Articulations

place of contact b/t bones,

-b/t bone and cartilage

- b/t bones and  teeth

 Three types of joints

- fibrous joint

- cartilaginous joint

- synovial joint

Fibrous Joint

occurs where bones are held together by dense regular connective tissue

Cartilaginous joint

where bones are joined by cartilage

Synovial Joint

- freely movable articulations

- classified as diarthroses

- bones are separated by space called a joint cavity

Function of joints is based on....

movements

Synarthrosis

immovable joint

Amphiarthrosis

slightly movable joint

Diarthrosis

freely movable joint

What are the three types of fibrous joints?

sutures, syndesmoses, gomphoses

Sutures

- immovable

- tightly binds certain bones of the skull to each other

- when closed = synostoses

Syndesmoses

- slightly movable

- found b/t the radius/ulna and the tibia/fibula

- bound together by a broad ligamentous sheet = interosseous membrane

Gomphoses

- immovable

- only occurs where the root of each tooth articulates w/ the socketsof the mandble and the maxilla

Two types of carilagionous joints

symphyses and synchondroses

Symphyses

- has a pad of fibrocartilage b/t the articulating bones

- slightly movable

- pubic symphysis and the intervertebral discs

Synchondroses

- bones are joined by hyaline cartilage

-immovable/slightly movable

- costochondral joints

General Anatomy of Synovial Joints

- auricular capsule encloses bones

- joint cavity filled w/ synovial fluid

- articular cartilage covers ends of bones

- stabilized by ligaments and tendons

- bursae form in/around joint

- articular discs (meniscus) and fat pads in/around some joints

Bursae

fibrous, sac like structure that contains synovial fluid and is lined by a synovial membrane

- helps w/ friction b/t bones & tendons

Fatpads

acts as the packing  material and provide some protection for the joit 

- fill the spaces that form when bones move and the joint cavity changes shape

- "peanuts" = UPS

Tendons

- attaches a muscle to a bone

- help stabilize joints

Uniaxial

bones moves in just one plane

Biaxial

bones moves in two planes

Multiaxial

when the bone moves in multiple planes

6 specific types of synovial joint

- planar (gliding) joints

- hinge joints

- pivot joints

- condyloid (ellipsoid) joints

- saddle joints

- ball-and-socket joints

Movement of Synovial Joints

- Angular motions

- Rotation

- Gliding

- Speacial movements

Adduction

movement of a bone toward the midline

Abduction

movement of a bone away from the midline

Flexion

angle b/t bones decrease

Extension

angle b/t bone increase

Hyperextension

extension movment continues past the anatomic position

Lateral Flexion

vertebral column moves in either lateral direction along a coronal plane

Pronation

rotation of the forearm whereby the palm is turned posteriorly

Supination

rotation of the forearm whereby the palm is turned anteriorly

Depression

movement of a body part inferiorly

Elevation

 movement of a body part superiorly

Dorsiflexion

 toes are pointed up

Plantar Flexion

toes are pointed down

Inversion

 twisting the foot that turns the sole medially

Eversion

twisting the feet so that the sole turns laterally

What stabalizes the joints?

Ligaments, muscle tone, articular surfaces

Sternoclavicular joint

- stable

- saddle joint (biaxial) - wide range of movements

- 4 major ligaments plus multiple muscles

Shoulder joint (glenohumeral)

- most movable joint = less stability

• shallow glenoid cavity
• looser joint capsule
• few ligaments
• stability from muscle tendons

1. biceps brachial
2. rotator cuff

Knee Joint

- Most complex - highly stabilized for compression

• many ligaments outside (ex. collaterals)
• two major ligaments inside (anterior and posterior cruciate)
• two articular discs
• muscle tendons, including quadriceps and hamstrings

- very vulnerable to horizontal blows

Arthritis

a group of infalmmatory or degernative diseases of joints that occur various forms

-swelling

- pain

-stiffness

Most prevalent crippling disease in the US

- gouty arthritis

- osteoarthritis

- rheumatoid arthritis