1
Q
what are the four components of the skeletal system
A
bones, cartilage, tendons, ligaments
2
Q
what are the functions of the skeletal system
A
support
protection
movement
storage
blood cell production
3
Q
Which of these is not a function of the skeletal system?
a. protection
b. conduction
c. blood formation
d. support
A
b. conduction
4
Q
what type of cartilage do most bones develop from
A
hyaline
5
Q
what forms matrix in hyaline cartilage
A
chondroblasts
6
Q
what do chondrocytes do in hyaline cartilage
A
maintain matrix
surrounded by matrix & occupy a lacunae
7
Q
what is the matrix structure in hyaline cartilage
A
collagen fibers plus proteoglycans
8
Q
what covers is the double layers connective tissue sheath that surrounds most of the cartilage
A
perichondrium
-does not surround articular joints
9
Q
T/F: articular joints have perichondrium
A
false
10
Q
what is the grow like of hyaline cartilage
A
- appositional
- interstitial
11
Q
appostional growth
A
when chondroblasts in the perichondrium add new cartilage to the outside egs of the existing cartilage (like a tree)
-chondroblasts lay down new matrix & add new chondrocytes to the outside of the tissues
-(new cartilage is added to the surface)
12
Q
what is interstitial growth
A
chondrocytes divide within the tissue, adding more matrix to the cells
13
Q
what type of growth is it when new cartilage is formed within the cartilage
A
interstitial growth
14
Q
what are the organic & organic parts of the bone matrix
A
-the collagen fibers/proteoglycans are the organic part that offer flexibility
-the hydroxyapatite & calcium phosphate are the inorganic part that offers weight bearing
15
Q
what is more prominent in the bone matrix, the organic part or the inorganic part?
A
the inorganic hydroxyapatite consists of 65%, while the collagen fibers consists of 35%
16
Q
if calcium is removed from bone, the bone becomes what
A
too bendable
17
Q
if collagen is removed from bone, the bone becomes what?
A
too brittle
18
Q
what is osteogenesis imperfecta
A
brittle bone disorder caused by lack of/too little collagen
19
Q
what is ossification
A
bones being formed
20
Q
lacunae
A
occupied spaces by the osteocyte cell body
21
Q
canaliculi
A
occupied by osteocyte cell processes
22
Q
how do nutrients get through to osteoblasts?
A
nutrients pass through the lacunae & canaliculi or through gap junctions
23
Q
how do osteoblasts communicate?
A
through gap junctions
24
Q
what do osteoblasts do?
A
form bone
25
what do osteoclasts do
reabsorption (breakdown)
26
characteristics of osteoclasts
-large multinucleated
-ruffled border
-hydrogen ions
-enzymes
27
what do H+ ions do in osteoclasts
decalcify the bone matrix
28
what do enzymes do in osteoclasts
digest protein component of the matrix
29
what are the stem cells in the bone cells called & what do they do
osteochondral progenitor cells
-become chondroblasts or osteoblasts
30
osteoporosis
porous bone
-result of loss of bone matrix
31
what is bone tissue classification based on
the organization of collagen fibers in the bone matrix
32
woven bone
collagen fibers randomly oriented
33
lamellar bone
mature bone (sheets)
34
cancellous (spongy) bone
trabeculae
35
compact bone
dense
36
what is immature bone
woven bone
37
when is woven bone seen
during fetal development & fracture repair
38
what is woven bone remodeled into
lamellar bone
39
what type of bone does remodeling
woven bone
-removing old bone & adding new
40
what type of bone is mature bone
lamellar bone
41
what are the sheets called in lamellar bone
lamellae
-collagen fibers oriented in one direction each layer
-each layer has dif direction which increases strength
42
T/F: each layer in lamellar bone is going the same direction
-F: they go in different directions which increases strength
43
whether woven or lamellar, bone can be classified according to the _________ ___ _______ within the bone
amount of space
44
what is trabeculae
interconnecting rods or plates of bone
-like scaffolding
45
what are the spaces in spongy bone filled with
blood vessels & bone marrow
46
where is trabeculae oriented in cancellous bone
along the stress line
47
T/F: trabeculae reorients with change in stress
true
48
T/F: trabecule is covered with multiple layers of cells (osteoblasts/osteocytes)
false; covered with a single layer
49
what do central/haversian canals contain & where are they
parallel to the long axis of compact bone & contain blood vessels, nerves, & LCT
50
osten (haversian) system
central canal lined with endosteum, its contents, concentric lamellae & osteocytes
51
what receives nutrients & removes waste through the canal system
osteocytes
52
what happens & where are perforating/volkman's canals
-where blood vessels from periosteum or medullary enter the bone
-perpendicular to the long axis
53
where do nutrients & wastes travel
between osteocytes
54
bone shapes
-long
-short
-flat
-irregular
55
long shape
upper & lower limbs
-longer than wide
56
short shape
carpals & tarsals
-nearly cube shaped
57
flat shape
ribs, sternum, skull, scapulae
-thin, flattened, curved
58
irregular shape
vertebrae, facial
59
diaphysis
(almost like the body of the bone)
shaft
-mostly compact
60
epiphysis
end of bone
(mostly cancellous)
61
medullary cavity
middle area of bone filled with red marrow in children, yellow marrow in adults (limb bones & skull), the rest is red marrow
62
epiphyseal plate
growth plate
-hyaline cartilage until growth stops
63
epiphyseal line
like this when bone stops growing in length
64
periosteum layers
-outer is fibrous
-inner is a single layers of osteoblasts, osteoclasts, & osteochondral progenitor cells)
65
sharpey's fibers
periosteal fibers penetrate through periosteum into bone
-strengthen tendon or ligament attachement to the bone
66
what strengthen tendon or ligament attachment to the bone
sharpey's fibers
67
what is the endosteum
similar inner layer as the periosteum
68
flat bone bone type
has a sandwich of cancellous bone between compact bone
69
short & irregular bone structure
compact bone that SURROUNDS cancellous - similar to the structure of epiphysis
70
do short & irregular bones have diaphysis
no & not elongated
-vertebrae & facial bones
71
what are the methods of ossification
-intramembranous ossification
-endochondral ossification
72
where is intramembranous ossification
in a CT membrane
73
where is endochondral ossification
in cartilage
74
what do both methods of ossification produce?
woven bone that is then remodeled
75
when is intramembranous ossification finished by?
2 yr old
76
where does intramembranous ossification occur?
in the CT membrane from embryonic mesenchymal cells
77
what are fontanels
large membrane-covered spaces between developing skull bones; unossified
78
what are centers of ossification?
sites where CT membrane where ossification begin
79
how do centers of ossification contribute to bone growth?
they expand and gradually ossify the membrane to form bone
80
__________ cells in the membrane become __________ __________ cells which…
Specialize to become ________ which…
Produce _____ ______ that surrounds the…
Collagen fibers of the CT membrane…
________ then become ______…
Which then form tiny trabeculae of _________ bone.
-mesenchymal
-osteochondral progenitor
-osteoblasts
-bone matrix
-osteoblasts
-osteocytes
-woven
81
what gathers on the trabeculae to produce more spongy bone?
osteoblasts
82
cells in the spongy bone specialize to from what?
red bone marrow
83
cells surrounding the developing bone specialize to form what?
the periosteum
84
what lays down bone matrix to form an outer surface of compact bone?
osteoblasts from the periosteum
85
when does cartilage formation begin?
4th week of embryo
86
what has undergone endochondrial ossification?
base of the skull, part of the mandible, epiphysis of the clavicles, mot of the remaining bones of skeleton
87
when does ossification begin & when does some other parts of it begin?
-8th week of embryo
-18-20 yo (medial epiphysis of clavicle)
88
where do long bones grow in length at?
the epiphyseal plate
89
T/F: bones use interstital growth
false- only cartilage uses interstitial growth
90
appositional growth for bones
new layers of bone on surface of old bone or cartilage
91
what type of cartilage does not ossify?
articular cartilage
92
zone of resting cartilage
cartilage attaches to the epiphysis
93
zone of proliferation
new cartilage is produced on the epiphyseal side of the plate as the chondrocytes divide & form stacks of cells
94
zone of hypertrophy
chondrocytes mature & enlarge
95
zone of calcification
matrix is calcified & chondrocytes die
96
ossified bone
calcified cartilage on the diaphyseal side of the plate is replaced by bone
97
what results in the increased size of epophyses
growth at the articular cartilage
98
can the articular cartilage increase the size of bones with no epiphyses (short bones)?
yes
99
what are chondrocytes near the surface of articular cartilage similar to?
those in the zone of resting cartilage
100
what is pituitary gigantism
excess growth hormone before the plates close
101
what is acromegaly
excess growth hormone after the growth plates close
-plates close & there is no where to grow except for in the smooshed little area
102
what is achondroplastic dwarf
improper growth at the growth plate
103
what can causes small bones
lack of calcium & protein during growth
104
what happens with lack of vitamin d in childhood
rickets
-decreased mineralization of bone matrix
105
what is osteomalacia
lack of vitamin d in adulthood
-softening of bone
-result of calcium depletion
106
what is vitamin c needed for
to turn osteoblasts to collagen
107
what is scurvy
deficiency of vitamin d
108
what stimulates closure of epiphyseal plates
sex hormones
109
where does growth hormone come from
anterior pituitary
110
what does growth hormone do
interstitial cartilage growth & appositional growth
111
what thyroid hormone important for
development of all tissues
112
which hormone stimulates closure of epihyseal plates
estrogen
113
what is BMU
basic multicellular unit
-a temporary group of osteoclasts & osteoblasts (tears down old bone matrix & replaces with new bone matrix)
114
how long does BMU last
6 months
115
how long to renew whole skeleton
10 yrs
116
what are the functions of bone remodeling
aids in bone growth, changes in shape, adjustments to stress, bone repair, & calcium ion refulation
117
how do you get osteon in compact bone
-osteoclasts breakdown the matrix & form a tunnel
-osteoblasts form lamellae around the tunnel wall forming a concentric lamellae (process continues until an osteon is formed
118
bone repair order
hematoma formation
callus formation
callus ossification
bone remodeling
119
hematoma formation
blood from blood vessels forms a clot
(happens after a break)
120
callus formation
-internal callus: blood vessels grow into clot
osteoclasts dissolve debris
macrophages clean up debris
fibroblasts produce collagen & granulation tissue
chondroblasts produce collagen
osteoblasts lay down new bone
external:osteoblasts & chondroblasts, bone/cartilage collar stabilizes 2 pieces
121
callus ossidication
callus is replaced by woven, cancellous bone
(endochondral ossification)
122
bone remodeling
replacement of woven bone to lamellar compact bone
123
what do osteoclasts release to tear down bone
hydrogen ions & protein digesting enzymes into the sealed compartment
124
what early structure helps stabilize a fracture during bone repair
callus
125
what cells or tissues do not play a major role in bone repair in the callus formation stage
a. chondroblasts
b. macrophages
c. compact bone
d. osteoblasts
compact bone
126
what is calcium homeostasis important in
membrane potentials & muscle contractions
127
what is the major storage site of calcium
bones
128
where does calcium come from that flows through blood
bones
129
if youre blood calcium levels get low, what happens
need to break down bone to get calcium & vicer versa
130
what does calcium enter the bone through
osteoblasts
131
what does calcium leave the bone through
osteoclasts
132
what hormone regulates blood calcium levels
parathyroid hormone & calcitonin
133
what does parathyroid hormone do
raised calcium in the blood by stimulating osteoclasts
134
what does calcitonin do
lowers calcium in blood by inhibiting osteoclast activity
135
what are the effects of aging on the skeletal system
bone matrix decreases
-more brittle due to lack of collagen & less hydroxyapatite
bone mass decreases
-men denser (testosterone),
136
who has higher bone mass african americans or asians
african americans & hispanics = higher bone mass
asians & caucasians = lower bone mass
137
how much does bone loss decrease after menopause & what is lost first, spongy or compact?
x 10 after menopause
-spongy
138
open (compound) fracture
bone break + open wound (bone may be sticking out)
139
closed (simple) fracture
no break to skin
140
incomplete fracture
not across the whole bone
141
greenstick (incomplete)
fracture on the convex side of the curve of a bone
142
hairline
two sections of bone do not separate
143
comminuted fracture
more than two pieces
144
impaced fracture
one fragment is driven into the cancellous portion of another fragment
a&p
flashcards
Decks in class (21)
# Cards
-
chapter 169
-
a & p lab one40
-
chapter 262
-
chapter 3159
-
a + p lab 233
-
chapter 4184
-
chapter 5149
-
chapter 6144
-
a&p lab exam26
-
chapter 7142
-
chapter 9 (& some of 10)210
-
chapter 11219
-
chapter 12145
-
lab exam46
-
chapter 13126
-
chapter 15285
-
chapter 1694
-
chapter 1795
-
lab exam18
-
exam 6 q16
-
chapter 18107
