Articulations
Chapter 9
Biology 210
Instructor: John McGill
Original PowerPoint: Jack Bagwell
Supplemental Notes: Beth Wyatt
Last updated: March 18, 2016
INTRODUCTION TO
ARTICULATIONS
• DEFINITION
– Articulations (joints) are the junctions between
bones.
• FUNCTION
– They bind the various parts of the skeletal
system together.
– They permit bone growth and enable body
parts to move in response to skeletal muscle
contractions.
CLASSIFICATION-SUMMARY
• Joints vary greatly in structure and
function.
• They can be classified by the types of
tissues that bind the bones together at
junctions
– Synarthroses-fibrous
– Amphiarthroses-cartilaginous
– Diarthroses-synovial
CLASSIFICATION OF JOINTS:
Structural
• Based on Design, There Are 3 Types of
Joints
• FIBROUS JOINTS
– Fibrous Tissue Located B/T Bones
• CARTILAGINOUS JOINTS
– Cartilage Located B/T Bones
• SYNOVIAL JOINTS
– Fluid-Filled Space Located B/T Bones
CLASSIFICATION OF JOINTS:
Functional
• Based on Degree of Movement Permitted, There Are 3
Types of Joints
– Synarthroses (fibrous)
• no movement (or very limited movement), suture
• bones at these joints are fastened tightly by a layer of fibrous
connective tissue
– Amphiarthroses (cartilagenous)
• cartilaginous joints
• slightly moveable, symphysis pubis
• bones at these joints are connected by hyaline cartilage
– Diarthrosis (synovial)
• freely moveable, shoulder joint
• 7 major components of these joints
Synarthroses (Fibrous joints)
• Syndesmoses
• Sutures
• Gomphoses
Synarthroses (Fibrous joints)
• Syndesmoses
– Bones are bound
together by
ligaments
– Limited movement
is possible
– Ex: Joint between
distal end of radius
and ulna
Synarthroses (Fibrous joints)
• Sutures
– Occur only between the
flat bones of the skull.
– United by a connective
tissue called a sutural
ligament; eventually this
ligament becomes
ossified.
– Joints between skull
bones
Synarthroses (Fibrous joints)
• Gomphoses
– The union of a coneshaped bony process
in a bony socket.
– Ex: a tooth is fastened
to the jawbone by a
peridontal ligament.
Amphiarthroses (Cartilaginous
Joints)
• Synchondroses
• Sympheses
Amphiarthroses (Cartilaginous
Joints)
• Synchondroses
– United by bands of hyaline
cartilage.
– Many of these joints are
temporary structures that
disappear as a result of the
growth process
– Examples
• Epiphyseal plate between
the epiphysis and the
diaphysis
• costal cartilage (ribs
articulate with sternum)
Amphiarthroses (Cartilaginous
Joints)
• Sympheses
– Joint in which a pad or
disk of fibrocartilage
connects two bones
– Most are located in the
midline of the body.
– Example:
• symphysis pubis
• intervertebral disks
Structure of the Synovial (Diarthroses)
Joint: Elbow, Knee, Shoulder, Hip, etc…
• Joint capsule
– sleeve like extension of
the periosteum
– forms a covering around
the ends of the bones and
binds the bones together.
• Synovial membrane
– moist membrane which
lines the inner surface of
the joint capsule
– secretes synovial fluid
• Articular cartilage
– covers and cushions the
articulating surfaces of the
bones
Structure of the Synovial
(Diarthroses) Joint:
• Joint cavity
– small space
between the
articulating surface
of the 2 bones of
the joint
Structure of the Synovial
(Diarthroses) Joint: Elbow,
Knee, Shoulder, Hip, etc…
• Mensci (articular
disk)
– pads of
cartilage
between the
articulating
ends of bone
Structure of the Synovial (Diarthroses) Joint:
Elbow, Knee, Shoulder, Hip, etc…
• Ligaments
– helps hold the
articular cartilages
together
Structure of the Synovial (Diarthroses) Joint:
Elbow, Knee, Shoulder, Hip, etc…
• Bursae
– pillow-like
structure formed
from the synovial
membrane
TYPES AND RANGE OF MOVEMENT AT
SYNOVIAL/DIARTHROSES
• Angular movements
– Flexion
• decreases the angle between two
bones
• “bending” a body part
– Extension
• increases the angle between two
bones
• “straightening” a joint
ANGULAR DIARTHROTIC MOVEMENT
• Angular movements
– PLANTAR FLEXION
• Straightening the Foot
• Downward (Points Toes
Downward)
– DORSIFLEXION
• Bending the Foot
Upward
ANGULAR DIARTHROTIC MOVEMENT
Angular movements
continued…
– Abduction
• move a body part away
from the midline
– Adduction
• moves body part
toward the midline
CIRCULAR DIARTHROTIC MOVEMENT
• CIRCULAR
MOVEMENTS
– ROTATION
• Bone Pivots Around a
Fixed Point
– CIRCUMDUCTION
• Moves a Body Part so
That Its Distal End
Describes a Circle
CIRCULAR DIARTHROTIC MOVEMENT
• CIRCULAR MOVEMENTS
– SUPINATION
• Moves the Forearm so as to
Turn the Palm Up
– PRONATION
• Moves the Forearm so as to
Turn the Palm Down
GLIDING DIARTHROTIC MOVEMENT
• GLIDING
MOVEMENTS
– Sliding Between
Flat Surfaces
– Carpals & tarsals
– Articular facets
GLIDING DIARTHROTIC MOVEMENT
• SPECIAL MOVEMENTS
– INVERSION
• Turns the Sole of the Foot
Inward
– EVERSION
• Turns the Sole of the Foot
Outward
SPECIAL DIARTHROTIC MOVEMENT
• SPECIAL MOVEMENTS
continued…
– PROTRACTION
• Moves a Body Part Forward
• Sticking out jaw
– RETRACTION
• Moves a Body Part
Backward
SPECIAL DIARTHROTIC MOVEMENT
• SPECIAL MOVEMENTS
continued…
– ELEVATION
• Raises a Body Part
• Closing one’s mouth
– DEPRESSION
• Lowers a Body Part
• Opposite of elevation
TYPES OF SYNOVIAL/DIARTHROSES
(Moveable)
• Uniaxial joints
• Biaxial joints
• Multiaxial joints
Uniaxial joints-Hinge
• Permit movement
around one axis and in
one plane.
– Hinge joints
• the convex surface of one
bone fits into the concave
surface of another bone.
• Elbows, phalanges, knee
• Flexion & Extension
Uniaxial joints-Pivot
• Permit movement around
one axis and in one
plane.
– Pivot joints
• the cylindrical surface of
one bone rotates within a
ring formed from the
fibrous tissue of a
ligament.
• Neck turning (1st and 2nd
cervical vertebrae)
• Rotation
Biaxial Joints-Saddle
• Permit movement around two
perpendicular axes in 2
perpendicular planes.
– Saddle joints
• formed between bones whose
articulating surfaces have both
convex and concave regions.
• Thumb joint between first
metacarpal and carpal bone
• Flexion, extension, abduction,
adduction
Biaxial Joints-Condyloid
• Permit movement around two
perpendicular axes in 2
perpendicular planes.
– Condyloid (ellipsoidal) joints
• a condyle fits into an
elliptical socket.
• Joint between radius and
carpal bones
• Flexion, extension,
abduction, adduction
Multiaxial joint-Gliding
• Joint that permits movement
around 3 or more planes
– Gliding joints
• articulating surfaces are
nearly flat or slightly
curved
• these joints only sliding
(back and forth) motion
(least movable)
• Processes between
vertebrae (articular
facets)
• gliding
Multiaxial joint-Ball and Socket
•
Joint that permits movement around 3 or
more planes
– Ball and socket joints
• consists of a bone with a slightly
egg-shaped head that articulates
with the cup-shaped cavity of
another bone
• allows for the broadest range of
movements.
• Shoulder and hip
• Flexion, extension, abduction,
adduction, rotation, circumduction
REPRESENTATIVE SYNOVIAL
JOINTS
• SHOULDER JOINT
• HIP JOINT
• KNEE JOINT
SHOULDER JOINT
• The Most Moveable Diarthrosis
• Reason: Glenoid Cavity (Scapula) Shallow, Head
of Humerus Doesn’t Fit Deep
HIP JOINT
• The Most Stable Diarthrosis
• Reason: Acetabulum (Os Coxa) Deep, Head
of Femur Fits Deep
KNEE JOINT
• The Major Weight
Bearing Diarthrosis
• The Most Frequently
Injured Diarthrosis
– Reasons
• Fit Between Femur and
Tibia (Condyles)
Unstable
• Little Muscle Over Knee
Joint
Anatomy of the Knee
http://www.aclsolutions.com/i
mages/Seif_what is ACL.jpg
Diseases
Normal Femur
Osteoporotic Head
Resources
• http://www.innerbody.com/image/skelfov.h
tml
• Publisher site:
http://evolve.elsevier.com/ProductPage?pr
oduct=0323016286
Case Study
• http://www.recoverymedicine.com/rheumat
oid_arthritis.htm
• http://www.recoverymedicine.com/tendiniti
s_bursitis.htm
Classification of Joints
Start with LEAST movable
Functional
Structural
1.
a.
b. suturesc.
2.
a.
b.
3.
cartilagenous
Classification of Joints
Start with LEAST movable
Functional
1. synarthroses
a.syndesmoses-ligaments,
radius/ulna
b. sutures-b/w skull bones
c. gomphoses-teeth
2.Amphiarthroses
a.synchondrosesribs/sternum and epi plate
b.Symphyses-b/w pelvi
3.diathroses-movableuni/bi/multi
Structural
fibrous
cartilagenous
synovial