Lesson 8

Question 1

skeletal system

Answer 1

composed of bones, cartilages, and ligaments joined to form a framework for the body

Question 2

osteology

Answer 2

study of bone

Question 3

how many major bones are in the human body?

Answer 3

206

Question 4

_____ is the forerunner of most bones and covers joint surfaces

Answer 4

cartilage

Question 5

_____ hold bones together at joint

Answer 5

ligaments

Question 6

_____ attach muscle to bone

Answer 6

tendons

Question 7

roles of the skeleton (6)

Answer 7

1. support
2. movement
3. protection
4. electrolyte and acid-base balance
5. blood formation
6. hormone secretion

Question 8

osseous tissue

Answer 8

connective tissue with the matrix hardened by calcium phosphate and other minerals

Question 9

mineralization/calcification

Answer 9

the hardening process of bone

Question 10

flat bones

Answer 10

thin, curved plates; protect soft organs

Question 11

examples of flat bones (5)

Answer 11

parietal bones of the skull, sternum, scapula, ribs, hip bones

Question 12

long bones

Answer 12

longer than wide; rigid levers acted upon by muscles; crucial for movement

Question 13

examples of long bones (9)

Answer 13

humerus, radius, ulna, femur, tibia, fibula, metacarpals, metatarsals, phalanges

Question 14

short bones

Answer 14

approximately equal in length and width

Question 15

examples of short bones (2)

Answer 15

bones of the wrists and ankles

Question 16

irregular bones

Answer 16

elaborate shapes

Question 17

examples of irregular bones

Answer 17

vertebrae and some skull bones

Question 18

what do depressions, groves, and tunnels indicated along the bone surface?

Answer 18

where blood vessels and nerves run along side the bone of enter bone

Question 19

what do elevations or projections indicate on bone?

Answer 19

where tendons and ligaments attach onto bone; where joints occur with bone

Question 20

compact bone

Answer 20

dense outer shell of bone; enclosed the marrow (medullary) cavity containing yellow marrow

Question 21

spongy bone

Answer 21

loosely organized bone tissue found in the ends and center of long bones and in the middle of nearly all others

Question 22

skeleton is _____ compact and ____ spongy bone by weight

Answer 22

3/4, 1/4

Question 23

diaphysis

Answer 23

shaft that provides leverage

Question 24

epiphysis

Answer 24

enlarged end of a long bone; strengthen join and anchor ligaments and tendons

Question 25

epiphyseal line

Answer 25

remnant of childhood growth zone; epiphyseal plate (composed of cartilage)

Question 26

articular cartilage

Answer 26

layer of hyaline cartilage that covers joint surfaces; allows joint to move more freely

Question 27

periosteum

Answer 27

external sheath covering most of bone

Question 28

perforating fibers

Answer 28

of the periosteum; penetrate underlying bone matrix

Question 29

outer fibrous layer of _____ and inner osteogenic layer of _____ _____ _____

Answer 29

collagen, bone-forming cells

Question 30

functions of the periosteum (3)

Answer 30

- isolate bone - provide route for blood vessels and nerves - participates in bone growth and repair

Question 31

endosteum

Answer 31

thin layer of reticular connective tissue lining marrow cavity and all internal bone surfaces

Question 32

functions of the endosteum (5)

Answer 32

- is an incomplete cellular layer (not a continuous sheet) - covers the trabeculae of spongy bone - lines the central canals of osteons - contains osteogenic cells, osteoblasts, and osteoclasts - active in bone growth/repair

Question 33

diploe

Answer 33

inner and outer tables of compact bone enclosing layer of spongy bone in between

Question 34

osteogenic/osteoprogenitor cells

Answer 34

mesenchymal stem cells found in endosteum and inner layer of periosteum

Question 35

osteoblasts

Answer 35

bone-forming cells in endosteum and inner layer of periosteum

Question 36

osteogenesis

Answer 36

synthesize soft organic matter of matrix and promote its mineralization

Question 37

_____ stimulates osteogenic cells to multiply rapidly and increase the number of osteoblasts which reinforce bone.

Answer 37

stress

Question 38

osteocyte

Answer 38

former osteoblasts that have become trapped in the matrix they deposited

Question 39

lacunae

Answer 39

tiny cavities where osteocytes reside

Question 40

canaliculi

Answer 40

little channels that connect lacunae

Question 41

_____ _____ allow for passage of nutrients, wastes, and signals between osteocytes

Answer 41

gap junctions

Question 42

osteocytes do two things...

Answer 42

1. deposit matrix 2. absorb matrix

Question 43

how do osteocytes act as strain sensors?

Answer 43

when they're stressed, they produce biochemical signals that regulate bone remodeling

Question 44

osteocalcin

Answer 44

part of body's acute stress response, increases insulin sensitivity, promotes energy availability

Question 45

osteoclasts

Answer 45

bone-dissolving cells found on the bone surface

Question 46

osteolysis

Answer 46

the breakdown of bone as part of bone remodeling; important in releasing calcium and phosphate into body fluid

Question 47

what type of cells do not form from osteogenic cells?

Answer 47

osteoclasts; they develop from the same bone marrow stem cells that give rise to macrophages

Question 48

by dry weight, bone averages _____ organic and _____ inorganic matter

Answer 48

1/3, 2/3

Question 49

organic matter of the bone matrix consists of...

Answer 49

collagen and carbohydrate-protein complexes

Question 50

inorganic matter of the bone matrix consists of...

Answer 50

85% hydroxyapatite 10% calcium carbonate inorganic ions such as Mg, fluoride, and sodium

Question 51

Rickets (disease)

Answer 51

caused by mineral deficiency and resulting in soft, deformed bones; not enough calcium from diet (could also be caused by not enough UV light for vitamin D3 synthesis)

Question 52

collagen molecules contain _____ _____ that break under stress and dissipate shock under load

Answer 52

sacrificial bonds

Question 53

brittle bone disease

Answer 53

osteogenesis imperfecta - results from a defect in collagen deposition

Question 54

concentric lamellae

Answer 54

layers of matrix surrounding a central canal running longitudinally

Question 55

a central canal and its lamellae constitute an _____

Answer 55

osteon

Question 56

central canals are connected by transverse _____ _____

Answer 56

perforating canals

Question 57

circumferential lamellae

Answer 57

encircle inner outer region of dense bone

Question 58

interstitial lamellae

Answer 58

fill irregular regions between osteons

Question 59

spicules

Answer 59

lattice of bone slivers in spongy bone

Question 60

trabeculae

Answer 60

lattice of bone plates covered in endosteum in spongy bone

Question 61

spaces within spongy bone are filled with _____ _____ _____

Answer 61

red bone marrow

Question 62

bone marrow

Answer 62

soft tissue occupying marrow cavities of long bones and small spaces of spongy bone

Question 63

myeloid tissue

Answer 63

red bone marrow - contains multiple tissues including hematopoietic tissue - in nearly every bone in a child - in adults, found in skull, vertebrae, ribs, sternum, part of pelvic girdle, and proximal heads of humerus and femur

Question 64

yellow bone marrow (2)

Answer 64

- adipose tissue, does not produce blood - can transform back into red bone marrow in the event of chronic anemia

Question 65

homeostasis (in bones)

Answer 65

bone building and recycling must be balanced

Question 66

what conditions are because bone breakdown is faster than bone building causing bones to be weaker? (2)

Answer 66

osteopenia and osteoporosis

Question 67

What type of bone cells build bone?

Answer 67

osteoblasts

Question 68

What type of bone cells break down bone?

Answer 68

osteoclasts