MSK 3a: bones and joints Flashcards

1
Q

Fibrous joint types? (tough fibrous tissue, no synovial cavity, for strength)

A
  1. Syndesmoses: slightly movable. E.g. middle radioulnar and middle tibiofibular joints
  2. Gomphoses: immovable, teeth articulating with maxillae or mandible
  3. Sutures: immovable, only in flat bones of the skull. Not fixed in early life so skull can slightly deform to pass through birth canal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Catilaginous joint types? (fibro- or hyaline. No synovial cavity. Act as shock absorbers)

A
  1. Synchondroses: hyaline cartilage. Immovable to slightly moveable. E.g. the joint between the diaphysis and epiphysis of a growing long bone
  2. Symphyses: fibro- or hyaline cartilage. Slightly moveable e.g. pubic symphysis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a joint?

A

An articulation (arthrosis) between neighbouring bones/cartilage and bone/teeth and bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a synarthrosis?

A

An immoveable joint

E.g. suture, synchondrosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is an amphiarthrosis?

A

A slightly moveable joint

E.g. syndesmosis, symphysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a diarthrosis?

A

A freely-moveable joint

All types of synovial joint

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a synovial joint?

A

Filled with synovial fluid, usually fully-moveable

The main joint type of the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Planar synovial joint?

A

Gliding movement
E.g. sternoclavicular joint
Articulating surfaces flat/slight curve, non-axial movement (side to side or back and forth)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Hinge synovial joint?

A

Monoaxial
Convex surface of one bone fits into concave surface of another
Movements: flexion, extension
E.g. knee, elbow, ankle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Pivot synovial joint?

A

Monoaxial. Rotation may occur
Rounded or point of one bone articulates within a ring partly formed by a ligament
E.g. proximal radio-ulnar joint

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Condyloid (aka ellipsoidal) joint?

A

Biaxial: flexion, extension, abduction, adduction, circumduction
Oval-shaped condyle of one bone rests in elliptical cavity of another
E.g. wrist, MCPJ and MTPJ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Saddle synovial joint?

A

Biaxial, more freedom than condyloid
Articular surface of one bone is saddle shaped and that of another resembles the legs of a rider in a saddle
E.g. between trapezium and base of 1st metacarpal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Ball and socket synovial joint?

A

Multi-axial: the 4 angular movements plus rotation
A rounded surface of one bone rests against a cuplike depression of another
E.g. shoulder, hip

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is a bursa?

A

Sac lined with synovial membrane and filled with synovial fluid
Can communicate with joint cavity
Purpose is friction reduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is a tendon sheath?

A

An elongated bursa that is wrapped around a tendon
Double sheet but doesn’t completely enclose
Permits free gliding of tendons by reducing friction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe articular cartilage of synovial joints

A

Allows smooth, low-friction movement and resists compression

Hyaline (except acromioclavicular, sternoclavicular and temporomandibular which are fibrocartilage)

17
Q

Describe the fibrous capsule of synovial joints

A

Collagen-longitudinal and interweaving bundles
Encloses joint except where interrupted by synovial protrusions
Stabilises joint

18
Q

Structure of the synovial membrane

A

Thin and very vascular
Does not cover articular cartilage or menisci
Lines capsule, covers exposed bony surfaces, tendon sheaths and bursae
Produces synovial fluid

19
Q

Composition of synovial fluid?

A

Hyaluronic acid
Proteinase
Lubricin
Collagenase

20
Q

Function of synovial fluid?

A

Reduced friction
Shock absorption
Nutrient and waste transport

21
Q

Blood supply to synovial joints?

A

Periarticular arterial plexus around most
Cartilage avasular
Fibrous capsule and ligaments poor supply
So depends on diffusion through synovial fluid

22
Q

General functions of the skeleton?

A
Support
Protection
Movement
Storage
Haematopoeisis
23
Q

Bone classification?

A

FLAT-curved, protect organs. E.g. frontal bone (skull)
SHORT-equal in length and width. E.g. carpal bones
SESAMOID-embedded within a tendon or muscle. E.g. patella
SUTURAL-within a cranial structure
IRREGULAR: e.g. vertebrae
LONG-longer than wide, muscles act on them as rigid levers. E.g. femur

24
Q

Structure of long bones?

A

Mainly compact bone
Some spongy at extremities
Epiphysis at distal and proximal ends, metaphysis in between the epiphysis and diaphysis on each end, diaphysis (shaft) middle part
Covered in endosteum which is covered in periosteum
Nutrient arteries within

25
Structure of short, flat and sesamoid bones?
Mainly spongy Thin layer of periosteum-covered compact bone on outside Bone marrow between trabeculae No epiphyses or diaphysis
26
What is avascular necrosis?
Loss of blood supply causing death of bone Cause: fracture, dislocation, steroids, radiation, decompression sickness Effects: collapse of the necrotic section and secondary osteoarthritis
27
What contributes to stability of a joint?
``` Structure and shape of articulatory bones Strength and tension of ligaments Arrangement and tone of muscles arround Apposition of neighbouring soft tissue Hormones Disuse of joint ```
28
Effects of ageing on joints?
Decreased synovial fluid production Thinning of articular cartilage Shortened ligaments and decreased flexibility Degenerative changes
29
Theory on why joints crack?
Bones pulled away from each other Synovial cavity expands but fluid volume remains constant Partial vacuum results Gases dissolved in synovial fluid are pulled out of solution, causing popping sound
30
Osteoarthritis summary?
Cause: heavy use of joints over many years which wears away articular cartilage and underlying bone (usually joints tht support full body weight: hips and knee) Effect: decreased capacity as a shock absorber, roughened edges cause further damage and repeated friction causes the symptoms
31
Rheumatoid arthritis summary?
Cause: autoantibodies attack synovium causing inflammation Effect: joint erosion and deformity. Also can damage eyes, skin, lungs, heart etc X ray features: bones still in union but incorrect orientation. Narrowing of joint space, periarticular osteopenia, subluxation and gross deformity
32
Osteoporosis summary?
Cause: decreased bone density or atrophy of skeletal muscle. Osteoclast activity exceeds osteoblast activity Effect: bones become brittle, lose their elasticity, fracture easily Risk factors: age, female as decreased oestrogen after menopause, ethnicity, smoking, immobility, dietary insufficiencies of Vit D and Ca2+
33
Osteomalacia summary?
Vitamin D/Ca2+ deficiency in adults Problem with bone remodelling causing softening of the bones Osteoid laid down by osteoblasts is poorly mineralised, so bones are weakened
34
Rickets summary?
Vitamin D/Ca2+ deficiency in children. Osteoid is poorly mineralised and remains pliable Epiphyseal growth plates can then become distorted under the weight of the body, causing skeletal deformities. Presents often with bowing of the legs, knock knees, etc
35
Paget's disease of bone?
Increased bone turnover in focal areas Increased abnormal osteoclast activity Increased no. osteoblasts due to the loss of bone New bone is disorganised and mechanically weaker