Joints and ligaments

Question 1

What is a joint?

Answer 1

Articulation of two bones as they meet / connect

Question 2

What does Joint Structure determine

Answer 2

Determines direction and distance of movement

Range of Motion (ROM)

Question 3

3 structural Classes of Joints

Answer 3

Fibrous
Cartilaginous
Synovial

Question 4

3 Functional classes: based on degree of motion

Answer 4

• Synarthrosis: non-movable
• Amphiarthrosis: slightly movable
• Diarthrosis: freely movable

Question 5

Characteristics of fibrous joints

Answer 5

United by fibrous connective tissue
•Have no joint cavity
•Move little or not at all

Question 6

Types of fibrous joints

Answer 6

• Sutures- no movement (skull)
• Syndesmoses- little movement (DRUJ)
• Gomphosis- Fibrous peg into socket (tooth)

Question 7

Properties of Fibrous Joints: Sutures

Answer 7

Opposing bones interdigitate. •Periosteum of one bone is continuous with the periosteum of the other.•Sutural ligament: two periostea plus dense, fibrous, connective tissue between.•In adults may ossify completely: synostosis. •Fontanels: membranous areas in the suture between bones. Allow change in shape of head during birth and rapid growth of the brain after birth.

Question 8

Properties of Fibrous Joints: Syndesmoses

Answer 8

Bones farther apart than suture and joined by ligaments
•Some movement may occur
•Examples: radioulnar (interosseous membrane)

Question 9

What is a Cartilaginous Joint

primary and secondary

Answer 9

2 bones united by continuous pad or cartilage
•Primary= synchrondosis
•Hyaline cartilage
•Occur at epiphyseal growth plates

• Secondary= symphysis
• Fibrocartilage
• Occur in midline of body
• Small range of controlled movement

Question 10

Cartilaginous Joints properties

Answer 10

Joined by hyaline cartilage
•Little or no movement
•Some are temporary and are replaced by synostoses
•Some are permanent
•Some like costochondral joints develop into synovial joints
•Examples: Epiphyseal plates, sternocostal jt, sphenooccipital

Question 11

Synovial Joints properties

Answer 11

Class of freely mobile joints
•Allow considerable movement
•Contain synovial fluid
•Movement limited by …•Muscle•Ligament •Joint capsule•Shape

•Most joints that unite bones of appendicular skeleton reflecting greater mobility of appendicular skeleton compared to axial skeleton.

Question 12

explain a uniaxial Synovial Joints

Answer 12

Occurring around one axis, e.g. •Elbow•Ankle

Question 13

explain a biaxial Synovial Joints

Answer 13

Occurring around two axes at right angles to each other, e.g. •MCPJ (metacarple phalangeal joint)
•RCJ (radiocarpal joint)

Question 14

explain a multiaxial Synovial Joints

Answer 14

Occurring around several axes, e.g.

•Shoulder•Hip

Question 15

Plane or gliding joints properties

Answer 15

Uniaxial. Some rotation possible but limited by surrounding structures, e.g.:Intervertebral, intercarpal, acromioclavicular, carpometacarpal, costovertebral, intertarsal, sacroiliac, tarsometatarsa

Question 16

Saddle joints properties

Answer 16

Biaxial, e.g.Thumb (carpometacarpal pollicis), intercarpal, sternoclavicular

Question 17

Hinge joints properties

Answer 17

Uniaxial. Convex cylinder in one bone; corresponding concavity in the other e.g.:Elbow, ankle, interphalangea

Question 18

Pivot joints properties

Answer 18

Uniaxial. Rotation around a single axis.•Cylindrical bony process rotating within a circle of bone and ligament e.g.: Articulation between dens of axis and atlas (atlantoaxial), proximal radioulnar, distal radioulnar

Question 19

Ball-and-socket properties

Answer 19

Multiaxial•Examples: shoulder and hip joints

Question 20

Ellipsoid (Condyloid)

Answer 20

Modified ball-and-socket; articular surfaces are ellipsoid•Biaxial•Example: atlantooccipital

Question 21

What is the role of Synovial cartilage (hyaline

Answer 21

cushions the joint absorbs shock and prevents friction and wear and tear between the bone ends.

Question 22

Synovial membrane function

Answer 22

connective tissue which lines the inner surface of the capsule of a synovial joint and secretes synovial fluid which serves a lubricating function, allowing joint surfaces to smoothly move across each other

Question 23

joint Capsule function

Answer 23

Encloses joint

Vital to the function of synovial joints. It seals the joint space, provides passive stability by limiting movements, provides active stability

Question 24

Ligament function

Answer 24

Ligaments tough, fibrous connective tissue

connect bone to bone and helps to keep them stabilized within a joint space

Question 25

Fat pad function

Answer 25

protective cushion / shock absorbstion

Question 26

Bursa function

Answer 26

Friction reduction

Pockets of synovial membrane and fluid that extend from the joint. Found in areas of friction•Bursitis

Question 27

Articular discs are in which joints?•Temperomandibular, Sternoclavicular, Acromioclavicular

Answer 27

•Temperomandibular,
Sternoclavicular,
Acromioclavicular

Question 28

Menisci functions

Answer 28

Fibrocartilaginous pads in the knee

Question 29

tendons function

Answer 29

Join contractile muscle to bone

•Stabilisation

Question 30

muscle functions

Answer 30

Primary movement force

Question 31

Tendon sheaths - what are they?

Answer 31

•Synovial sacs that surround tendons as they pass near or over bone