Test Three Module 7 Flashcards
1
Q
The skeletal system consists of: (4)
A
- The bones of the skeleton
- Cartilages between bones
- Ligaments connecting bones
- Connective tissues surrounding all of these
2
Q
What are the 6 functions of the skeletal system?
A
- Support
- Protection (e.g. skull, ribs)
- Leverage for muscle contractions
- Storage of calcium, phosphate
- Storage of lipids (yellow bone marrow)
- Blood cell production (red bone marrow)
3
Q
What is stored in the yellow bone marrow?
A
lipids
4
Q
Bone itself is a _____?
A
tissue
5
Q
Bone is formally called _____?
A
osseous tissue
6
Q
Bone or osseous tissue is a type of _____ tissue?
A
supporting connective tissue
7
Q
Osseous tissue has more extracellular matrix than _____?
A
cells
8
Q
The extracellular matrix is the _____?
A
solid bone mineral
9
Q
Bones can be classified and categorized by?
A
(Shape and location)
- Shape of individual bone
- How the bone tissue is organized in a specific location within a larger bone
10
Q
Within an individual bone, the osseous tissue/bone can be organized into one of what two ways?
A
- Compact bone
2. Spongy bone
11
Q
Compact bone is also known as?
A
- Dense bone
- Cortical bone
12
Q
_____ bone is the outer layer of bones?
A
Compact
13
Q
Ho much of compact bone can be space?
A
30%
14
Q
In compact bone only 5-30% is ____ or ___?
A
pores or spaces
15
Q
What are mostly the pores or spaces in compact bone?
A
Lacunae and canaliculi holding osteocytes
16
Q
Compact bone consists of _____of bone grouped together?
A
cylinders
17
Q
Each cylinder of bone is called an _____?
A
osteon
18
Q
What is another name for a osteon?
A
Haversian system
19
Q
Each osteon is made up of concentric rings called ______?
A
lamellae
20
Q
Spongy bone is also called?
A
- Cancellous bone
- Trabecular bone
21
Q
______ bone is the inner layer of all bone?
A
Spongy
22
Q
Spongy bone is 30-90% _____ created by a lattice of rods and plates?
A
pores
23
Q
_____ and ____ travel through the spaces in spongy bone and the rest of the space is often filled with re or yellow bone marrow?
A
blood vessels and nerves
24
Q
In spongy bone, _____ are the small projections of bone that make up the solid part of spongy (trabecular) bone?
A
Trabeculae
25
Long bones have an additional feature, a ______?
Cavity
26
What is a cavity?
Empty of bone but filled with other tissues
27
In long bones, the ______ is where additional red or yellow bone marrow is kept?
Medullary cavity
28
Where else in bone marrow found?
It is kept between trabeculae of spongy bones
29
In childhood the medullary cavity is filled with ______ bone marrow?
Red bone marrow
30
In adulthood all the marrow in the medullary cavity has switched over to _____ bone marrow?
Yellow bone marrow
31
The spongy bone around the medullary cavity still has some _____ marrow in between its trabeculae?
Red marrow
32
_____ marrow is a respiratory of specialized mesenchymal stem cells that have specialized into hematopoietic stem cells?
Red bone marrow
33
In red bone marrow, the ______ stem cells divide and specialize into all the red and white blood cells that will leave bone marrow and enter the blood?
hematompoietic stem cells
34
Most of the developing hematompoietic stem cells will specialize into _____ blood cells, which is why red bone marrow is red?
red blood cells
35
Mesenchymal stem cells can develop into any connective tissue cell type, but _____ stem cells have specialized into a stem cell that will only develop into blood cells?
hematopoietic
36
_____ bone marrow is a repository of mostly adipose tissue (fat)?
Yellow bone marrow
37
As a person ages, the hematopoietic stem cells of red bone marrow are replaced with _____ tissue in the medullary cavities of all the long bones, converting red bone marrow to yellow bone marrow?
adipose tissue
38
Adipose tissue is vaguely _____ colored, which is why it is called yellow bone marrow?
Yellow
39
In adults red bone marrow with hematopoietic stem cells remains only in spongy bone and only in a few locations: (4)
- In the spongy bone at the ends (heads) of the femur and tibia bones.
- In the spongy bone of flat bones like the skull bones and ribs.
- In the spongy bone of the coxal bones.
- In the spongy bone of the vertebrae.
40
Bones are osseous tissue, the densest type of _____ connective tissue?
supportive connective tissue
41
Like all connective tissue, _____ tissue consists of interspersed cells in an elaborate extracellular matrix?
osseous
42
Two thirds of bone extracellular matrix is _____?
Hydroxyapatite
43
Hydroxyapatite is _____ that has reacted with _____ to form crystals of hydroxyapatite?
Calcum phosphate and calcium hydroxide
44
The _____ binds up other calcium salts and other ions and incorporates them into the now solid extracellular matrix?
hydroxyapatite
45
One third of bone extracellular matrix is _____?
collagen protein fibers
46
The hydroxyapatite crystals deposit on the _____, creating a solid matrix around them?
collagen protein fibers
47
What are the two things that make up bone extracellular matrix?
hydroxyapatite and collagen protein fibers
48
Cells make up only __% of bone mass?
2%
49
Bone contains what 4 types of cells?
1. osteocytes
2. osteolasts
3. osteprogenittor cells
4. osteoclasts
50
_____ are mature bone cells that maintain the bone matrix?
osteocytes
51
Where are osteocytes found?
Throughout the bone interior, completely surrounded by solid extracellular matrix
52
Cytoplasmic extensions from one osteocyte meets up and is joined via _____ to a cytoplasmic extension from a neighboring osteocyte?
gap junctions
53
Osteocytes are found in openings in extracellular matrix called _____?
lacunae
54
If the osteocytes were not in _____, the mineral extracellular matrix would crush them?
lacunae
55
What are canaliculi?
Canaliculi are not the cellular extensions; they are the tunnels the extensions are found in.
56
Osteocytes are found between _____ (concentric rings) of osteons and trabeculae?
lamellae
57
_____ do not divide?
osteocytes
58
What are the main functions of osteocytes?
+To maintain protein and mineral content of nearby existing extracellular matrix by both removing and replacing nearby extracellular matrix components.
+Osteocytes alter the contents of the bone extracellular matrix on small-scale; other bone cells remove and replace bone mineral on a larger scale.
59
_____ are immature bone cells that secrete extracellular matrix compounds and build new extracellular matrix in a process called osteogenesis?
Osteoblasts
60
_____ are located in the periosteum the membrane surrounding the exterior of bones and in the endosteum lining medullary canals, central canals, and spongy bone?
Osteoblasts
61
Osteoblasts first lay down _____?
osteoid
62
_____ is extracellular matrix produced by osteoblasts, with collagen and phosphate, but not any calcium?
osteoid
63
Osteoblasts that have secreted enough extracellular matrix to become surrounded by bone mineral and collagen convert to _____?
osteocytes
64
Osteoblasts just _____ bone, don't actively remove and replace it like osteocytes?
build
65
What does osteoid lack?
calcium
66
_____ is a somatic stem cell that divides to produce two daughter cells, one that remains an osteoprogenitor cell, the other specializes into an osteoblast. The osteoblast will eventually specialize into an osteocyte?
osteoprogenitor cells
67
Osteoprogenitor cells assist in _____ repair, but not much in normal growth of intact bones?
fracture
68
_____ stem cells can be converted to osteoprogenitor cells?
mesenchymal stem cells
69
What is another name for osteoprogenitor cells?
osteogenic cells
70
_____ cells are giant, multi-nucleate cells?
osteoclast
71
_____ cells secrete protein-digesting enzymes that break down the collagen fibers in bone extracellular matrix?
Osteoclast
72
_____ cells also secrete acids that release the calcium and phosphate in bone extracellular matrix dissolving the bone mineral?
Osteoclast
73
Osteoclast _____ small portions of bone?
collapse
74
This process of using osteoclasts to collapse small portions of bone is called _____ or ____?
osteolysis or bone resorption
75
_____ are not derived from osteoprogenitor cells, but derive from the same hematopoietic stem cells that produce macrophages (white blood cells that engulf & digest pathogens)?
osteoclasts
76
Where are osteoclasts found or located?
In the inner layer o the endosteum lining the medullary cavity, central canal, and trabeulae
77
where are osteocytes found or located?
In the lamellae of compact and spongy bone
78
Where are osteoblasts found or located?
in the periosteum lining the outside of bones and in inner layer of the endosteum?
79
Where are osteoprogenitor cells found or located?
in the periosteum lining the outside of bones and in the inner layer of the endosteum
80
What are the two "membranes" that line bones?
Periosteum and endosteum
81
Periostuem lines _____ bones?
outside
82
Endosteum lines_____ bones?
Inside
83
Both "membranes", periosteum and endosteum consist of a layer of _____ over a layer of bone cells without the bone extracellular material around them?
irregular dense connective tissue proper
84
The _____ on the exterior surface of bones is a layer of irregular dense connective tissue proper + a layer of bone cells?
periosteum
85
The _____ covers the surfaces of all bones regardless of location or bone type?
periosteum
86
What are the functions of periostium? (3)
+It isolates bone from surrounding tissues.
+Its outer layer of irregular dense connective tissue proper provides a route for blood vessels, lymph vessels, nerves to connect to bone.
+Its inner layer of cells (not surrounded by bone mineral) participates in bone growth and repair because it is a layer of osteoprogenitor cells and osteoblasts – bone cells which build new bone mineral.
87
The _____ is attached tightly to the bone underneath it and allows tight attachment of tendons and ligaments to bones due to its perforating fibers?
periosteum
88
What three things do perforating fibers connect?
bone, periosteum, ligaments/tendons
89
What are perforating fibers?
The collagen fibers of the periosteum that extend out of the periosteum and connect
90
These perforating fibers provide a very strong attachment between bones and their _____ or _____?
ligaments or tendons
91
The _____ is the layer of irregular dense connective tissue proper plus a layer of bone cells found inside bones?
endosteum
92
What does the endosteum line and cover? (3)
+It lines the medullary cavity (contains marrow) of long bones.
+It covers trabeculae of spongy bone.
+It lines central canals of compact bone osteons.
93
What is the main difference between endosteum and periosteum/
endosteum’s inner layer of bone cells has osteoclasts,(not found in periosteum), as well as osteoprogenitor cells and osteoblasts (are found in periosteum.).
94
_____ is active in bone growth, bone repair, and bone remodeling because its inner layer houses osteoclasts as well as osteoblasts and osteoprogenitor cells ?
Endosteum
95
_____ outside bones only have osteoprogenitor cells and osteoblasts next to its irregular dense connective tissue proper layer?
periosteum
96
What two cells are involved in bone remodeling?
Osteoblast and osteoclast
97
_____ Dismantle some bone existing extracellular matrix, but _____ deposit some new bone extracellular matrix around existing extracellular matrix?
osteoclast / osteoblast
98
What happens during bone remodeling?
Bones extracellular matrix is removed and then immediately replaced
99
When bone _____ is maintained the extent of bone dismantling by osteoclasts is balanced by the extent of bone deposition by osteoblasts?
homeostasis
100
In a young adult, approximately _____ of all bone is removed and replaced each year without significant changes in total bone mass?
1/5th
101
Removal of bone by _____ is balanced by equal amounts of new bone formation by ______?
osteoclasts / osteoblasts
102
_____ such as lead, strontium, cobalt, uranium, plutonium can be "accidentally" incorporated into new bone if too abundant in the body?
heavy metals
103
_____ are also known for building brand new bone?
osteoblasts
104
_____ do not dismantle any extracellular matrix, only add to it?
osteoblasts
105
If osteoblast bone deposition outpaces osteoclast bone removal the net result is _____?
bone growth
106
osteoblast are found both in _____ outside of bone and in the _____ inside of bone, so growth can occur outwards and inwards?
periosteum and endosteum
107
_____ are also involved in the dismantling existing bone?
osteoclasts
108
Some bones change shape during growth so _____ needed to dismantle unneeded sections?
osteoclasts
109
If the body’s calcium ion levels are too low, osteoclasts will be signaled to dismantle bone to release _____ that can be taken up by cells throughout the body that need it?
calcium
110
If osteoblast activity drops below osteoclast activitym there is _____?
net bone loss
111
_____ bones becomes thicker and stronger?
heavily stressed (ex. exercise)
112
The _____ induces osteoblasts to build extra bone?
stress
113
Bone _____ quickly, up to one third on bone mass can be lost in a few weeks of inactivity probably because of lower _____ activity?
degenerates and osteoblast
114
Compact bone mostly consists of _____ of bone grouped together?
cylinders
115
Each cyclinder in compact bone is called an ______?
Osteon or haversion system
116
Interior of compact bone consists of many _____ stacked on top of each other?
osteons
117
The bone in each osteon is arranged in concentric circles, each circle is a _____?
concentric lamella
118
Where are osteocytes found in osteons?
they are found at the edges of lamellae
119
What is the central canal?
It is the tunnel in the center of each osteon
120
What does the central canal contain?
Blood vessels and nerves that penetrate the compact bone
121
What lines the central canal?
Endosteum
122
What are perforating canals?
they travel perpendicular to the central canal and carry blood vessels into deeper bone, eventually reaching spongy bone and the medullary cavity in the center of long bones
123
Within the concentric lamellae of osteons, the collagen protein fibers in the bone ecm ______?
run up the osteon and run at a slant
124
The partially dismantled osteons are called _____?
interstitial lamellae
125
Intact osteons are partially dismantled by _____ creating irregularly shaped interstitial lamellae?
osteoclasts
126
What are interstitial lamellae?
Partially dismantled osteons
127
On the outer surfaces and the most inner surfaces of bones is _____ that circle the entire bone?
circumferential lamellae
128
_____ bone does not have true osteons?
spongy bone
129
The tissue forms an open web like network of _____ which are the threads that make up the solid portions of spongy bone?
trabeculae
130
Each _____ has concentric rings of lamellae similar to the make up of an osteon but without a central canal?
trabeculae
131
What do trabeculae lack that is found in osteons?
Central canals
132
Trabeculae have no ____ or no _____?
central canal or blood vessels
133
But the spaces between trabecular have _____, _____, and _____ that travel from perforating canals in compact bone?
blood vessels, lymph vessels, and nerves
134
Trabeculae are covered with ____ the connective tissue + bone cells wrapper that also line central canals in compact bone?
endosteum
135
The remaining spaces (not filled with blood vessels, lymph vessels, or nerves) between trabeculae are filled with _____ ?
bone marrow
136
Initially _____ bone marrow fills the spaces in spongy bone, where new red and white blood cells are formed?
red
137
In later life, some red bone marrow is replaced with _____ which mostly consists of fat in the form of adipocytes?
yellow bone marrow
138
What are some nutritional factors needed for normal bone growth? (3)
+A dietary source of calcium and phosphate salts
+Plus small amounts of magnesium, fluoride, iron, and manganese
+and various vitamins
139
What vitamin deficiency causes rickets?
Vitamin D deficiency
140
How do we get vitamin D3?
it is produced in skin using UV light or obtained through diet
141
What is vitamin D3 use?
Its used to produce the hormone calcitriol, which allows the body's cells to take up ca2+ efficiently
142
Why do bone cells need to take up Ca2+?
in order to deposit it in osteoid and solidify into true bone
143
What is rickets?
When developing bones of legs do not have enough calcium to solidify entirely, bend under weight of body
144
What is required for collagen sythesis?
vitamin C
145
What is required for stimulation of differentiation of osteoprogenitor cells in osteoblast?
vitamin C
146
What cause scurvy?
Vitamin C deficiency
147
What are symptoms of scurvy?
Bleading, hair and tooth loss, joint pain, fatigue, and eventually death
148
What stimulates osteoclast activity, necessary for proper bone remodeling?
vitamin A
149
What vitamin deficiency causes blindness?
vitamin A
150
Vitamin A also affects ____ but eyes are more noticeably affected?
bones
151
What vitamin is necessary for proper osteoblast activity?
vitamin K
152
What vitamin deficiency cause hemophilia and lower bone density?
vitamin K
153
______ deficiency results in less bone growth, but it is also necessary for blood clotting, so a _____ deficiency is more noticeable for producing excess bleeding?
vitamin K
154
What 5 hormones are needed for bone growth and maintenance?
1. Calcitriol
2. Growth hormones
3, Thyroxine
4. Estrogens and adrogens
5. Calcitonin and parathyroid hormone
155
Where is calcitriol produce and from what?
produced from vitamin D3 in kidneys
156
What does calcitriol help?
helps in calcium, phosphate absorption in digestive tract
157
Where is growth hormone produced?
in pituitary gland, stimulates protein synthesis & cell growth in all cells, including osteoblasts
158
Where is thyroxine produced?
in the thyroid gland and stimulates osteoblasts
159
What do estrogens and androgens do?
Stimulate osteoblast
160
What do calcitonin and parathyroid hormone do?
regulate calcium and phosphate levels
161
As an embryo starts developing, most of the bones in the skeleton are initially made out of _____?
hyaline cartilage
162
When does cartilage start to gradually convert from cartilage to bone?
after the embryo develops into a fetus
163
What are most bones initially made from during fetal development?
cartilage
164
The fetus' cartilage is replace by bone in a process known as _____?
endochondral ossification
165
What are the 6 steps of endochondral ossification?
1. A skeletal component is made of cartilage.
2. Chondrocytes (cartilage cells) die.
3. Osteoprogenitor cells move in.
4. Osteoprogenitor cells convert to osteoblasts.
5. Osteoblasts replace cartilage extracellular matrix with bone extracellular matrix.
6. Osteoblasts surround themselves with bone mineral and convert to osteocytes.
166
Growth in long bone is both in ______ and _____?
width and length
167
To allow lengthwise growth in long bones there is an _____?
epiphyseal plate
168
Where are the epiphysis?
on either end of the long bone
169
Where is diaphysis?
on the shaft of the bone, between the 2 epiphysis on each end of long bone
170
The _____ is a band of cartilage near each end (epiphysis) of any long bone? AKA the growth plate?
epiphyseal plate
171
After birth, the _____ is the site at which length is added to long bones?
epiphyseal plate
172
What are the 3 steps that the epiphyseal plate allow long bone to add length after birth?
1. At the side of the epiphyseal plate closer to the end of the bone, chondrocytes in the cartilage produce more cartilage.
2. On the side of the epiphyseal plate closer to the shaft of the bone, osteoblasts remove cartilage and replace it with bone mineral (called calcification).
3. It lengthens the bone without lengthening the epiphyseal plate.
173
Once a person reaches adulthood and stops growing, the entire epiphyseal plate is converted to _____ (calcified) and all that remains is an epiphyseal line, still visible in X-rays or by direct examination?
compact bone
174
What are some of the bones that never start out as cartilage and develop later by intramembranous ossification?
flat bone of skull , clavicle, and mandible
175
Name the 6 steps of intramembranous ossification?
1. Dense connective tissue proper forms in the region that will later be bone.
2. Messenchymal stem cells from the connective tissue convert to osteoprogenitor cells that line the inner layer of the connective tissue.
3. The osteoprogenitor cells convert to osteoblasts.
4. The osteoblasts lay down bone mineral.
5. Osteoblasts surround themselves with bone mineral and convert to osteocytes.
6. Most of the connective tissue is replaced with bone, but the outer layer becomes periosteum.
176
What is osteopenia?
The condition where bone density is less the optimal
177
Bones become thinner and weaker with age s part of the _____?
normal aging process
178
When do most people start to experience osteopenia?
between the ages of 30 and 40
179
Why does osteopenia happen?
Because osteoblast activity starts to drop and less new bone is made, but osteoclast activity remains steady and bone removal starts outpacing bone productions
180
Once osteopenia has started, women lose __% of bone mass per decade and men lose __%?
8% and 3%
181
What is most affected by osteopenia?
the ends of long bones, the vertebrae, and jaws
182
What are some results of the ends of long bones, the vertebrae, and jaws being the most affected by ostoepenia?
Fragile bones, reduction in height, and tooth loss
183
What is not a symptom of osteopenia?
Kyphosis or dowager humps
184
What is osteoporosis?
severe bone loss that adversely affects normal function
185
What age does osteoporosis mostly occur?
over age 45
186
What is osteoporosis linked to?
Linked to the drop in estrogens (in women post-menopause) and androgens (in men not dramatic until post-60s) with age
187
_____ is extreme osteopenia?
Osteoporosis
188
What test, test bone mineral density?
DEXA test
189
What do angrogens and estrogens stimulate?
osteoblast
190
So when androgen and estrogen levels drop with age, ____ keep removing bone, but osteoblasts are slower to replace it?
osteoclasts
191
What can cause kyphosis or dowager humps?
osteoporosis weakening the vertebrae in backbone and leading to them cracking and compressing
192
______ can weaken vertebrae in backbone and lead to them cracking and compressing?
osteoporosis
193
What is kyphosis?
An extreme forward rounding of the back
194
Dowager humps are more common in _____ than _____ because osteoporosis is more common in older _____?
women / men / women
