Skeletal System (highschool) Flashcards
1
Q
The process by which blood cells are formed is classifed as what?
A
hemopoiesis
(hemo = blood; poie = making)
2
Q
What term fits the following definition?:
A small depression or space; in bone or cartilage, lacunae are occupied by cells here
A
lacuna
3
Q
What is a large multinuclear cell associated with physiologic bone destruction, reabsorption and remodeling called?
A
osteoclast
(osteon = bone)
4
Q
What are five functions the skeleton provides to the body?
A
- support (body framework)
- movement (muscle attachment to skeleton; movable joints)
- protection (for vital internal organs)
- mineral reservoir (storage of certain minerals)
- hemopoiesis (production of blood cells)
5
Q
What are the four classifications of bones?
A
- long bones
- short bones
- flat bones
- irregular bones
6
Q
Long bones can be described as..
A
- long axis (longer than they are wide)
- ex: most bones of upper and lower limbs
7
Q
Most bones of upper and lower limbs are classifed as what out of the four types of bones?
A
long bones
8
Q
Short bones can be described as..
A
- lacks long axis
- ex: carpals, tarsals
9
Q
Flat bones can be described as..
A
- thin bones
- ex: ribs
10
Q
Irregular bones can be described as..
A
- bones that do not fit the other 3 categories
- ex: vertebrae, pelvic girdles
11
Q
Apart of the four different classifications of bones..
Which classification describes the following?:
* long axis (longer than they are wide)
* ex: most bones of upper and lower limbs
A
long bones
12
Q
Apart of the four different classifications of bones..
Which classification describes the following?:
* lacks long axis
* ex: carpals, tarsals
A
short bones
13
Q
Apart of the four different classifications of bones..
Which classification describes the following?:
* thin bones
* ex: ribs
A
flat bones
14
Q
Apart of the four different classifications of bones..
Which classification describes the following?:
* bones that do not fit the other 3 categories
* ex: vertebrae, pelvic girdles
A
irregular bones
15
Q
A typical long bone has a shaft, what is that shaft called?
A
diaphysis
16
Q
A typical long bone has two ends which fall under two different terms, what are these two terms called?
A
- proximal epiphyses
- distal epiphyses
17
Q
Fill the blank for the following:
The diaphysis is formed of a hollow cylinder of ____________ that surrounds a ____________.
A
- compact bone
- medullary cavity
18
Q
In a typical long bone, the place used as a fat storage site is called what?
A
[the] medullary cavity
19
Q
The medullary cavity can also be called..?
A
[the] yellow bone marrow cavity
20
Q
What thin connective tissue layer lines the yellow bone marrow cavity (medullary cavity)?
A
[the] endosteum
21
Q
The outer surfaces of the epiphyses are also formed of what bone?
A
compact bone
22
Q
What interconnecting plates fill the central regions of the epiphyses?
A
spongy (cancellous) bone
23
Q
What lines the cavities between the bony plates of spongy bones?
A
[the] endosteum
24
Q
In some certain bones, what kind of marrow is contained within the spongy bone in the epiphyses?
A
red bone marrow
25
In children and young adults, what separates the diaphysis and epiphysis?
an epiphyseal cartilage (or plate)
26
An epiphyseal cartilage (or plate), present in children and young adults, helps provide what?
length
| (helps the bone to increase in length)
27
In adults, what happens to the epiphyseal cartilage (or plate) when skeletal growth has been completed?
* replaced by bone
* uniting the epiphysis with the rest of the bone
* bony junction is now called the epiphyseal line
28
What is not present in a flat bone?
there is no medullary cavity
29
A flat bone is formed of a special kind of spongy bone called a what?
diploe
30
Diploe in a flat bone is sandwiched between wo surface layers, what comprises these two surface layers?
compact bone
31
Diploe is spongy bone that contains what?
red marrow
32
Bones are covered with a double layer of dense connective tissue, what is this double layer of dense connective tissue called?
[the] periosteum
33
In joints where the bone is covered with an articular cartilage, what is not present?
there is no periosteum
34
The outer layer of the periosteum is well supplied with what two things?
* blood vessels
* nerves
| (some of which enter the bone)
35
The inner layer of the periosteum is anchored to the bone by collagenous bundles that pentrate the bone, what are these collagenous bundles called?
sharpey's fibers
36
Under a microscope, compact bone is seen to be composed of many organized systems of interconneting canals. The unit of structure of adult compact bone is called the what?
[the] haversian system (osteon)
37
In compact bone, what does each haversian system contain?
a central haversian canal
38
What surrounds the haversian canal in each haversian system?
lamellae (layers of bone)
39
Small cavities are located between adjaent lamellae in a haversian system, what are these small cavities called?
lacunae
40
What kind of cell is contained In each lacuna (lacunae)?
[an] osteocyte
41
The tiny canals that help interconnect all lacunae within each haversian system is called what?
canaliculi
42
What is contained in each haversian canal, that helps provide a source of nutrients, and a means of waste removal, for osteocytes in lacunae?
[at least one] blood capillary
43
Blood vessels, as well as lymph vessels and nerves, enter and leave the marrow cavity by means of what canals (that penetrate the bone from the surface & communicate with the marrow cavity)?
nutrient canals
44
Blood vessels from the canals (nutrient canals) reach the haversian canals through what kind of canals (tha run at right angles [horizontal] to the haversian canals)?
volkmann's canals
45
At the external surface of a bone, just beneath the periosteum (connected to sharpeys fibers) are what kind of lamellae that follow the circumference of the shaft rather than surrounding a haversian canal?
circumferential lamellae
46
What's the difference between regular lamellae and circumferential lamellae?
* regular lamellae surround haversian canals
* circumferential lamellae surround or follow the circumference of the shaft
47
Up close in a microscope, what is the difference between spongy bone and compact bone?
* spongy bone is less organized compared to compact bone
| lamaellae are not arranged in layers but rather in various of directions
48
The intercellular substance of a tissue (like bone) can be called what?
[the] matrix
49
What is the intercellular substance (matrix) of bone composed of?
* an organic framework (collagenous fibers)
* inorganic salts (calcium & phosphate)
50
The organic framework which is one of the two main components in the matrix of the bone, is formed by what (similar to those found within other connective tissues)?
collagenous fibers (surrounding the fibers is a homogenous ground substance)
51
What are the inorganic salts of bone composed principally of?
* calcium
* phosphate
52
The collagenous fibers in the bone provide what to the bone?
great tensile strength (resistance to breaking under tension)
| (capable of resisting streching and twisting)
53
The inorganic salts found in bone provide what for the bone?
allow the bone to withstand compression
54
What two main components make the bones in our body exceptionally strong without being brittle?
* collagenous fibers
* inorganic salts
55
The skeleton develops by the transformation of what into bone?
embryonic connective tissues
56
# Under early development of bone:
What process occurs when embryonic connective tissue cells (specifically, mesodermal cells), that are transformed into bone, are undifferentiated?
intramembranous ossification
57
# Under early development of bone:
What process occurs when embryonic connective tissue cells (specifically, mesodermal cells) transform into cartilage-producing cells before bone formation begins?
endochondral (intracartilaginous) ossification
58
What is the main difference that occurs between intramembranous ossification and endochondral ossification?
the specific tissue that is replaced in each process
* endochondral - starts out as (hyaline) **cartilage** then replaced by bone
* intramembranous - starts out as (mesenchymal) **connective tissue** (undifferentiated) then replaced by bone
59
What is the first step in intramembranous ossification?
undifferentiated (mesenchymal) connective tissue cells gather together and begin to differentiate
* some into capillaries, others into osteogenic cells that later become osteoblasts
60
Although they will ultimately be spread out by the formation of bone tissue, early osteoblasts appear in a cluster. What is this cluster called?
[an] ossification center
61
Osteoblasts secrete an uncalcified matrix consisting of collagen precursors and other organic proteins, which calcifies (hardens) within a few days as mineral salts (such as calcium) are deposited on it. What is this uncalcified matrix called?
osteoid
62
Osteoblasts secrete osteoid, uncalcified matrix consisting of collagen precursors and other organic proteins, which calcifies (hardens) within a few days as mineral salts (such as calcium) are deposited on it. What happens as a result from this calcification?
Osteoblasts become trapped within lacunae
| mineral salts like calcium bind with osteoid causing calcification
63
What happens after osteoblasts become trapped within lacunae?
their activity slows, and they become mature bone cells called osteocytes
64
Osteoblasts that slow in activity and become mature bone cells begin to be classified as what?
osteocytes
65
Well-developed spicules of bone are known as what?
trabeculae
66
# Fill in the blank for the following:
The trabeculae radiate in all directions, uniting with one another to form a network of ____________.
spongy bone
67
Trabeculae unit with one another to create a network of spongy bone. However, in areas that will eventually form compact bone, what does the trabeculae do?
the trabeculae continue to thicken as osteoblasts deposit new bone matrix in layers around the trabeculae
* spaces between the trabeculae are narrowed and replaced with bone (immature compact bone)
68
# During intramembranous ossification..
Several clusters of osteoid unite around the capillaries to form a special matrix, what is this special matrix called?
[a] trabecular matrix
* spongy bone
69
# During intramembranous ossification..
The blood vessels that are surrounded by trabecular matrix (spongy bone), eventually form what?
red bone marrow
70
Undifferentiated (mesenchymal) connective tissue collect on the external surfaces of the bone forming a membrane. What is this membrane called?
[the] periosteum
71
Once the undifferentiated (mesenchymal) connective tissue form the periosteum, what happens next?
osteoblasts are created which begin forming (with osteoid) compact bone (superficial to spongy bone)
72
What is the second stage in intramembranous ossification?
Osteoblasts become entrapped by the osteoid they secrete, transforming them to osteocytes
73
What is the third stage in intramembranous ossification?
spongy bone and periosteum form
74
What is the fourth stage in intramembranous ossification?
Compat bone forms superficially to the spongy bone
75
What is the fifth and final stage in inramembranous ossification?
Blood vessels form the red marrow
76
What bone cell helps break down or reabsorb previously laid down bone (bone tissue)?
osteoclasts
77
Most bones form from what ossification?
endochondral ossification
78
During endochondral ossification, a fibrous connective tissue membane surrounds the outside of the cartilage. What is this fibrous connectivetissue membrane called?
perichondrium
79
What is the first stage in the endochondral ossification process?
perichondrium becomes periosteum
* differentiation occurs from new supplies of nutrients to undifferentiated (mesenchymal) connective tissue cells
* osteoblasts are created
80
After osteoblasts are created, what happens next? (second part of the first stage in the endochondral ossification proces)
osteoblasts gather at diaphysis wall to form "bone collar"
81
The place where the osteoblasts gather and form the "bone collar" is called what?
[the] primary ossification center
82
The cells that were responsible for building the hyaline cartilage blue-print (cells responsible for cartilage formation) are called what?
chondrocytes
83
# The beginning of second stage in the Endochondra Ossification process:
Once the "bone collar" is formed, chondrocytes that remain in the central cavity do what?
chonodrocytes enlarge and send a signal to the surrounding cartilage (matrix) to calcify
84
Why is the surrounding cartilage (matrix) calcified during the second stage of the Endochondral Ossification process?
* makes the cells become impermeable to nutrients
* causes cell death - making space
85
Once calcified cartilage (matrix) begins to deteroriate, what happens next in the second stage of the Endochondral Ossification process?
[a] central clearing starts to form where cells died (still supported by "bone collar")
86
After a central clearing (space) forms during the second stage of the Endochondral Ossification process, what happens next?
healthy chondrocytes not in central cavity (towards distal ends of bone) continue producing cartilage matrix and helps with elongating (making it longer) the bone
87
During the third stage of the Endochondral Ossification process, a new structure appears where central clearing (space) was, what is this new structure called?
[the] periosteal bud
88
Once the periosteal bud appears during the third stage of the Endochondral Ossification process, what does the periosteal bud consist of?
* an artery
* vein
* lymphatic vessels
* nerves
* osteogenic cells
89
With the addition of new osteogenic cells in the periosteal bud, what is created from these osteogenic cells (or now osteoblasts)?
spongy bone
90
With the addition of new osteogenic cells in the periosteal bud, what happens next in a result of these osteogenic cells (or now osteoclasts)?
osteoclasts begin to degrade cartilage matrix to make room for new spongy bone (deposited from the osteoblasts)
91
After osteoblasts make most of the spongy bone in the primary ossification center, osteoclasts do what?
osteoclasts start breaking down newly formed spongy bone from center/very beginning where it first started
* making way for the beginning stages of the medullary cavity
92
After medullary cavity is formed, cartilaginous growth now appears only in what part of the bone?
[the] epiphyses, bony epiphyseal plate starts to form, secondary ossification center appears!
93
Once cartilaginous growth becomes limited to the epiphyses and the bony epiphyseal plates begin to form, what appears?
[a] secondary ossification center (on one or both of the ends)
94
For the final stage of the endochondral ossification process, cartilage remainds only where?
* on the bone surface
* at epiphyseal plates
95
After osteoblasts gather to make the periosteum, the cartilage of the diaphysis becomes encased by what?
compact bone (laid down by the cells of the periosteum)
96
# During the Endochondral Ossification process...
While osteoblasts are trying to form bone on the periphery of the diaphysis ("bone collar"), what happens to the cartilage cells within the diaphysis?
cartilage cells enlarge, same with lacunae surrounding the cells
97
# During the Endochondral Ossification process..
Once the cartilage cells and lacunae surrounding the cells become enlarged, the cartilage matrix that lies deep to the sit of the peripheral ossification becomes reduced to what?
* thin partitions
* spicules
98
What happens to the cartilage matrix after enlargement of the cartilage cells within the diaphysis (along with their surrounding lacunae)?
Matrix begins to calcify, forming calcified cartilage
(makes diffusion of nutrients to cartilage cells impossible)
99
What happens to the calcified cartilage in the diaphysis?
cartilage cells die and calcified matrix begins to degenerate, leaving spaces within the calcified cartilage matrix (still supported by "bone collar")
100
The place where the osteoblasts gather and form the "bone collar" is called what?
[the] primary ossification center
101
By around the age of 25, what happens to the cartilage within the epiphyseal plate?
* becomes completely replaced by bone
* only an epiphyseal line remains & bones stop growing longer
102
Once the cartilage within the epiphyseal plate becomes completely replaced by bone, what remains?
an epiphyseal line
103
Once the cartilage within the epiphyseal plate becomes completely replaced by bone, what happens to the growth of the bone?
it stops growing (bones cannot grow any longer)
104
Bone cells concetrate large quanitities of calcium and phosphate, in return, what can bones supply to the body?
cells can release calcium phosphate compounds
* help with regulation of calcium in the blood
105
What does increased levels of the parathyroid hormone parathormone do to the bone?
* increases amount and activity of osteoclasts
* thus increasing the resorption of bone - releasing calcium ions from the bone into the blood (raising calcium level)
106
What does increased levels of the hormone calcitonin do to the bone?
* decreases resorptive activity of osteoclasts
* lowers blood calcium level
* may also stimulate the formation of new bone
107
What two main hormones are involved in any remodeling of a bone?
* parathormone
* calcitonin
108
Broken bones are referred to as what in anatomy?
fractures
109
# Under the five different kinds of fractures, which fits the following?:
The broken ends of the bone do not penetrate through the skin
simple fracture
110
# Under the five different kinds of fractures, which fits the following?:
The broken ends of the bone protrude through the skin
compound fracture
111
# Under the five different kinds of fractures, which fits the following?:
Rather than being broken in a single plane, the bone is splintered into many fragments at the site of the break
comminuted fracture
112
# Under the five different kinds of fractures, which fits the following?:
The broken region is pushed inward, as often occurs in fractures of the flat skull bones that form the roof over the brain
depressed fracture
113
# Under the five different kinds of fractures, which fits the following?:
The broken ends of the bone are driven into each other. Such fractures occur in falls in which the person lands on the ends of the bone.
impacted fracture
114
The first initial repair that happens in healing a fracture is what?
begins with the formation of a blood clot called a procallus
115
Once a procallus (blood clot) is formed, what invades the procallus?
* connective tissue invades procallus
* fibrocartilaginous callus replaces procallus
116
What replaces the procallus when connective tissue invades the procallus?
fibrocartilaginous callus
117
After the procallus is replaced with fibrocartilaginous (fibrous) callus, what replaces the fibrous callus?
bone (from cells in the periosteum)
118
Where is yellow marrow found in the bone?
in the medullary cavity
| (yellow marrow is associated with fat)
119
What type of bone is arranged in conentric layers?
compact [bone]
120
Where do you find red marrow?
* cancellous (spongy) bone
121
What is the end of the bone called?
epiphysis
122
Spongy bone is also called..?
cancellous bone
123
What cushions the ends of the bones at their joints?
articular cartilage
124
What structure connects osteocytes?
canaliculi
125
Osteocytes form rings called?
lamella
126
What canal is found in the center of the rings (lamella)?
haversian canal
127
Osteocytes are within chambers called?
lacuna
128
What common condition is classified as the progressive loss of bone calcium that leads to increased bone brittleness and a marked inrease in bone fractures?
osteoporosis
129
Osteoporosis is beleived to result from what?
* a gradual reduction in the rate of bone formation (osteoblasts)
* while the rate of bone absorption remains normal (osteoclasts)
130
Forman can be described as a what?
[a] hole
131
What three parts are apart of the axial skeleton?
* [the] skull
* vertebral column
* thorax (ribs and sternum)
132
What four parts are apart of the appendicular skeleton?
* pectoral girdle
* upper limbs
* pelvic girdle
* lower limbs
133
How many bones are in the adult body?
206 [bones]
134
What does the axial skeleton provide?
* main axial support for the body
* protects the central nervous system & organs of the thorax
135
What does the appendicular skeleton provide?
* supports the attachment and functions of the upper and lower limbs of the human body (helps with movement)
136
All of the bones of the adult skull are joined together by immovable joints. What are these immovable joints called?
sultures
