Sa Ortho - Joint Structure/function

Question 1

3 main categories of joints

Answer 1

Fibrous
Cartilaginous
Synovial

Question 2

Features & types of fibrous joints

Answer 2

Little movement, no cartilage
Suture - junction between flat bones
Syndesmosis (holding long bones together, lots of connective tissue
Gomphosis - cementum, periodontal ligament, alveolar bone - holds teeth in place

Question 3

Features and types of cartilaginous joints

Answer 3

Little to no movement, sychondroses, joined w hyaline cartilage, fibrocartilage or combo, can change with age
1 - hyaline cartilage
2 - fibrocartilage

Question 4

Hyaline cartilage (1* joint)

Answer 4

Physis (temporary conjoining) long bones
Costochondral junction (permanent)

Question 5

Fibrocartilage joints (2* joint)

Answer 5

Symphyses (pubic symphyses)
Slight movement
Permanent - occasionally ossify

Question 6

Characteristics and features of synovial joints

Answer 6

Greatest range of motion, can move freely on various planes (diathrosis) function to facilitate movement
Joint capsule, joint cavity, articular cartilage

Question 7

Structural features of synovial joint

Answer 7

Muscle and tendon
Fibrous joint capsule - provides support
Synovial membrane - produces joint fluid
Ligament - joints bones
Synovial fluid - lubricant & nutrients
Hyaline cartilage - reduces friction, shock absorber

Question 8

Normal joint function

Answer 8

Flexibility, movement, absorb shock, friction free

Question 9

Layers of joint capsule

Answer 9

Inner synovial membrane (functional)
Outer fibrous membrane ( fibrous )
Both make the articular capsule

Question 10

Features of synovial membrane

Answer 10

Intimate layer
- synovial A cells ; phagocytosis & pinocytosis, produce & recycle
- synovial B cells : protein secretion
Subinitmal layer
- fibrous, areolar & fatty tissue
- blood supply
- lots of Innervation in joints for spatial awareness

Question 11

Features of fibrous membrane

Answer 11

Type I collagen & elastin - parallel, proteogylcans (draw in water)
Stability thickens = ligaments/collateral ligaments
Hypertrophy w activity

Question 12

Features of synovial fluid

Answer 12

0.2-2ml / joint
Ultrafiltrate of plasma
Viscous
Low cellularity (WBC <3x10^3 L)

Question 13

Cellular features of hyaline cartilage

Answer 13

Chondrocytes & ECM
Smooth
No vessels / lymph
Transmits compression and force

Question 14

% of cell composition in hyaline cartilage

Answer 14

70% water
Dry weight
- 50% collage (type II)
- 35% proteoglycans
- 10% other glycoproteins
- 2-10% Chondrocytes

Question 15

Formation of collagen

Answer 15

Predominately type II in hyaline cartilage
Interlocking hoops - isotopic for structural support

Question 16

Function of proteoglycans

Answer 16

Hydrophilic, draw water into collagen

Question 17

Aggrecan

Answer 17

Type of proteoglycans

Question 18

Function of Chondrocytes

Answer 18

Healthy cartilage
Mesodermal
Maintains matrix

Question 19

Zones of articular cartilage

Answer 19

Superficial
Transitional
Radiate
Calcified

Question 20

Cells within articular zones

Answer 20

Superificial - Chondrocytes, collagen ( parallel)
Transitional - chondrocytes in matrix, collagen angel to surface
Radiate - chondrocytes, large in perpendicular columns, collagen perpendicular to surface, highest proteoglycan content
Calcified - TM, mineralized cells & matrix

Question 21

Features of subchondral bone

Answer 21

Epiphysis
Haversian systems are parallel - transmit forces