Joints

Question 1

Fibrous Joints

Answer 1

• Articulating bones are united by fibrous tissue
• Variable amount of mvt w/in different types of fibrous joints
• No joint capsule (direct connection b/w bones via fibrous tissue)
• Two types: suture (skull) and syndesmosis (interosseous membrane)
• Allows for little motion (more for stability than mobility)

Question 2

Cartilaginous Joints

Answer 2

• Articulating bones are united via hyaline cartilage or fibrocartilage
• No joint cavity or capsule (direct connection via cartilaginous tissue)
• Two type: syncondroses and symphyses

Question 3

Syncondroses Joint

Answer 3

• Type of cartilaginous joint
• Primary - hyaline cartilage, growth plate
• Prevent motion
• Sternum and 1st rib
• More for stability than mobility

Question 4

Symphyses Joint

Answer 4

• Type of cartilaginous joint
• Secondary - fibrocartilage
• Intervertebral disc, pubic symphysis
• Don’t want a lot of motion
• More for stability than mobility

Question 5

Synovial Joints

Answer 5

• Most common joint type in body
• Allow most motion
• Articulating bones are united by joint capsule (fibrous layer and synovial membrane)
• Joint cavity (synovial fluid secreted by synovial membrane, filtrate of blood)
• Articular cartilage covers articulating surfaces of the bone
• Perisosteum blends with the fibrous layer of the joint capsule
• Often reinforced with ligaments
• Richly supplied with sensory nerves and blood vessels

Question 6

Types of Synovial Joints

Answer 6

• Plane (Gliding)
• Hinge
• Pivot
• Condyloid/ellipsoid
• Saddle
• Ball in socket

Question 7

Gliding Joint

Answer 7

• Two bones gliding/sliding to one another
• Non-axial
• Do whatever they want
• Carpals are good example
• Usually b/w 2 flat surfaces and allows the least movement of all synovial joints

Question 8

Hinge Joint

Answer 8

• Elbow
• Only allows mvt in one plane
• Flex/Ext

Question 9

Pivot Joint

Answer 9

• Radial head in forearm
• C1 relative to C2
• Spins in rotation
• Designed to allow one bone to rotate around surface of another bone

Question 10

Ellipsoid/Condyloid Joint

Answer 10

• Allow flex/ext, add/abd
• Concave/convex but not as deep
• Oval-shaped end of one bone articulating with the elliptical basin of another
• Radiocarpal in wrist

Question 11

Saddle Joint

Answer 11

• CMC joint
• Really specific
• Modified ellipsoid joint composed of convex and concave articulating surfaces

Question 12

Ball and Socket Joint

Answer 12

• Most amount of mobility
• Spherical surface of one bone fits into dish-shaped depression of another bone
• Capable of mvt in all planes
• Ex: glenohumeral joint of the shoulder