ARTICULATIONS
Articulations
Where 2 bones meet
Strength, stability, & flexibility
Joints
Pages 165-175
Concept questions pg 172 & 173
Types of joints- grouped according
to movement
Synarthrosis – immovable, fibrous or cartilaginous
ex. skull - sutures
Amphiarthrossis – semi-movable, fibrous or
cartilaginous
ex. btwn tibia & fibula,
pubic symphysis
Diarthrosis = synovial join – movable, at end of long
bones
ex. knee
SYNARTHROSES
immovable joint (no movement allowed)
Examples:
1) Suture- between bones of the skull
2) Gomphosis- ligament binds each tooth
within a bony socket
AMPHIARTHROSES
slightly movable joints (permits very limited
movement)
Bones connected by collagen fibers or
cartilage
Examples -
1
Examples of amphiarthroses
2.
Symphysis
bones are separated by a pad cartilage (joint between
1)Syndesmosis – ligament connects
tibia & fibula
Diarthroses - Synovial
Wide range of motion
Largest = knee – ligaments present to
keep it stabilized – see page 175 ( fibular
collateral , patella ,tibial medial collateral,
& cruciate ligaments
Categorized according to type of
movement allowed
spinal vertebrae, pubic symphysis)
Diarthrosis
Synovial joints
Move freely
Ligaments
Can have a great amount of force
Dislocation possible
Functions: protect the articular cartilage,
lubricate, provide nutrients,
shock absorber
Structure of Synovial Joints
Joint Capsule- surrounds joint and is
lined by synovial membrane
Ends of long bones are covered in articular
cartilage to prevent bone on bone
movement
Synovial membrane is lined with synovial
fluid
Fluid provides lubrication to reduce friction within
the joint
2
Types of Synovial Joints
Gliding joint
Hinge joint
Pivot joint
Ellipsoidal joint
Saddle joint
Ball and Socket joint
Categories of Synovial Joints
1. Gliding joints- flat articular surfaces slide
across one another. Permits slight
movement in almost any direction ex.
btwn carpal bones, tarsal bones,
ends of clavicles
Synovial joint
2.Hinge Joints
Permit movement in one plane only angular
movement, ex. elbow, knee, ankle,
interphalangeal
Example- atlas and occipital bone; elbow;
knee; and interphalangeal joints)
Synovial
3.Pivot Joints
Permit only rotational movements
ex. moving your head to say “no”, btwn
radius and ulna which allows pronation &
supination, atlas & axis
3
synovial
4. Angular (ellipsoidal)
angular movement in 2 planes, ex. in
hands, feet –radius with the carpal
bones, phalanges with the metacarpals
synovial
5. Saddle
Specialized joint between carpals and
metacarpals at the thumb.
Allows angular motion but prevents rotation,
circumduction, ex. base of thumb
6. Ball and Socket
Allows for all combinations of movement,
circumduction and rotation,
ex. shoulder and hip
4
Knee Joint
requires more support structures
Menisci- fibro cartilage pads that act as
shock absorbers
Page 175
Ligaments
Bursae
Located either inside or
outside of the joint capsule
Provides extra support to
joint
Fat pad- protect articular cartilage
Small pockets
containing synovial
fluid
Form at areas of
friction within joint
Found in shoulder,
elbow, and knee
5
Types of Joint Movements
Flexion- movement in the sagittal plane
that decreases the angle between the
two bones
Extension- movement in the
anterior/posterior plane that increases
the angle between the two bones
Abduction- movement away from the
midline of the body in the frontal plane
Adduction- movement toward the midline
of the body in the frontal plane
Circumduction- movement of arm in a
loop
Rotation- moving a bone around the
longitudinal axis of the body or limb
Supination- turning hand palm side up
Pronation- turning hand palm side down
6
Joint Disorders
Rheumatism
Types of Rheumatism
General term describing pain and stiffness that
affect the skeletal or muscular systems
SEVERAL TYPES OF RHEUMATISM
Wearing away of articular cartilage (bone on
bone articulation)
Very painful
Treated by medication
Extreme cases treated with surgery
Types of Rheumatism
Osteoarthritis (Degenerative arthritis,
Degenerative joint disease)
Affects individuals 60 years of age or
older
Caused by wear and tear on joint
surfaces
Also caused by genetic factors
Arthritis- disease that affects all of the
synovial joints
Always involves damage to the articular
cartilages
Cause of this damage can vary
Bacterial or Viral infection
Injury to the joint
Metabolic problems
Severe physical stress
Types of Rheumatism
Rheumatoid arthritis
Inflammatory condition that affects roughly
2.5 percent of the adult population
Cases involve immune system response
attacking joint tissues
Allergies, bacteria, viruses, and genetic
factors are possible triggers
Terms to know
Movement and strength of a joint are indirectly
proportional
So the stronger the joint, the __ movement
more freely moving joints will need ____
Joint with the greatest movement is the
______
Ulna with the humerus is stronger and thus
less ____
Flexion- smaller angle
Extension
Abduction- away
Adduction-toward the body
Circumduction
Rotation
Pronation- palm- facing back
Supination- palm- facing forward
7