Topic 10: Skeletal System - Articulations / Joints (structural)

Question 1

What are joints/articulations?

Answer 1

• points of contact between 2 or more bones

Question 2

What are the 2 classes of joints?

Answer 2

• structural and functional

Question 3

What is the structural classification (anatomical) based on? (2)

Answer 3

• presence/absence of joint cavity (articulation point)
• type of CT

Question 4

What are the 3 types of structural joints?

Answer 4

• fibrous joints
• cartilaginous joints
• synovial joints

Question 5

What are the characteristics of fibrous joints? (2)

Answer 5

• no joint cavity
• fibrous CT (dense regular/irregular)
• ex. sutures in skull (fontanels in newborn)

Question 6

What are the characteristics of cartilaginous joints? (2)

Answer 6

• no joint cavity
• cartilage attaches bones
  ex. pubic symphysis, costal cartilage of ribs

Question 7

What are examples of synovial joints?

Answer 7

• shoulder, elbow, knee, hip

Question 8

What are the 3 parts of synovial joints?

Answer 8

• articular cartilage (hyaline)
• joint cavity
• articular/joint capsule

Question 9

What does the joint cavity of synovial joints contain?

Answer 9

• synovial fluid
  in lecture, it reduces friction between bones and adds nutrients

Question 10

What is the outer layer of synovial joint capsule? (2)

Answer 10

• fibrous capsule
• may have ligaments within (capsule is thickened) or separate

Question 11

What is the inner layer of the synovial joint capsule?

Answer 11

• synovial membrane (CT only)
• secretes synovial fluid

Question 12

How are the types of synovial joints determined?

Answer 12

• grouped according to shape of articulating bones

Question 13

Name the 4 types of synovial joints.

Answer 13

• Plane/gliding
• hinge
• pivot
• ball and socket

Question 14

What are plane/gliding joints?

Answer 14

• flat surfaces
• ex. sacroiliac

Question 15

What are hinge joints?

Answer 15

• convex/concave surfaces
  ex. elbow, knee
  note one plane of movement

Question 16

What are pivot joints?

Answer 16

• projection in ring
  ex. dens (on axis) in atlas, radioulnar joint

Question 17

What is a ball and socket joint?

Answer 17

• great freedom of movement
• ex. femur in acetabulum (hip0
  ex. humerous in glenoid fossa

Question 18

What is the functional classification (physiological) of joints based on?

Answer 18

• degree of movement

Question 19

Name the 3 functional joints

Answer 19

1) synarthrotic
2) Amphiarthrotic
3) Diarthrotic

Question 20

What are synarthrotic joints?

Answer 20

• immovable
  ex. skull suture

Question 21

What are amphiarthrotic joints?

Answer 21

• slightly moveable
  ex. pubic symphysis (important for walking or giving birth)

Question 22

What are diarthrotic joints?

Answer 22

• freely moveable synovial joints
  ex. hip, shoulder
  lecture says most synovial joints are diarthrotic