The Skeletal System

Question 1

AXIAL SKELETON

Answer 1

80 fused bones giving limited motion

• Cranium (22)
• Auditory ossicles (6)
• Hyoid bone (1)
• Vertebral column (26)
• Ribs (24)
• Sternum (1)

Question 2

APPENDICULAR SKELETON

Answer 2

126 unfused bones allowing motion

• Pectoral girdles (4)
• Arm and forearm (6) * Hands (54)
• Pelvis (2)
• Thigh and leg (8)
• Feet (52)

Question 3

Long Bones

Answer 3

Bones whose length exceeds their width

Function
* Leverage
* Blood cell production

Examples
* Femur, humerus

Question 4

Short Bones

Answer 4

Bones with equal length and width

Function
* Weight bearing

Examples
* Tarsals, carpals

Question 5

Flat bones

Answer 5

Thin bones that tend to be curved rather than flat

Function
* Protection

Examples
* Cranium, sternum

Question 6

Irregular Bones

Answer 6

Bones that do not fit into the other three categories

Function
* Individualised

Examples
* Vertebrae, sacrum

Question 7

Functions of the skeleton

Answer 7

1. Protection
2. Support
3. Movement
4. Blood production
5. Storage
6. Shape

Question 8

Protection

Answer 8

• Protects the vital organs

Question 9

Support

Answer 9

• Soft tissues supported by the skeleton

Question 10

Movement

Answer 10

• Comprised of numerous joints which allow movement through leverage
• Occurs due to muscles pulling on bones via tendons

Question 11

Blood Production

Answer 11

• Red and white blood cells are formed in the marrow cavities of some long bones
• Controlled by the hormone erythropoietin (EPO)

Question 12

Storage

Answer 12

• Bones store numerous minerals such as calcium, phosphorous, potassium and sodium
• Storage occurs mostly in long bones

Question 13

Shape

Answer 13

• The skeleton gives the body its shape * Body shape genetically determined

Question 14

Cortical Bones

Answer 14

• Also known as compact bone
• Very dense and hard
• Formed for protection and structure

Question 15

Cancellous Bones

Answer 15

• Also know as spongy bone
• Lighter and less dense than cortical bone
• Contains bone marrow

Question 16

Epiphysis

Answer 16

• The area at each end of a long bone.
• Made mostly of cartilage in childhood which hardens to become cancellous (spongy) bone in adulthood.
• Contains red marrow.

Question 17

Diaphysis

Answer 17

The central shaft of a long bone made of cortical (compact) bone.

Question 18

Periosteum

Answer 18

• A thin fibrous membrane which covers the surface of bone.
• It contains blood vessels which supply nutrients and nerves which signal pain.

Question 19

Epiphyseal Disks Lines

Answer 19

• Lie between the epiphysis and the diaphysis.
• Growth area where cartilage cells form columns
• Push older cells towards the middle of the bone shaft.

Question 20

Medullary Cavity

Answer 20

• A hollow or canal inside the shaft of the bone
• Contains red marrow used to produce blood cells
• Contains yellow marrow which is a store for fat.

Question 21

Articular Cartilage

Answer 21

• Forms a smooth, white, shiny mass on the surface that looks like marble.
• Protects the bone tissue and helps to reduce friction between the bones.