The Muscular-Skeletal System

Question 1

What are the 5 functions of the skeleton?

Answer 1

• Support and protection
• Mineral storage
• Growth/development
• Production of blood cells
• To provide a framework which allows movement

Question 2

How many bones, on average, does an adult have?

Answer 2

206

Question 3

What are the 5 types of bone?

Answer 3

• Long
• Short
• Flat
• Irregular
• Sesamoid

Question 4

Long bone?

Answer 4

• Hard, dense bones that provide strength, structure, and mobility.
• E.g. femur

Question 5

Short bone?

Answer 5

• Shaped roughly as a cube.
• Contains mostly spongy bone.
• The outside surface is comprised of a thin layer of compact bone.
• E.g. carpal bones in wrist; tarsal bones in ankles.

Question 6

Flat bone?

Answer 6

• Made up of a layer of spongy bone between 2 compact, thin layers.
• Have a flat shape, not rounded; for protection.
• E.g. skull; ribs; sternum

Question 7

Irregular bone?

Answer 7

• Vary in shape and structure, therefore don’t fit in any other category.
• E.g. vertebrae; sacrum; coccyx; mandible

Question 8

Sesamoid bone?

Answer 8

• Small bone, commonly embedded within a muscle or tendon, near joint surfaces.
• E.g. Patella

Question 9

Structure of the bone (vertical)?

Answer 9

• Made from Cancellous and Compact bone.
• Cancellous: Trabecullar (spongy); Contains blood vessels and marrow; Lighter and less dense; More flexible than compact bone.
• Compact: A dense layer on the outside of the bone; Strong and durable; 80% of adult bone mass.
• Articular cartilage on the Distol Epiphysis.
• The Diaphysis is central, containing the Medullary Cavity (and bone marrow).
• The Proximal Epiphysis is the top end, where lots of the spongy bone is.

Question 10

Structure of the bone (horizontal)?

Answer 10

• A central Volkmanns Canal, in the Trabecullar bone.
• Surrounded by compact bone.
• Osteon in the compact bone.

Question 11

Osteon?

Answer 11

• Have folds known as Lamellae.
• Channels known as Canaliculi.
• Blood supply: Haversian Canal.

Question 12

What is bone marrow?

Answer 12

• A spongy tissue inside some bones.
• Contains stem cells
• Adult stem cells can differentiate into related cell types.

Question 13

What do Osteoblasts do?

Answer 13

Responsible for the formation of bone; work with Osteoclasts.

Question 14

What do Osteoclasts do?

Answer 14

Responsible for the breakdown of bone; work with Osteoblasts.

Question 15

What are Osteocytes?

Answer 15

Matured Osteoblasts that oversee the bone growth.

Question 16

Impact of low Oestrogen levels on the growth of bone?

Answer 16

• Low Oestrogen results in low Osteoblast production.
• Low Osteoblast production means bone is being cut away quicker than it is being replaced.
• Bones become fragile.