bone/muscle/joints Flashcards
0
Q
Example of sesamoid bone
A
Patella
1
Q
What makes bone hard?
A
Salts in the AGS crystallise to form a matrix - making bone super hard
2
Q
What is the diaphysis?
A
Shaft, or middle of the bone
3
Q
What Is the junction called between the diaphysis and the epiphysis?
A
Metaphysis
4
Q
What covers the epiphysis?
A
Articular cartilage
5
Q
What is inside the medullary cavity?
A
Yellow Marrow/ fat
6
Q
What is the middle of the long bone shaft called?
A
Medullary cavity
7
Q
What is the outer most layer covering the bone?
A
Periosteum, dense irregular connective tissue
8
Q
cells of bone
A
osteogenic, osteoblast, osteocyte, osteoclast
9
Q
what do osteogenic cells become?
A
osteoblasts
10
Q
where are osteogenic cells found?
A
on the edge of bone ie. periosteum, endosteum
11
Q
function of osteoblasts
A
bone forming cells
making of collagen/AGS/proteins
12
Q
what do osteoblasts become and how?
A
osteoctyes, when it becomes trapped in matrix they have deposited
13
Q
what are osteocytes
A
main bone cell, maintain bone via spidery fingers
14
Q
where are osteocytes located?
A
in Lacuna
15
Q
what are osteoclasts?
A
cell which eats/digests bone, not derived from osteogenic cells,
16
Q
structure of osteoclasts
A
large cell(10X bigger than other bone cells), multinucleated cell lots of cells come together to form this cell, has lots of lysosomes,
17
Q
location of osteoclast
A
edge of bone in pits next to osteogenic and osteoblast cells,
18
Q
only bone cell in the middle of the bone
A
osteocytes
19
Q
what is the contents of the bone matrix?
A
inorganic(calcium/phosphate = forms crystal matrix) + organic
20
Q
what triggers mineralisation/crystallisation in bone and what is it made of?
A
osteoblast, salts(calcium and phosphate)
21
Q
so what actually happens in mineralisation/calcification of bone?
A
osteoblasts trigger the deposit of mineral crystals around collagen fibres causing the matrix to harden
22
Q
where is compact bone found?
A
edge of diaphysis
23
Q
what structures does compact bone consist of?
A
osteons or Haversion systems and
24
what are osteons?
bone matris laid down in rings around blood vessels
25
what does the Haversian canal contain?
blood vessels
26
why are there blood vessels in bone?
bring in nutrients and carry away waste
27
how are osteons aligned?
alone lines of stress
28
types of lamellae
interstitial and circumferential
29
what are interstitial lamellae
old osteon that have been partially removed
bone was remade or remodelled due to changes in stress
all thats left is a few plates of bone, that used to be a ring but are now just plates
30
what are the black spaces within the bone matrix?
lacuna
31
what are lacuna?
empty spaces in bone where osteocytes sit
32
what connects lacuna?
canaliculi
33
what cells sit on the edge of bone?
osteogenic, osteoclast, osteoblasts
34
why are lacuna necessary?
as osteocytes have delicate arms and would be crushed by hard bone matrix
35
what is the space called that the "arms/legs" of osteocytes sit in?
canaliculi "little tunnel"
36
what is the importance of the lacuna/canaliculi structures in bone...besides protection from bone matrix
help move nutrients and oxygen through bone as nutrients cannot flow through rock hard bone matrix to get to cells(from blood vessels in Haversian canal
37
how is movement of nutrients through bone possible?
network of lacuna and canaliculi passing between osteocytes
38
what connects osteocytes?
gap junctions...they "hold hands (':"
39
where is spongey bone located?
in the epiphysis
40
what makes it spongey?
little spaces with bone
41
what do the spaces in spongey bone contain?
red bone marrow, developing red/white blood cells
42
why aren't all our bone compact?
too heavy!
43
structure of spongey bone
Does not have Haversian canals...need because blood vessel can simply run through empty space
just have lamellae and lacuna containing osteocytes
don't form osteons
44
function of yellow bone marrow?
fat (energy storage)
45
advantage of having energy storage such as yellow marrow within the bone?
as developing red/white blood cells in the red marrow within the epiphysis requires a lot of energy
46
difference between cartilage and bone
rubbery(not calcified or mineralised), proteins make the rubbery function
bone requires movement but not damage ends,
47
why is the end of bones covered in articular cartilage
to avoid damage to bone, resist compression, absorb shock, smooth reduces friction thus reducing pain
48
what are the cells of cartilage called?
"CHONDRO" - cells of cartilage
| chondroblast, chondrocyte,
49
location and function of chondroblasts
near edge of bone, secret cartilage matrix
50
function and location of chondrocytes
maintain cartilage, sit within lacuna as pressure on joints could crush the poor chondrocyte
51
why is cartilage avascular?
as joints constantly experience pressure and stresses making it hard not to burst delicate blood vessels
52
does cartilage have blood vessels?
no
53
where does protective articular cartilage of a joint get its nutrients from?
fluid in joints(in living person), synovial fluid also from the blood vessels in the bone! nutrients diffuse across into cartilage
54
types of cartilage
articular/hyline
| fibro
55
what is articular/hyaline cartilage consist of?
collagen, elastin in equal amounts
56
what does fibrocartilage mainly consist of?
collagen (more fibres)
57
what is the advantage of equal amounts of collagen and elastin fibres in articular cartilage?
strength and rubbery function
| to maintain shape and function
58
where is fibrocartilage found?
intervertebral vertebra, not much movement is needed and more support is needed (entire body weight)
59
where is elastic cartilage found?
nose/ears
60
describe the appearance of fibrocartilage:
rows of chondrocytes in lacunae plus extensive bundles of collagen
61
location and function of the epiglottis
very back of throat, stops food going down wind pipe
62
how many bones do we have as a baby vs an adult?
270 vs 206
63
what is ossification?
formation of bone
64
when does ossification begin?
in early embryonic life
65
what are the two ossification methods?
intermembranous and endochondral ossification
66
what is intermembranous ossification?
bone formation from connective tissue
67
what is endochondral ossification?
bone formation from hyaline/articular cartilage
68
what kind of bone forms from inter membranous ossification?
flat and irregular bone
69
examples of flat bone
skull, sternum, ribs
70
example of long bones
tibia, fibula, femur, humerus
71
how does long bone form?
endochondral ossification?
72
step 1 of intermembranous ossification:
1) lump of connective tissue in an embryo, somewhere the skull/any other flat/irregular bone will eventually form
73
what is mesenchym? and what are its cells called
connective tissue in an embryo, mesenchymal cells
74
step 2 of intermembranous ossification
osteoblasts forming bone, becomes trapped, thus becomes osteocytes, now a lump of bone
75
step 3 of intermembranous ossification
blood vessel pierces lump of bone, bring in osteoclasts which make and destroy bone eventually making medulla spaces
formation of trabeculae
76
step 4 of intermembranous ossification
develops into skull through bone remodelling
77
general steps in endochondral ossification:
connective tissue --> cartilage --> bone!
78
step 1 of endochondral ossification:
embryonic fibroblasts(mesenchymal cells) becomes chondroblasts which makes cartilage, a lump of cartilage then appears in that space in the shape of the bone it will make
79
what type of bone does endochondral ossification make?
long bone
80
step 2 of endochondral ossification:
growth of cartilage model in length(chondrocyte division within matrix) and width(formation of new cartilage at edge of bone);
81
step 3 of endochondral ossification:
the chondrocytes in the mid region of the cartilage model(bone shaped cartilage) get really fat due to ingesting lots of glycogen(sugars) and burst, releasing their contents into the cartilage matrix/GS/fluid changing the pH and triggers calcification(calcium forms salts), salts stick on collagen which make bone hence death of chondrocytes.
82
step 4 of endochondral ossification:
all cells die due to calcification of cartilage and stop of nutrient flow, shaft hollows out, blood vessels penetrate shaft bringing osteoclasts, osteoclasts eat away all the dead cartilage, resulting in a large empty space...eventually filling with yellow marrow
83
summarise what happens after one chondrocyte ingests too much glycogen
chondrocytes get big, they die, causing calcification, making matrix in there really hard, kills of other living cells as they cant get nutrients anymore, dead tissue in the middle is removed by the osteoclasts brought in by blood vessles end up with a big space
84
endochondral ossification...AFTER birth
development of secondary ossification centre, blood vessel entre cartilage in epiphysis at birth, bringing osteoclasts eat away cartilage and osteoblasts enter forming spongey bone
85
during the after birth stage of endochondral ossification is all cartilage eaten away by osteoclasts?
no, some articular cartilage remains at the top(nice and smooth) and small amount remains between epiphysis and metaphysis called epiphyseal plate
86
what is the function of the epiphyseal plate?
responsible for bone growth in length
87
types of bone growth:
Length and width
| Interstitial and appositional
88
where does interstitial bone growth occur?
epiphyseal plate
89
how does epiphyseal plate increase length of bone
cartilage divides, new cartilage creates new bone, slowly long bone will increase in length
90
what age does interstitial bone growth occur?
until the age of 18-25 years "growths spurts"
91
are epiphyseal plates renewable?
no, they only last for a certain amount of time, once they are gone epiphysis is completely spongey bone on the inside and length of bone is final
92
looking at an x-ray of a long bone, how would you tell whether it came from an adult or a child?
presence of epiphyseal plate(comes up as a black line)
93
Super simple summarisation of how epiphyseal plate increases length of bone
cartilage cells get really fat, they burst, they die, replaced with bone
94
where does cartilage become bone after birth?
the epiphyseal plate
95
process of appositional bone growth
osteogenic cells sitting on the edge of bone make osteoblasts which lay bone down around blood vessels
96
how does nutrition affect bone growth?
we don't make minerals, so need to be getting adequate amounts from our diet (eg. calcium and phosphate) and vitamins (vit C for collagen)
other we just can't make bone!
97
what is responsible for the "growth spurt"?
sex hormones produced at puberty
98
how do increase of sex hormone production stimulate growth?
hormones bind to chondrocytes in epiphyseal plate, basically tells/triggers them to make more bone thus rapidly increasing length of bone
and bind to osteoblasts increasing width
99
why do adolescent girls grow taller and faster than boys?
as oestrogen initially has a stronger effect than testosterone on bone cells, HOWEVER the effect wears out over time
where as testosterone tends to effect bone cells for longer, thus males grow for a longer period of time
100
what does hypertrophy mean?
over active
101
Which hormone has the largest effect on growth?
human growth hormone
102
where is the human growth hormone found?
pituitary gland(hangs of the back of the brain)
103
if we just kept growing and growing what would we be endanger of?
heart failure, too difficult to support that much tissue/organs
104
so is bone shaped fixed after growth spurt?
no, as an adult your bones are constantly being remade(replenished) and remodelled.
105
how ofter is the distal femur replaced?
around every 4 months
106
Why are fractures more likely to occur in inactive people?
as when you're inactive less bone will be created by the osteoblasts however osteoclasts will not slow in eating your bone weakening the bone, decrease in bone density can lead to osteoporosis
107
types of fractures:
```
stress(abnormal physical trauma eg. falling down stairs)
AND
pathological fracture(bone weakened by disease eg. cancer, osteoporosis
```
108
how are joints classified?
function and structer
109
what is a joint?
where two bones meet..but can permit movement
110
types of structural joints (SC)
fibrous
cartilaginous
synovial
(based on whats between the bones)
111
types of functional classification of joints (FC)
immovable
slightly movable
freely moveable
112
description of a fibrous joint:
no cavity, bones connected via collagen..limiting movability
113
example of fibrous joints:
skull joints
| immovable
114
what type of joint is the tibia and fibula?
fibrous immovable
115
description of cartilaginous joint
no cavity, little or no movement
| cartilage is found between bone
116
example of cartilaginous joint:
intervertebral discs, stacked on top of one another with cartilage between them
117
description of synovial joints:
cavity containing fluid(synovial) and cartilage
| freely movable
118
what contains the synovial fluid?
synovial membrane...reinforced by dense connective tissue(capsule)
119
what is the joint capsule made of and what is its function?
dense connective tissue, ensure synovial membrane does not break
120
what connects bone to muscle
tendons
121
what connects bone to bone?
ligament(dense regular connective tissue)
122
what does the joint capsule become after time?
joint ligament
123
where does synovial fluid come from?
made in the synovial membrane
124
what is the function of synovial fluid?
allows freely moveable joints
| provides nutrients to cartilage
125
name of the special ligament in knees
articular ligaments
126
whats different about articular ligaments?
they are inside the joint
| kind of cross over to avoid knee joints clashing together
127
what is an articular disk and where is it found?
plate of fibro(tough) cartilage that sits inside the knee, just kinda of in the middle
128
function of articular disk
matches both edges allowing joint to fit together nicely, thus making it more stable
129
what exists in a joint where there is friction between bone and skin?
sack of fluid called "bursa"
130
how many types of synovial joints?
6
131
where are ball and socket joints found?
shoulder and hip
132
what is the main function of the ball and socket joint?
allows the most movement of any joint in the body
133
difference between shoulder and hip ball and socket joints
hip socket is deeper than shoulder socket
| hip has to support more weight for longer periods of time
134
which ball and socket joint is more stable: hip or shoulder?
hip
135
what cells secrete the organic components of the bone matrix?
osteoblasts
136
muscle tissue has the ability to
extensibility, elasticity, contractibility, excitability, responds to stimuli
137
what is the movement of your arm towards your ear called?
abduction
138
the movement of your arm towards your hip called?
adduction
139
how does the bone grow during appositional bone growth?
width
140
endochondral ossification begins with the formation of an
cartilage model, in the shape of the bone it will create(long bone)
141
where is fat stored within bone?
medullary cavity
142
where do secondary ossification centres occur?
in the epiphysis
143
the delicate connective tissue that surrounds the skeleton muscle fibres and ties adjacent muscle fibres together is the:
endomysium
144
the dense layer of connective tissue that surrounds the entire skeletal muscle is the:
epimysium
145
the interconnecting tiny arches of bone tissue found in spongy bone are called:
trabeculae
146
the lining of the medullary cavity is called the:
endosteum
147
what does the medullary cavity of bone contain?
marrow
148
what is the most abundant cell type in bone?
osteoctyes
149
the narrow passageways that contain cytoplasmic extensions of osteocytes are called:
canaliculi
150
what is the sarcolemma?
the plasma membrane of muscle cells
151
what allows action potenital to penetrate skeletal muscle cells?
transverse (T) tubules
152
what is the movement of palm side facing up called?
supination
153
what is the movement of palm side facing down called?
pronation
154
how are trabeculae organised in spongy bone?
along lines of stress
155
how is bone matrix dissolved
through action of osteoclasts
156
what is used as a means of naming muscles?
location, action, shape, attachment
157
functions of the skeletal system
protection of internal organs
body support
blood cell production
calcium homeostasis
158
function of sarcoplasmic reticulum
storage and release site for calcium ions
159
what allows action potential to travel quickly from one cardiac muscle cell to another?
gap junctions and intercalated discs
160
what is the motor protein that facilitates contraction in muscle cells?
myosin
161
function of osteogenic cell?
stem cell that develops into osteoblasts
162
function of osteoblast
bone making cell, secretes organic components of bone matrix eg. protein and collagen
163
function of osteocyte?
maintain bone matrix and allow nutrients and oxygen to pass through bone
164
function of osteoclast?
resorption of bone
165
How does x-rays of bones work?
patients are exposed to short x-ray bursts, calcium within bones absorbs x-rays making bones appear white in x-ray images
166
where can hyline/articular cartilage be found?
end of bones
in ribs and trachea
epiphyseal plate
167
where can fibro-cartilage be found?
```
intervertebral discs
articular discs (menisci)...in knee
```
168
example of where elastic fibres can be found?
external ear
epiglottis
nose
169
what do are all connective tissues made of?
cells, fibres and extracellular matrix
170
what is the prefix for muscle cells
SARCO
171
can muscle cells divide?
no, however some satellite(stem) cells are present on the edge of muscles which can give rise to a few replacement cells
172
describe the contraction of muscles
an action potential(from nerve fibres) runs along muscle cells, penetrating through transverse (T) tubules triggering the sarcoplasmic reticulum to release masses of calcium into the cell which bind with action potential and causing actin to slide over myosin thus contracting the muscle
173
what are the striations that you see in skeletal muscle?
myosin
174
what is myofibral?
within muscle cell, two main components
myosin a thick protein
actin a thin filament
175
what is the benefit of the branching structure of cardiac muscle?
allow withstand of pulling forces in many directions
mainly the ability to rapidly spread signals to contract from cell to cell
1 - 2 - 4 - 8 ..
176
what is "special" about contraction of smooth muscle?
irregular arrangement of actin allows contraction of all directions, overall "shrinkage of cell"
177
what are the 2 types of smooth muscle cell?
visceral (single unit)
| multiunit smooth muscle cell
178
what is the job of the prime mover in muscle contraction?
does most of the heavy lifting
179
what is the job of the relaxant muscle or "antagonist"?
to remain relaxed and allow extension to prevent damage
180
what is the job of the synergist muscle in contraction?
to stabilise joint, and ensure bone does not move incorrectly
181
what is the job of the fixator muscle in muscle contraction?
prevents movement of the bone that the prime mover is attached to.
