Joints

Question 1

modes of loading

Answer 1

Question 2

Avulsion fracture vs. impacted fractue

Answer 2

tension

compression

Question 3

Transverse fracture vs butterfly fracture

Answer 3

bending vs. compression and bending

Question 4

Wolff’s Law (1892)

Answer 4

Bone tissue places itself in the direction of functional demands.

Question 5

Cortical bone can

Answer 5

thicken or
hypertrophy in response to
mechanical demand

Question 6

Joint or articulation (arthrosis):

Answer 6

union between 2 or more skeletal elements

Question 7

types of joints

Answer 7

1. Nonsynovial
2. Synovial (diarthrosis)

Question 8

Nonsynovial fibrous joints

Answer 8

bones joined by fibrous connective
tissue

Question 9

non synovial Cartilaginous (amphiarthrosis)

Answer 9

bones joined by hyaline cartilage or
fibrocartilage

Question 10

synarthrosis examples

Answer 10

Suture
(skull)
Gomphosis
(tooth attachment)
Syndesmosis
(distal/inferior
tibiofibular jt)

Question 11

types of amphiarthrosis

Answer 11

1⁰ Cartilaginous or
Synchondrosis
(cartilage growth plate
of a long bone in
subadult )
2⁰ Cartilaginous or
Symphysis
(pubic symphysis)

Question 12

Characteristics of Joints < Synovial

Answer 12

Adjacent surfaces covered in
articular cartilage
 Joint capsule
 inner synovial membrane
which produces synovial fluid
 outer fibrous membrane
 Few include a fibrocartilage structure (not illustrated above)
 (e.g., menisci of knee)
 functions to…
• improves articulation
• increase range of joint motion
• absorb compression forces (i.e., shock absorption)
Articular cartilage

Question 13

Synovial Joint Classifications

Answer 13

Simple: joint formed by two articular
surfaces e.g., interphalangeal joint

Compound: joint formed by three
or more articular surfaces
Complex: joint possessing a disc or
meniscus

Composite Joint: combination of a compound and complex
joint

Question 14

joints can

Answer 14

translate and rotate

Question 15

bone development) occurs either through:

Answer 15

1- Intramembranous Ossification
or
2- Endochondral Ossification

Question 16

Mesenchymal Stage

Answer 16

Mesenchyme cells condense
and become chondrocytes

Question 17

Cartilaginous Stage/Chondrification

Answer 17

Chondrocytes form a
cartilaginous template for the
future bone

Question 18

Osseous Stage

Answer 18

Blood vessels enter the cartilaginous
model bringing forth osteoblasts/bone
progenitors and isolating the growth of
chondrocytes to the ends of the bone
Chondrocytes near the diaphysis (shaft)
undergo hypertrophy and then die,
mineralizing the surrounding matrix
Osteoblasts attach to the mineralized matrix
and deposit bone matrices. This area
becomes the primary ossification center.

Later, blood vessels enter the
epiphyses and secondary ossification
centers form
 Growth of the bone, especially length
is maintained by multiplying
chondrocyctes within the epiphyseal
plate (growth plate or physis)
When bone achieves full length,
growth plates disappear by fusing to
the respective diaphysis (synostosis)

Question 19

Fibroblastic tissue then
transforms into:

Answer 19

Synovial tissue
• Articular cartilage
• Menisci and enclosed
ligaments

Question 20

Mesenchymal sheath

Answer 20

surrounding interzone becomes
joint capsule

Question 21

Mesenchyme at future joint
(interzone) differentiates into

Answer 21

fibroblastic tissue (connective
tissue)

Question 22

Bone & Joint Development < Nonsynovial Jts

Answer 22

Formation of a fibrous or cartilaginous joints is
simpler.
 Fibrous: interzone becomes collagen
 Cartilaginous
 Synchrondrosis: interzone becomes hyaline cartilage
 Symphysis: interzone becomes mostly fibrocartilage