Skeletal System Flashcards
(171 cards)
1
Q
What type of bone is produced in intramembranous ossification?
A
woven bone (later remodeled to compact bone)
2
Q
What accounts for the flexibility and compressibility of cartilage?
A
water in the ground substance (60-80%)
3
Q
How do osteocytes communicate?
A
via gap junctions
4
Q
Cartilage is covered by the ____; bone is covered by the ____.
A
perichondrium; periosteum
5
Q
What type of cartilage would you find in these articular areas? Knee, TMJ, shoulder, sternum - ligaments, tendons, pubic symphysis?
A
fibrocartilage
6
Q
___ is the deposit of urates and uric acid crystals into joints.
A
Gout
7
Q
What callous forms after the provisional callous?
A
bony
8
Q
A ____ fracture is a bone broken into several pieces.
A
comminuted
9
Q
What type of systems does compact bone contain?
A
Haversian systems (osteons)
10
Q
The ___ surrounds the central core called the nucleus pulposus in intervertebral discs.
A
annulus pulposus
11
Q
Cartilage is ___ in juveniles and ___ in adults.
A
widespread; limited
12
Q
What are osteoclasts derived from?
A
a monocyte to macrophage lineage (phagocytic)
13
Q
What vitamin is necessary for the synthesis of collagen?
A
vitamin C
14
Q
Ends of bones are composed of ___ bone covered in ____ cartilage.
A
cancellous; hyaline articular
15
Q
What are the longitudinal canals in bone that connect Haversian canals?
A
Volkmann’s canals
16
Q
____ growth is when new cartilage forms at the surface or periphery of pre-existing cartilage.
A
Appositional
17
Q
After a fracture, mesenchymal cells differentiate into ___ and secrete matrix to progressively replace granulation tissue by hyaline cartilage to produce a ___.
A
chondroblasts; provisional callous
18
Q
In adults, insufficient calcium and vitamin D can lead to ____.
A
osteomalacia
19
Q
____ contains blood vessels in what are called ____.
A
Thick; secondary cartilage canals
20
Q
How are osteons produced?
A
via bony remodeling
21
Q
What types of cells does the periosteum contain?
A
fibroblasts and osteoprogenitor cells
22
Q
What is the ground substance of cartilage made up of?
A
collagen; H2O; proteoglycans
23
Q
At the fracture site, which types of cells from the edge of the wound produce a meshwork of woven bone?
A
osteoprogenitor cells and osteoblasts
24
Q
Isogenous groups are separated by ____.
A
extracellular matrix
25
What are the two ways cartilage can grow?
interstitial growth and appositional growth
26
___ happens when there is a vitamin C deficiency and the bone matrix is not calcified.
Scurvy
27
Where are osteoclasts primarily found?
in endosteal/periosteal surface depressions called Howship's lacunae
28
What proportions produce the three major types of cartilage?
relative proportions of matrix and fibers
29
What is the order of differentiation from mesenchymal cells to cartilage?
mesenchymal cells of inner perichondrium >> chondroblasts >> chondrocytes
30
What type of tissue does repair generally produce?
dense connective tissue (fibrosis)
31
What two antagonistic hormones regulate calcium homeostasis?
parathormone and calcitonin
32
____ cartilage differs from hyaline cartilage in that it has the addition of large numbers of elastic fibers in the extracellular matrix.
Elastic
33
A ____ fracture has no break in the skin.
simple/closed
34
____ lead to the production of irregular new bone at edges of surfaces called "bone spurs."
Osteophytes
35
How does the exchange of metabolites occur in cartilage?
via diffusion through the ground substance
36
What non-collagenous organic molecule is concentrated from plasma?
sialoproteins
37
Are synovial joints a kind of epithelium?
NO - no basement membrane so not a true epithelium
38
What are the two main forms of bone?
woven and lamellar
39
What are some examples of GAG's (glycosaminoglycans)?
hyaluronic acid, chondroitin sulfate, heparin sulfate
40
____ growth is when cartilage forms within mass because chondrocytes maintain ability to divide.
Interstitial
41
____ differentiate into rounded chondroblasts which grow and synthesize ground substance and fibrous extracellular matrix and trap chondroblasts in lacunae.
Stellate mesenchymal cells
42
A ____ fracture has damage to the skin, exposing bone.
compound/open
43
In intramembranous ossification (vault of the skull), how are the cells differentiated?
mesenchymal cells >> osteoblasts >> osteoid >> mineralize into bone matrix
44
What are trabeculae? What are open spaces of bone?
spicules; marrow cavity
45
What is ankylosis?
bony fusion of joint with loss of mobility
46
In appositional growth, where do we see more mature chondrocytes?
in the center of the mass; younger cells at periphery
47
Is there cell proliferation in the Zone of Reserve Cartilage?
NO
48
____ lowers blood Ca levels by stimulating bone deposition.
Calcitonin
49
Matrix vesicles in bone contain what enzyme?
alkaline phosphatase
50
Is fibrocartilage mostly made up of ground substance?
YES
51
Which cells are responsible for making the extracellular matrix in collagen?
osteoblasts
52
Synovial joints have two types of cells: A and B. Type A synoviocytes resemble ___ and Type B synoviocytes resemble ___.
macrophages; fibroblasts
53
What proliferates into the fracture site to form granulation tissue?
fibroblasts and capillaries
54
What accounts for the relative strengths of bone and cartilage?
ground substance properties and extracellular fibers
55
What does parathormone do?
increases blood Ca levels
| decreases renal excretion
56
What 3 hormones are involved in calcium homeostasis?
parathormone, calcitonin and somatotropin
57
After a break, what is progressively developed and remodeled to form mature lamellar bone?
the bony callous
58
You would only find Haversian systems in ___ bone.
compact lamellar
59
Fibrocartilage lacks ___ and is found in intervertebral discs and some articular areas.
perichondrium
60
Where would one find hyaline cartilage?
articular surfaces, growth plates, nasal septum, costal cartilage, tracheal and bronchial rings
61
What does bone have an affinity for?
heavy metals and radioactive isotopes (why lead paint in harmful)
62
Mineralized bone is in the form of ____ crystals (salts).
hydroxyapatite
63
Osteocalcin, osteonectin, and sialoproteins are all ____ organic molecules.
non-collagenous
64
How do osteoclasts function in homeostasis?
calcium homeostasis by producing acids and lysozymes that digest bone
65
Where would you find elastic cartilage?
external ear, auditory and Eustacian canals, epiglottis and larynx
66
Vascular collagenous tissue becomes more fibrous and then forms ____.
fibrous granulation tissue
67
What are the secondary centers of ossification in endochondral ossification?
epiphyses (mineralization spreads across cartilage matrix)
68
What MAY be inhibitory to tumor development in cartilage?
its lack of blood vessels (i.e. lack of nutrients overall)
69
What cells produce organic acids, such as carbonic anhydrase?
osteoclasts
70
Alkaline phosphatase buds off osteoblasts via vesicles and ___.
causes precipitation of mineral salts (calcium + phosphate) into the matrix of bone
71
In which zone do chondrocytes increase in size (hypertrophy)?
Zone of Maturation
72
What is exchanged in Haversian vessels?
waste and nutrients
73
New chondrocytes are derived from ___.
mesenchymal cells of inner perichondrium
74
Where would we see endochondral ossification?
in the fetus
75
____ stimulates osteoclast activity to allow bone resporption.
Parathormone
76
What do osteoblasts mature into?
osteocytes (within lacunae)
77
What is a primary cartilage joint? What is a secondary cartilage joint?
synchondrosis (contains single layer of hyaline cartilage); symphysis (contains two hyaline cartilage surfaces connected by a fibrocartilage plate)
78
What are the two classifications of joints?
Synovial (movable) and non-sinovial (non-movable) joints
79
What is hyaline cartilage characterized by?
small aggregates of chondrocytes in ground substance reinforced by Type II collagen fibers
80
_____ is the direct replacement of mesenchyme by bone and does not have. cartilage precursor.
Intramembranous ossification
81
___ in intervertebral joints are derived from the notochord.
Intervertebral discs
82
What is the replacement of articular cartilage with fibrovascular tissue called?
Pannus
83
What happens at maturity in mammals, when hormonal changes decrease cartilage proliferation?
closure of epiphysis
84
What is the most common glycoprotein in the cartilaginous extracellular matrix?
chondronectin
85
What does the Haversian canal contain?
blood vessels and nerves
86
The shaft of a long bone is composed of ___ bone; the medullary cavity is composed of ____ bone.
compact; cancellous
87
___ bones have a shaft (diaphysis), metaphyses, and epiphyses.
Long
88
____ stimulates growth of epiphyseal cartilage and bone and decreases blood calcium levels (bone deposition).
Somatotropin
89
What are the four types of bone cells?
osteoprogenitor cells, osteoblasts, osteoclasts, and osteocytes
90
Where does the primary center of ossification occur in endochondral ossification?
middle of diaphysis
91
What are the 2 ways bone growth is controlled?
endochondral ossification and intermembranous ossification
92
Why is repair in cartilage limited?
because repair requires an adequate amount of blood flow to allow inflammatory response
93
In ____, the resorption of bone by osteoclasts exceeds deposition by osteoblasts and leads to loss of bone mass.
osteoporosis
94
The ____ is when the fracture site is completely bridged by woven bone.
bony union
95
What layer is the internal marrow cavity lined by?
endosteum
96
The broken bone needs to be set before what happens?
the transformation of the bony callous
97
Intervertebral joints are a special type of ___ joint.
symphysis
98
In which zone do capillaries grow into growth plate and chondrocytes degenerate and lacunae are invaded by osteogenic cells?
Zone of Degeneration (Death)
99
In the ____, blood vessels grow into cartilage mass and osteogenic cells differentiate into osteoblasts and form bony trabeculae?
Zone of Ossification
100
What type of bone lacks a Haversian system?
spongy and woven bone
101
What parts of bones are compact? What parts of bones are spongy?
cortex of long bones; ends of bones
102
___ joints, or diarthroses, are surrounded by a connective tissue capsule and lined by a thick synovium which secretes synovial fluid.
Synovial
103
___ bone can be dense and compact or cancellous/spongy.
Lamellar
104
Is cartilage vascular or avascular?
avascular
105
What is dense fibrous tissue in between bone called?
syndesmosis
106
Damage to what part of the intervertebral disc can cause the nucleus pulposus to herniate?
annulus pulposus
107
What are inactive Haversian systems known as?
interstitial systems
108
___ is secreted by the parathyroid hormone and ___ is secreted by the thyroid gland.
Parathormone; calcitonin
109
What bone cells can differentiate into osteoblasts and osteocytes?
osteoprogenitor cells (resting mesenchymal cells)
110
How may osteoporosis be treated?
oral calcium and vitamin D supplementation; chondroitin, glucosamine, and gelatin
111
Which joints lack an articular surface?
non-synovial
112
___ are actively involved in the resorption and remodeling of bone.
Osteoclasts
113
What type of cartilage is the precursor for bone in most of the skeleton?
hyaline cartilage
114
In the skull, what are the sutures of the bone derived from and called?
syndesmosis; synostosis
115
What non-collagenous organic molecule binds intracellular calcium during mineralization?
osteocalcin
116
GAG's of bone ground substance are mostly:
hyaluronic acid, chondroitin sulfate and keratin sulfate
117
In ____, the body produces antibodies that attack joints and cause damage to articular cartilage, thickening and inflaming synovial membrane.
rheumatoid arthritis
118
What happens due to calcification of cartilage matrix?
calcification inhibits diffusion of nutrients, which leads to death of chondrocytes and spread of osteoblasts
119
____ is the peripheral zone of dense connective tissue containing fibroblasts, collagen and immature chondroblasts.
Perichondrium
120
Osteoprogenitor cells from the periosteum migrate into the bone's ___, along with growing blood vessels.
medulla
121
___ bone is the immature form characterized by random orientation of collagen fibers.
Woven
122
Where does cartilage formation begin?
stellate mesenchymal cells
123
Is cartilage a bone precursor?
YES
124
Do long bones contain both fatty and red marrow?
YES
125
____ stimulates osteoblast activity, thereby inhibiting osteoclasts and allowing bone deposition.
Calcitonin
126
____ is the replacement of cartilage by bone.
Endochondral ossification
127
____ consists of alternating layers of hyaline cartilage and dense connective tissue (Type I and Type II collagen).
Fibrocartilage
128
Red wine, meat, asparagus, broccoli, cauliflower and Brussels sprouts (which are high in nitrogen) can all potentially cause ___.
gout
129
Are new and old osteons mixed?
YES (may minimize fractures)
130
Bony repair is like a cross between which two responses?
inflammatory response and intramembranous ossification
131
What is cartilage surrounded by?
perichondrium
132
What is territorial matrix?
slightly darker staining matrix seen right around isogenous groups
133
Which zone has successive mitotic division of chondrocytes?
Zone of Proliferation
134
What non-collagenous organic molecule binds collagen and minerals?
osteonectin
135
Bone and cartilage are both derived from ____ cells.
primitive mesenchymal
136
What kind of tissue are non-synovial joints joined by?
dense connective tissue
137
In ____, the resulting woven bone is remodeled by resorption and appositional growth.
endochondral ossification
138
In humans, which long bone is the last to close?
femur
139
Osteocytes are connected by small canals called ____.
canaliculi
140
What type of bone is later remodeled into lamellar bone and contains concentric layers with parallel collagen fibers?
Woven
141
What layer is the external surface of bone covered by?
periosteum (fibrous connective tissue)
142
What are the secondary functions of the skeletal system?
protection, mineral storage, and hematopoiesis
143
As compared to synovial joints, ___ joints have very limited movement.
non-synovial
144
How do cells differentiate in intramembranous ossification?
mesenchymal cells differentiate immediately into osteoblasts and begin synthesizing osteoid at MULTIPLE sites
145
Further mitotic divisions produce clusters of ___, which are referred to as isogenous groups.
chondrocytes
146
Where do osteoprogenitor cells reside in the bone?
in the periosteum and endosteum
147
What kind of cartilage is the precursor of a long bone formed from?
hyaline cartilage
148
Those affected by ___ have bones that do not calcify normally due to insufficient calcium or vitamin D.
rickets
149
What hormone leads to gigantism or acromegaly if over-secreted and pituitary dwarfism if under-secreted?
Somatotropin
150
Which WBC is the first to arrive on scene after a fracture (acute phase)?
neutrophils
151
____ is the progressive degeneration and loss of articular cartilage.
Osteoarthritis
152
___ synthesize large amounts of protein and proteoglycans within their cytoplasm.
Osteoblasts
153
Weakening of the periodontal ligaments and breakdown of old scars and wounds is indicative of a ___ deficiency.
vitamin C ( = collagen breakdown
154
Where is the digested bone secreted into?
the ruffled border
155
____ bone contains a network of thin, bony trabeculae and open spaces.
Cancellous (spongy)
156
When blood fills a fracture site, what is it called?
hematoma
157
What are osteoblasts responsible for?
calcification of matrix via secretion of matrix vesicles
158
Which cells secrete osteoid, which mineralizes and forms the periosteal cuff?
osteoprogenitor cells and osteoblasts
159
Why does cartilage harden with age?
because the invasion of the site with blood vessels results in death of chondrocytes and formation of bone (calcification via deposition of calcium phosphate crystals into matrix)
160
What so stellate mesenchymal cells differentiate into?
chondroblasts
161
In the ____, chondrocytes greatly enlarge and contain large amounts of glycogen, become vacuolated, and calcify.
Zone of Hypertrophy (and Calcification)
162
What is the general ultrastructure of cortical bone?
outer periphery is arranged in circumferential lamallae and covered by periosteum
163
What leads to the formation of a cement line in an osteon?
edge of hole dug by osteoclast and then invasion of the hole by osteoblasts
164
What is interterritorial matrix?
paler staining matrix further out from isogenous groups
165
These fibers extend from the periosteum and insert into the superficial layers of bone and provide anchors of support.
Sharpey's fibers
166
Osteoarthritis leads to and causes:
Inflammation of joints
Pitting, erosion, eburnation and pain of joint capsule
Limits range of motion
Bone spurs
Progressive buildup of osteophytes which could lead to bony fusion
167
What does the metaphysis contain?
epiphyseal plate
168
More than 90% of the organic component of bone is ___.
Type I collagen
169
Are osteoclasts multinucleate cells?
YES
170
What material made by osteoblasts is similar to cartilage and later mineralizes to form new bone?
osteoid
171
What is essentially the only synchondrosis in the body?
the joint between the sternum and the first rib
