The Skeletal System

Question 1

What are the functions of bone & skeletal system

Answer 1

1) Support- structural framework
2) Protection
3) Assisting in movement
4) Mineral homeostasis
5) Production of blood cells- red bone marrow
6) Triglyceride storage - yellow bone marrow

Question 2

What is Haemopoiesis

Answer 2

Production of blood cells

Question 3

What does red bone marrow produce?

Answer 3

red blood cells , white blood cells, and platelets

Question 4

What cells does yellow bone marrow produce?

Answer 4

Adipose cells

Question 5

Why are triglycerides stored?

Answer 5

As a potential chemical energy reserve

Question 6

What are the types of bones

Answer 6

Long, short, flat, irregular bones.
Compact and cancellous bone

Question 7

What is an extracellular matrix composed of?

Answer 7

25% water, 25% collagen fibres, 50% crystallised mineral salts

Question 8

Describe compact bones

Answer 8

1) Contains few spaces, made up from Osteons
2) Found beneath the periosteum and makes up the bulk of the diaphysis in long bones
3) Provides protection and support and resists the stresses of weight and movement

Question 9

Describe spongy bones

Answer 9

1)an irregular lattice work of bone
2) Lighter than compact bone so it moves more readily when pulled by skeletal muscle
3) Supports and protects red bone marrow

Question 10

What is ossification and what are the 4 principal situations in which it occurs

Answer 10

Bone formations. Occurs in 4 principal situations:
1) initial formation of bones in an embryo and foetus
2) growth of bones during infancy and childhood
3) remodelling of bone during lifetime
4) repair of fractures

Question 11

Describe growth in bone length related to the epiphyseal plate

Answer 11

As bone grows, new cells on the epiphyseal side are formed, while old cells on the diaphyseal side are replaced by bone, so bone grows on the diaphyseal side

Question 12

Describe growth in bone thickness

Answer 12

You have continual bone formation inside of bone, as well as bone destruction caused by osteoclasts inside the medullary cavity. Bone destruction occurs at a slower rate so the medullary cavity enlarges as the bone increases in thickness

Question 13

What is bone resorption

Answer 13

Removal of minerals and collagen fibres from bone by osteoclasts (results in destruction of extracellular matrix)

Question 14

What us bone deposition

Answer 14

The addition of minerals and collagen fibres to bone by osteoblasts (results in formation of extracellular matrix)

Question 15

What is bone remodelling

Answer 15

The ongoing replacement of old bone with new

Question 16

Describe bone fractures

Answer 16

• Can be partial, complete, closed (simple) or open (compound)
• Repair involves several steps
  -Phagocytes remove dead bone tissue
• Chondroblasts form fibrocartilage that bridges the broken ends of the bone
• Fibrocartilage turns into spongy bone
• Remodelling where the spongy bone is converted into compact bone
• Slow process

Question 17

What are the factors that affect bone growth

Answer 17

• Adequate minerals (Ca, P, and Mg)
• Vitamins A,C and D
• Several hormones ( human GH, Insulin Growth factor, thyroid)
• Weight bearing exercise

Question 18

Describe the bone’s role in calcium homeostasis

Answer 18

1) Some stimulus disrupts homeostasis by decreasing blood Ca2+ level
2)Parathyroid gland cells detect this (receptors)
3) This causes an increased production of cyclic AMP (control centre)
4) PTH gene turned on
5) Increased release of PTH
6) Effectors - osteoclasts increase bone resorption
Kidneys retain CA2+ in blood & produce calcitriol
7) Increase in blood CA2+ level

Question 19

What happens to bone tissue during exercise

Answer 19

• Bone tissue alters its strength in response to mechanical stress
• Bone strength is increased as mechanical stress increases deposition of mineral salts and production of collagen fibres
• Removal of mechanical stress weakens bone through demineralisation and collagen fibre reduction

Question 20

What are the common bone disorders

Answer 20

1) osteoporosis - porous bones due to depletion of calcium in the body
2) rickets & osteomalacia - disorders where bone calcification fails
3) herniated disc
4) hip fracture

Question 21

What is an isotope bone scan

Answer 21

• radioactive tracer
• tracer uptake related to blood flow to the bone
• hot spots = increased uptake indicating bone cancer, abnormal healing of fracture or abnormal bone growth
• cold spots = degenerative bone disease, decalcified bone, fractures etc

Question 22

How many bones are there in total and what are axial and appendicular bones

Answer 22

206 in total
Axial: bones that lie around the longitudinal axis of the body (80)
Appendicular: consists of the bones of the girdles and upper & lower limbs

Question 23

What do the 8 cranium bones in the skull do?

Answer 23

Encloses and protects the brain

Question 24

What do inner and outer surfaces of the skull do?

Answer 24

Inner surface: attach membranes that stabilise position of the brain, blood vessels and nerves
Outer surfaces provide area for attachment to muscle for head movement

Question 25

How many facial bones are there and whats their function

Answer 25

14 facial bones
Protects & provides support for the entrances of digestive & respiratory systems
Muscle attachments for facial features
Protect & support the delicate special sense organs for vision, smell, taste, hearing & balance.

Question 26

What is the function of the vertebral column?

Answer 26

• permits movement
• encloses & protects spinal cord
• point of attachment for the ribs and muscles of the back

Question 27

What is the function of the thorax?

Answer 27

• encloses and protects thoracic cavity organs
• provides support for the bones of the shoulder and upper arm

Question 28

What do the pectoral girdles do

Answer 28

Attach bones of the upper limbs to the axial skeleton

Question 29

What is the function of the pelvic (hip) girdle

Answer 29

• 2 hip bones
• strong stable support for vertebral column
• attaches the lower limbs to the trunk at the sacrum

Question 30

What are the 30 bones of the lower limb

Answer 30

Femur, patella, tibia, fibula, 7 tarsals (ankle), 5 metatarsals (foot) and 14 phalanges (toes)

Question 31

What is the difference between male and female skeletons

Answer 31

• Male bones are generally larger and heavier
• Male bones have more prominent markings for muscle attachment
• Female pelvis is adapted for pregnancy & childbirth
• Female pelvis is wider and shallower

Question 32

What are the effects of aging of the skeletal system?

Answer 32

• Loss of calcium from bones resulting in osteoporosis
• Decreased production of extracellular matrix proteins (mainly collagen fibres)
• Bones become more brittle and susceptible to fracture