BIO 210
I.
II.
CHAPTER 9
ARTICULATIONS - SUPPLEMENT
INTRODUCTION TO ARTICULATIONS
A.
DEFINITION
Articulations Are Joints (Where Bones Join)
B.
FUNCTIONS
Binds Bones Together
Usually Permit Movement Between Bones
CLASSIFICATION OF JOINTS
A.
STRUCTURAL CLASSIFICATION
Based on Design, There Are 3 Types of Joints
1.
FIBROUS JOINTS
Fibrous Tissue Located B/T Bones
2.
CARTILAGINOUS JOINTS
Cartilage Located B/T Bones
3.
SYNOVIAL JOINTS
Fluid-Filled Space Located B/T Bones
B.
FUNCTIONAL CLASSIFICATION
Based on Degree of Movement Permitted, There Are 3 Types of
Joints
1.
SYNARTHROSES
Immovable Joints
2.
AMPHIARTHROSES
Slightly Moveable Joints
3.
DIARTHROSES
Freely Moveable Joints
C.
RELATIONSHIP BETWEEN STRUCTURAL AND FUNCTIONAL CLASSIFICATION
Fibrous Joints Are Synarthroses
Cartilaginous Joints Are Amphiarthroses
Synovial Joints Are Diarthroses
D.
FIBROUS/SYNARTHROSES – TYPES
1.
SYNDESMOSES
Fibrous Tissue B/T Bones is Ligaments
Ligaments: Fibrous Cords That Bind Bone to Bone
Examples: Joint B/T Radius and Ulna, Joint B/T Tibia
and Fibula
NOTE: Syndesmoses Permit Slight Movement B/C Ligaments
Contain Elastic Fibers
2.
SUTURES
Immovable Joints Between Skull Bones (Fibrous Tissue
Located B/T Skull Bones)
3.
GOMPHOSES
Fibrous Tissue B/T Bones is Periodontal Membrane
Example: Joints B/T Teeth and Jaw Bones
E.
CARTILAGINOUS/AMPHIARTHROSES - TYPES
1.
SYNCHONDROSES
Type of Cartilage B/T Bones is Hyaline
Examples: Joints B/T Ribs and Sternum (Contain Costal
Cartilage), Joint B/T Epiphyses and Diaphysis
Contains Epiphyseal Plate)
2.
SYMPHYSES
Type of Cartilage B/T Bones is Fibrocartilage
Examples: Joint B/T Pelvic Bones (Symphysis Pubis),
Joints B/T Bodies of Vertebrae (Contain Intervertebral Disks)
Symphyses Are Usually Located in the Midline of the
Body
F.
SYNOVIAL/DIARTHROSES
1.
STRUCTURE
a.
JOINT CAPSULE
- Extension of Periosteum of Both Bones
- Forms Covering Around Ends of Both Bones Binding
Bones Together
b.
SYNOVIAL MEMBRANE
- Lines Joint Capsule
- Secretes Synovial Fluid (Nourishes/Lubricates)
c.
ARTICULAR CARTILAGE
- Joining Cartilage
- Cushions Bones
d.
JOINT CAVITY
- Space that Contains Synovial Fluid
e.
LIGAMENTS
- Fibrous Cords that Join Bone to Bone
- Assist Joint Capsule in Holding Bones Together
f.
MENISCI (ARTICULAR DISKS)
- Fibrocartilage Pads Located on Top of Articular
Cartilage in High Stress Joints (Knee)
- Extra Cushioning Between Bones
g.
BURSAE
- Fluid Filled Sacs Located in Bony Joints (Shoulder,
Elbow, Knee)
- Cushions /Relieves Pressure Over Moving Parts
2.
TYPES AND RANGE OF MOVEMENT AT SYNOVIAL/DIARTHROSES
a.
RANGE OF MOTION (ROM)
- Movements Permitted by a Diarthrosis
b.
TYPES OF MOVEMENT
1.
ANGULAR MOVEMENTS
a.
FLEXION
- Bending a Body Part
b.
EXTENSION AND HYPEREXTENSION
- Straightening a Body Part
- Stretching a Body Part
Beyond Anatomical Position
c.
PLANTAR FLEXION
- Straightening the Foot
Downward (Points Toes
Downward)
d.
DORSIFLEXION
- Bending the Foot Upward
e.
ABDUCTION
- Moves a Body Part Away
from the Midline
f.
ADDUCTION
- Moves a Body Part Toward
the Midline
2.
CIRCULAR MOVEMENTS
a.
ROTATION
- Bone Pivots Around a Fixed
Point
b.
CIRCUMDUCTION
- Moves a Body Part so That
Its Distal End Describes a
Circle
c.
SUPINATION
-
Moves the Forearm so as to
Turn the Palm Up
d.
PRONATION
- Moves the Forearm so as to
Turn the Palm Down
3.
GLIDING MOVEMENTS
- Sliding Between Flat Surfaces
4.
SPECIAL MOVEMENTS
a.
INVERSION
- Turns the Sole of the Foot
Inward
b.
EVERSION
- Turns the Sole of the Foot
Outward
c.
PROTRACTION
- Moves a Body Part Forward
d.
RETRACTION
- Moves a Body Part Backward
e.
ELEVATION
- Raises a Body Part
f.
DEPRESSION
- Lowers a Body Part
3.
TYPES OF SYNOVIAL/DIARTHROSES
a.
UNIAXIAL JOINTS
1.
HINGE JOINTS
- Examples: Elbow, Knee
- Movements Permitted: Flexion, Extension
2.
PIVOT JOINTS
- Example: Between Atlas/Axis
- Movement Permitted: Rotation
b.
BIAXIAL JOINTS
1.
SADDLE JOINTS
- Example: Thumb Joint
(Carpometacarpal)
- Movements Permitted: Flexion, Extension,
Abduction, Adduction
2.
CONDYLOID JOINTS
- Example: Between Occipital Bone
(Condyles) and Atlas
- Movements Permitted: Same as
Saddle Joints
c.
MULTIAXIAL JOINTS
1.
BALL AND SOCKET JOINTS
- Examples: Shoulder, Hip
- Movements Permitted: Flexion, Extension,
Abduction, Adduction, Rotation,
Circumduction
- Most Moveable Diarthroses
2.
GLIDING JOINTS
- Examples: Between Articular
Processes of Vertebrae, Between
Carpals, Between Tarsals
- Movements Permitted: Gliding
- Least Moveable Diarthroses
III. REPRESENTATIVE SYNOVIAL JOINTS
A.
SHOULDER JOINT
- The Most Moveable Diarthrosis
B.
C.
- 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