The Skeletal System Flashcards
1
Q
list the functions of the skeletal system
A
- organ protection
- mineral storage
- body movement
- blood cell production
- body support
2
Q
describe this skeletal system function: organ protection
A
bone surrounds and protects vulnerable organs and structures (brain, heart, lungs, etc.)
3
Q
describe this skeletal system function: mineral storage
A
- bone serves as a storage location for minerals including calcium and phosphorus (in phosphate)
- Ca2+, PO43+
- calcium and phosphate salt makes the bones hard
- the bones can store and give to blood in a regulated way
4
Q
describe this skeletal system function: body movement
A
- bone works with muscles and ligaments to produce body movements
- muscular system produces the force, skeletal system anchors muscles and is what is actually being moved
5
Q
describe this skeletal system function: blood cell production
A
- bone houses red bone marrow which gives rise to all blood cells
- all bones have blood cell forming tissue (red bone marrow)
6
Q
describe this skeletal system function: body support
A
- bone’s dense makeup is well suited for bearing the body’s weight
- bone is hard and does to bend allowing it to bear weight
- skeletal system is a scaffold: rigid structure that all soft structures can attach to
7
Q
what are the two part of the skeleton
A
- axial skeleton
- appendicular skeleton
8
Q
define axial skeleton
A
a vertical axis for the system
9
Q
define appendicular skeleton
A
bones that form the appendages and the girdles
10
Q
describe why the hyoid bone is special
A
it is the only bone that doesn’t connect to any other bone
11
Q
what important structure originates at the hyoid bone
A
- tongue muscles
- important for swallowing and talking
12
Q
what are the parts of the hip
A
- sacrum
- pubic bone (ilium, ischium, pubis)
13
Q
what is the term for a single side of the pelvis
A
os coxa
14
Q
what is the term for both sides of the pelvis
A
os coxae
15
Q
what are the three regions of the pelvis
A
- ilium
- ischium
- pubis
16
Q
when do the ilium, ischium, and pubis fuse to form one solid bone
A
around the age of 10-12
17
Q
what is the purpose of girdles (pelvic and shoulder)
A
connect appendages to the axial skeleton
18
Q
what are the components of the shoulder girdle
A
- clavicle
- scapula
19
Q
what is the most often broken bone in the body
A
clavicle
20
Q
why is the clavicle the most often broken bone in the body
A
- it is very superficial
- when you fall on your arms, the clavicle takes a lot of the force
21
Q
what are the main functions of the skull
A
- protect the brain
- house organs of special senses
- provide place for intake of food and mastication (teeth, mandible, powerful muscles)
22
Q
what are the two parts of the skull
A
- cranium
- facial bones
23
Q
how many bones are in the cranium and how many are facial bones
A
- cranium: 8 bones
- facial bones: 14 bones
24
Q
define skull
A
collection of bones within the cephalic region
25
how many bones are in the cephalon
22 bones (not including ossicles)
26
what is the difference between the cephalon and the cranium
- cephalon: whole head made of 22 bones
- cranium: 8 bones protecting the brain
27
what are the ossicles
- 6 bones, 3 on each side of the temporal bone
- make up the middle ear
28
describe the middle ear
- airspace on each side of the temporal bone
- each made of 3 ossicles
- transmits soundwaves from the eardrum to the inner ear
29
what are the names of the discrete openings in the skull
- foramina
- fissures
- canals
30
what is the purpose of foramina, fissures, and canals
provide passage for soft tissue structure (nerves, blood vessels)
31
which is singular and which is plural: foramina, foramen
- foramina: plural
- foramen: singular
32
describe how you would prepare a view of the floor of the cranium
cut off the skull cap (calvaria)
33
define calvaria
the skull cap
34
where do the first 4 cranial nerves all have at least 1 branch that runs through
superior orbital fissure
35
which cranial nerves run through the acoustic canals
- facial nerve 7
- vestibulocochlear nerve 8
36
which cranial nerves and structures run through the jugular foramen
- internal jugular vein
- glossopharyngeal nerve 9
- vagus nerve 10
- spinal accessory nerve 11
37
what structures run through the carotid canal
internal carotid artery
38
what structure runs through the foramen magnum
spinal cord
39
is the spinal cord a nerve
no, it is part of the CNS
40
which foramen run through the sphenoid bone
- spinosum
- rotundum
- ovale
41
are teeth bones
- no
- they are bone-like structures
- organs
42
define the nasal concha
- flat plates of bone on both sides of the nasal cavity
- superior, middle, and inferior concha on each side
- lined with mucous membranes
43
what is the function of the nasal concha
- increase the surface area of the nasal cavity
- allows for more entrapment of particles
- easier to warm and humidify air when inhaling
44
are there any perfect structures in the human body
no, evolution happens until a structure has more benefits than downsides
45
describe sinuses
- airspace within the skull
- named after the bone that the sinus in embedded in
46
what is the function of sinuses
- lightens the front of the head
- resonance chamber for sound
47
describe the downside of sinuses
- easily infected
- drainage hole for sinuses to the nasal cavity is usually very small
48
describe what happens when a sinus gets infected
- the drainage hole shrinks allowing less fluid to exit, building pressure
- voice may sound weird because sound cannot resonate through the sinus
49
explain why the maxillary sinus is weird
it must drain upwards, against the flow of gravity
50
describe the shape of the spine
- elongated S shape
- the spinal column sits on the dorsal side of the body
- organs sit anterior to the spinal column
51
why is the S shape of the spine important
the curve centers the weight of the body optimally over the hips
52
describe how the spine is shaped differently at birth and why it changes
- spine is a C shape when born
- shifts to an S shape when the baby begins walking to match shift in the center of gravity
53
what is the only vertebrae without a body
C1, atlas
54
what happens to the size of the body of the vertebrae as you move down the spinal column and why
- the body of the vertebrae gets larger as you move from cervical to thoracic to lumbar vertebrae
- the larger body size is important for the spine to carry the weight above it
55
what is another name for the first and second cervical vertebrae
- C1, atlas
- C2, axis
56
how many cervical, thoracic, lumbar, sacral, and coccyx vertebrae are there
- 7 cervical
- 12 thoracic
- 5 lumbar
- 5 sacral
- 4 coccyx
57
describe how the sacral and coccyx vertebrae are different than other vertebrae
- they are unfused early in life
- they fuse later in life
58
what does the C1, atlas vertebrae articulate with
- occipital bone
- holds the head
59
what are the visible bumps on someone's back
spinous processes of vertebrae
60
what are the 5 types of bones
- long bones
- flat bones
- irregular bones
- short bones
- sesamoid bones
61
describe the characteristics of long bones
- longer than they are wide
- most of the length is straight and cylindrical
- have at least 1 bulge at the end of the shaft
62
examples of long bones
- femur
- humerus
- distal phalanx of pinky
63
describe the characteristics of flat bones
mostly or completely flat
64
examples of flat bones
- sternum
- occipital bone
- parietal bones
- ribs
65
describe the characteristics of irregular bones
- do not fit into any other categories
- no specific geometric shape
66
examples of irregular bones
- sphenoid bone
- vertebrae
- ischium
- ilium
- pubis
67
describe the characteristics of short bones
- boxy shaped
- as long as they are wide
68
examples of short bones
carpals in wrist
69
describe the characteristics of sesamoid bones
- seed shaped
- all develop within a tendon
70
examples of sesamoid bones
- patella
- some bones in the hands and feet that are variable in umber between people
71
describe the characteristic that made sesamoid bones different from short bones
all sesamoid bones develop within a tendon
72
what is a synonym of compact bone
cortical bone
73
describe compact/cortical bone
- looks like solid bone
- the outermost layer of bones, the surface you see
- composed of multiple osteons
74
describe osteons
- cylinders going up and down the diaphyseal wall of compact bone
- anatomical unit of compact bone
- made of concentric rings/lamellae, osteocytes in lacunae, haversian canal
75
which is singular and which is plural: lamella, lamellae
- singular: lamella
- plural: lamellae
76
which is singular and which is plural: lacuna, lacunae
- singular: lacuna
- plural: lacunae
77
define lacunae
- little spaces within an osteon
- each space contains 1 osteocyte
78
what is the most prevalent bone cell in the living skeleton
osteocyte
79
define the central/haversian canal
- canal running up and down the diaphyseal wall of bone
- within an osteon
- contains an artery, vein, nerve
- how blood can get to osteocytes
80
what type of tissue is bone tissue
connective tissue
81
does bone tissue have more cells or more extracellular matrix
- mostly extracellular matric
- little cells
82
describe canaliculu
- small canals radiating in all directions from lacunae
- connect to haversian canals
- get nutrients to osteocytes
83
describe interstitial lamellae
lamellae between the concentric lamellae of osteons
84
describe circumferential lamellae
- lamellae around the circumference of the bones
- closest to the periosteum
85
describe the perforating/volkmanns canal
- canals running perpendicular to haversian canals
- start from the periosteum and connect to haversian canals
- how blood vessels and nerves move from outside the bone to the haversian canals inside the bone
- can connect 2 haversian canals to each other
86
define periosteum
the connective tissue surrounding all living bone
87
what are the functions of the periosteum
- scaffolding that allows blood vessels and nerves to move through the bone
- creates osteoblasts and houses them on the inner surface of the periosteum
- attachment site for tendons and ligaments
88
describe bruised bone
- the nerves and blood vessels of the periosteum has been damaged
- not broken bone
89
what bones have spongy bone in them
all bones
90
where is spongy bone always located
internal to compact bone
91
why is it called spongy bone
- looks like a dried out sponge
- dead spongy bone tissues has many holes in it like a sponge
92
what are synonyms for spongy bone
- cancellous bone
- trabecular bone
93
define diploe
spongy bone and red bone marrow
94
define trabecula
single beam/strut in spongy bone
95
how are trabeculae arranged in non-weight bearing bones
in random directions
96
how are trabeculae arranged in weight bearing bones
- arranged along the lines of stress
- becomes defined as you get older
97
what is the point of trabeculae arranging along line of stress in spongy bone
helps the epiphysis become stronger and able to carry weight
98
what is in the spaces between trabeculae in spongy bone
- red bone marrow
- blood vessels
99
what is similar between a trabecula (spongy bone) and an osteon (compact bone)
- both are made of rings of lamellae
- both have lacuna containing a single osteocyte
- both have canaliculi radiating from the lacunae
100
what is different between a trabecula (spongy bone) and an osteon (compact bone)
- trabeculae don't have a haversian canal
- trabeculae are macroscopic (can be seen with the naked eye) while osteons are microscopic
- trabeculae are covered by a membrane called the endosteum
101
define endosteum
membrane surrounding the outermost lamellae of a trabecula
102
what is the function of the endosteum
- scaffolding for blood vessels and nerves to travel down/through the trabeculae
- create osteoblasts
- have osteoclasts
103
where are osteoclasts and osteoblasts found in trabeculae
within the endosteum lining the trabeculae
104
define appositional growth in bone
- growth by adding to the free surface of the bone
- accomplished by osteoblasts
105
describe osteoclasts in spongy bone
- multinucleated
- destroy bone
- exist within the endosteum surrounding trabeculae
106
describe bone remodeling
- done throughout the day
- osteoblasts and osteoclasts collaborate
- osteoclasts break down bone to give calcium to the blood when needed
- osteoblasts build new bone when calcium is taken in
107
define hematopoietic tissue
red bone marrow
108
what is in the medullary cavity of long bones when you are first born and what replaces it as you age
- full of red bone marrow when born
- replaced by yellow bone marrow as you age
109
what is your skeleton made of as am embryo
hyaline cartilage
110
what are the 2 ways that hyaline cartilage can grow
- appositionally
- interstitially
111
what is the 1 way that bone tissue can groq
appositionally
112
describe appositional growth of hyaline cartilage
- growing from the outside surface
- chondroblasts in the perichondrium build more cartilage
113
describe interstitial growth of hyaline cartilage
- growing from the inside
- chondrocytes in lacunae go through mitosis
- new chondrocytes move through the gelatinous extracellular matrix
114
why can't bones grow interstitially
- the extracellular matrix of bone is calcified
- there would be nowhere for new cells inside the bone to go
115
define primary ossification
- regulated destruction of diaphyseal cartilage that is replaced by bone
- endochondral ossification (ossification within cartilage)
116
when does primary ossification occur
fetus at 2-3 months to birth
117
define secondary ossification
- epiphysis of long bones undergoes ossification
- lengthening and widening of bone at the epiphyseal/growth plate
118
what type of bone tissue is the majority of the epiphysis and metaphysis of long bones
spongy bone
119
what happens to the outer layer of cortical bone in the epiphysis
- gets thinner
- still is there
120
describe the difference between juvenile and adult bones in terms of the epiphyseal plate/line
- juvenile: has a robust epiphyseal plate where the bone is growing
- adult: doesn't have epiphyseal plate, has epiphyseal line where plate used to be
121
describe the difference between juvenile and adult bones in terms of how the spongy bone in the epiphysis is arranged
- juvenile: trabeculae are unorganized and go in random directions
- adult: trabeculae are organized along stress lines to be better at weight-bearing
122
describe the difference between juvenile and adult bones in terms of the contents of the medullary cavity
- juvenile: medullary cavity filled with red bone marrow
- adult: medullary cavity filled with yellow bone marrow
123
what is special about the medullary cavity of the proximal femur and humerus in adults
the proximal end of the femur and humerus and adults retains some red bone marrow
124
describe the type of location of bone in the diaphysis of long bones
- mostly compact bone on the outside
- some spongy bone is on the very innermost surface lining the medullary cavity
125
when does juvenile bone officially become adult bone
when the last epiphyseal plate stops functioning and becomes an epiphyseal line
126
do all long bones become adult bones at the same time
- no
- different bones have different average ages that they become adult bones
127
at what average age are all your bones adult bones
- 21-23
- females have all adult bone earlier than males
128
are osteons visible with the naked eye
no
129
what are the layers of the periosteum
- inner layer
- outer layer
130
describe the inner layer of the periosteum
makes osteoblasts
131
describe the outer later of the periosteum
- thicker layer
- where tendons and ligaments attach
132
list the 4 types of bone cells
- osteoprogenitors
- osteoblasts
- osteocytes
- osteoclasts
133
define stem cell
- not yet a functional cell
- destined to become either a particular cell type or to exist as a stem cell
134
what happens to the daughter cells of stem cells after mitosis
- one becomes a particular cell type
- one stays as a stem cell
135
describe how osteoprogenitors, osteoblasts, and osteocytes are all connected
- different cell types that originate from each other
- osteoprogenitor becomes osteoblast becomes osteocyte
- 1 cell that transitions through different cell types
136
define osteoprogenitors
- stem cells for bone
- when the divide, one cell will become an osteoblast
137
describe the structure of osteoprogenitors
they look flattened
138
where are osteoprogenitor cells found
at the outer edge of the inner layer of the periosteum or endosteum
139
where are osteoblasts found
at the inner edge of the inner layer of the periosteum or endosteum
140
what do osteoblasts secrete/do
- secrete collagen
- secrete organic matrix
- induce formation of inorganic matrix
- form new bone
- remodel existing bone
141
which is created first: organic or inorganic matrix
organic matrix
142
where are osteocytes found
in lacunae within bone
143
what do osteocytes do
stabilize and maintain bone matrix
144
where are osteoclasts found
in the periosteum and endosteum
145
describe the structure of osteoclasts
- large cells
- multinucleated
146
what do osteoclasts do
reabsorb calcified bone matrix
147
define howships lacuna
the space created between an osteoclast and the bone as the osteoclasts breaks down the bone
148
describe how osteoclasts are made
- when bone starts producing red bone marrow during early ossification of bone, monocytes are formed
- monocytes fuse together into larger cells that become osteoclasts
149
describe exocytosis
- cell packages materials within into vesicles
- melds the vesicle to the cell membrane
- dumps contents of vesicle into the interstitial fluid/space
150
how are most things secreted from cells
exocytosis
151
what mediates the fusion of the vesicular membrane with the cell membrane in exocytosis
proteins
152
what are the two types of endocytosis
- phagocytosis
- pinocytosis
153
describe the cells that are capable of phagocytosis
- few cells are capable
- usually immune cells such as macrophages
154
describe phagocytosis
- type of endocytosis
- a cells swallows something from the extracellular space and brings it into the cell
- large gulp of interstitial fluid
155
describe the cells that are capable of pinocytosis
most cells are capable
156
describe pinocytosis
- type of endocytosis
- very common in cells
- cell takes a small sip of extracellular fluid
157
what tool must be used to see pinocytosis in action
electron microscope
158
describe transcytosis
- the linkage between endocytosis and exocytosis
- swallowing something on one side of the cell, moving it across the cell, dumping contents on the other side of the cell
159
how many red blood cells can fit through a capillary at a time
1 RBC
160
why is it important for capillaries to be one cell wall thick
to maximize the transfer of nutrients and wastes with the bloodstream and surrounding cells
161
what type of cells make up the walls of capillaries
endothelium (epithelial cells)
162
how many cell lengths away do all cells need to be from a capillary to stay alive
8 cells away
163
what does the cytoskeleton in a cell do
maintains cell shape
164
what fibers make up the cytoskeleton
- microfilaments
- microtubules
- intermediate filaments
165
list the fibers in the cytoskeleton in order from smallest to largest
- microfilaments: 8nm
- intermediate filaments: 10nm
- microtubules: 25 nm
166
which fibers in the cytoskeleton act like human muscles and why
- microfilaments and microtubules
- can rapidly elongate or shorten to generate force
167
what is another name for microfilaments
actin filaments/strands
168
what are microfilaments made of
polymers of the protein actin
169
where are microfilaments usually found
near the internal surface of the cell membrane
170
describe the function of microfilaments
- rapidly extend and contract
- change the shape of the cell membrane
- creates microvilli in cells
171
which fiber in the cytoskeleton act like the human skeleton and why
- intermediate filaments
- rigid protein strands that do not contract
172
what fiber in the cytoskeleton will become keratin in some epidermal cells
intermediate filaments
173
which cytoskeletal fiber drives mitosis
microtubules
174
which cytoskeletal fiber do motor proteins move along
microtubules
175
what do microtubules do during mitosis
- move chromosomes to the center of the cell
- pull apart sister chromatids
176
describe pump proteins
- transmembrane proteins in all cell membranes
- can move material against the concentration gradient
177
does the movement of materials against the concentration gradient with protein pumps require energy
yes
178
describe proton pumps
- transmembrane proteins that pump hydronium ions (H3O+) against the concentration gradient
179
what are the two ways that hydronium is often written
- H+
- H3O+
180
what is the equation for pH
pH = -log(H+)
181
what happens to pH when there is higher H+
higher H+ = lower pH
182
what happens to pH when there is lower H+
lower H+ = higher pH
183
describe podocytes
- circular rings of extensions on osteoclasts
- seals the osteoclast to the bone so osteoclasts secretions that dissolve bone don't go somewhere else
184
what secretions to osteoclasts produce
- H3O+
- hydrolytic enzymes
185
why is H3O+ an osteoclast secretion
creates an acidic environment that will dissolve the calcium phosphate salt (hydroxyapatite) of bone
186
what is the chemical weakness of calcium phosphate salt (hydroxyapatite) in bone
dissolves in high acidity
187
what components of bone do hydrolytic enzymes secreted by osteoclasts dissolve
organic molecules in bone such as collagen
188
describe how osteoclasts use transcytosis
- break down calcium in bone on one side
- use endocytosis to take up the calcium
- move the calcium to the other side of the cell facing the extracellular space
- use exocytosis to secrete the calcium into the bloodstream
189
what type of fiber in the cytoskeleton makes microvilli
actin filaments
190
why is it important for osteoclasts to have microvilli
increase surface area on the bottom of the osteoclasts so it can secrete more materials to dissolve bone
191
where are osteocytes found in the bone
within a lacunae that is surrounded by bone matrix
192
how are osteocytes connected
through canaliculi that connect the lacunae in the bone matrix
193
describe how canaliculi are formed as osteoblasts become osteocytes
- osteoblasts start laying bone matrix that will surround the cell
- before the matrix a hardened, osteoblast extend their body and meet with extensions of other cells which creates a gap junction
- the space surrounding the extensions fills with interstitial fluid
- the bone matrix hardens around the lacunae and the canaliculi
194
describe what is inside each canaliculi in bone
- extensions of osteocytes in the canaliculi meet with other cell's extensions
- a gap junction is created between cells
- the empty space surrounding the cell extensions in filled with interstitial fluid
195
why are gap junctions important for osteocytes
so the cells can communicate and trade nutrients/wastes/materials
196
what are the two major components of the extracellular component of bone matrix
- organic matrix
- inorganic matrix
197
which part of the extracellular bone matrix is produced first by osteoblasts
organic matrix
198
what is another name for the organic bone matrix
osteoid
199
what are the components of the organic bone matrix
- ground substance
- extracellular fibers
200
what are the components of the ground substance of organic bone matrix
- proteoglycan aggregates
- hyaluronic acid
201
is the ground substance of organic bone matrix fibrous
no
202
what type of macromolecule is hyaluronic acid
carbohydrate
203
what does hyaluronic acid do
increases viscosity of extracellular fluid
204
where is hyaluronic acid found in the body
- ground substance of organic bone matrix
- serous fluid
205
what are the components of the extracellular fibers of organic bone matrix
mainly type 1 collagen fibers
206
how many types of collagen fibers are there
20
207
describe type 1 collagen
- very strong
- gives bone tensile strength
208
what is the main component of the inorganic bone matrix
hydroxyapatite
209
what is hydroxyapatite made of
calcium phosphate salt
210
when is the inorganic bone matrix secreted
after the organic bone matrix
211
describe how osteoblasts help to create hydroxyapatite
- osteoblasts secrete a material that lowers the solubility of hydroxyapatite which causes precipitation
- once one tiny crystal of hydroxyapatite is formed, it will attract more material to make it grow
212
what type of feedback is the growth of hydroxyapatite
- positive feedback
- a small crystal is formed causing more and more crystals to form exponentially until there is no more space left for hydroxyapatite to form
213
how is an authentic human bone in a lab similar/different to a bone in a living human
- similar in shape and geometry
- living bone has organic matrix while nonliving bone does not, nonliving bone only has hydroxyapatite so it weighs less and is more fragile
214
what types of strength does bone have
- compressive strength
- tensile strength
215
define synergism
- A+B=A+B+C
- emergent property
216
describe compressive strength in bone
- originates from hydroxyapatite: hard, rigid, unbending
- helps bone be protective and unbending under weight
217
describe tensile strength
- originates from collagen fibers in the bone
- helps bone to resist twisting and bending
218
what does the mixture of hydroxyapatite and collagen diminish
brittleness of bone
219
describe the analogous structures in bone to steel cable reinforced concrete
- steel cables: collagen
- concrete: hydroxyapatite
220
what happens to bone if there is less hydroxyapatite
causes the bone to bend easily
221
what happens to bone if there is less collagen
becomes very brittle and will break easily
222
what are the two types of ossification
- endochondral ossification
- intramembranous ossification
223
what is the most common type of ossification
endochondral ossification
224
describe endochondral ossification
takes place within the hyaline cartilage that will become bone
225
describe intramembranous ossification
takes place within the embryonic mesenchyme which will become bone
226
which bones undergo intramembranous ossification
- skull bones
- clavicle
227
when does intramembranous ossification occur in comparison to endochondral ossification and why
- intramembranous ossification occurs earlier than endochondral ossification
- the brain develops very earlier after conception to skull bones must have a way to ossify earlier to protect it
228
what are the 2 ways that tissue can grow
- hyperplasia
- hypertrophy
229
define hyperplasia
increasing cell number by mitosis
230
define hypertrophy
individual cells increase in volume/size
231
when is a solid hyaline cartilage bone precursor made after conception
made within 1-2 months (4-8 weeks) of conception
232
what are the two ways that the hyaline cartilage bone precursor can grow
- appositionally
- interstitially
233
what surrounds the hyaline cartilage bone precursor and what is it made of
- perichondrium
- made of connective tissue
234
when after conception does primary ossification occur
2-3 months (8-12 weeks)
235
what occurs during primary ossification
- perichondrium differentiates into periosteum in the diaphysis
- osteoblasts begin laying bone matrix (bone collar)
- bone becomes longer and wider
- chondrocytes start to hypertrophy
- a blood vessel (periosteal bud) enters the bone
- woven bone starts to form within the diaphysis and later becomes spongy bone
- osteoclasts will be made and activated to start chewing away the spongy bone in the diaphysis to create the medullary cavity
236
explain why chondrocytes will hypertrophy during primary ossification
precursor to apoptosis (good cell death)
237
describe the process of apoptosis in chondrocytes during primary ossification
- chondrocytes in the center of the bone start to hypertrophy
- cells surround themselves with an ossified matrix and make no canaliculi
- there is no way for nutrients to get to the cells so they die
238
what is the name of the blood vessel that enters the bone during primary ossification
periosteal bud
239
what is the purpose of the periosteal bud during primary ossification
- becomes a place where osteoblasts can travel and get nutrients
- branches through bone matrix to provide nourishment for proliferation of red bone marrow
240
where do osteoblasts grow the extracellular bone matrix during primary ossification
where the chondrocytes died (on top of the chondrocyte graveyard)
241
what type of bone is always made first
woven bone
242
how does woven bone compare/contrast to spongy bone
looks a lot like spongy bone but it has thicker beams/struts
243
what are the 3 fates of woven bone
- remodeled into compact bone
- destroyed
- remodeled into spongy bone
244
what is the fate of woven bone in the center of the diaphysis in primary ossification
remodeled into spongy bone
245
describe the zone of continued chondrocyte hypertrophy during primary ossification
- zone of cartilage that surrounds the bone collar as the bone calcifies
- migrates to the epiphysis as bone matrix is continually made in the diaphysis
- new bone will replace the dead cartilage which extends the diaphysis
246
when after conception does woven bone become spongy bone
close to birth
247
when after conception are osteoclasts activated
close to birth
248
what is the main purpose of osteoclasts during the end of primary ossification
chew away spongy bone to hollow the medullary cavity
249
what does the medullary cavity fill with during the end of primary ossification
red bone marrow
250
what signifies the beginning of secondary ossification
a sphere of chondrocyte hypertrophy proliferates in the center of the cartilaginous epiphyses
251
what occurs during secondary ossification - infancy to toddler
- osteoblasts and osteoclasts make woven bone tissue in the epiphyses as cartilage continues to hypertrophy
- 1/2 of the epiphysis is still cartilage making the bones unable to bear much weight
- periosteal bud blood vessel enters each epiphysis
252
what occurs during secondary ossification - toddler to 20s
- expansion of bone in epiphyses as chondrocyte hypertrophy continues in a ring around the epiphyses
- woven bone becomes spongy bone in epiphyses
- red bone marrow fills the space between trabeculae in the epiphyses
- cartilage stays at the epiphyseal growth plate where the length of the bone will expand
253
when does bone become mature bone
in late teens or early 20s
254
what signifies that a bone is mature
the epiphyseal plate has ossified to become the epiphyseal line
255
which bones use both types of ossification: endochondral and intramembranous
- occipital bone
- clavicle
256
when does the clavicle stop growing
at age 30
257
what does bone undergoing intramembranous ossification start out as
curved plate of embryonic mesenchyme
258
when does intramembranous ossification occur
by week 5 after conception
259
what is the first thing to proliferate in intramembranous ossification
ossification centers within the embryonic mesenchyme
260
describe ossification centers in intramembranous ossification
- when mesenchyme cells become osteoblasts
- osteoblasts grow through fingerlike projections that meld into each other
- osteoblasts surround themselves with bone matrix
261
what bone is first built in the center of the mesenchyme plate during intramembranous ossification
woven bone
262
list the steps of intramembranous ossification
- ossification centers grow within embryonic mesenchyme
- osteoblasts build woven bone in the center of the mesenchyme plate
- blood vessels enter the woven bone and create red bone marrow
- mesenchyme differentiates into the periosteum
- osteoblasts from the periosteum lay down more bone matrix
- spongy bone is built in the center and compact bone is built on either side
263
describe what happens to mesenchyme surrounding the beginnings of intramembranous bone before it becomes the periosteum
- as the bone grows, the mesenchyme cells will be pushed closer together and will flatten
- there will be less extracellular space
264
what type of tissue do x-rays, CAT scans, and MRIs detect
- x-ray: hard tissue
- CAT scan: soft tissue
- MRI: soft tissue
265
describe how you can differentiate between the epiphyseal plate and the rest of the bone on an x-ray
the epiphyseal plate is less dense than regular bone so it will show up lighter on the x-ray
266
describe why a break of the epiphyseal plate must be carefully corrected with surgery
damage could cause stunted growth in that bone
267
does the epiphyseal plate change in thickness as the bone grows
no, the growth of cartilage and apoptosis of cartilage occur at the same rate
268
list the 5 zones of the epiphyseal plate from the epiphyseal to teh diaphyseal side
- zone of reserved/resting cartilage
- zone of proliferation/hyperplasia
- zone of hypertrophy
- zone of calcification
- calcified bone
269
describe the zone of reserved/resting cartilage in the epiphyseal plate
- where stem cells of chondrocytes are
- as the cells divide, 1 will stay in this zone as a stem cell and 1 will enter the next zone as a chondrocyte
270
describe the zone of proliferation/hyperplasia in the epiphyseal plate
- chondrocytes undergo mitosis
- causes interstitial growth of cartilage as more chondrocytes fill the interstitial space
- creates stacks of chondrocytes on top of one another
271
describe the zone of hypertrophy in the epiphyseal plate
- chondrocytes increase in size/volume
- precursor to apoptosis of chondrocytes
272
describe the zone of calcification in the epiphyseal plate
- chondrocytes undergo apoptosis
- creates an environment for osteoblasts to lay down bone matrix
273
describe the calcified bone zone in the epiphyseal plate
- osteoblasts and osteoclasts migrate up from the diaphyseal region
- osteoblasts begin to lay bone matrix and create new diaphyseal bone
274
what two things occur as bones grow wider
- widening of the medullary cavity
- thickening of the diaphyseal wall of compact bone
275
what cells widen the medullary cavity to make bones wider
osteoclasts
276
what cells thicken the diaphyseal wall to make bones wider
osteoblasts
277
which cell must have a higher activity to make bones wider: osteoblasts or osteoclasts
- osteoblasts must have higher activity than osteoclasts
- this is necessary to the diaphyseal wall will actually thicken
278
describe what happens to the trabeculae of spongy bone during toddlerhood
trabeculae rearrange on stress lines to be better at weight bearing
279
define Wolff's law
- bones thicken in areas where they are the most stressed
- more stress on bones (exercise, physical labor) makes bones thicker, stronger, and denser
280
what happens to bone and muscles during long periods of inactivity
atrophy
281
what happens to bone and muscles when someone lives in space/zero gravity conditions
atrophy
282
why do astronauts exercise in space
to keep bones and muscles from atrophying
283
how much weight is 1 femur built to withstand
1/2 of your body weight
284
what happens to osteoblast activity as you age
lessens
285
where on the femur is compressive stress felt the most
medial diaphyseal wall
286
where on the femur is most likely to bend from compressive stress
medial diaphyseal wall
287
where is the femur typically the thickest and why
- medial diaphyseal wall
- area that feels the most compressive stress and it most likely to bend
288
what happens when you compress a mineral
it induces an electrical current called piezo electricity
289
describe how piezo electricity can explain how bone detects compressive force
- piezo electricity is induced when minerals are compressed
- can change the balance between osteoblasts and osteoclasts through paracrine factors
290
what does paracrine mean
- next to secretion
- secretion moves through interstitial fluid and enters a neighboring cell (1-10 cells away)
291
describe how bone can sense pressure differences and how that can help bones detect compressive force
- the organic matrix of bone is squishy
- pressure can compress lacunae and osteocytes
- osteocytes may feel this and secrete something that affects other cells
292
what type of secretion are growth factors
paracrine
293
what are nonhormonal factors that affect bone growth
- genetics
- nutrition
294
describe the distribution of heights
bell-shaped distribution
295
what type of phenotype is height
polygenic phenotype (multiple genes involved)
296
describe why having a diet that lacks calcium and phosphate is problematic for bone growth
- calcium and phosphate make up the hydroxyapatite in the bone matric
- calcium and phosphorus can only be obtained through diet
297
describe why having a diet that lacks protein is problematic for bone growth
- proteins are a major component of collagen and the ground substance in bones
- some amino acids are essential, meaning they must be obtained from the diet
298
what hormone is created during stress that can stunt bone growth
cortisol
299
what type of hormone is cortisol
- steroid hormone
- stress hormone
300
what are steroid hormones
hormones derived from cholesterol
301
what stress hormone is released only during acute stress
adrenaline
302
what stress hormone is released during acute and chronic stress
cortisol
303
where is cortisol produced
adrenal cortex
304
why is cortisol secreted during long-term stress situations
helps the body physiologically adapt to stressful situations
305
what happens if the body doesn't secrete enough cortisol
you can't adapt to stressful situations
306
what happens if the body secretes too much cortisol
can stunt skeletal growth
307
is cholesterol always bad
no, it is only bad if you have too much
308
what happens if you have too much cholesterol
- can narrow arteries and block blood flow
- causes heart attack or stroke
309
describe why blockage of arteries to the heart and brain is extremely dangerous
the heart and brain do not have any redundant (back-up) arteries
310
describe why cholesterol is necessary for life
- maintains the cell membrane of all cells (temperature regulation and membrane flexibility)
- creates steroid hormones which are needed to live
311
what is a vitamin
- organic molecule
- supports the biochemistry reactions in the body
- cannot be made yourself
312
what does vitamin D do
promotes absorption of calcium from intestines
313
what is vitamin D
- vitamin
- hormone
314
describe why vitamin D is considered both a vitamin and a hormone
- was first thought to be only a vitamin (unable to be made by the body)
- later discovered that it is made by the body, moves through the bloodstream, and binds to intestinal cells
315
what can a lack of vitamin D in kids cause
- rickets
- stunts growth of bones
316
what does vitamin C do
necessary for the synthesis of mature collagen by osteoblasts
317
what disease is caused by inadequate vitamin C intake
scurvy
318
describe why vitamin C is essential for all body systems
- vitamin C is needed to make collagen
- collagen is important for all connective tissue in the body
319
describe why a lack of vitamin C is dangerous for arteries
- vitamin C helps to synthesize mature collagen
- arteries are fortified with collagen
- a lack of vitamin C creates a lack of collagen which means arteries are no longer fortified and can easily rupture
320
what are symptoms of a lack of vitamin C
- bloody gums
- loose teeth, teeth falling out
- internal hemorrhaging
321
what does vitamin K do
necessary for blood clotting
322
describe how you can ~sorta~ make vitamin K yourself
- your own cells can't make vitamin K
- bacteria in the colon can make vitamin K and give it to your cells
323
list hormones that influence bone growth
- somatotropin (growth hormone)
- insulin-like growth factor-1 (IGF-1)
- thyroid hormones (T3 and T4)
- gonadal sex hormones (estrogen and testosterone)
- calcitriol (vitamin D)
324
what does the phrase necessary and sufficient mean
- a hormone is necessary for a specific function
- the hormone can produce the function by itself
325
what does the phrase necessary and insufficient mean
- a hormone is necessary for a specific function
- the hormone cannot produce the function by itself; additional factors are needed to complete the function process
326
is somatotropin (growth hormone) necessary and sufficient or necessary and insufficient
necessary and insufficient
327
break down the term somatotropin
- soma = body
- tropin = activates
- hormone that activates body growth
328
what organ secretes somatotropin (growth hormone)
pituitary gland
329
what is the main target for somatotropin (growth hormone)
liver
330
does somatotropin (growth hormone) have direct or indirect effects on bone growth
both, but mostly indirect
331
what organ secretes insulin-like growth factor-1 (IGF-1)
liver (specifically hepatocytes)
332
what is the main target for insulin-like growth factor-1 (IGF-1)
epiphyseal growth plate
333
describe why the name insulin-like growth factor-1 (IGF-1) is it accurate and not accurate
- protein with similar amino acid sequence to insulin
- does not have insulin-like effects
334
describe the GH-IGF-1 hormone axis
- the pituitary gland secretes GH
- GH runs through the bloodstream to the liver
- hepatocytes in the liver secretes IGF-1
- IGF-1 runs through the bloodstream to the epiphyseal growth plate
335
describe the effects/functions of thyroid hormones
- role in linear bone growth and growth/development of the brain
- regulates basal metabolic rate and body temperature
- stimulate and support other hormones
336
what are thyroid hormones made from
- 2 tyrosine amino acids
- iodine
337
why is tyrosine important
- component of thyroid hormones
- component of melanin
338
what are symptoms of hypothyroidism
- fatigue
- weight gain
339
how can hypothyroidism be treated
hormone replacement therapy
340
why is hypothyroidism dangerous for young people who are growing
- connections between neurons won't form
- stunts skeletal growth
341
describe cretinism
- caused by low T3 and T4 hormone levels during growing years
- results in stunted skeletal growth and limited neuron connections in the brain
342
what are the symptoms of hyperthyroidism
- weight loss
- easily agitated
- can't relax or sleep
- protruding eyes
343
what often causes hyperthyroidism
tumor
344
how can hyperthyroidism be treated
- surgical removal of a tumor
- taking radioactive iodine (I-131)
345
how does taking radioactive iodine (I-131) treat hyperthyroidism
- the iodine will bind to the thyroid gland and kill it
- will need to take synthetic thyroid hormones
346
where are gonadal sex hormones (estrogen and testosterone) secreted
ovaries or testes
347
what type of hormone are gonadal sex hormones (estrogen and testosterone)
steroid hormones
348
what do gonadal sex hormones (estrogen and testosterone) do
- cause growth at puberty by stimulating the epiphyseal plates
- cause the closure of epiphyseal plates
349
describe how testosterone differs from estrogen
- stimulates growth later than females
- harder driver of growth at the epiphyseal growth plate: longer and more intense growth spurt, makes men taller than women
- lazier about closing the epiphyseal growth plate: men grow longer and stop growing later than women
350
describe how estrogen differs from testosterone
- produced before male sex hormones are: girls have a growth spurt first
- more aggressive about closing the epiphyseal growth plate: girls stop growing earlier than boys
351
what is the set point for calcium in the blood
9 mg/dl
352
what are symptoms of low calcium levels
- muscles contract too often without regulation
- can cause full body tetanus which can lead to death
353
what are symptoms of high calcium levels
- muscle weakness
- lethargy
- coma
354
which is more critical: low calcium levels or high calcium levels
low calcium levels
355
describe the parathyroid glands
- 4 glands
- lentil-sized and shaped
- beside the thyroid gland
356
what are the receptors and controllers during negative feedback of low calcium levels
- parathyroid glands
- kidneys
357
describe how the parathyroid glands are receptors and controllers during negative feedback of low calcium levels
- receptor: cells detect low calcium levels in the blood
- controller: secretes parathyroid hormone (PTH)
358
describe how the kidneys are receptors, controllers, and effectors during negative feedback of low calcium levels
- receptor: cells receive parathyroid hormone (PTH)
- controller: PTH activates calcitriol that is produced in the kidneys
- effector: PTH stimulates the kidneys to reabsorb calcium
359
what are the effectors during negative feedback of low calcium levels
- osteoclasts in the bones
- kidneys
- small intestine
360
describe how osteoclasts in the bones are effectors during negative feedback of low calcium levels
PTH and calcitriol stimulate the formation of osteoclasts in bone which will increase blood calcium levels
361
describe how the small intestine is an effector during negative feedback of low calcium levels
calcitriol stimulates calcium uptake in the small intestine
362
what are the effects of parathyroid hormone during negative feedback of low calcium levels
- stimulates osteoclast activity
- stimulates calcium reabsorption in kidney tubules
363
what are the effects of calcitriol during negative feedback of low calcium levels
- stimulates osteoclast activity
- stimulates uptake of calcium in the small intestine
364
are PTH and calcitriol hypercalcemic or hypocalcemic
hypercalcemic: increase calcium levels
365
describe how the kidneys filter blood
- filters out all components of the blood
- reabsorbs what is needed
366
describe what would happen to digested calcium if calcitriol was not present
the calcium would not be absorbed in high amounts
367
when does PTH stop being produced during the negative feedback of low calcium levels
- when there is sufficient calcium in the blood
- the receptors will no longer detect a signal
368
what are the receptors and controllers during negative feedback of high calcium levels
thyroid gland
369
describe how the thyroid gland is a receptor and controller during negative feedback of high calcium levels
c cells in the thyroid gland detect high calcium levels and secrete calcitonin
370
what are the effectors during negative feedback of high calcium levels
- osteoclasts in the bones
- kidneys
371
describe how the osteoclasts in bones are an effector during negative feedback of high calcium levels
calcitonin inhibits osteoclast activity so less calcium is absorbed
372
describe how the kidneys are an effector during negative feedback of high calcium levels
calcitonin causes the kidney to allow more calcium to be deposited in the urine (less calcium reabsorbed into the bloodstream)
373
what are the effects of calcitonin during negative feedback of high calcium levels
- inhibits osteoclast activity in the bones
- stimulates the kidneys to absorb less calcium into the blood
374
is calcitonin hypercalcemic or hypocalcemic
hypocalcemic: decreases calcium levels
375
which is more physiologically important: PTH or calcitonin
PTH
376
describe why calcitonin is important for people who are growing
- helps to deposit lots of calcium into the bone
- may help support rapid bone growth
377
describe parathyroid tumors
- overproduce PTH
- can cause too high levels of calcium in the blood
- usually not cancerous
378
how many organs and organ systems are necessary to synthesize vitamin D in the body
- 3 organs
- 3 organ systems
379
what is required for the synthesis of vitamin D in the body
UV light produced by the sun
380
what happens if you get too much or too little UV light exposure
- too much: skin cancer
- too little: no vitamin D production in the body
381
where does the first hydroxylation of vitamin D production take place
skin
382
describe the first hydroxylation of vitamin D production
- UV light stimulates the enzyme 7-dehydrocholesterol in the skin
- the enzyme 7-decholesterol activates the attachment of a hydroxyl group to create cholecalciferol which enters the bloodstream
383
where does the second hydroxylation of vitamin D production take place
liver
384
describe the second hydroxylation of vitamin D production
- cholecalciferol enters the liver
- liver enzymes stimulate the attachment of another hydroxyl group to create calcidiol which enters the bloodstream
385
where does the third hydroxylation of vitamin D production take place
kidneys
386
describe the third hydroxylation of vitamin D production
- calcidiol enters the kidneys
- kidney enzymes are stimulated by PTH to attach another hydroxyl group to create calcitriol which enters the bloodstream
387
what is the scientific name for vitamin D
calcitriol
388
describe what it means that vitamin D production is PTH dependent
- the kidney enzymes during the third hydroxylation won't be stimulated unless PTH is present
- vitamin D will not be formed without PTH
389
what does IGF-1 do once it enters the epiphyseal growth plate
- stimulates cells in the EGP to divide
- these cells will them produce IGF-1 themselves within the EGP
390
define paracrine factors
- secretions similar to endocrine but they do not enter the blood stream
- secretions move through interstitial fluid, up to 8 cell lengths
- stimulate neighboring cells
391
what are common paracrine factors
many growth factors
392
is IGF-1 a paracrine factor or a hormone
- hormone as it is produced in the liver and travels through the bloodstream to the epiphyseal growth plate
- paracrine factor as it is secreted by cells in the epiphyseal growth plate and stimulates neighboring cells
393
what is vitamin D3
cholecalciferol
394
what race and gender are more likely to get osteoporosis
- caucasian
- women
395
how does osteoporosis in men compare to osteoporosis in women
- women are more likely to get osteoporosis
- in men, osteoporosis generally starts later and is less severe than in women
396
describe what is generally happening during osteoporosis
osteoclast activity outpaces osteoblast activity
397
what can exacerbate osteoporosis
low vitamin D and calcium levels
398
what ages does Wolff's law apply to
- any age
- bones can grow thicker and denser with activity at almost any age
399
define osteopenia
- pro-osteoporosis
- may become osteoporosis
400
at what ages is osteoblast activity greater than osteoclast activity
0-20s
401
at what ages is osteoblast activity equal to osteoblast activity
20s-40s
402
at what age is osteoblast activity less than osteoclast activity
- 40s+
- larger imbalance than normal in people with osteoporosis
403
describe the difference in trabeculae between a bone with and without osteoporosis
- without osteoporosis: trabeculae are thick and solid
- with osteoporosis: trabeculae are thinner and have holes and craters
404
what type of bone is hit hardest by osteoporosis
spongy bone
405
describe what happens to bones with osteoporosis
- weaker
- more easily broken
- thinner
- unable to withstand force
406
what test can diagnose osteoporosis
bone density scan
407
when is osteoporosis often detected
when someone breaks a bone with little force
408
what is the worst bone to break, especially for older adults
hip (breaking the neck of the femur)
409
describe why women are more likely to get osteoporosis than men
- sex steroid (testosterone and estrogen) stimulate osteoblast activity; men lessen testosterone gradually overtime; women drastically lose estrogen levels after menopause (late 40s) when ovaries stop producing it
- women have less dense/thick skeletons anyway
410
list treatments for osteoporosis
- estrogen replacement therapy
- selective estrogen receptor modulators (SERMs)
- bisphosphonates
- exercise (Wolff's law)
- vitamin D and calcium supplementation
- hormone replacement with calcitonin or parathyroid hormone (PTH)
411
what are the risks of estrogen replacement therapy for osteoporosis
- heart attack
- stroke
- uterine/mammary cancer
412
what is a possible less dangerous way to administer estrogen to lessen the risks
- through a skin patch
- transdermal
- slow introduction of estrogen into the system
413
define selective estrogen receptor modulators (SERMs) as a treatment for osteoporosis
- organic molecule crated in a lab that modulates certain estrogen receptors in osteoblasts
- different enough from estrogen that it doesn't have the same cardiovascular risks
414
define bisphosphonates as a treatment for osteoporosis
- lessen osteoclast activity
- accelerate the apoptosis of osteoclasts to equalize osteoblast and osteoclast activity
415
describe how exercise can be a treatment for osteoporosis
- Wolff's law: exercise can stimulate bone to grow thicker and denser
- gentle exercises
416
what are exacerbating factors of osteoporosis
low calcium and vitamin D
417
is supplementing vitamin D and calcium a good single treatment for osteoporosis
- no
- won't address the main cause
- will aid in bone density slightly
418
define calcitonin as a treatment for osteoporosis
inhibits osteoclasts
419
what type of calcitonin is prescribed for osteoporosis treatment
- salmon calcitonin
- more powerful in humans than human calcitonin is
420
how is salmon calcitonin administered as a treatment for osteoporosis
snort it
421
describe how parathyroid hormone (PTH) can be a treatment for osteoporosis, despite the fact that it normally stimulates osteoclasts
when administered in large doses at specific intervals, PTH can have the opposite effect than it usually does
422
what classified someone as having dwarfism
- being less than 4'4"
- having parents of normal height
423
what are the two types of dwarfism
- pituitary dwarfism
- achondroplastic dwarfism
424
which type of dwarfism is the most rare
pituitary dwarfism
425
which type of dwarfism is the most common
achondroplastic dwarfism
426
define pituitary dwarfism
- pituitary secretes too little growth hormone, and therefore too little IGF-1
- individuals are still proportional, just shorter
427
what is the treatment for pituitary dwarfism
injection of authentic human growth hormone
428
define achondroplastic dwarfism
- without chondrocyte hyperplasia
- unresponsiveness to fibroblast growth factor
- underperforming epiphyseal growth plates
- individuals have shortened long bones but a normal sized head and torso
429
what is the treatment for achondroplastic dwarfism
none, other than expensive and dangerous limb lengthening surgery
430
define cretinism
- low thyroid hormone during early infancy/toddler stage
- individuals have a short stature and profound cognitive deficit
431
describe why cretinism causes limited bone growth
- low thyroid hormone
- thyroid hormone stimulates the GH-IGF-1 hormone axis
- without this hormone axis, IGF-1 is not being sent to the epiphyseal growth plates and therefore bones aren't lengthening
432
why does cretinism cause cognitive deficits
- low thyroid hormone
- thyroid hormone stimulates brain growth and development
433
what is the treatment for cretinism
thyroid hormone replacement
434
what is the difference between rickets and osteomalacia
- same disease; named differently for different ages
- rickets: children
- osteomalacia: adults
435
what causes rickets and osteomalacia
not enough vitamin D or calcium
436
what is the treatment for rickets and osteomalacia
supplementation with vitamin D and/or calcium
437
what is the most common cause of rickets and osteomalacia
lack of vitamin D
438
describe how a lack of vitamin D can lead to rickets and osteomalacia
- not taking in enough calcium from your diet
- osteoblasts can make the organic matrix but not hydroxyapatite
- bones aren't hard enough and will start to bend under weight
439
why is rickets and osteomalacia very painful
bending of bones compresses nerves
440
what causes gigantism and/or acromegaly
pituitary adenoma (tumor) making too much growth hormone
441
what are the treatments for gigantism and/or acromegaly
- surgery
- hormone therapy
442
who had gigantism
Robert Wadlow
443
how tall was Robert Wadlow
almost 9'
444
when and why did Robert Wadlow die
- died in 20s
- died from complications with blood flow due to gigantism
445
how would someone develep acromegaly without gigantism
pituitary adenoma develops after epiphyseal growth plates close
446
who had acromegaly and gigantism
Andre the Giant
447
how tall was Andre the Giant
7'4"
448
describe what happens when someone has both gigantism and acromegaly
- bones grow linearly before epiphyseal growth plates close
- after epiphyseal growth plates close, the head will continue to grow
449
what aspects of the head tend to clearly grow in size in someone with acromegaly
- forehead
- nose
- jaw
450
when and why did Andre the Giant die
- died at 45
- heart disease: overgrown heart with thin walls
451
who was Harvey Cushing
father of neurosurgery
452
describe the surgery to treat gigantism and/or acromegaly
- neurosurgery to debulk the pituitary adenoma
- conducted up through the nose into the brain
453
what 2 hormones synthesized in the hypothalamus control growth hormone production in the pituitary gland
- GH inhibiting hormone (somatostatin)
- GH releasing hormone
454
what hormone replacement can be given as a treatment for gigantism and/or acromegaly
GH inhibiting hormone (somatostatin)
455
what classifies a broken bone
any damage deeper than the periosteum
456
define a linear bone fracture
- parallel to the diaphysis
- vertical
457
define a complete bone fracture
- bone snaps in half
- two separate pieces are formed
458
define an incomplete bone fracture
- bone doesn't snap in half
- entire bone still connected with a break in it
459
define a comminuted bone fracture
- bone is shattered
- usually requires orthopedic surgery
460
define a transverse bone fracture
- perpendicular to the diaphysis
- horizontal
461
define an impacted bone fracture
- broken ends of bone are jammed together by force
- ex: broken hip (proximal neck of femur)
462
define a spiral bone fracture
- breaks wraps around the bone
- bone twisted
463
define an oblique bone fracture
- angle of fracture between transverse and linear
- sloped line
464
what are the stages of bone healing after a break
- hematoma formation
- callus formation
- callus ossification
- bone remodeling
465
describe the first stage of bone healing after a break
- hematoma formation
- accumulation of blood around the break
- swelling from interstitial fluid accumulation
- pain as fluid pushes on nerves
466
describe the second stage of bone healing after a break
- callus formation
- happens over days to weeks
- fibroblasts and chondroblasts create fibrocartilage covering around the break
467
what type of cartilage creates the callus around a broken bone
fibrocartilage
468
define a bone reduction
- bones being set after a break
- aligned at the ends so it heals well
469
describe the third stage of bone healing after a break
- callus ossification
- osteoblasts convert fibrocartilage callus to woven bone
470
describe the fourth stage of bone healing after a break
- bone remodeling
- woven bone callus remodeled into compact bone
- osteoclasts dissolve the woven bone in the medullary cavity
471
how long can it take for bone to be completely healed following a break
4 months
472
what does the root arthro mean
joints
473
what are the categories of joints based on mobility
- synarthroses
- amphiarthroses
- diarthroses
474
define synarthroses
immovable joints
475
define amphiarthroses
slightly movable joints
476
define diarthroses
freely movable joints
477
what is the singular form of the types of joints based on mobility
- synarthrosis
- amphiarthrosis
- diarthrosis
478
what is the plural form of the types of joints based on mobility
- synarthroses
- amphiarthroses
- diarthroses
479
what is the adjectival form of the types of joints based on mobility
- synarthrotic
- amphiarthrotic
- diarthrotic
480
what are the categories of joints based on structure
- fibrous
- cartilaginous
- synovial
481
what are the types of fibrous joints
- sutures
- syndesmoses
- gomphoses
482
where are sutures only found
skull
483
what tissue type is between flat bones of the skull in suture joints
dense irregular connective tissue
484
at what point in time do you have the most surface area of a suture joint
at birth
485
define fontanelles
- sutures in the skull of babies
- areas where dense irregular connective tissue is connecting flat bones of the skull
- diminish as you grow
486
what does fontanelle literally translate to and why is it given that name
- fountain of blood
- you can feel a baby's pulse on the top of their head at the fontanelle location
487
when do suture joints completely disappear
- 4th decade of life
- 30s and 40s
488
define synostoses
- joints that were once made of connective tissue
- connective tissue lessens and bones are fused together
- synarthrotic
489
what are the joints that become synostoses
- suture joints in the skull
- synchondrosis at the epiphyseal growth plate
- synchondrosis at the acetabulum
490
what type of mobility to suture joints have
- amphiarthrotic
- small amount of movement is allowed
491
why is it important for suture joints of the skull to be amphiarthrotic
need to move slightly during birth so the baby can move through the birth canal
492
how can you determine the age of a skeleton
based on the fusion level of suture joints in the skull
493
define syndesmoses
- fibrous joints
- bones connected by short ligaments of dense regular connective tissue
- some classified as synarthrotic while others are amphiarthrotic
494
when would a syndesmosis joint be classified as synarthrotic
when the ligament connecting the bones is short, allowing for less movement
495
when would a syndesmosis joint be classified as amphiarthrotic
when the ligament connecting the bones is long, allowing for more movement
496
example of a syndesmosis joint
radio-ulnar syndesmosis
497
is the radio-ulnar syndesmosis considered synarthrotic or amphiarthrotic
amphiarthrotic
498
are amphiarthrotic joints classified by slight movement microscopically or with the naked eye
with the naked eye
499
define gomphoses
- fibrous joints
- peg in socket joints between a tooth and the mandible or maxilla
- synarthrotic
500
what type of movement do gomphosis joints provide
synarthrotic
501
how are teeth connected to the mandible or maxilla in gomphesis joints
periodontal ligaments
502
describe periodontal ligaments
- keep tooth in the socket
- network of ligaments for each tooth
- partially calcified
- made of dense regular connective tissue
503
what cranial nerve innervates the teeth
trigeminal nerve V
504
what happens if bacteria get between the gumline and the tooth root
- can soften periodontal ligaments
- make teeth more likely to fall out
505
define crown of the tooth
above the gumline
506
define neck of the tooth
even with the gumline
507
define root of the tooth
under the gumline
508
describe enamel
- white part of the tooth
- outer covering
- made of almost pure hydroxyapatite
509
describe why enamel being almost pure hydroxyapatite is good and bad
- makes the teeth extremely hard
- without the organic matrix, the teeth are very brittle and prone to chipping
510
what is the hardest substance in the human body
enamel
511
can tooth enamel regenerate
- no
- cells producing enamel are gone by the time the tooth erupts
512
what substance is known to damage tooth enamel
- acid
- causes cavities to develop
513
why is fluoride beneficial to teeth
makes the tooth better at resisting degradation by acid
514
define dentin
- part of tooth under the enamel
- arranged in columns
- bone-like: hydroxyapatite and collagen
- softer than enamel
515
what makes dentin
osteoblasts
516
can dentin be regenerated
- yes
- made by osteoblasts, which the body always has
517
define cartilaginous joints
bones joined by cartilage without a joint cavity
518
what are the types of cartilaginous joints
- synchondroses
- symphyses
519
define synchondroses
- cartilaginous joint
- thin plate of hyaline cartilage unites bones
- synarthrotic
520
what happens to the cartilage in synchondrosis joints as you age
cartilage gets thinner
521
example of synchondrosis joints
- epiphyseal plates
- first rib and the manubrium
- acetabulum: ilium + ischium + pubis
522
which synchondrosis joints will fuse to become synostosis joints
- epiphyseal plates
- acetabulum: ilium + ischium + pubis
523
when does the acetabulum synchondrosis joint fuse to become a synostosis joint
age 11
524
define symphyses
- cartilaginous joint
- bones covered with fibrocartilage pad
- amphiarthrotic
525
examples of symphysis joints
- intervertebral disks
- pubic symphysis
526
describe why it's important for the pubic symphysis to be amphiarthrotic
- bones need to move anteriorly and laterally when a woman is in labor
- allows the baby's head to move through
527
describe the fibrocartilage pad in symphysis joints
- large area of fibrocartilage
- fibrocartilage surrounded by thin layers of hyaline cartilage which articulates with the bone
528
what type of movement do synovial joints provide
diarthrotic
529
what is the main importance of synovial joints
frictionless movement
530
what types of nerves are in synovial joints
- pain receptors
- proprioceptors
531
what are the two parts of the joints capsule in synovial joints
- fibrous capsule
- synovial membrane
532
describe the fibrous capsule of the joint capsule in synovial joints
- outer surface
- tough, provides structural integrity
- joins the two bones together
533
describe the synovial membrane of the joint capsule in synovial joints
- inner surface
- delicate
- makes synovial fluid
534
why is synovial fluid necessary
lessens friction
535
define proprioception
- unconscious and conscious
- all proprioceptors combine to give the brain information on how the body is positioned/oriented in space
536
where are proprioceptors found
- in the joint capsules of all diarthrotic/synovial joints
- skeletal muscle
