B5a: Skeletons

Question 1

What are the advantages of an internal skeleton compared to an external skeleton(4)

Answer 1

provides internal framework for the body

grows with the rest of the body

flexible as it contains many joints

allows easy attachment of muscles

Question 2

Describe cartilage and bones(3)

Answer 2

both are living tissues containing living cells

• therefore are susceptible to infection by bacteria and viruses
• are able to grow and repair themselves

Question 3

Describe the structure of a long bone(2)

Answer 3

at each end there is a head covered with cartilage

consists of a long shaft containing bone marrow with blood vessels

Question 4

Why are long bones that are hollow advantageous

Answer 4

Stronger and lighter than solid bones

Question 5

Describe the development of the skeleton(3)

Answer 5

skeleton starts off as cartilage

cartilage is slowly replaced by the addition of calcium and phosphorus (ossification)

whether a person is still growing can be determined by the amount of cartilage present
(-if some cartilage remains between the head and shaft, the bone and the person is still growing)

Question 6

Bones are _ but can still be broken by _

Answer 6

very strong, sharp knock

Question 7

Why are elderly people more prone to fractures

Answer 7

The bones of elderlies lack calcium and phosphorus, which can result in osteoporosis, making them prone to fractures

Question 8

Why can it be dangerous to move a person with a suspected fracture

Answer 8

Broken vertebrae in the backbone can damage the spinal chord, resulting in paralysis or death

Question 9

Describe the structure of synovial joints

Answer 9

Contains synovial fluid, a synovial membrane, ligaments and cartilage

Question 10

Describe the movement of a hinge joint

Answer 10

restricted to only an up and down movement

Question 11

Describe the movement of a ball and socket joint

Answer 11

has a wider range of movement than a hinge joint - can rotate

Question 12

Describe the function of synovial fluid

Answer 12

acts as a cushion against shock and a lubricant for easy movement

Question 13

Describe the function of a synovial membrane

Answer 13

holds in the synovial fluid

Question 14

Describe the function of cartilage

Answer 14

protects the bone head

Question 15

Describe the function of ligaments

Answer 15

hold the bones in place

Question 16

Describe how the biceps and triceps muscles operate(3)

Answer 16

they are antagonistic muscles which work together to bend or straighten the arm

• to raise the forearm, biceps contracts and triceps relaxes
• to lower the forearm, biceps relaxes and triceps contracts

Question 17

How is arm bending and straightening an example of a liver

Answer 17

elbow acts as a pivot(fulcrum)