints• dense connective tissues connect bones• between bones in close contact

• Cartilaginous Joints• hyaline cartilage or fibrocartilage connect bones

• Synovial Joints• most complex• allow free movement

• synarthrotic• immovable

• amphiarthrotic• slightly movable

• diarthrotic• freely movable

Fibrous Joints

3 Types• Syndesmosis• Suture• Gomphosis

Syndesmosis•a sheet or bundle of fibrous tissue connects bones• amphiarthrotic• lies between tibia and fibula

Fibrous Joints

Suture• between flat bones• synarthrotic• thin layer of connective tissue connects bones

Gomphosis• cone-shaped bony process in a socket• tooth in jawbone• synarthrotic

4

Cartilaginous Joints

2 Types• Synchondrosis• Symphysis

Synchondrosis• bands of hyaline cartilage unite bones• epiphyseal plate (temporary)• between manubrium and first rib• synarthrotic

Cartilaginous Joints

Symphysis• pad of fibrocartilage between bones• pubis symphysis• joint between bodies of adjacent vertebrae• amphiarthrotic

Synovial Joints

• diarthrotic• joint cavity• synovial fluid• joint capsule• synovial membrane• bursae

5

Area where to bones meetParts:

Cartilagesynovial fluidLigamentssynovial membraneBursatendons

ArticularArticular JointJoint

LigamentLigamentConnects bones togetherFibrous connective tissueAllows bones to move but not separate

CartilageCartilage

Found on surface of end (epiphysis) of boneCushioning materialShock absorber

6

SynovialSynovial JointsJoints

Synovial MembraneMembrane

Produces synovial fluid

SynovialSynovial FluidFluidLubricates to reduce friction on bone surface

BursaBursaFluid filled sac“Cushion”

Found in shoulder & knee

TendonTendon

Connects muscle to bone

7

8

Types of Synovial Joints

Ball-and-Socket Joint• hip• shoulder

Condyloid Joint• between metacarpals and phalanges

Hinge JointHinge Joint

•Elbow•Knee•Restrictedmovement

•Bend only in one direction

9

Types of Synovial Joints

Gliding Joint• between carpals• between tarsals

Hinge Joint• elbow• between phalanges

Types of Synovial Joints

Pivot Joint• between proximal ends of radius and ulna

Saddle Joint• between carpal and metacarpal of thumb

10

Types of Joint Movements

• abduction/adduction• dorsiflexion/plantarflexion• flexion/extension/hyperextension

Types of Joint Movements

• rotation/circumduction• supination/pronation

Types of Joint Movements

• eversion/inversion• protraction/retraction• elevation/depression

11

Shoulder Joint

• ball-and-socket• head of humerus• glenoid cavity of scapula• loose joint capsule• bursae• ligaments prevent displacement• very wide range of movement

Shoulder Joint

Elbow Joint

• hinge joint• trochlea of humerus• trochlear notch of ulna

• gliding joint• capitulum of humerus• head of radius

• flexion and extension• many reinforcing ligaments• stable joint

12

Elbow Joint

Hip Joint

• ball-and-socket joint• head of femur• acetabulum of coxa• heavy joint capsule• many reinforcing ligaments• less freedom of movement than shoulder joint

Hip Joint

13

Knee Joint

• largest joint• most complex• medial and lateral condyles of distal end of femur• medial and lateral condyles of proximal end of tibia• femur articulates anteriorly with patella• modified hinge joint• flexion/extension/little rotation• strengthened by many ligaments and tendons• menisci separate femur and tibia• bursae

Knee Joint

Life-Span Changes

• Joint stiffness is an early sign of aging•Fibrous joints first to change; can strengthen over a lifetime• Changes in symphysis joints of vertebral column diminish flexibility and decrease height • Synovial joints lose elasticity• Disuse hampers the blood supply• Activity and exercise can keep joints functional longer

14

Clinical Application

Joint DisordersSprains• damage to cartilage, ligaments, or tendons associated with joints• forceful twisting of joint

Bursitis• inflammation of a bursa• overuse of a joint

Arthritis• inflamed, swollen, painful joints

• Rheumatoid Arthritis• Osteoarthritis• Gout

This document was created with Win2PDF available at http://www.win2pdf.com.The unregistered version of Win2PDF is for evaluation or non-commercial use only.This page will not be added after purchasing Win2PDF.