MSK system bones and joints

Question 1

Four components of the
musculoskeletal system?

Answer 1

1. Connective tissue
   ◦ Fat
   ◦ Fibrous tissue
2. Skeletal tissue
   ◦ Cartilage
   ◦ Bone
3. Muscular tissue
   ◦ Skeletal muscles
4. Joints

Question 2

Name the connective tissues and their roles

Answer 2

Fat:
◦ Insulates, “packs”, absorbs shock (e.g.
heel)

Fibrous tissue:
- Ligaments: pass from bone to bone,
around joints
- Tendons: attach muscle to bone
- Protective membranes e.g. around muscles and bones

Question 3

what are the 2 types of cartilage

Answer 3

Hyaline cartilage (or articular cartilage)

Fibrocartilage

Question 4

what does Hyaline cartilage (or articular cartilage) do?

Answer 4

covers the articular surfaces of bones to prevent friction

Question 5

what does Fibrocartilage do?

Answer 5

present among collagen fibres to
strengthen and support framework:
- intervertebral discs
- menisci

Question 6

what are some functions of bones?

Answer 6

• provide the body’s framework
• provides attachment to muscles and tendons

-allows movement of whole body/body parts

• forms boundaries of cavities e.g., cranial, thoracic
• protects delicate organs
• production of blood cells in red bone marrow
• mineral reservoir

Question 7

what are the 4 classes of bone?

Answer 7

• Long
• Short
• Flat: thin and flat
• Irregular

Question 8

What do Long bones allow for?
name some.

Answer 8

• Movement
• the humerus, radius, ulna, femur, tibia, fibula, phalanges

Question 9

Short bones are strong and compact.

how much movement do they allow for? name some short bones.

Answer 9

• some movement
• carpals, tarsals

Question 10

What do Flat bones allow for?
name some.

Answer 10

• muscle attachments and / or protection
• cranial cavity, ribs, sternum

Question 11

name some Irregular bones

Answer 11

• some skull bones, vertebrae, pelvis

Question 12

Describe the structure of a Long bone

Answer 12

Diaphysis - shaft
- compact bone

surrounds the:
- medullar cavity (fat storage)

lined by:
- endosteum

Epiphyses (proximal & distal) ends
- outer surface (compact bone)
- central regions (spongy bone)

• Periosteum covering

Question 13

what is the Periosteum?

Answer 13

tough layer that covers all bones (but not the joints)
- contains cells that can make bone

• important to increasing bone thickness
• important in bone repair
• continuous with ligaments and tendons

Question 14

(bone cells) what are Osteoblasts?

Answer 14

Osteoblasts: bone forming cells

Question 15

(bone cells) what are Osteocytes?

Answer 15

Osteocytes: mature bone cells which monitor and maintain bone tissue

Question 16

(bone cells) what are Osteoclasts?

Answer 16

Osteoclasts: bone dissolving cells - to remove bone tissue

Question 17

what is the working relationship between Osteoblasts and Osteoclasts?

what do they keep relatively constant?

Answer 17

Osteoblasts (deposit) and osteoclasts (reabsorb) work
continuously throughout life thus the overall bone mass
should remain relatively constant

Question 18

what types of things does bone activity depend on?

Answer 18

• hormones
• blood calcium levels
• patterns of activity
• balance of activity of bone cells

Question 19

where and when do bones begin to form?

Answer 19

Firstly:

in a primary ossification centre: at weeks 7-12 of gestation

After birth:

in secondary ossification centres appearing in Long Bones

Question 20

(bone growth) what happens in the Epiphyseal region within bone?

Answer 20

the Epiphyseal is a region of cartilage where the diaphysis continues to grow

when bone growth completed, epiphyseal cartilage is replaced by bone, uniting the epiphyses with the rest of the bone

Question 21

What do joints enable?

Answer 21

Movement

Question 22

3 main types of joint?

Answer 22

Fibrous
Cartilaginous
Synovial

Question 23

what are the main characteristics of fibrous joints?

Answer 23

• the tissue is made up of collagen fibres which run between the bones
• there is no joint cavity
• the degree of movement is limited

Question 24

what are the three SUBTYPES of FIBROUS joints?

Answer 24

• Suture: only occurs in skull
• Syndesmosis: cord or sheet of dense fibrous connective tissue.
  The tibia/fibula and radius/ulna joints connecting these are syndesmosis
• Gomphosis: peg-in-socket fibrous joint. (the articulations of teeth)

Question 25

what are some characteristics of Cartilaginous joints?

Answer 25

• very strong, flexible and elastic
• no joint cavity
• limited or no movement

example: articulation of 1st rib to sternum, intervertebral discs

Question 26

what are some characteristics of Synovial joints?

Answer 26

• the presence of a cavity between the bones; the joint or synovial cavity
• all are freely moveable
• account for the majority of articulations between bones

Question 27

What are Strength, Stability and ROM determined by?

Answer 27

1. the shape of the articular surfaces of the bones
2. the ligaments: strong bands of dense fibrous connective tissue which bind the adjacent bones together
3. muscles which extend between the two bones comprising the joint

Question 28

Types of synovial joints

Answer 28

Plane: surfaces are flat or slightly curved and can glide over one another (inter carpal joints)

Hinge: convex portion of one bone fits onto the concave portion of another (elbow/knee)

Pivot: rounded part of one bone fits into a groove of the other to allow rotation (radio ulnar joint, atlas and axis)

Ellipsoidal / Condyloid: oval surface of one bone fits onto a concave area of another
◦ Radio carpal, MCP joints

Saddle: similar to condyloid but greater
movement enabled
◦ base of thumb

Ball and socket: all movements enabled
◦ Hip
◦ Shoulder