4 Skeletal System

Question 1

What are the functions of the skeletal system?

Answer 1

• Support
• Protection
• Movement
• Mineral homeostasis
• Storage
• Blood cell production (hemapoiesis/hematopoiesis)
  
  • Blood cells are only made in marrow (plasma is another story)

Question 2

What part of bone is the diaphysis? What is its translation and AKA’s?

Answer 2

• The long main portion of the bone
• a.k.a. body, shaft
• Means “Growing between”

Question 3

What part of the bone is epiphyses and what is its translation?

Answer 3

• The ends of the bone
• Means “growing over”
• sing. epihysis, adj. epiphyseal

Question 4

What part of the bone is the metaphyses?

Answer 4

• sing. Metaphysis
• The regions between the diaphysis and the epiphyses
• Contains the epiphyseal growth plate/epiphyseal line
• Made up of constantly-dividing cartilage during growth

Question 5

What’s the epiphyseal growth plate, how does it function and what happens if it breaks during growth?

Answer 5

• A cartilaginous area within the metaphysis of a growing bone
• Once growth stops, what remains is the epiphyseal line
• If a young child has a break along the epiphyseal growth plate, they may end up up with limbs growing at different rates, e.g. one leg longer than the other

Question 6

What is articular cartilage and where is it located?

Answer 6

• A thin layer of hyaline cartilage covering the epiphyses
• It’s avascular and aneural

Question 7

Describe periosteum and its function

Answer 7

• A Tough CT covering that surrounds the bone
• Protects, nourishes and heals bone
• It is an attachment for tendons and ligaments
• Outer layer is tough and supportive/protective
• Inner layer has bone forming cells
• Well vascularized and innervated

Question 8

What is the medullary cavity, where is it located and what is its AKA?

Answer 8

• aka Marrow cavity
• The space within the diaphysis that contains:
  
  1. Red marrow (for blood cell formation)
  2. Yellow marrow (for adipose storage)

Question 9

What is bone matrix made up of?

Answer 9

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

Question 10

What kinds of cells are found in (normal) bone?

Answer 10

• Osteoprogenitor (a.k.a. Osteogenic) cells
  
  • This is the earliest stage, before cells become blasts
• Osteoblasts (bone building cells)
• Osteocytes (mature bone cells)
• Osteoclasts (bone ‘eating’ cells– take out damaged cells)

Question 11

Describe spongy bone

Answer 11