Joints

Question 1

How are joints classified?

Answer 1

• structural classification
• functional classification

Question 2

3 structural classifications of joints

Answer 2

1. fibrous
2. cartilaginous
3. synovial

Question 3

3 functional classifications of joints

Answer 3

1. immovable (synarthroses)
2. slightly movable (amphiarthroses)
3. movable (diarthroses)

Question 4

fibrous joints or immovable joints (synarthroses)

Answer 4

• lack synovial cavity
• articulating bones held together by a dense irregular connective tissue (DICT)
• permit little or no movement
• three types

Question 5

3 types of fibrous or immovable joints

Answer 5

1. sutures
2. syndesmoses
3. gomphosis

Question 6

Sutures

Answer 6

• type of fibrous / immovable joint
• found in the skull
• composed of thin DICT
• irregular interlocking edges (added strength & decrease chance of fracturing)
• slighlty movable (amphithroses) in infants; immovable (synarthroses) in adults
• shock absorbant in skull
• some sutures replaced by bones in adults (syntrosis)

Question 7

Syndesmoses

Answer 7

• type of fibrous / immovable joint
• syndesmo = band or ligament
• greater distance between the articulating surfaces compared to sutures
• more DICT compared to sutures
• DICT arranged as a bundle (ligament) allowing the joint to permit limited movement
• examples: distal tibiofibular joint, dentoalveolar joint (gomphosis)*

Question 8

Interosseous membrane

Answer 8

• fibrous sheet of DICT that spans the space between two bones forming a type of syndesmosis joint
• joints do not ossify
• permits slight movement (amphiarthroses)

Question 9

Cartliginous joints

Answer 9

• lacks synovial cavity and allows little or no movement
• articulating bones are tightly connected by either hyaline cartilage or fibrocartilage
• two types

Question 10

Two types of cartilaginous joints

Answer 10

1. synchondroses
2. symphyses

Question 11

Synchondroses

Answer 11

• type of cartilaginous joint
• connective tissue is hyaline cartilage
• immovable joint (synarthroses)
• when bone elongation ceases, the bone replaces the hyaline cartilage

Question 12

Gomphosis

Answer 12

• type of fibrous joint
• peg & socket joints between tooth & its socket (root of tooth - periodontal ligaments - alveolar bone)

Question 13

Smphyses & examples

Answer 13

• cartilaginous joint
• ends of the articulating bone are covered with hyaline cartilage
• broad, flat disc of fibrocartilage connects the bones
• mostly midline
  e. g.

: pubic symphysis

: manubiosternal joint

Question 14

Synovial joints

Answer 14

• synovial cavity / joint cavity between the articulating bones
• bones covered by a layer of hyaline cartilage / articular cartilage
• articular capsule / joint capsule encloses the synovial cavity

: 2 layers (outer fibrous membrane & inner synovial membrane)

• 6 types of synovial joints

Question 15

Label the image

Answer 15

Question 16

What are the 6 types of synovial joints?

Answer 16

BCPPSH

1. Ball-and-socket
2. Condyloid
3. Plane
4. Pivot
5. Saddle
6. Hinge

Question 17

Planar Joints

Answer 17

• type of synovial joint
• bones with articulating surfaces that are flat or slightly curved faces
• gliding movement
• limited range of movement & does not allow rotation
  i. e. carpal & tarsal bones

Question 18

Hinge Joints

Answer 18

• type of synovial joint
• slightly rounded end of one bone fits into the hollow end of another bone
• one bone moves whilst the other is stationary
  e. g. elbow