Module One - Musculoskeletal system

Question 1

What is a joint?

Answer 1

Sites where two or more bones meet. Facilitates bone movement.

Question 2

What is a ligament?

Answer 2

Connect the articulating bones at a joint.

Question 3

What is cartilage?

Answer 3

supports body structure, connects bones, maintains shape of body structures, resists compression, has tensile strength and is composed of chondrocytes and on extra cellular matrix.

Question 4

What are the three different types of cartilage?

Answer 4

Hyaline cartilage, elastic cartilage and fibrocartilage

Question 5

Hyaline Cartilage

Answer 5

covers the ends of the articulating bones, connects ribs to sternum and forms the epiphyseal plate of bones

Question 6

elastic Cartilage

Answer 6

forms the auricle of the ear

Question 7

Firbocartilage

Answer 7

forms menisci, connects individual vertebrae, connects hip bones

Question 8

What are the 5 functions of bones?

Answer 8

Support, protection, storage of minerals and triglycerides, blood cell protection, and movement.

Question 9

The axial skeleton

Answer 9

Includes bones of the skull, vertebral column and rib cage

Question 10

The appendicular skeleton

Answer 10

Upper limbs, lower limbs, shoulder girdles and pelvic girdle

Question 11

What are the different shapes of bones?

Answer 11

Long bones, shorts bones, flat bones and irregular bones

Question 12

What are surface features (landmarks) of bones?

Answer 12

Projections, depressions, and openings on the surface of bones function as:
- Site of muscle, tendon or ligament attachment

Question 13

What are the different types of tissues bones contain?

Answer 13

• Connective tissue (osseous tissue, adipsoe tissue and hyaline caritilage)
• Nevrous tissue (sensory neurons)
• Muscle and epithelial tissue (blood vessels)

Question 14

Osseous tissue

Answer 14

A connective tissue that contains specialised cells and in extracellular matrix

Question 15

What is the matrix made of?

Answer 15

Consists of ground substance, collagen fibres and calcium phosphate crystals. Makes bones hard, slightly flexible and strong.

Question 16

Collagen fibres (matrix component)

Answer 16

Provides felxibilty and tensile strength

Question 17

Calcium Phosphate crystals

Answer 17

Makes bones hard and provides compressive strength

Question 18

What are the different types of specialised cells?

Answer 18

• Osteoprogenitor cells (stem cells that differentiate into osteoblasts)
• Osteoblasts (bone building cells that secrete collegen fibres and ground substance
• Osteoclasts (bone resorbing cells that break down the matric and release stored minerals)
• osteocytes (mature bone cells that maintain the matrix)

Question 19

Structure of bone

Answer 19

Every bone has an:
-outer layer of dense, smooth compact bone and an internal layer of spongy bone.
outer connective tissue membrane = periosteum (covers compact bone and contains blood vessles and nerves)
internal connective tissue membrane = endosteum (covers spongy bone)

Question 20

Compact bone

Answer 20

Osseous tissue is arranged into osteons.
Each osteon:
- runs parallel to the long axis of bone
consists of:
- a central canal (blood vessels and nerves)
- concentric circles (hollow circles) of matrix
- Osteocytes - lies between the cylinders of matrix
Acts as tiny weight bearing pillar (resists force applied)

Question 21

Spongy bone

Answer 21

Osseous tissue arranged into an irregular lattice of thin needle like structure called trabeculae (precisely orientated to resist forces from all directions and transfer wieght without breaking.

Question 22

What are the types of bone growth?

Answer 22

Appositional growth and interstitial growth

Question 23

Interstitial growth

Answer 23

Occurs at the epiphyseal plates of long bones (lengthens bones)

Question 24

Appositional growth

Answer 24

Occurs at outer surface of all bones (widens)

Question 25

What hormones regulate bone growth in children?

Answer 25

Growth hormone and thyroid hormone

Question 26

What hormones regulate growth in adolesence

Answer 26

GH, TH, testosterone and estrogen

Question 27

How do hormones regulate bone growth?

Answer 27

Promote the growth spurt in adolesense. | End growth by inducing epiphyseal plate closure

Question 28

Bone remodelling

Answer 28

Occures throughout life Maintains bone mass and strength Replaces old matrix Involves bone resorbtion and bone deposition

Question 29

Bone resorption

Answer 29

Osteoclasts break down old matrix

Question 30

Bone deposition

Answer 30

osteoblasts produce new matric

Question 31

Factors that affect bone growth and remodelling

Answer 31

Adequate amounts of: - calcium - vitamin c - vitamin A - vitamin D - Vitmain K and B - weight bearing exercise

Question 32

What is a bone fracture

Answer 32

Any crack or break in a bone, and can be classified as: - classified (simple) fracture: bone doesnt break skin - open (compound) fracture: bone protrudes through the skin - greenstick: incomplete - compression fracture: bone is crushed - spiral fracrure: ragged break caused by exessive twisting - epiphyseal fracture

Question 33

What are some more types of bone fractures?

Answer 33

- transverse fracture: breaks along the long axis - depressed fracture: broken bone is pressed inwards - avulsion fracture: tears away from bone - pathological fracture: caused by a disease that weakens bones - colles fracture: radius - scaphoid fracture: carpals - Potts fracture: tib/fib

Question 34

What does fracture treatment involve?

Answer 34

1. reduction: realignment of bone ends 2. immobilisation: cast, sling etc 3. rehabilitation: restore function

Question 35

What are the four steps to fracture repair?

Answer 35

1. Haematoma forms 2. Fibrocartilaginous callus forms 3. Bony callus forms 4. Bone remodelling

Question 36

What are different types of bone diseases?

Answer 36

- osteomalacia or rickets (bones are poorly mineralised) - osteogenesis imperfecta (brittle bones) - osteoporosis (reduction in bone mass)

Question 37

What is a joint?

Answer 37

Formed where the surfaces of two or more bones connect. Holds the skeleton together.

Question 38

How are joints functionally classified?

Answer 38

- synarthrosis (immovable joint) - ampiarthrosis (slighlty moveable) - diarthrosis (freely moveable)

Question 39

How are joints structurally classified?

Answer 39

- Fibrous - Cartilaginous - synovial

Question 40

Fibrous joints

Answer 40

articulating bones are united by fibrous connective tissue. Joint cavity is absent. - are immovable or slightly moveable

Question 41

Cartilaginous joints

Answer 41

articulating bones are united by cartilage (hyaline or fibrocartilage). joint cavity is absent. - Immovable or slightly moveable

Question 42

Synovial joints

Answer 42

articulating bone ends are covered in articulating cartilage. Joint cavity present. - freely movable (wide range)

Question 43

What is the general structure of a synovial joint?

Answer 43

1. articulating capsule (surround entire joint and encloses joint cavity. 2 layers : tough outer fibrous layer, inner synovial membrane) 2. Joing (synovial) cavity (seperates articulating bones, contains synovial fluid) 3. synovial fluid (shock absoption, reduces friction) 4. articular cartilage (covers ends or articulating bones, shock absoprtion and redecues friction) 5. reinforcing ligament (stabilises synovial joint)

Question 44

What are some additional structures that may be present at a synovial joint?

Answer 44

- Menisci: discs of fibrocartilage - Muscle tendons: stabilise - Bursae and tendon sheaths: bags of synovial fluid - Fat pads: mass of adipose tissue (protects joint structure)

Question 45

Type of movement allowed by synovial joints

Answer 45

- angular movements: flextion, extension, adduction, abduction etc. - rotational movements: rotation (medial and lateral), supination and pronation - special movements: protraction, retraction, opposition, depression, elevation etc.

Question 46

What are the 6 types of synovial joints?1

Answer 46

1. pivot joint 2. plane joint (gliding) 3. condylar joiny (flexion etc.) e.g. metacarpophalangeal joint and wrist 4. saddle joint e.g. thumb 5. hinge joint e.g. elbow 6. ball and socket joint e.g. shoulder and hip

Question 47

What is a sprain?

Answer 47

ligaments are stretched or torn. | - painful and immobilising

Question 48

Osteoarthrisis

Answer 48

most prevelant form of chronic arthrisis. degenerative joint disease in which joint cartilage gradually deteriorates

Question 49

Rheumatoid arthrisis

Answer 49

autoimmune disease that targets the synovial membranes lining synovial joints