1. Joints of the Skeletal System
How do They Stick Together?

2. Objectives I will be able to:
name the three major structural categories of joints.
compare the amount of movement allowed by each type of joint.
name and describe the various types of fractures.

3. Joints
Joints, also called articulations, are the sites where two or more bones meet.
Joints have two functions:
hold bones together and
allow movement of the skeleton.
articulation: an area where two bones are attached for the purpose of motion of body parts

4. Joints Joints are classified by function and by structure.
3 Functional Categories:
synarthroses: immovable joints
amphiarthroses: slightly movable joints
diarthroses: freely movable joints

5. Joints
Joints are structurally classified by the substance separating the articulating bones.
Fibrous joints
Composed of connective tissue fibers
Generally immovable
Cartilaginous joints
Composed of cartilage
Immovable or slightly moveable

6. Joints Synovial joints Composed of: articular (hyaline) cartilage,
articular capsule,
joint cavity filled with synovial fluid, and
reinforcing ligaments
Freely moveable

7. Fibrous Joints Bones united by fibrous tissue Examples Sutures
Syndesmoses
Allows more movement than sutures
Example: distal end of tibia and fibula

8. Cartilaginous Joints Bones connected by cartilage Examples
Intervertebral joints
Pubic symphysis

9. Synovial Joints Articulating bones are separated by a joint cavity
Synovial fluid is found in the joint cavity
In synovial joints, the articulating surfaces are covered with articular cartilage and enclosed by a synovial membrane that secretes synovial fluid for lubrication.

10. Types of Synovial Joints
Plane Joints:
allow for gliding movements
Hinge Joints:
one bone moves while the other remains stationary, like the hinge of a door
Ball-and-Socket Joints:
all movement types are possible in all directions

11. Types of Synovial Joints
Saddle Joints:
allow angular movements
Pivot Joints:
allows rotational movement
Ellipsoid Joints:
allows angular movement along two axes

12. 
What is the major structural difference between synovial joints and other types of joints?
What are the functions of joints?
A joint cavity filled with synovial fluid
hold bones together and allow movement of the skeleton.

13. Bone Fractures fracture: a break in bone or cartilage
Types of bone fractures
Closed (simple) fracture –does not penetrate the skin
Open (compound) fracture – broken bone penetrates through the skin
Bone fractures are treated by reduction and immobilization
reduction: restoring broken bone ends (or a dislocated bone) to its original position
immobilization: the process of holding a joint or bone in place with a splint, cast, or brace

14. Common Types of Fractures

15. Repair of Bone Fractures
Hematoma is formed
Blood fills in between the break to provide nutrients
Fibrocartilage callus forms
from cartilage matrix, bone matrix, and collagen fibers; “splints” the broken bone
Bony callus is formed (by osteoblasts)
Fibrocartilage callus gradually replaced by spongy bone
Bone remodeling occurs (by osteoblasts and osteoclasts)
Bony callus remodeled over time in response to mechanical stress

16. Repair of Bone Fractures

17. Common Types of Fractures

18.  What are the four steps of bone repair?
What type of fracture is likely to occur if your head slams into the windshield during a car accident?
Hematoma is formed, Fibrocartilage callus forms, Bony callus is formed, Bone remodeling occurs
depressed

19. Websites Bone Research Society
Osteoblast vs. Osteoclast

20. Inflammatory Conditions Associated with Joints
Bursitis – inflammation of a bursa usually caused by a blow or friction
Tendonitis – inflammation of tendon sheaths
Arthritis – inflammatory or degenerative diseases of joints
Over 100 different types
The most widespread crippling disease in the United States

21. Clinical Forms of Arthritis
Osteoarthritis
Most common chronic arthritis
Probably related to normal aging processes
Rheumatoid arthritis
An autoimmune disease – the immune system attacks the joints
Symptoms begin with bilateral inflammation of certain joints
Often leads to deformities

22. Clinical Forms of Arthritis
Gouty Arthritis
Inflammation of joints is caused by a deposition of urate crystals from the blood
Can usually be controlled with diet