Bones and Skeletal Tissue

Question 1

What does the skeletal system include?

Answer 1

• Bones
• Cartilages, ligaments, and other connective tissues

Question 2

What are the 5 primary functions of the skeletal system?

Answer 2

• Support
• Storage of minerals and lipids
• Blood cell production
• Protection
• Leverage

Question 3

What are the three parts that makes up the structure of a long bone?

Answer 3

• Diaphysis (shaft)
• Epiphysis (wide part at each end)
• Metaphysis

Question 4

What is the diaphysis in the bone?

Answer 4

The wall of compact bone. Has a central space called medullary cavity (marrow cavity)

Question 5

What is the epiphysis in the bone?

Answer 5

Mostly spongy bone

Question 6

What is the metaphysis in the bone?

Answer 6

Where diaphysis and epiphysis meet

Question 7

What are the 4 characteristics of bone?

Answer 7

• Dense matrix
• Osteocytes (bone cells) within lacunae organized around blood cells
• Canaliculi
• Periosteum

Question 8

What are canaliculi?

Answer 8

Narrow passageways that allow for exchange of nutrients, wastes, and gases

Question 9

What does periosteum do?

Answer 9

Covers outer surfaces of bones except at joints

Question 10

What is the makeup of bone matrix?

Answer 10

2/3 calcium phosphate and 1/3 collagen fibers

Question 11

What does calcium phosphate form crystals of?

Answer 11

Hydroxyapatite

Question 12

What are the four types of bone cells?

Answer 12

• Osteogenic cells
• Osteoblasts
• Osteocytes
• Osteoclasts

Question 13

What do osteogenic cells do?

Answer 13

• Divide to produce osteoblasts
• Assist in fracture repair

Question 14

What do osteoblasts do?

Answer 14

Produce new bone matrix during osteogenesis (ossification)

Question 15

Osteoblasts surrounded by bone matrix become __________________

Answer 15

Osteocytes

Question 16

What are osteocytes’s two major functions?

Answer 16

• Maintain protein and mineral content of matrix
• Help repair damaged bone

Question 17

What do osteoclasts do?

Answer 17

• Absorbs and removes bone matrix
• Secretes acids and protein-digesting enzymes

Question 18

________ is the functional unit of compact bone

Answer 18

Osteon

Question 19

What are the three components of the Osteon?

Answer 19

• Central canal
• Perforating canals
• Lamellae

Question 20

What are the three layers of lamellae?

Answer 20

• Concentric lamellae
• Interstitial lamellae
• Circumferential lamellae

Question 21

______________ lacks osteons

Answer 21

Spongy bone

Question 22

______________ fills spaces between trabeculae and forms blood cells

Answer 22

Red bone marrow

Question 23

________ bone marrow stores fat

Answer 23

Yellow

Question 24

___________ is the membrane that covers the outside of bones and increases the strength of attachments

Answer 24

Periosteum

Question 25

The endosteum is the cellular layer that lines the ___________

Answer 25

Medullary cavity

Question 26

What are the two PARTS of bone development?

Answer 26

- Ossification (osteogenesis) - Calcification

Question 27

What are the two forms of ossification?

Answer 27

- Endochondral ossification - Intramembranous ossification

Question 28

Endochondral or intramembranous ossification: which way do most bones form?

Answer 28

Endochondral

Question 29

Instramembranous ossification produces dermal bones such as __________ and ___________

Answer 29

- Mandible (lower jaw) - Clavicles (collarbones)

Question 30

Interstitial growth is growth in _______

Answer 30

Length

Question 31

Appositional growth is growth in _______

Answer 31

Width

Question 32

What three types of bone cells are involved in bone remodeling?

Answer 32

- Osteocytes - Osteoblasts - Osteoclasts

Question 33

If removal is faster than replacement, bones __(1)___. If deposition predominates, bones ____(2)____.

Answer 33

1) Weaken 2) Strengthen

Question 34

What two minerals are required in the diet?

Answer 34

Calcium and Phosphorous

Question 35

What is the purpose of calcitriol and vitamin D3?

Answer 35

Allows calcium and phosphate ion absorption in digestive tract

Question 36

Bones store 99% of the body's what?

Answer 36

Calcium

Question 37

This hormone increase blood calcium ion levels by: - Stimulating osteoclast activity (indirectly) - Increasing intestinal absorption - Decreasing calcium excretion by kidney

Answer 37

Parathyroid hormone (PTH)

Question 38

What are the two types of bone fractures?

Answer 38

Open (compound) or closed (simple)

Question 39

______________ is inadequate ossification (reduction of bone mass)

Answer 39

Osteopenia

Question 40

______________ is the severe loss of bone mass

Answer 40

Osteoporosis