Bones And Joints

Question 1

Name some of the functions of the skeleton.

Answer 1

Support, protection, movement, mineral/growth factor storage, haematopoeisis

Question 2

Give an example of an irregular bone.

Answer 2

Vertebrae

Question 3

What is a sesamoid bone?

Answer 3

This is a bone which is embedded within a tendon, such as the patella.

Question 4

Describe the difference between a long bone and a short bone.

Answer 4

A long bone is made up primarily of compact bone, whilst a short bone is made up of spongy bone.

Question 5

Where is the blood supply to a bone?

Answer 5

Typically, bones have a nutrient artery which supplies the diaphysis.

Question 6

What are the name of the arteries which supply the outer 1/3 of the cortex of bone?

Answer 6

Periosteum arteries

Question 7

What can be said about blood supply and growth plates?

Answer 7

Arteries do not cross the growth plates. This means that the epiphysises of the bone must have their own blood supply.

Question 8

What is a common complication which must be considered in bone fracture?

Answer 8

Avascular necrosis. The necrotic bone can collapse and lead to secondary arthritis.

Question 9

What is the functional classification of a joint?

Answer 9

This defines how movable a joint is. It includes synarthrosis, amphiarthrosis, diarthrosis.

Question 10

Define synarthrosis.

Answer 10

This is an immovable joint.

Question 11

What is the functional classification of a joint that is freely moveable?

Answer 11

Diarthrosis.

Question 12

What is an amphiarthrosis?

Answer 12

This is a slightly moveable joint.

Question 13

What are the three structural classifications of joints?

Answer 13

Fibrous, cartilaginous and synovial.

Question 14

What is a fibrous joint?

Answer 14

A joint in which the articulating bones are held very closely together by fibrous connective tissue.

Question 15

What is a syndesmosis and what classification of joint does it fall into?

Answer 15

These joints are amphiarthrosis as they allow small amounts of movement, and are found in places such as the interosseous membrane in the forearm. Structurally they are fibrous joints.

Question 16

What is a gomphosis? What functional classification is this?

Answer 16

This is a joint in which a peg fits into a cone shaped socket, like the tooth into the jaw bone. It is a synarthrosis.

Question 17

Give an example of a fibrous joint found on the cranium

Answer 17

Suture.

Question 18

Describe what a cartilaginous joint is?

Answer 18

It is a joint in which the two articulating bones are joined by cartilage.

Question 19

What is a synchondrosis?

Answer 19

This is a cartilaginous joint such as a epiphyseal growth plate where the two bones are joined by hyaline cartilage.

Question 20

What is a symphysis?

Answer 20

This is a cartilaginous joint where there is a fibrocartilage pad between the two bones. An example is an intervertebral disk.

Question 21

Define a synovial joint. What functional classification are they normally represented by?

Answer 21

It is a joint which has a capsule containing synovial fluid. Normally these are freely moveable joints and are classified as diarthrosis.

Question 22

What is the most common type of joint?

Answer 22

Synovial

Question 23

List three features of a synovial joint:

Answer 23

Articular cartilage, fibrous capsule, synovial membrane.

Question 24

What is the role of articular cartilage in a synovial joint?

Answer 24

It allows a smooth low friction movement and resists compression.

Question 25

What is the role of the fibrous capsule?

Answer 25

It encloses and stabilises the joint, except where there are synovial protrusions.

Question 26

What structures in a synovial joint are covered with synovial membrane, and what is its function?

Answer 26

All surfaces except the articular cartilage. It is a thinly vascularised membrane which secretes synovial fluid.

Question 27

Define a bursae

Answer 27

A bursae is a sac lined with synovial membrane, filled with synovial fluid which can be communicating/ non-communicating with the joint cavity.

Question 28

What name is given to an elongated bursa which is wrapped around a tendon?

Answer 28

Tendon sheath.

Question 29

State two properties of synovial fluid.

Answer 29

It is a pale yellow/clear and slightly alkaline fluid.

Question 30

Name three roles of synovial fluid in joints:

Answer 30

Reduces friction, shock absorption and transport of nutrients and waste products.

Question 31

Why do joints have a periarticular arterial plexus?

Answer 31

This ensures that when the joint is in its fully flexed position there is still sufficient blood supply.

Question 32

What is hiltons law?

Answer 32

Nerves supplying the joint capsule also supply the skin over the joint and the muscles which move the joint.

Question 33

What are interarticular menisci/ discs comprised of?

Answer 33

They are fibrocartilage and not synovial covered.

Question 34

What is a planar joint?

Answer 34

This is where the articulating surface is flat/curved and the two bones slide/glide over one and other.

Question 35

Give an example of a hinge joint.

Answer 35

Elbow/ knee.

Question 36

What parts make up a pivot joint?

Answer 36

Pivot joints are where a rounded bone articulates with a ring formed from a cavity and a fibrous ligament.

Question 37

What type of joint is the metacarpophalangeal joint?

Answer 37

This is a condyloid/ ellipsoidal joint where the oval condyloid of one bone rests in the elliptical cavity of another bone.

Question 38

What movements can be performed at a saddle joint?

Answer 38

Flexion, extension, abduction, Adduction. This is because it is like a saddle sitting over a horses back.

Question 39

What is a distinct property of a ball and socket joint?

Answer 39

They show a large range of movement (multi axial) but also for this reason are quite unstable.

Question 40

Name some features which can affect joint stability.

Answer 40

Bone strength and structure, ligament strength, arrangement of muscles and tone, apposition of neighbouring soft tissues, use/ disuse.

Question 41

What three changes occur to joints when we age?

Answer 41

Reduced synovial fluid production, thinking of articular cartilage and shortening of ligaments.

Question 42

What is arthritis?

Answer 42

This is inflammation and stiffness writhing a joint.