Module 3A: Skeletal System Flashcards
(119 cards)
1
Q
what are the three types of cartilage in the skeleton?
A
- hyaline
- elastic
- fibrocartilage
2
Q
is ALL cartilage resilient?
A
yes, it resists compression
3
Q
relative to bone, does cartilage have higher or lower levels of water and minerals?
A
high level of water and low level of minerals
- this gives its resiliency towards compressive forces
4
Q
what does hyaline cartilage do for us?
A
provides support with flexibility and resilience
5
Q
which cartilage is the most abundant of the skeletal cartilages?
A
hyaline cartilage
6
Q
the different types of cartilage have different amounts of?
A
water and fiber concentration
- this dictates the behavior and responses they have
7
Q
what dictates the behaviors and responses that cartilage has?
A
water and fiber concentration
8
Q
what are the locations of hyaline cartilage on the skeletal system?
A
- articular
- costal
- respiratory
- nasal
9
Q
where is our hyaline articular cartilage?
A
lying within the joints
10
Q
where is our hyaline costal cartilage?
A
where your ribs meet your sternum
11
Q
where is our hyaline respiratory cartilage?
A
in our larynx, in our voice box
- all the air that comes in and out is coming through cartilage
12
Q
the respiratory system is based on what?
A
cartilage, NOT bone
- specifically- HYALINE cartilage
13
Q
where is our hyaline nasal cartilage?
A
the nasal area; the nose
- what we can move in our nose is cartilage
14
Q
which cartilage has more elastic fibers, elastic or hyaline?
A
elastic
15
Q
which cartilage is better able to stand up to repeated bending?
A
elastic
16
Q
where can elastic cartilage NOT be used? why?
A
in places that require structural function. because it is not tough enough
17
Q
what are the locations of elastic cartilage?
A
- external ear
- epiglottis (peaks out behind the larynx)
18
Q
what does your epiglottis do
A
lifts when you breath in
lowers when you swallow something
- blocks trachea when swallowing so it goes down into the esophagus instead of chocking
19
Q
which cartilage is more prevalent in the body, fibrocartilage or elastic?
A
fibrocartilage, but still less than hyaline
20
Q
what is the strongest cartilage? why?
A
fibrocartilage because it has a lot of thick collagen fibers
- has great tensile strength
21
Q
fibrocartilage is going to be located in sites that are?
A
subject to both pressure and stretch
22
Q
how are the chondrocytes and the collagen fibers arranged in fibrocartilage?
A
in parallel rows and this gives it its strength and its ability to resist that compression and pressure
23
Q
where is fibrocartilage located?
A
- menisci of knee
- intervertebral disc
- symphysis pubis
24
Q
when we take a step, about how much weight are we putting up through the limb?
A
1.5x our body weight
25
when we are running, about how much weight are we putting up through the limb?
3-7x our body weight/ foot contact
26
what does our symphysis pubis do?
hold the left and right bones of our pelvis together
27
are bones an organ?
yes
- made up of many types of tissues
28
what are the functions of bones?
- support
- protection
- anchorage (attachment point for muscles)
- mineral/growth factor storage
- hormone production
Bone Marrow
- blood cell formation
- triglyceride (fat) storage
29
what are the two main ways that bones are classified?
1. location (axial vs appendicular)
2. shape
30
what is our axial skeleton?
- skull
- vertebral column
- ribs
- sternum
- essentially- the axis of the body; where everything else attached
31
what is our appendicular skeleton
- limbs, pelvis, shoulder girdle
- appendages
32
what are the different shapes a bone can be?
1. long
2. short
3. flat
4. irregular
5. sesamoid
33
what are long bones?
- longer than they are wide
- have shafts with expanded ends
- ex. femur, humerus
34
what are short bones?
- mostly cube shaped
- about the same length on each side
- ex. wrist and ankle bones (talus, trapezoid)
35
what are flat bones?
- thin, flattened but usually curved
- ex. sternum, skull bones
36
what are irregular bones?
- don't really fit in any other category
ex. vertebrae
37
what are the sesamoid bones?
- patella
38
how the bone is set up is related to?
the shape and location of the bone
39
what is compact bone?
- dense outer layer
- appears smooth and solid
40
what is spongey bone?
- the internal layer
- it looks like a sponge in a cross section
- trabeculae form honeycomb-like structure
- contains marrow
41
what is bone marrow?
the soft substance where blood cells are produced or where we store some fat
42
what is the traditional structure of short, flat and irregular bones?
- no shaft
- no expanded ends
- spongey bone inside with compact on ends
- trabeculae in the spongey bone
43
what is the traditional structure of long bones?
- have shafts (called diaphysis)
- have boney ends (called epiphyses)
- have membranes
- have articular cartilage
44
what is the shaft of a long bone called?
a diaphysis
- this is where compact bone is going to surround spongey bone that has trabeculae and will have yellow marrow in an adult
45
what is an epiphysis?
the ends of the long bones
- proximal and distal
46
is a diaphysis or epiphysis broader?
an epiphysis
47
where is yellow marrow?
in the long bones of adults
48
what is yellow marrow for?
fat storage
49
where is the articular cartilage of long bones?
covering the outer edge of the bones to act as a cushion and absorb stress
50
the membranes that cover the long bones contain what?
the bone stem cells (the osteogenic cells) that become bone cells
51
what is the endosteum?
the delicate connection tissue that covers internal bone surfaces like in the trabeculae
52
what are the two long bone membranes?
1. endosteum
2. periosteum
53
what is the periosteum?
covers the outside of the long bone except for where the hyaline cartilage is
54
what are the two types of bone marrow?
1. red marrow
2. yellow marrow
55
what is red marrow for?
blood cell production
56
where is red marrow located?
in trabecular cavities (epiphysis only) of long and flat bones
57
who has all red marrow and who has very little?
newborns have almost all red marrow and adults have very little
58
what is yellow marrow for?
fat storage
59
in adults, yellow marrow can do what if the adult has severe anemia?
turn back into red marrow
60
who has all yellow marrow and who has very little?
adults are almost all yellow marrow and newborns have very little
61
how much marrow does short bones have?
a negligible amount. this is because they have little spongey bone
62
which bone, compact or spongey, has lots of passageways for nerves and blood vessels?
compact
63
what is the structural unit of compact bone?
Osteon (Haversian System)
64
what is the structure of osteon?
- long-cylinder parallel to axis of bone acting like tiny weight-bearing pillars
- have groups of hollow tubes (lamellae) of bone matrix rings (like the rings of a tree trunk)
65
what does the collagen within adjacent lamellae run in?
opposite directions
66
what helps resist the twisting forces applied to bones?
the collagen within adjacent lamellae running in opposite directions
67
what are the three different types of lamellae?
1. complete
2. interstitial
3. circumferential
68
which type of lamellae make up full rings around osteon?
complete lamellae
69
what is between the osteons?
interstitial lamellae
70
what is circumferential lamellae?
around the outside of the bone between the endosteum and periosteum
71
what are the outer vessels located in the endosteum and the periosteum?
1. The Haversian (Central) canal
2. Volkmann's (Perforating) canals
72
where are the Haversian (central) canals located?
core of each osteon; contains nerves/blood vessels
73
where are the Volkmann's (perforating) canals for?
they connect Haversian canals to outer vessels
74
what are canaliculi?
canals connecting adjacent lamellae is an osteon
75
what does bone growth start with?
osteogenic mitotically active stem cells that will develop into type B osteoblasts
- located in the periosteum and endosteum membranes
76
what are the three stages of bone growth?
osteoprogenitor cell --> osteoblast --> osteocyte
77
what are osteoblasts?
bone-forming cells that are active mitotically that will secrete bone matrix, collagen and calcium binding proteins
78
what happens when osteoblasts become completely surrounded by matrix?
they become type C, osteocytes
79
what are osteocytes?
mature bone cells that monitor matrix and act as stress sensors
80
what does osteoclasts do?
break down old cells and absorb surrounding matrix
81
what is ossification?
bone formation
82
what are the two methods of ossification?
1. intramembranous
2. endochondral
83
what is intramembranous ossification?
bone develops from a fibrous membrane
- ex. clavicle, bones of skull
84
what is endochondral ossification?
when bone replaces hyaline cartilage
- ex. almost all bones in body form this way
85
what is the first step of the intramembranous ossification?
the development of the ossification center;
at a site where the bone will develop, osteoblasts clump in the fibrous tissue and form spongey bone and these osteoblast secrete extracellular matrix
86
what is an osteoid?
an immature bone
87
what are the four steps of intramembranous ossification?
1. development of ossification center
2. calcification
3. formation of trabeculae
4. development of the periosteum
88
what happen at the calcification step of intramembranous ossification?
the secretion stops, the matrix hardens, it calcifies and the cells are now called osteocytes
89
what happens at the formation of trabeculae step of intramembranous ossification?
extracellular matrix develops into trabeculae that fuse to form into spongy bone and red marrow will appear
90
what happens at the development of the periosteum step of intramembranous ossification?
mesenchyme at the periphery of the bone condenses and develops into the periosteum and then we get the layer of compact bone
91
how does bone grow?
osteoclasts break down bone to form larger ones
- breaks down old cells and absorb the surrounding matrix
92
what cartilage ossifies to bone?
hyaline
93
what are the steps of endochondral ossification?
(not important)
1. development of cartilage model
2. growth of cartilage model
3. development of primary ossification center
4. development of the medullary (marrow) cavity
5. development of secondary ossification
6. formation of articular cartilage and epiphyseal plate
94
what are the steps of endochondral ossification?
(important)
- bone grows on outside of diaphysis
- cartilage in the center of the diaphysis will calcify and develop a cavity
- the blood vessels will invade the internal cavity which becomes spongey bone
- the diaphysis will elongate and officially a medullary cavity will form
- a secondary ossification will appear in the epiphyses and the epiphyses will ossify
- then we get the formation of our articular cartilage and our epiphyseal growth plate
95
how does bone grow?
with endochondral ossification, it will occur at the end of the bone as well as near the epiphyseal plate of interstitial growth
96
at what age does the epiphyseal plate become ossified? (epiphyseal plate closure)
age 18 to 21
97
what is the only way that the diaphysis can increase in length?
the activity of the epiphyseal plate
98
what do the chondrocytes do as the bone grows?
the chondrocytes proliferate on the epiphyseal side of the plate and new chondrocytes replace the older ones that are destroyed by the calcification process
- the change of cartilage to bone
thus, the cartilage is replaced on this side of the epiphyseal plate so the diaphaseal side (the shaft side of the plate) and the thickness of the epiphyseal plate is able to stay about the same as this bone is growing in length
99
how do bones maintain the same shape and strength when growing longer?
they need to grow in width (bone remodelling)
100
how do bones grow in width?
osteoblasts secreting new matrix beneath the periosteum in some areas and the osteoclast-reabsorbing bone in other areas to keep the proper width to match the new length
101
how much of bone mass is recycled per week?
5-7%
102
how often is spongey bone replaced?
every 3-4 years
103
how often is compact bone replaced?
every 10 years
104
what happens to the bones is calcium sits too long in them?
the bones will become brittle
105
what are the two sites of control we have for the control of bone growth?
1. hormonal
2. mechanical stress (tension vs compression)
106
what are the three considerations of a bone fracture?
1. position of bone (displaced vs non-displaced)
2. completeness of break (complete vs incomplete)
3. skin penetration (closed aka simple vs open aka compound)
107
what is a comminuted bone fracture?
bone fragments into three or more pieces
- common in the elder because of brittleness
108
what is a compression bone fracture?
bone is crushed
109
what is a spiral fracture?
ragged break occurs when excessive twisting forces are applied to a bone
110
what is an epiphyseal fracture?
epiphysis separates from the diaphysis along the epiphyseal plate
111
what is a depression fracture?
portion of broken bone is pressed inward
- typical in skull fracture
112
what is a greenstick fracture
bone breaks incompletely. one side of diaphysis is broken and the other side bends
- common in children
113
what is a closed (external) reduction?
in a displaced bone fracture repair, a physician manually coaxes bone ends back into position
114
what is an open (internal) reduction?
in a displaced bone fracture repair, bone ends are secured surgically with pins or wires
115
what are the steps of a fracture healing?
- blood rushes to the area with repair cells
- fibrocartilaginous callus forms
- bony callus forms (remodeling)
116
what is osteomalacia?
a bone disorder in adults
- soft/weak bones due to poor mineralization
- vitamin d or calcium deficiency
- will leave you "bowl legged"
- same disorder in children is called rickets
117
what is rickets?
a bone disorder in children
- called osteomalacia in adults
- analogous disease in children
- more dangerous since bones are growing rapidly
- epiphyseal plate cannot calcify so long bones become enlarged
- seen in poverty and in underdeveloped nations (because diets are poor)
- will leave you "bowl legged"
118
what is osteoporosis?
bone reabsorption happens at a higher rate than the forming of bone (deposition)
- common in older adults
- bones get more brittle
- more common in women
- treatment: Calcium, Vitamin D, Hormone Replacement Therapy
- prevention: adequate nutrition, load-bearing exercise
119
the amount of bone tissue in the skeleton (bone mass) can keep growing and accumulating until what age?
late 20s
- you'll reach your maximum strength and density or peek bone mass
- important to have best strength and density
