Muscoloskeletal System

Question 1

What is the skeletal system made up of?

Answer 1

Cartilage and bone.

Question 2

What is the axial skeleton and the appendicular skeleton?

Answer 2

Axial - skull, vertebrae, ribs, sternum.
Appendicular - bones of upper and lower limbs.

Question 3

What are the 2 structural patterns for bone?

Answer 3

Compact - dense outer shell, surrounds spongy bone
Trabecular/spongy - inside bones

Question 4

What 3 things do bone cells contain?

Answer 4

Osteocytes - osteoblasts encased in bone, maintain mineral levels
Osteoblasts - build bone
Osteoclasts - reabsorb bone

Question 5

What are features of cartilage and the function?

Answer 5

Semi rigid but flexible, a vascular and no nerve supply.
Functions: smooth surface for bones to arrive at joints, shock absorber, growth and development of long bones.

Question 6

What are the 5 types of bones?

Answer 6

Long - long shaft, expanded at either end. Eg. Humerus
Short - mostly spongy bone eg. Wrist
Flat - smooth and thin, protects soft internal structures eg. Skull
Irregular - elaborate shape eg. Vertebrae
Sesamoid

Question 7

What are the structural roles of the skeleton?

Answer 7

Physical support, attachment points for muscles, protection of internal structures.

Question 9

What is intramembranous ossification?

Answer 9

Bone development from general connective tissue.

Question 12

Why is calcium so important?

Answer 12

It makes bones hard.

Question 14

What is the process of sliding filament theory?

Answer 14

1. AP from motor neurone triggers Ca2+ release from SR
2. Ca2+ binds to troponin on actin, so tropomyosin moves and exposes myosin binding site
3. Myosin head binds onto actin and pulls it along
4. ATP causes myosin head to disconnect
5. When Ca2+ removed, binding sites covered.

Question 15

What is endochondral ossification?

Answer 15

Bone develops from precursor made of cartilage.

Question 16

How do osteoblasts work?

Answer 16

Produce extra cellular matrix, which becomes calcified, then becomes an osteocyte.

Question 17

What is the function of osteoclasts?

Answer 17

Break down old bone material for maintenance and reshaping, either in response to damage or to adapt to demands.

Question 18

What conditions and malnutrition are linked to calcium?

Answer 18

Rickets and osteomalacia - low calcium and vitamin
Osteoporosis - rate of bone reabsorption outweighs bone production

Question 19

What are the key features of muscles?

Answer 19

Contain actin and myosin protein filaments.
Antagonistic pairs
Muscle cell = myocyte
Can only pull insertions towards origins.

Question 20

What are fascicles?

Answer 20

Fibres arranged in bundles in skeletal muscles. Arrange to make the whole muscle.