Bones/Joints

Question 1

Give an example of each classification of bones?

Answer 1

Long (femur), short (carpal), sesamoid (patella), irregular (vertebrae), flat (cranial bones), sutural (within a cranial suture)

Question 2

Features of short bones?

Answer 2

Equal in length and width, have a layer of periosteum covering a v thin layer of compact bone but are mainly spongy/cancellous. Spongy bone has bone marrow between trabeculae.

Question 3

What are the three areas of a long bone?

Answer 3

Epiphyses (proximal and distal), metaphyses, diapyses

Question 4

What are the functions of bone?

Answer 4

Support, protection, movement (eg attachment of muscles), mineral storage, haematopoeisis

Question 5

Where does haematopoeisis occur in children? Where in adults?

Answer 5

Children- long bones. Adults- pelvis, cranium, sternum, vertebrae

Question 6

Characteristics of seesamoid bones?

Answer 6

Developed in tendons/muscles, they are mostly bone but consist of some fibrous tissue and cartilage too. Can be part of a synovial joint ensheathed in a Fibrous capsule.

Question 7

What is the function of sesamoid bones?

Answer 7

Resist friction and compression of joint, enhancce joint movement, assist local circulation.

Question 8

What is avascular necrosis?

Answer 8

Death of bone tissue, due to loss of arterial blood supply. Also called osteonecrosis, aseptic necrosis, ischaemic necrosis.

Question 9

What is a joint?

Answer 9

An articulation between two or more bones

Question 10

How can joints be classified?

Answer 10

Structurally and functionally.

Question 11

What are the structural classifications of joints?

Answer 11

Fibrous, synovial, cartilaginous

Question 12

What are the functional classfications of joints?

Answer 12

Synarthrosis (immovable), amphiarthrosis (slightly movable), diarthrosis (freely movable)

Question 13

What does synarthrosis mean?

Answer 13

Immovable (regarding a joint)

Question 14

What does amphiarthrosis mean?

Answer 14

Slightly movable (regarding a joint)

Question 15

What does diarthrosis mean?

Answer 15

Freely movable (regarding a joint)

Question 16

When can avascular necrosis happen?

Answer 16

After fracture, excessive steroid use, the bends, dislocation compressing artery.

Question 17

Characteristics of fibrous joints?

Answer 17

Bones joined by fibres/fibrous tissue. Movement/flexibilty depends on length of the fibres, ie longer fibres=more flexible

Question 18

Examples of fibrous joints?

Answer 18

Suture, syndesmosis (eg radioulnar interosseous membrane), gomphosis (fibres join tooth to mandible/maxilla)

Question 19

what are the two types of cartilaginous joints?

Answer 19

Synchondrosis, Symphysis

Question 20

What is the difference between the two types of cartilaginous joints? And name them.

Answer 20

Synchondrosis (primary joint)- two surfaces united by hyaline cartilage TF synarthrosis. Symphysis (secondary joint)- articulating surfaces covered in hyaline with pad of fibrocartilage between TF amphiarthrosis

Question 21

Example of secondary cartilaginous joint?

Answer 21

Pubic symphysis, intervertebral disc, manubriosternal joint

Question 22

Example of primary cartilaginous joint?

Answer 22

(Synchondrosis) epiphyseal plate, 1st sternocostal joint, Xiphisternal joint

Question 23

What flexibility does a synovial joint have?

Answer 23

Diarthrosis

Question 24

What is the most common type of joint?

Answer 24

Synovial

Question 25

What makes up a synovial joint?

Answer 25

Articulating surface covered in hyaline cartilage, outer fibrous membrane, surrounding synovial membrane. (Synovial membrane doesnt cover articulating surface). Cavity filled with synovial fluid.

Question 26

What is the fibrous capsule of a synovial joint? What is its function?

Answer 26

Made up of collagen ligaments, with poor blood supply, permits movement but prevents dislocation.

Question 27

What is the synovial membrane and what does it do?

Answer 27

Thin, highly vascularised, produces synovial fluid.

Question 28

What is synovial fluid? What does it do?

Answer 28

Hyaluronic acid, lubricin, proteinase, collagenase. Reduces friction, shock absorption, nutrient/waste transport.

Question 29

What is Hilton’s Law?

Answer 29

The nerves supplying the joint capsule also supply the muscle moving it and the skin covering it too.

Question 30

What are the different types of joints, movement wise?

Answer 30

Planar, hinge, pivot, condyloid/ellipsoidal, saddle, ball and socket

Question 31

What movement can occur with a planar joint? Give an example

Answer 31

Gliding, sliding. Sternoclavicular, acromioclavicular

Question 32

What movement can be done with a hinge joint? Give an example

Answer 32

Flexion, extension. Knee, ankle, humeroulnar joint of elbow.

Question 33

What movement can be done with a pivot joint? Give an example

Answer 33

Rotation, eg pronation, supination. Proximal radioulnar joint

Question 34

What movement can be done with a ball and socket joint? Give an example

Answer 34

(Poly/multi-axial) Flexion, extension, ABduction, ADduction, (TF circumduction), rotation. Hip, shoulder.

Question 35

What movement can be done with a saddle joint? Give an example

Answer 35

Biaxial- Flexion, extension, ABduction, ADduction. 1st carpometacarpal joint

Question 36

What movement can be done with a condyloid/ellipsoidal joint? Give an example

Answer 36

Biaxial- flexion, extension, ABduction, ADduction, (circumduction). Radiocarpal joint (wrist), metacarpophalangeal joints.

Question 37

List some factors which affect the stability of a joint

Answer 37

Structure of articulating bones, use/disuse, tone and arrangement of muscles, strength and tension of joint ligaments, some hormones eg Relaxin.

Question 38

What effects does age have on joints?

Answer 38

Thinner articulating cartilage, decreased production of synovial fluid, decreased length of ligaments, decreased flexibility.