Joint Articulation

Joints

Sites where two bones meet. Physical communication

3 Types of Structural Classifications

Fibrous, cartilaginous, synovial

Fibrous Joints

Dense fibrous connective tissue between bones
- no joint cavity
- most are immovable

Fibrous Joint : Suture

Rigid, interlocking joints of the skull.
- Allow for growth during youth.
- Contains short connective tissue fibers that allow for expansion
- Sutures ossify and fuse.
Closed immovable sutures referred to as synostoses

Fibrous Joint : Syndesmoses

Bones connected by ligaments
Fiber length varies
Short fibers-no movement
Long fibers-larger amount of movement

Fibrous Joint : Gomphoses

Peg-in-socket joints of teeth in alveolar sockets
Fibrous connection is the periodontal ligament

Cartilaginous Joints

Cartilage between bones.
- Bones united by cartilage
- Like fibrous joints, have no joint cavity
- Not highly movable.

Cartilaginous Joints : Synchondroses

A bar or plate of hyaline cartilage unites the bones
All are synarthrotic (immovable).
- Examples are : temporary epiphyseal plate joints or cartilage of 1st rib with manubrium of sternum.

Cartilaginous Joints : Symphyses

Fibrocartilage unites bone
- Hyaline cartilage present as articular cartilage
- Strong, flexible amphiarthroses (slightly movable).
Examples : intervertebral joints, pubic symphysis, meniscus of knee joints

Synovial Joints

Synovial cavity between bones, synovial means similar to the texture of egg whites

Synovial Joints : Articular cartilage

Consists of hyaline cartilage covering the ends of bones (prevents crushing of bone ends)

Synovial Joints : Joint (synovial) cavity

Small, fluid-filled potential space that is unique to synovial Joints

Synovial Joints : Articular Joint Capsule

External fibrous layer (dense irregular CT) & Inner synovial membrane (loose CT that secretes fluid)

Synovial Joints : Synovial Fluid

Viscous, slippery filtrate of plasma and hyaluronic acid
Lubricates and nourishes articular cartilage
Contains phagocytic cells to remove microbes and debris

Synovial Joints : Nerves & Blood Vessels

Nerves detect pain; monitor joint position and stretch
Capillary beds supply filtrate for synovial fluid

Fatty pads

for cushioning between fibrous layer and synovial membrane or bone

Articular discs

Another term for menisci (singular = meniscus), the fibrocartilage pads between opposing surfaces in a joint

Bursae

flattened fibrous sacs lined with synovial membrane and containing a thin film of synovial fluid

Tendon Sheaths

Elongated bursa wrapped completely around tendon subjected to friction

3 Factors influencing Stability of Synovial Joints

the shapes of the articular surfaces, the number and positioning of ligaments, and muscle tone

What happens if you work out often?

Your body is well toned.

What happens if you don't work out often?

Your body will have random contractions of muscles at rest to keep them warm, supple and heating + ready to respond at any moment.

knee joint

largest and most complex joint in the body
- Has 3 joints : femoropatellar, lateral and medial joint