Articulations

Question 1

What are joint articulations?

Answer 1

Body movement occurs at joints where 2 bones connect
Joint structure determines direction and range of movement
Joint strength decreases as mobility increases

Question 2

What are the two classifications of joints?

Answer 2

Functional:
- No movement, synarthrosis
- Little movement, amphiarthrosis
- More movement, diarthrosis

Structural:
- Bony
- Fibrous
- Cartilagenous
- Synovial

Question 3

What are synarthrosis joints?

Answer 3

Immovable joints
Very strong
Edges of bones may touch or interlock
4 Types:
Suture (fibrous)
Gomphosis (fibrous)
Synchondrosis (cartilaginous)
Synostosis (Bony)

Question 4

What is the synarthrosis: suture?

Answer 4

Bones interlocked
Bound by dense fibrous connective tissue
Only in skull

Question 5

What is synarthrosis: gomphoais?

Answer 5

Fibrous connection (periodontal ligament)
Binds teeth to sockets

Question 6

What is synarthrosis: synchondrosis?

Answer 6

Rigid cartilaginous bridge between 2 bones:
- epiphyseal cartilage of growing long bones
- between ribs and sternum (costochondral junction)

Question 7

What is synarthrosis: synostosis?

Answer 7

Fused bones:
metopic suture of the frontal bone of an adult skull
epiphyseal lines of non growing adult long bones

Question 8

What is amphiarthrosis?

Answer 8

Slightly movable

2 types:
syndesmosis:
e.g., superior and inferior tibiofibular joints

symphysis:
e.g., intervertebral discs – symphysis pubis

Question 9

What are diarthroses joints?

Answer 9

Moveable joints
Synovial joints
At ends of long bones
Component:
- joint capsule
- synovial membrane
- articular cartilage
- joint cavity containing synovial fluid

Question 10

What is articular cartilages?

Answer 10

Pad articulating surfaces within articular capsules:
- prevent bones from touching

Smooth surfaces lubricated by synovial fluid:
- secreted by fibroblasts in the synovial membrane
- contains hyaluronan & slippery proteoglycans
- functions: lubrication  reduce friction, nutrient distribution, and shock absorption

Question 11

What are synovial joints: accessory structures?

Answer 11

Cartilages (menisci) :
cushion the joint

Fat pads:
superficial to the joint capsule

Ligaments:
for support and strength

Tendons:
attach to muscles around joint

Bursae:
pockets of synovial fluid
cushion areas where tendons or ligaments rub