9.4 Synovial Joints

Question 1

Synovial joint

Answer 1

Synovial cavity
Diarthrosis
-bones at synovial joint are covered in hyaline cartilage called Articular Cartilage

Question 2

Articulate cartilage

Answer 2

Reduces friction between bones and absorbs shock

Question 3

Articular capsule (joint capsule)

Answer 3

• Surrounds a synovial joint, encloses synovial cavity, and unites articulating bones.
• composed of 2 layers.

Question 4

2 layers of Articular capsule:

Answer 4

• outer fibrous membrane: dense irregular connective tissue that attaches to periosteum of articulating bones (like a web?)
• inner synovial membrane: areolar connective tissue with elastic fibers

Question 5

Ligaments

Answer 5

One of the principal factors that hold bones close together in a synovial joint

Question 6

Articular fat pads

Answer 6

Accumulations of adipose tissue

Question 7

Double jointed

Answer 7

Not really extra joints, but rather greater flexibility in ligaments and Articular capsules.

Question 8

Synovial fluid

Answer 8

Consists of hyaluronic acid secreted by synovial cells in synovial membrane and interstitial fluid filtered from blood plasma.

• forms a thin film over surfaces within articular capsule
• lubricates the joint, absorbs shock, and exchanging nutrients and expelling waste

Question 9

Accessory ligaments

Answer 9

2 types

1) extracapsular ligaments
2) intracapsular ligaments

Question 10

Extracapsular ligament

Answer 10

Lie outside the Articular capsule

Ex: tibia and fibula collateral ligaments of knee joint

Question 11

Intracapsular ligaments

Answer 11

Occur within the Articular capsule

Question 12

Articular discs (menisci)

Answer 12

Subdivide synovial cavity into two spaces.
Functions:

1) shock absorption
2) better fit between bony surfaces
3) helps movement
4) aids in weight distribution
5) distribution of synovial lubricant accross Articular surface of joint

Question 13

Labrum

Answer 13

Found in the ball-and-socket joints of shoulder and hips.

Fibrocartilaginous lip that extends from the edge of the joint socket.

Helps deepen the joint socket and increases the area of contact between the socket and all like surface.

Question 14

Bursae

Answer 14

Saclike structures that alleviate friction in joints

Found in shoulder and knee joints, found in between the skin and bones, tendons and bones…etc

Question 15

Tendon sheaths

Answer 15

(Synovial sheaths) are tubelike bursae: they wrap around tendons that experience high friction as they pass through tunnels formed by connective tissue.