Chapter 6- Joints

Question 1

articulation

Answer 1

where bone meets

• another bone
• cartilage
• teeth

Question 2

function of joints

Answer 2

• give skeleton mobility

- hold skeleton mobility

Question 3

classification of joints

Answer 3

• functional

- structural

Question 4

functional classification

Answer 4

amount of movement joint allows

1) synarthroses- immovable
2) amphiarthroses- slightly movable
3) diarthroses- freely movable

Question 5

structural classification

Answer 5

based on material binding bones and presence of joint cavity

1) fibrous- collagen
2) cartilaginous- holding bone to something else
3) synovial- mostly diarthroses

Question 6

fibrous joints

Answer 6

• sutures
• syndemoses
• gomphoses

Question 7

sutures

Answer 7

• rigid, interlocking joints
• immovable joints for brain protection
• short connective tissue fibres
• growth during youth
• sutures ossify and fuse in middle age

Question 8

syndemoses

Answer 8

• bones connected by ligaments
• fibre length varies so movement varies:
• little to no movement at distal tibiofibular joint
• large amount of movement at interosseous membrane of radius/ulna

Question 9

gomphoses

Answer 9

• peg-in-socket teeth joints

- fibrous connection is periodontal ligament

Question 10

cartilaginous joints

Answer 10

-bones unites by cartilage
-no joint cavity
-not highly movable
2 types
-synchondroses
-symphyses

Question 11

synchondroses

Answer 11

• bar/plate of hyaline cartilage unites bone (epiphyseal plate, cartilage of 1st rib with manubrium)
• all are synarthrotic (no movement)

Question 12

symphyses

Answer 12

• fibrocartilage unites bone
• resists tension in one axis (hyaline cartilage)
• strong, flexible, amphiarthroses (slightly movable)

Question 13

synovial joints

Answer 13

• bones separated by fluid-filled joint cavity
• all are diarthrotic (freely movable)
• all limbs and most joints

Question 14

features of synovial joints (6)

Answer 14

• articular cartilage
• joint cavity
• articular capsule
• synovial fluid
• reinforcing ligaments
• nerves and blood vessels

Question 15

articular cartilage

Answer 15

• hyaline cartilage (frictionless cartilage)
• prevents crushing of bone ends
• prevents bones from rubbing

Question 16

joint cavity

Answer 16

• small, fluid-filled potential space

- shape can change

Question 17

articular capsule

Answer 17

2 layers

• external fibrous layer: dense irregular connective tissue, strong collagen
• inner synovial membrane: loose connective tissue, more areolar. makes synovial fluid allowing for frictionless movement

Question 18

synovial fluid

Answer 18

• viscous, slippery filtrate of plasma and hyaluronic acid
• lubricates and nourishes articular cartilage
• has phagoncytic cells to remove microbe and debris

Question 19

reinforcing ligaments

Answer 19

1) capsular: thickened part of fibrous layer
2) extracapsular: outside capsule
3) intracapsular: deep to capsule, covered by synovial membrane

Question 20

double jointed

Answer 20

• loose, stretchy joint capsule and ligaments

- ligaments allow for greater range of motion than normal

Question 21

nerves and blood vessels

Answer 21

• nerve fibers detect pain, monitor joint position and stretch
• capillary beds supply filtrate for synovial fluid

Question 22

fatty pads

Answer 22

• for cushioning between fibrous layer and synovial membrane or bone
• hip and knee

Question 23

articular discs

Answer 23

• fibrocartilage separates articular surfaces to improve fit of bone ends
• stabilize joint and reduce wear and tear
• knees (menisci) , jaw etc.

Question 24

bursae

Answer 24

• sacs lined with synovial membrane containing synovial fluid
• reduce friction

Question 25

tendon sheaths

Answer 25

elongated bursa wrapped around tendon subjected to friction

Question 26

stabilizing factors of synovial joints

Answer 26

1) shapes of articular surfaces 2) ligament number and location 3) muscle tendons that cross joint (muscle tone keeps tendons taut) most important factor

Question 27

origin and insertion

Answer 27

- all muscles attach at no fewer than 2 points - origin: attachment to immovable bone - insertion: attachment to movable bone, the one that gets pulled - insertion moves toward origin - movement occurs along transverse, frontal, or sagittal planes

Question 28

types of synovial joint motion (4)

Answer 28

1) gilding 2) angular movements 3) rotation 4) special movements

Question 29

gliding

Answer 29

- flat bone over another similar surface - not fixed around pivot point - intercarpal joints, inter tarsal joints, articular processes of vertebrae

Question 30

angular movements

Answer 30

- flexion, extension, hyperextension - abduction, adduction - circumduction

Question 31

flexion, extension, hyperextention

Answer 31

- increase or decrease angle between 2 bones - movement alone sagittal plane - flexion: decrease angle - extension: increase angle - Hyperextension: excessive extension beyond normal range of motion

Question 32

abduction, adduction

Answer 32

- movement along frontal plane - abduction: movement away from midline - adduction: movement toward midline

Question 33

circumduction

Answer 33

- involves flexion, abduction, extension, and adduction of limb - limb describes cone in space - proximal end stays stationary, distal end goes in circular motion - only upper and lower limbs

Question 34

rotation

Answer 34

- turning of bone around its own axis - toward or away from midline - medial and lateral rotation - between C1 and C2 vertebrae, rotation of humerus and femur, pronation and supination

Question 35

synovial joint shapes (6)

Answer 35

- plane joints (wrist) - hinge joints (elbow) - pivot joints (radioulnar) - condylar joints (MCP) - saddle joints (CMC) - ball-and-socket joints (hip, shoulder)

Question 36

special joint movements (6)

Answer 36

- pronation & supination - dorsiflexion & plantar flexion - inversion & eversion - protraction & retraction - elevation & depression - opposition