Cartilage, Bone, and Musklez Flashcards
(262 cards)
0
Q
skeletal muscle also includes (3):
A
tongue, upper esophagus, diaphragm
1
Q
Which layer of muscle connective tissue is closest to deep fascia?
A
epimysium
2
Q
five functions of muscle
A
produce body movements, stabilize body positions, regulate organ volume, flow of substances within the body, temperature
3
Q
properties of muscle tissue (5)
A
excitability, elasticity, extensibility, conductivity, contractility
(EEECC)
4
Q
Method of regeneration skeletal muscle?
A
limited regeneration via satelite cells
5
Q
Where would you find T Tubules in relation to sarcomere?
A
at boundary of I/M lines
6
Q
what is sarcolemma made of?
A
plasma membrane of the cell and external lamina
7
Q
what layer is the epimysium adjacent to?
A
deep fascia
8
Q
Cell types in cartilage?
A
chondrocytes/chondroblasts
9
Q
Cartilage ground substance is made of:
A
glycosaminoglycans, proteoglycans, and glycoproteins
10
Q
cartilage glycosaminoglycans include:
A
hyaluronic acid, chondroitin sulfate
11
Q
cartilage glycoproteins include:
A
chondronectin
12
Q
types of fibers in cartilage include:
A
elastic and collagen
13
Q
three cartilage types
A
hyaline, elastic, fibrocartilage
14
Q
collagen type in hyaline cartilage
A
Type II
15
Q
What cartilage forms temporary skeleton in embryo?
A
hyaline
16
Q
epiphyseal plates are made up of ____ cartilage
A
hyaline
17
Q
articular surfaces of moveable joints are made of
A
hyaline cartilage
18
Q
ends of ribs = ___ cartilage
A
hyaline
19
Q
respiratory passages = ____ cartilage type
A
hyaline
20
Q
Why is elastic cartilage yellow?
A
elastin
21
Q
Fiber types in elastic cartilage
A
Type II collagen and elastic fibers
22
Q
Where is elastic cartilage found?
A
Eustachian tube, auricle of the ear, epiglottis
23
Q
Fibers in fibrocartilage?
A
Type I collagen
24
fibrocartilage is associated with ____ CT
dense
25
Where to find fibrocartilage?
menisci of the knee, intervertebral and articular discs, pubic symphysis
26
SOX-9
induces transition of mesenchymal cells to chondroblasts (transcription factor)
27
isogenous nest
multiple chondrocytes in a single lacunae
28
Which cartilage types lack perichondrium?
articular and fibrocartilage
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inner layer of perichondrium contains:
chondrogenic cells
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what is the periochondrium?
dense CT outer layer of cartilage
31
perichondrium is a source of:
nutrition and chondrogenic cells
32
Why do new chondrocyte cell matrices stain darker after mitosis?
increased amount of proteoglycans
33
What is an implication of cartilage lacking perichondrium?
No appositional growth and therefore, weak repair
34
5 risk factors to osteoarthritis
>45 years of age, female, genetic defects of cartilage, obesity, previous joint damage
35
Fiber types in bone
Type I Collagen
36
What types of ground substance in bone?
proteoglycans, glycoproteins
37
What types of glycoproteins in bone?
osteonectin, osteocalcin
38
cell types in bones?
osteoblasts, osteocytes, osteoclasts
39
Bones are organs comprised of (6):
1. bone tissue
2. hematopoietic tissue
3. adipose tissue
4. cartilage
5. blood vessels
6. nerves
40
Periosteum is composed of two layers
fibrous outer layer and osteogenic layer
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endosteum
thin layer inside bone that is source of osteoblasts
42
bone matrix converts ____ into ____ which are contained in ____
osteoblasts --> osteocytes in lacunae
43
source of osteoclasts
hematopoietic cells
44
Where are osteoprogenitor cells found?
periosteum and endosteum
45
when are osteoprogenitor cells active?
bone growth and repair
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osteoprogenitor cells differentiate into
osteoblasts
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where are osteoblasts found?
bone surface
48
what do osteoblasts produce?
organic components of the osteoid (bone matrix)
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active shape vs. inactive shape of osteoblasts?
active = rounded, inactive = flat
50
When does an osteoblast become an osteocyte?
once it is surrounded in matrix...it will never again replicate...
51
What is Stella's favorite flower?
catnip
52
What actually becomes calcified in the bones?
the osteoid
53
Describe osteoblast deposition of matrix.
It is polar. They deposit on the side towards the existing bone. Osteoblasts behind them will secrete additional matrix to cover them.
54
What is the function of osteocytes?
maintenance of bone matrix
55
describe osteocyte communication with other cells
cytoplasmic connections via canaliculi which have gap junctions
56
osteoclasts are derived from
monocytes
57
osteoclasts: relative size? mobility? nucleus?
large, motile, multinucleated
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clear zone
area of osteoclasts with a tight seal between cytoplasm and the ruffled border which stains lightly. few organelles are present here.
59
clear zone surrounds
periphery of ruffled border
60
clear zone is rich in
actin filaments
61
clear zone serves as
site of osteoclast adherence to the bone matrix
62
ruffled border
site of bone resorption which contains infoldings of the plasma membrane
63
Gross organization of bone vs. microscopic
compact/spongy (cancellous) vs. immature/mature
64
what forces do spongy bone resist? compact?
compression...bending
65
immature bone is ____, _____
primary, woven
66
immature bone has ___ osteocytes, ___ mineral content, and _____ array of collagen fibers
many osteocytes, low mineral content, irregular array of collagen fibers
67
mature bone is _____, _____
secondary, lamellar
68
spongy bone contains ____ lamellae, compact bone contains _____ lamellae
parallel; circular (osteons)
69
what are osteons arranged around?
Haversian canals
70
Harversian canals contain
artery and vein
71
fibers in concentric lamellae are organized at ____ to add strength to bone matrix
right angles
72
between layers of the osteon are
lacunae containing osteocytes
73
how are adjacent lacunae connected?
canaliculi
74
Volkman's canals
connect the blood vessels of adjacent Haversian systems
75
running parallel to the bone surface and adjacent to the periosteum/endosteum are
outer and inner circumferential lamellae
76
what fills the space between osteons?
interstitial lamellae
77
what are interstitial lamellae
remnants of prior osteons that were partially removed by osteoclasts during remodeling. they occupy the spaces between osteons.
78
in both osteogenesis processes, bone is first
produced in a trabecular network
79
flat bones/irregular bones formed by
intramembranous ossification
80
I.O. is the process used by what two layers of bone
periosteum/endosteum
81
fractures heal by a process analogous to
IO
82
how does IO start?
condensation of mesenchyme
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mesenchyme differentiate into ____ in intramembranous ossification
osteoprogrenitor cells --> osteoblasts
84
what happens to spaces between trabeculae in areas that will remain spongy bone?
filled with hematopoietic tissue
85
what happens to trabeculae in formation of compact bone?
compaction - the trabeculae thicken until intervening spaces are obliterated
86
initial bone that is laid down in the process of bone formation is ____ or ____ bone.
woven or immature
87
when is immature bone converted to mature?
during bone remodeling
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fontanelles
gaps in flat bones that don't initially meet one another. allows for compressibility of the skull and allows the skull to expand with brain growth.
89
endochondral ossification is used to form
long, short, and some irregular bones
90
prior to conversion into bone, the bones formed by endochondral ossification are
hyaline cartilage models
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EO, Step 1: Formation of cartilage model
clustering of mesenchymal cells with transformation into chondroblasts which lay down matrix, encase in lacunae, then become chondrocytes
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EO, Step 2: Growth of cartilage model
appositional and interstitial
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EO, Step 3: Formation of the bone collar
molecular signals cause perichondrial cells to differentiate into osteoblasts which generate the compact bone collar just below periosteum
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EO, Step 4: Chondrocytes hypertrophy
chondrocytes beneat the bone collar begin to swell and die because nutrition is no longer diffusing
95
EO, Step 5: hypertrophic cells secrete:
type X collagen, alkaline phosphatase, and VEGF
| - promote calcification of cartilage matrix and vascular invasion
96
EO, Step 6: death of ___ by ____
chondrocytes and disintegration of the matrix by matrix metalloproteases
- begins in shaft of the long bone, later involves epiphyses
- osteoprogenitor cells also invade with the blood vessels and differentiate into osteoblasts
97
EO, Step 7: invasion of ____ and ____
invasion of periosteal blood vessels and osteoprogenitor cells by ossification
98
EO, Step 8: osteoprogenitor cells differentiate into:
osteoblasts that secrete osteoid.
- first occurs in areas of calcified cartilage (appears purple)
- pink areas = osteoid being laid down around spicules.
99
EO, Step 9: formation of _____ _______ centers
secondary ossification centers
100
primary vs secondary ossification centers
shaft = primary, secondary = ends of long bones
101
what separates ossification centers?
cartilage plate
102
at the end of EO, where does cartilage remain?
epiphyseal plate and articular surfaces
103
a long bone can only increase in length if
the epiphyseal cartilage (growth plate) is intact
104
5 Zones in the cartilage of epiphyseal plate
resting zone, zone of proliferation, zone of hypertrophy, zone of calcification, zone of ossification
105
resting zone is made up of
hyaline cartilage
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in zone of proliferation, chondrocytes
rapidly mitose and form columns of cells
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in zone of hypertrophy, cells ____ and secrete ____
hypertrophy and secrete Type X collagen, alkaline phopshatase, and VEGF
108
in zone of calcification what happens to cells?
matrix calcified, cells die
109
What is happening in zone of ossification?
blood vessels invade bringing osteoprogenitor cells, osteoblasts deposit bone matrix on calcified matrix
110
epiphyseal plate contributes to length or width?
both
111
with respect to the epiphyseal plate, where does bone growth occur? bone deposition?
proliferation of cartilage on epiphyseal side of the plate, bone deposition on the diaphyseal side
112
what stimulates activity on the epiphyseal plate?
growth hormone
113
why can't bones grow in length during adulthood despite excess GH?
no more epiphyseal plates
114
how is the size of the marrow cavity increased?
bone resorbed
115
when is bone remodeled?
osteogenesis (primary > secondary), growth, repair, and in response to applied forces
116
What is osteopenia? Most common type?
too little bone, osteoporosis (bone that exists has a normal appearance but there's too little of it)
117
peak content of bone tissue occurs
during third decade of life
118
when do women start to lose bone most rapidly?
after menopause
119
calcitonin is produced by
thyroid gland
120
fn of calcitonin
reduce osteoclastic activity and result in reduced blood calcium levels
121
PTH produced by
parathyroid gland
122
PTH fn
increases osteoclastic activity and results in elevated blood calcium.
- stimulates GI tract to absorb calcium
- reduces calcium excretion from the kidney
123
skeletal muscle also includes
tongue, upper esophagus, and diaphragm
124
diameter of skeletal muscle cells
10-100 um
125
syncytium of skeletal muscle?
multinucleated
126
mitosis in SkM
none, limited regeneration with satellite cells
127
SkM supported by
epimysium, perimysium, endomysium (all are CT)
128
sarcolemma includes
plasma membrane of the muscle cell + external lamina
129
above epimysium is
deep fascia
130
Muscle > > > >
muscle > fascicle > fiber > myofibrils > myofilaments (thick/thin)
131
skeletal muscle can be up to ____ long
100 cm
132
every individual SkM cell is packed with ____ which contain ____
myofibrils, myofilaments
133
every mature muscle cell develops from about ___ _____ that fuse together during _____ development
~100 myoblasts that fuse together during fetal development
134
middle of a contractile unit?
A band
135
primary reason for the dark A band?
presence of heavy, myosin filaments
136
why are some portions of the A band darker than others?
overlapping actin filaments
137
three protein types in myofibrils
contractile, regulatory proteins, structural proteins
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two types of contractile proteins in myofibrils
myosin II and actin
139
three types of regulatory proteins in myofibrils (and what do they do?)
troponin complex, tropomyosin, myosin light chain kinase (MLCK)
- turn contraction on and off
140
5 types of structural proteins in myofibrils
titin, myomesin, nebulin, alpha-actinin, dystrophin
141
three classes of intermediate filaments in myofibrils
desmin, vimentin, synemin
142
each myosin filament has ___ actin surrounding it each of which is _______ with another myosin
6, shared
143
major protein of the A band?
myosin II
144
describe the 4+ proteins in the head region of Myosin II
2 heavy with globular head, 2 essential light chians, 2 regulatory light chains
145
function of Actin binding protein?
binds actin to form cross-bridges
146
mechanoenzyme
ATPase that hydrolyzes ATP, detaches crossbridges
147
how do myosin molecules assemble?
- self assemble into long, bipolar aggregates bound at their tails
- features a bare zone in between
~300-600 molecules of myosin II form a thick filament
149
what meets at Z line?
+ ends of actin
150
M line
where myosin tails meet (bare area) + myosin-binding structural proteins
151
which area remains the same throughout contraction?
A band
152
when calcium binds troponin,
configuration changes to pull tropomyosin away from the myosin binding site on actin fibers. this exposes the site to adjacent myosin molecuels which contain sites for interaction with actin. this begins the process of muscle contraction.
153
binding of myosin to the myosin-binding site on actin causes
- ADP release from head of myosin molecule
- leads to conformational change to pull actin toward minus end of actin filament
- + end is anchored to Z disk which pulls adjacent Z disks closer
- this contraction process does not expend energy
154
how does myosin head release grip on actin filament?
cocked myosin head must bind ATP
| - without ATP the muscles can't relax
155
release of actin filament does not require
ATP hydrolysis
156
what is required for recocking of the head of myosin molecule?
ATP molecule hydrolysis
157
phosphorous remains attached to myosin until
myosin interacts with another free myosin binding site on an adjacent actin filament
158
triad (muscle)
T tubules together with term cisternae
159
motor unit
all of the muscle fibers innervated by one nerve fiber that tend to contract synchronously
160
synaptic end bulbs
swellings of axon terminals with synaptic vesicles that contain ACh
161
one motor end plate membrane contains
30 million ACh receptors
162
CM vs. SkM (similarities, dissimilarities)
both striated
- but CM has centrally located nuclei, intercalated discs on CM, and branching
163
CM: striations? length? shape? branching?
striated, short, quadrangular, branching fibers
164
how many cells in CM? nucleus?
single cells w/ central nucleus
165
how are CM cells connected?
intercalated discs with gap junctions
166
transverse vs. vertical portions of CM?
transverse have fascia adherens which are like broad desmosomes
- vertical have true desmosomes and many gap junctions
167
T tubules in SkM vs. CM?
SkM = triad, CM = dyad
168
growth of CM
no mitosis, no regeneration (or very little), hypertrophy in response to demand
169
Smooth Muscle (SM)
- cells?
- nucleus?
- striations?
- communication?
- single, fusiform cells
- central nucleus
- no striations, no clear indication of contractile system
- no clear indication of communication
170
SM often appears in ____ surrounded by a _____
layers, lumen
171
nuclei of SM have an "____" and "___" appearance
open, wavy
172
arrector pili muscle (muscle type and function)
goosebumps, SM
173
instead of T-tubules, SM has
invagination and vesicle-like caveolae
174
in response to demand, what happens to SM?
hyperplasia/hypertrophy
175
mitosis/regeneration in SM?
both occur in SM
176
indention of nuclei of SM?
nuceli of SM cells may be indented when cells contract since there ar emultiple fibers bridging across the cell.
177
SM cells are surrounded by a network of
network of reticular fibers
178
how much SR in SM? what junction types? what type of endocytosis?
modest, gap, pinocytotic vesicles
179
SM actin and myosin attach to
dense bodies along plasma membrane
180
dense bodies contain ____ which allows for _______ contraction
alpha-actinin +, allows for corkscrew contraction
181
SM movement is dependent upon
interaction between myosin heads and actin
182
initiation of SM contraction requires increase of ________ which binds to _______. this activates ___________ which ________. this changes the configuration of ______ to allow it to bind to _______.
requires increase of EC calcium to bind calmodulin. MLCK is then activated and phosphorylates myosin light chains. this changes ocnfiguration of inactive myosin and allows it to bind with actin.
183
what terminates contraction of SM?
phosphatases
184
what causes uterine contraction?
oxytocin
185
____ and ____ are required for the initiation of contraction.
CA2+ and calmodulinf
186
myosin light chain is phosphorylated at ______ by ______
serine 19 by MLCK
187
hhow do neurotransmitters reach SM?
caricosisties with vesicles of neurotransmitters at various points along axon terminals
188
two types of smooth muscle units?
visceral type and multiunit type
189
```
visceral type SM unit
sheets of SM working in ____ to do _____
found where? (2)
innervation?
junctions?
```
working in coordination for peristalsis
gut, uterus
sparse innervation
extensive gap junctions
190
multiunit type of SM unit
- contraction is ___ and ____
- found where? (2)
- innervation?
fast, rapid
- SM of eye, arrector pili
- heavily innervated
191
myoepithelial cells
- derive from
- located near ____
- help with _____
- are they SM? contractile?
derive from epithelium
- located near glands
- help with secretion movement
- not SM, they reside inside basement membrane of epithelium
- no actin/myosin, are contractile
192
what is in the H band?
myosin only, no actin overlap, part of A band
193
four functions of cartilage
1. structural support of soft tissues
2. shcok absorption in joints
3. reduce friction
4. role in growth/development of bones
194
hyaline ECM is primarily
Type II collagen
195
what forms epiphyseal plates of growing long bone?
hyaline
196
what is diff between articular cartilage and hyaline?
articular has no perichondrium
197
fibrocartilage is a cross between
hyaline cartilage and dense CT
198
resists what two force types?
shearing/compression
199
in fibrocartilage, the chondrocytes are arranged
in rows
200
perichondrium of fibrocartilage
not present
201
all supportive tissue derived from
mesenchymal cells
202
most cartilage is surrounded by a layer of
dense CT called the perichondrium
203
medullary cavity =
marrow
204
where is the periosteum not found?
areas with articular cartilage for articulation with other bones
205
how does the periosteum attach to bone?
via collagen fibers from the periosteum penetrating the bone itself (aka Sharpey's fibers)
206
how many layers of cells in the endosteum?
single layer
207
what is found in the endosteum?
osteoprogenitor cells and osteoblasts
208
periosteal cells vs. osteoprogenitor cells?
same cell but periosteal are found on the outside. endosteal are on the inside.
209
how do osteoblasts initiate calcification?
by secreting vesicles with alkaline phosphatase
210
bone matrix fibers are primarily
type I collagen
211
collagen fibers within a given lamellae are typically ___ but in adjacent they are ___
parallel, perpendicular
212
lucanae containing osteocytes vs. lamellae
found in between and occasionally within
213
when does bone formation begin?
embryo
214
growth factors involved in transition from mesenchyme to osteoblasts to osteocytes (2)
TGF-beta (transforming growth factor - beta), bone morphogenic protein (BMP)
215
Ihh
indian hedgehog involved with differentation and hypertrophy of chondrocytes in endochondral bone formation
216
calvaria
roof of the skull
217
clavicle is formed by
I.O.
218
mandible is formed by
I.O.
219
primary ossification center
site where mesenchymal cells migrate to
220
what does osteocalcin do?
binds calcium
221
osteonectin
glycoprotein which binds matrix components such as collagen to the minerals (Ca2+ + phosphate in the form of hydroxyapatite crystals
222
how do spicules grow?
osteoblasts congregate on the edges of the psicules and secrete more matrix
223
if dvlping bone will become spongy,
reamining mesenchyme becomes bone marrow cells
224
what regulates the initial stages of hyaline cartilage model fromation?
mesenchymal-epithelial cell interactions
225
what happens to perichondrial cells during E.O.?
stop produceing chondroblasts and switch to osteoblasts
226
what disintegrates the matrix and ocntributes to death of chondrocytes in step 6 of EO?
matrix metalloproteases
227
how do they stain? cartilage ______ bone _____
cartilage - basophilic, bone - eosinophilic
228
zone of reserve
typical hyaline cartilage (chondrocytes in resting state)
229
zone of proliferation
chondrocytes dividing rapidly, form columns parallel to long axis
230
zone of hypertrophy
large chondrocytes whose cytoplasm has accumulated glycogen, and narrow areas of matrix between lacunae
231
zone of calcification
matrix is becoming calcified and chondrocytes die via apoptosis
232
zone of ossification
are where osteoprogenitor cells are invading and differentiating into osteoblasts; osteoblasts secrete bone matrix onto the calcified cartilage matrix
233
somatotropin
growth hormone
234
when do epiphysis and diaphysis meet?
when epiphyseal closure occurs which is dictated by hormones
235
what is the primary source of bone width change?
expansion of the marrow cavity (appositional growth) by intramembranous ossification
236
in response to rising Ca2+ levels thyroid gland secretes
calcitonin
237
rickets
calcium deficiency in chldren
238
role of vitamin D
absorption of calcium by the GI tract
239
muscles controlling eye movement are what type?
skeletal
240
muscles supporting pelvic contents?
skeletal
241
tongue is what muscle type?
skeletal
242
skeletal muscle fibers result from the fusion of
multiple myoblasts
243
barbed end of actin
+ end which is anchored to the Z line and are associated with the scaffolding protein nebulin
244
titin
molecular spring to prevent overstretching of the sarcomere; holds myosin II thick filaments together
245
what stabilizes the sarcolemma?
the membrane cytoskeleton composed of actin, dystrophin, and other proteins
246
defects in dystrophin
muscular dystrophy
247
myotendinous junction
utilizes integrins to establish the connection between actin filaments of hte terminal sarcomere and the ECM
248
3 things required for contraction of a skeletal muscle cell
Ca2++, ATP, and motor axon innervation
249
what is a motor unit
single axon with all the muscle fibers it innervates
250
what triggers depolarization of the sarcolemma?
release of acetylcholine
251
what provides a structural framework for SM?
intermediate filaments
252
in SM, actin filaments are anchored at
membrane associated and cytoplasmic dense plaques
253
where are myosin thick filaments in SM?
interdigitated with actin filaments in a 3D network with leittle resemblance to sarcomeres
254
calcium regulated tronponin/tropomyosin system in SM?
not present, instead they use myosin light chain kinase (MLCK) to trigger actin-myosin contraction occuring through either calcium-calmodulin or other ways (cAMP activation)
255
contracted smooth muscle resembles
corkscrews
256
neuromuscular junctions in cardiac cells
not present, although autonomic snerves do release neuotransmitter in the vicinity to the cells
257
intercalated discs are made up of
desmosomes, fascia adherens, and gap junctions
258
mitochondria in cardiac vs SkM
more in cardiac
259
energy dependent calcium channels in SkM
pump Ca2+ back into SR
260
epimysium
deep fascia,
261
how is muscle fiber separated from the endomysium?
external lamina which is part of hte sarcolemma
262
what kind of CT are tendons?
dense regular CT
