Lesson 7: Ch.11: Articulations and Body Movements (1/3)

articulation (joint) functions

1. hold bones together

2. allows skeletal system flexibility

structural classes of joints

1. Fibrous joints

2. Cartilaginous joints

3. Synovial joints

fibrous joints composition

joined by fibrous tissue

fibrous joints movement

mostly synarthrotic: no movements

2 major types of fibrous joints

1. sutures

2. syndesmoses

sutures

interlock bones (skull)

syndesmoses

articulating bones connected by short ligaments

cartilaginous joins composition

articulating bone connected by cartilage plate ot pad

cartilaginous joints movement

mostly amphiarthrotic: slight movements

2 major types of cartilaginous joints

1. symphyses

2. synchondroses

symphyses

bones connected by broad, flat fibrocartilage disc

synchondroses

bony portions united by hyaline cartilage

synchondroses example

• 1st rib/sternum

• epiphyseal plate

symphyses example

• intervertebral disc

• pubic symphysis

syndesmoses example

tibia/fibula

synovial joint movement

all diarthroses: free movement

synovial joints composition

articulating bone ends separated by joint cavity filled with synovial fluid

synovial joint features

1. articular capsule

2. synovial membrane

3. fibrous capsule

4. articular

5. joint cavity

synovial features: articular capsule

• enclose joint surface

• reinforced by ligaments

• may contain bursae (fluid sacs)

• may contain fibrocartilage pads (articular discs)

synovial features: synovial membrane

inner smooth connective tissue membrane layer that produces synovial fluid

synovial features: fibrous capsule

outer layer of dense irregular connective tissue

synovial features: articular (hyaline) cartilage

covers bone ends at joint

synovial features: joint cavity

• encompassed by articular cartilage (covers the epiphysis of bones) and synovial membrane

• filled with synovial fluid

types of synovial joints

1. plane

2. hinge

3. pivot

4. condlyloid/ellipsoidal

5. saddle

6. ball and socket

plane joint

flat surface

plane joint example

• intercarpal/tarsal joints

• vertebrocostal joints of ribs 2-7

hinge joint

round end to concave surface

hing joint example

elbow & interphalangeal jointsj

pivot joint

round/conical bone to shallow depression/foramen

pivot joint example

atlas & axis

condyloid/ellipsoidal joint

oval condyle to ellipsoidal depression

condyloid/ellipsoidal joint example

• radiocarpal joint

• metacarpal & trapezium of wrist

ball and socket joint

ball-shaped head fits into cuplike depression

ball and socket joint example

ball-shaped head fits into cuplike depression

inserted muscles

move bone towards muscle origin

flexion

decrease joint angle

extension

increase joint angle

hyperextension

increase joint angle over 180 degrees

abduction

limb away from midline

adduction

limb toward midline

rotation

movement around longitudinal axis

circumduction

distal end moves in circle

pronation

palm from anterior to posterior

supination

palm from posterior to anterior

foot inversion

medial turn of sole

foot eversion

lateral turn of sole

dorsiflexion

ankle joint dorsal movement

plantar flexion

ankle joint flex downward