Transcript Joints and Joint Movements

Joints
• AKA “articulations” – functional
junctions between bones
• Functions:
– Bind parts of the skeletal system
– Make bone growth possible
– Permit parts of the skeleton to change
shape during childbirth
– Enable the body to move in response to
skeletal muscle contractions
Types of Joints
• Fibrous joints
• Cartilaginous joints
• Synovial joints
– Ball-and-socket joints
– Condyloid joint
– Gliding joints
– Hinge joint
– Pivot joint
– Saddle joint
Fibrous Joints
• Between bones that closely contact
each other
• Bones are joined by thin layer of dense
connective tissue
• No big movement at these joints
• Where do you think they would be
found?
Cartilaginous Joints
• Bones connected by hyaline cartilage
(fibrocartilage)
• Limited movement
• Examples: intervertebral discs,
symphysis pubis, rib 1 at the sternum
Synovial Joint
• Free movement
• Articular ends of bones are covered
with hyaline cartilage (articular
cartilage).
• Bones are held together with a
surrounding, tubular capsule (joint
capsule) of dense connective tissue.
– Outer layer of ligaments
– Inner lining of synovial membrane, which
secretes synovial fluid that lubricates the
Synovial Joint, continued…..
• Some contain shock-absorbing pads of
fibrocartilage, called menisci
(meniscus, sing.) between articulating
surfaces.
• Some have bursae, fluid-filled sacs
which are lined with synovial
membranes. (Bursae are commonly
located between the skin and the
underlying bony prominence.)
Types of Synovial Joints
1. Ball-and-socket joint --- allows for
widest range of motion
(Examples:????)
2. Condyloid joint
– oval-shaped condyle of one bone fits into
elliptical cavity of another
– No rotation movement
– EX: b/t phalanges and metacarpals
3. Gliding joint
– Articulating surfaces are nearly flat
– Allow sliding and twisting movement
Types of Synovial Joints,
continued…..
4. Hinge joint
– Convex surface of one joint fits into
concave surface of another
– Resembles hinged door, allowing
movement in one plane only
– Examples: ?????
Types of Synovial Joints,
continued…..
5. Pivot joint
– Cylindrical surface of one bone rotates
within ring formed of bone and ligament
– Movement is only rotation around a
central axis
– Example: Joint b/t proximal ends of
radius and ulna
6. Saddle joint
– Between bones with both convex and
concave regions
– Allows for variety of movement
– Example: Joint b/t metacarpal and carpal
of thumb
•
•
Which metacarpal is this?
What is the name of this carpal bone????
Types of Joint Movement
1. Flexion – bending
2. Extension – straightening
3. Dorsiflexion – bending foot toward
shin
4. Plantar flexion – bending foot toward
sole
5. Hyperextension – extension BEYOND
anatomical position
6. Abduction – away from midline of
Types of Joint Movement,
continued…..
8. Rotation – moving around an axis
9. Circumduction – moving a part so its
END follows a circular path
10. Pronation – turning hand posteriorly
11. Supination – turning hand anteriorly
12. Eversion – turning foot so sole faces
laterally
13. Inversion – turning sole medially
14. Retraction – moving a part backward
Types of Joint Movement,
continued…..
16. Elevation – raising a part
17. Depression – lowering a part