Skeletal System Flashcards
1
Q
What are the 6 functions of bones?
A
Support framework, store and release minerals, storage of energy, hematopoiesis, external protective covering, assistance in movement
2
Q
Site of formed elements formation
A
Hematopoiesis
3
Q
What makes up the dense matrix?
A
1/4 water, 1/4 collagen fibers, 1/2 hydroxyapatite crystals
4
Q
Part of the matrix that bends slightly, will not tear when pulled, provides skeleton with flexibility
A
Collagen fibers
5
Q
Part of the matrix that resists applied pressure without breaking, provides hardness of skeleton
A
Hydroxyapatite crystals
6
Q
What does the lacunae contain?
A
Osteocytes
7
Q
Mature bone cells that maintain bone matrix
A
Osteocytes
8
Q
What are the 2 factors that classify bones?
A
Shape and internal tissue organization
9
Q
Shaft of bone
A
Diaphysis
10
Q
Central space in bone
A
Medullary cavity
11
Q
Ends of bones
A
Epiphysis
12
Q
What does the epiphysis articulate with?
A
Other bones
13
Q
Separates diaphysis from epiphysis, grows in length and made of hyaline cartilage
A
Epiphyseal plate
14
Q
Small area between diaphysis and epiphysis
A
Metaphysis
15
Q
Cover ends of epiphyses; made of hyaline cartilage
A
Articular cartilage
16
Q
Fibrous outer layer; osteogenic inner layer; does not cover articular cartilage
A
Periosteum
17
Q
What is the periosteum an attachment point for?
A
Tendons and ligaments
18
Q
Connects bone to bone
A
Ligament
19
Q
Connects bone to muscle
A
Tendon
20
Q
Contains yellow bone marrow
A
Medullary cavity
21
Q
Thin membrane that lines marrow cavity; active in bone growth and repair
A
Endosteum
22
Q
Dense, solid bone
A
Compact bone
23
Q
Open networks of struts
A
Spongy bone
24
Q
Bone marrow in developing bones of fetus and newborn, around spongy bone in adults
A
Red bone marrow
25
What is the function of red bone marrow?
Hematopoiesis
26
Bone marrow in medullary cavities in adults
Yellow bone marrow
27
What is the function of yellow bone marrow?
Energy storage (lipids)
28
Cells of bone make up ___% of bone mass
2
29
Stem cells that divide to produce osteoblasts
Osteogenic cells
30
Where are osteogenic cells located?
Inner layer of endosteum and periosteum
31
Immature bone cells that secrete bone matrix
Osteoblasts
32
When do osteoblasts become osteocytes?
When it is surrounded by matrix
33
Mature cells that maintain matrix and repair damaged bone
Osteocytes
34
Breaks down bone matrix
Osteoclasts
35
What is the order of osteocyte production?
Osteogenic, osteoblast (secrete matrix), osteocyte
36
What are the 2 major types of bone?
Compact and spongy
37
What is compact bone made up of?
Osteons
38
What does the central canal contain?
lymphatic vessels, blood vessels, nerves
39
Circular layers of bone matrix
Concentric lamellae
40
Osteocytes are housed in
Lacunae
41
How are substances transported to/from osteocytes if they are surrounded by a hard matrix in compact bone?
Canaliculi
42
Canals that interconnect lacunae of an osteon. Nutrients and oxygen pass through
canaliculi
43
Fills in space between osteons in compact bone; older osteons partially removed by bone remodeling
Interstitial lamellae
44
Where is spongy bone found?
Inside of long bones and flat bones
45
Spongy bones ____ ____ osteons
Don't have
46
Lamellae form an open network of struts that have no blood vessels
Trabeculae
47
What are open spaces between trabeculae filled with?
Blood, lymphatic vessels, nerves, red bone marrow
48
How are substances transported to/from osteocytes in spongy bone if there is no canal with blood?
Through canaliculi that open onto surface of trabeculae
49
What is the function of compact bone?
Stress in 1 direction
50
What is the function of spongy bone?
Multidirectional stresses
51
Is compact or spongy bone stronger?
Compact
52
Before 8 weeks of development, what is the skeleton made of?
Embryonic connective tissue
53
When is embryonic tissue replaced with bone during fetal development?
8 weeks
54
Process of replacing connective tissues with bone
Ossification
55
What are the 2 forms of ossification?
intramembranous, endochondral
56
What does intramembranous ossification begin with?
Mesenchyme
57
What types of bones does intramembranous ossification create?
Mandible, clavical, flat bones of skull
58
What is the first step of intramembranous ossification?
Ossification center develops from mesenchymal cells in membrane differentiating into osteoblasts, osteoblasts secrete matrix and become osteocytes
59
What is the second step of intramembranous ossification?
Calcification occurs due to mineral deposits
60
What is the third step of intramembranous ossification?
Trabeculae are formed in the interior = spongy bone
61
What is the fourth step of intramembranous ossification
Mesenchyme is replaced with periosteum and a thin layer of compact bone
62
Form normal bone in wrong place after a minor injury
Fibrodysplasia Ossificans Progressiva (FOP)
63
What is the result of organs growing faster than bone?
Fibrous membrane in gaps between developing bone
64
Soft spots on a baby's head
Fontanelle
65
What does endochondral ossification begin with?
Cartilage
66
What does endochondral ossification form?
Most of the skeleton
67
What is the first step in endochondral ossification?
Cartilage model forms
68
What is the second step in endochondral ossification?
Model grows in length and width
69
What is the third step in endochondral ossification?
Primary ossification center develops in center from osteoblasts producing spongy bone trabeculae
70
What is the fourth step in endochondral ossification?
Medullary cavity develops from osteoclasts dissolving newly formed spongy bone
71
What is the fifth step in endochondral ossification?
Secondary ossification center develops at epiphyses
72
What is the sixth step in endochondral ossification?
Epiphyses are filled with spongy bone. Cartilage becomes articular cartilage, epiphyseal plate separates epiphysis from diaphysis
73
What does an epiphyseal plate become after puberty?
Epiphyseal line
74
Involved in interstitial growth; increases bone length
Epiphyseal plate
75
Bone growth in width
Appositional growth
76
What is the 1st step in appositional growth?
Ridges in periosteum create groove for periosteal blood vessels
77
What is the 2nd step in appositional growth?
Periosteal ridges fuse forming an endosteum lined tunnel
78
What is the 3rd step in appositional growth?
Osteoblasts in endosteum build concentric lamellae inward toward the center of the tunnel forming a new osteon
79
What is the 4th step in appositional growth?
Bone grows outward as osteoblasts in periosteum build new circumferential lamellae
80
What is the 1st step in bone remodeling?
Osteoclasts erode a groove in outer region of bone
81
What is the 2nd step in bone remodeling?
Blood vessels from periosteum invade area
82
What is the 3rd step in bone remodeling?
Groove is converted into a tunnel as osteoblasts lay down matrix
83
What is the 4th step in bone remodeling?
Lamellae of matrix laid down by osteoblasts
84
What is the 1st step in bone fracture repair?
Fracture hematoma forms
85
What is the 2nd step in bone fracture repair?
Internal and external calli form
86
What is the 3rd step in bone fracture repair?
Cartilage of calli is replaced by trabeculae bone
87
What is the 4th step in bone fracture repair?
Remodeling occurs
88
What are the effects of exercise on bone?
Mineral recycling allows bones to adapt to stress, changes bone shape
89
Why does bone degeneration occur?
Inactivity
90
How much bone mass can be lost due to inactivity?
1/3
91
Calcium ions are vital to...
Neurons, muscle cells
92
Do osteoblasts or osteoclasts increase blood calcium?
Osteoclasts
93
Do osteoblasts of osteoclasts decrease blood calcium?
Osteoblasts
94
Stimulates osteoclasts; decrease calcium loos by kidneys, enhances effect of calcitriol; increases blood calcium levels
Parathyroid hormone
95
Activates osteoblasts; promotes calcium loss by kidneys, acts to decrease calcitriol levels; decrease blood calcium levels
Calcitonin
96
Stimulate osteoblast activity; makes epiphyseal plate close faster; decrease blood calcium levels
Estrogen and testosterone
97
What would happen if a person's epiphyseal cartilages already closed but the person is still producing growth hormone?
Bone will grow in width
98
Bone grows in width due to too much growth hormone
Acromegaly
99
Congenital disease caused by too much connective tissue in bones creating longer bones
Marfan syndrome
100
Pituitary gland doesn't grow properly, causes a decrease in bone length growth
Pituitary growth failure
101
Epiphyseal plates keep going, too much growth hormone from pituitary gland
Gigantism
102
Congenital disease caused by epiphyseal plate going away and closing early
Achondroplasia
