Chapter 7

Question 1

Functions of the skeleton

Answer 1

1. Support
2. Protection
3. Movement
4. Electrolyte balance
5. Acid-base balance
6. Blood formation
7. Hormone secretion

Question 2

Two types of bone (osseus) tissue is:

Answer 2

Compact and spongy

Question 3

Osseus tissue is hardened by the deposition of

Answer 3

Calcium phosphate salts

Question 4

Compact bone is also called

Answer 4

Dense or cortical bone

Question 5

Spongy bone is also called

Answer 5

Cancellous bone

Question 6

Spaces within spongy bone are filled with

Answer 6

Bone marrow

Question 7

Spaces within spongy bone are filled with

Answer 7

Bone marrow

Question 8

Externally bones are covered with a connective tissue sheath called the

Answer 8

Periosteum

Question 9

Osteogenic layer is important for…

Answer 9

Bone remodeling, growth, and fracture repair

Question 10

Perforating fibers strengthen…

Answer 10

the periosteum’s attachment to bone

Question 11

Inside of bones are covered by…

Answer 11

Endosteum

Question 12

Epiphyseal lines are remnants of the

Answer 12

Growth plates

Question 13

Major vessels that supply the long bones:

Answer 13

Nutrient artery and vein, metaphyseal vessels, periosteal vessels

Question 14

Osteoblasts

Answer 14

Initially build osteoid and calcification transforms osteoid to bone

Question 15

Osteocytes

Answer 15

Found in lacunae, connected by canaliculi

Question 16

Osteoclasts

Answer 16

Break down matrix

Question 17

Production of new bone matrix =

Answer 17

Osteogenesis

Question 18

Osteoblasts

Answer 18

-Secrete an unmineralized matrix (osteoid) that includes collagen and calcium-binding proteins
-Release alkaline phosphatase, which makes inorganic phosphate available – allows calcium phosphate salts to form

Question 19

Osteocyte

Answer 19

• Osteoblasts become osteocytes (trapped in matrix after it hardens)
• Canaliculi contain extensions of osteocyte cytoplasm and membrane
• Osteocytes connected to one another by gap junctions

Question 20

Breaking down of bone =

Answer 20

Osteolysis

Question 21

Osteon

Answer 21

Functional unit of compact bone

Question 22

Lamellae

Answer 22

“Little plates”, layers of matrix

Question 23

Central canal

Answer 23

Haversian canal; blood vessels and nerves

Question 24

Canaliculi

Answer 24

“Little canals”

Question 25

Collagen fibers run ______ orientations in adjacent lamellae

Answer 25

Opposite

Question 26

Spongy bone consists of:

Answer 26

Trabeculae and spicules

Question 27

Bone marrow =

Answer 27

Red marrow versus yellow (adipose)

Question 28

Lamellae are _____ arranged, only have a few cell layers

Answer 28

So central canals are not needed

Question 29

T or F ? = Lamellae have central canals

Answer 29

False

Question 30

Spongy bone is most abundance where bone is _____

Answer 30

Not heavily stressed or stresses originate from many directions

Question 31

Compact bone thickest where forces applied from _____

Answer 31

Limited number of directions

Question 32

Calcification =

Answer 32

Deposition of calcium salts

Question 33

Ossification =

Answer 33

Process of bone tissue formation

Question 34

Epiphyseal plates are areas of hyaline cartilage that …

Answer 34

Allow long bones to elongate until they ossify

Question 35

Interstitial growth

Answer 35

-Expand from within to increase in length -Division of chondrocytes of the epiphyseal cartilage -Bone replaces cartilage at roughly the same rate cartilage grows

Question 36

Appositional growth

Answer 36

- New matrix secreted against an external face of an existing boundary - Increase in width - thickens and strengthens long bone by adding layers of circumferential lamellae to outside - involves periosteum and endosteum - associated with increasing the thickness of bones, enlargement of the medullary cavity

Question 37

Repair of fractures steps:

Answer 37

1. Hematoma formation 2. Soft callus formation 3. Hard callus formation 4. Bone remodeling

Question 38

Callus formation occurs with _______ and _______

Answer 38

Fibroblasts, chondroblasts

Question 39

Callus ossification occurs with _______

Answer 39

Osteoblasts

Question 40

Bone remodeling occurs with _____

Answer 40

Osteoclasts

Question 41

Wolff’s law of bone states…

Answer 41

That the architecture of a bone is determined by the mechanical stresses placed upon it

Question 42

Bone remodeling :

Answer 42

-Involves osteocytes, osteoblasts, and osteoclasts -Recycle and renew bone matrix -Contributes to calcium homeostasis

Question 43

Bone remodeling :

Answer 43

-Involves osteocytes, osteoblasts, and osteoclasts -Recycle and renew bone matrix -Contributes to calcium homeostasis

Question 44

Osteopenia =

Answer 44

Loss bone density

Question 45

Osteoporosis =

Answer 45

Advanced loss of bone density where bones fracture easily, spinal deformities common due to the weight of upper body can collapse vertebrae

Question 46

Hypocalcemia

Answer 46

-Severe neuromuscular problems -hyperexcitability (levels too low)

Question 47

Hypercalcemia

Answer 47

-Nonresponsiveness (levels too high) -Deposits of calcium salts in blood vessels, kidneys can interfere with function

Question 48

Homeostatic mechanisms regulate :

Answer 48

Calcium storage, absorption, and excretion ; involves negative feedback

Question 49

Homeostatic mechanisms regulate :

Answer 49

Calcium storage, absorption, and excretion ; involves negative feedback