Chapter 6: Bones Flashcards
1
Q
What are the 5 functions of bones?
A
support, storage, blood cell production, protection and leverage
2
Q
how do bones support
A
framework for attachment of all kinds of softer tissus
3
Q
what do bones store
A
minerals and lipids
4
Q
What do bones produce and where?
A
blood cell production of all red blood cells and WBCs originate from stem cells in red bone marrow
5
Q
define hematopoiesis
A
production of blood cells
6
Q
How do bones protect
A
skull bones protect the brain
vertebrae protects spinal cord
ribs protect the heart and lungs
pelvis protects repro and digestive organs
7
Q
What is leverage of bones?
A
bones acts as lever to go along with muscle contractions to allow movement
8
Q
Give examples of long bone
A
arms, legs, hands, feet fingers and toes
9
Q
What are flat bones
A
bones of teh sull cap, sternum, scapulae (shoulder blade)
10
Q
purpose of flat bones
A
protection; extensive area for muscle attachment
11
Q
What is sutural bone
A
small, flat, irregularly shaped immovable join between flat bone of the skull= sutures
12
Q
define irregular bone
A
specialized and unique with complex shapes
13
Q
examples of irregular bones
A
vertebrae, hipbones, several skull and facial bones
14
Q
define short bones
A
small and boxy bones
15
Q
give examples of short bones and where they are found
A
carpals- wrist bones; 8 in each wrist
Tarsals: ankle bones; 7 in each anle
16
Q
Define sesamoid bones
A
develop inside tendons; assosciated with joins in hands, feet and knees
17
Q
How many locations of sesamoid bones are there?
A
26 locations but varies among people
18
Q
Give an example of a sesamoid bone
A
patella
19
Q
Define articulation
A
a joint; where two bones come together
20
Q
define arthritis
A
inflammation of joints
21
Q
define process
A
any projection or bump
22
Q
Name 4 processes where tendons and ligaments attach
A
trochanter, tibercle, spine and chest
23
Q
define trochanter
A
a large rough process
24
Q
define tubercle
A
a small rounded projection
25
define spine
pointed process
26
define crest
a prominent ridge
27
Name 3 processes for articulation with other bones
head (epiphysis), facet, condyle
28
define head (epiphysis)
expanded and separated from the shaft (diaphysis)by a neck (metaphysics)
29
define facet
small, flat articular surface (like on a gemstone)
30
Define condyle
smooth, rounded articular process
31
Name 2 depressions
fossa, sulcus
32
define fossa
shallow depression
33
define sulcus
narrow groove
34
Name 3 openings
foramen, fissure, sinus
35
Define foramen
rounded passageway for blood vessels and/or nerves
36
e.g. of foramen
foramen magnum- where the spinal cord emergences at the base of the skull
37
define fissure
long cleft (like a crack)
38
define sinus
a chamber w/in a bone, nomrally filled with air
39
What is the outside of the bone made of?
compact bone tissue
40
What is inside the diaphysis of the long bone?
marrow cavity and it has yellow marrow
41
What is inside the epiphyses of the long bone?
spongy bone
42
What does spongy bone contain?
trabeculae- branched network of short bone pieces
spaces b/w the trabeculae is red marrow
43
What is the 2 bone that spongy bone is made of?
trabecular bone and cancellous bone
44
What is the general set up for bones?
compact bone around the outside
spongy bone on the inside
marrow cavity- space with fat
45
What is the set up of flat bones?
spongy bone between two compact bones
46
Define bone matrix
very dense and has minerals
47
define osteocytes
(bone cells) exists in small places within the matric called launae - organized circular layers that surround blood vessels
48
Define caniliculi
narrow passageway that connects lacunae to blood vessels and to each other
49
Define periosteum
mostly dense irregular CT
50
Where is periosteum not covering?
at joints
51
How much of the bone mass of the bone matrix is cells?
2 %
52
What is 1/3 of the weight of bones?
collagen fibers--> stronger than steel when subjected to tension
53
what is 2/3 the weight of bones?
hydroxyapatite crystals- the minerals in bones
54
what does the combination of collagen fibers and hydroxyapatite create?
strong flexible and highly resistant to shattering material
55
define osteocytes
mature bone cells in lacunae
56
define lamellae
lacunae in circular layers of bone matrix
have long thin cytoplasmic extensions that are contained within canaliculi
57
function of lamellae
signal other bone cells to build and dissolve bone matrix
participate in bone repair if fractures
58
define the function of osteoblasts
produce new bone matric- osteogenesis(immature)
mature to osteocytes
59
define the function of osteoclasts
dissolve bone matrix and releases minerals back into blood circulation--> osteolysis
60
Describe osteoclasts
giant cells with 50 or more nuclei
related to macrophages
61
define osteoprogenitor cells
mesenchymal stem cells- divide to produce osteoblasts
assist in fracture repair
62
Where are osteoprogenitor cells located?
in the inner cellular layer of the periosteum & endosteum
63
define endosteum
lines surfaces inside fo bones
64
Effect of minerals as bone matrix is added or subtracted
minerals are added when bone matrix s added
minerals are subtracted when bone matrix is dissolved
65
What stimulates osteoblasts to build bone matrix?
excercise- weight bearing excercise puts stress on bones--> needed
66
define bone resorpbtion
same as osteolysis
67
what is compact bone tissue made out of?
haverian systems/ osteons= consists of several lamelae surrounding a haversian canal aka central canal- contains blood vessels
68
Define lamella
circular layer of bone matrix; containing lacunae interconnected by canaliculi
69
define lacunae
contains osteocytes and the canaliculi contains cytoplasmic extensions of the osteocytes
70
Describe spongy bone tissue structure
more light-weighted than compact bone & able to withstand stresses from many directions
71
what does spongy bone tissue not have?
haversians/osteons; has concentric lamellae
no central canal or blood vessels
72
How does spongy bone tissue get its nutrients?
by diffusion from the surrounding bone marrow through canaliculi that open on the surface of the trabeculae
73
Describe periosteum
has a fibrous outer layer and dense irregular CT and a cellular inner layer
74
Name 3 functions of periosteum
separates bone from surrounding tissue
a route for circulation and nerve supply to the bone
bone growth and repair
75
what is on the endosteum?
osteogentitor cells
76
what does the endosteum line and cover?
marrow cavities, trabeculae, and lines haversian canals
77
define cartilage models
serve as templates for future bones
78
when does bone formation start and complete
6 weeks after fertilization and until early adulthood
79
Two types of ossification
endochondral ossification
intramembranous ossification
80
define endochondral ossification
starting with cartilage
81
define intramembanous ossification
starting with a fibrous CT
82
know steps of endochondral ossification
83
define articular cartilage
a thin layer of the original cartilage
cushions the end of bones in joints
84
define epiphyseal cartilage
separates the epiphysis from the diaphysis at metaphysics aka growth plate
85
describe the process of bone lengthening
1. growth of epiphyseal cartilage
2., epiphysis gets pushed away from diaphysis
3. epiphysis side of the growth plate grows, diaphysis side gets ossified
4. growth hormone, sex hormones and thyroid hormones triggers fat bone growth - formation fo bone takes over growth plate- growth stops
5. if epiphyseal cartilage is present- still growing
6. ossification fo growth plate- visible line in the area is present=epiphyseal line
86
define late bloomers
kids that spend more time in child phase of growth and ends up being taller than if they have puberty earluer
87
define appositional growth
bones increase in diamter
- stems in the inner layer of periosteum differentiate into osteoblasts which add layers of circumferential lamellae around the outside of the bone
88
e.g of bone that does intramembranous ossification
dermal bones;
flat bones of the sull, mandible clavicles, scapulae, hip bones
89
know steps of intramembranous ossification
90
process of remodeling
minerals get released from the bone into circulation
minerals are deposited into the bone=shape and internal architecture fo bones are changed
91
how often does the skeleton get replaced in young adults?
1/5th of the skeleton
92
issue when heavy metals are in bones
not an issue in bones but if blood can cause problems
93
radioactive elements in storage of bones
cancer
94
How does excerise help?
hydroxyapatite crystals in bones develop a small electrical charge when subjected to stress such as exercise resulting in the stimulation of osteoblasts so bones gets stronger in places where there is stress
osteoblasts slow down without exercise
95
does electricity or stress affect osteoclasts?
no
96
what happens to the bumps and ridges and tubercles
they get longer to withstand forces due to exercise
97
define atrophy
bones lose bone mass; reduction in size of a cell, tissue or organ
98
How much mass does unstressed bones lose?
1/3 of mass
99
e.g. of unstressed bones
paralyzed, bedridden, astronauts in zero gravity
100
what happens to unstressed bones
lack of calcium and minerals
bones aren't doing mineral storage function
101
e.g of food sources for calcium and phosphorous
milk, cheese, dairy
102
function of vitamin c
essential for collagen syntheiss and osteoblast differentiation--> specialized and comes into its final form; present in diet
103
e.g. of foods with vitamin c
citrus fruits
104
scury disease
vitamin c deficiency; teeth fall otu
105
function of vitamin D
essential for calcium and phosphorous absorption
106
define rickets
children deprived of vitamin d; bone don't develop normally; poorly mineralized flexible bones; bowed legs
107
define osteomalacia
adults deprived of vitamin d;bones get weaker
108
define calcitriol
hormone that stiumlates the absorption of calcium and other minerals; absorption from the intestine nd into blood
109
What creates calcitriol and out of what?
kidneys; out of modified vitamin D molecules
110
Where does the growth hormone come from?
pituitary gland
111
Where does the thyroid hormone come from and function?
thyroid gland
essential for normal bone growth throughout childhood
112
What influences a period of fast bone growth?
effects of GH and thyroid hormones combine with the effects of sex hormones (estrogens and androgens) and epiphseal closure
113
Define calcitonin?
tones down calcium levels by inhibiting osteoclasts & promotes calcium loss by the kidneys through the urine
114
What is calcitonin secreted by?
thyroid gland
115
What does parathyroid hormone do?
raises blood calcium levels through stimulating osteoclasts, decreases rate of calcium excretion by kidney, promotes the synthesis of calcitriol
116
What are the 3 things that must remain during a fracture?
blood supply to bone, stems in periosteum and endosteum
117
What is the first step of fracture repair
fracture hematoma: a large blood clot that steops the bleeding but disrupts blood flow and results in some dead bone tissue around the fracture
118
What is the second step of fracture repair?
cells of endosteum and periosteum divide rapidly
--> results in the formation of internal and external callus
119
define a callus
made of cartilage and seal over the fracture around the outside and inside of the bone
120
What is the 3rd step fo fracture repair?
osteoblasts replace the cartilage with spongy bone (cast can be removed about now)
121
what will new bone tissue always be ?
spongy bone
122
What is the 4th step of fracture repair?
Osteoclasts & osteoblasts remodel the area, turning the spongy bone into compact bone (several month)
123
why will the fracture not occur in the same spot again?
can't break bone in the previously broken spot, maybe different spot
124
What is a closed or simple fracture?
no break in skin
125
What are open or compound fracture?
broken bone projects through
risk of excessive bleeding and bad infection
126
What is a communited fracture?
shattering of a bone
127
What is a Transverse
fracture?
the break is at a right angle to the long axis of the bone
128
What is a greenstick fracture?
one side of the bone breaks, while the other side bends; seen in children
129
define osteopenia
age related reduction is bone mass due to reduction is osteoblast activity while osteoclast activity remains the same
130
What is commonly affected by osteopenia?
epiphyses, vertebrae, and jaws
fragile limbs, reduced height and loss of teeth
131
Define osteoporosis
reduction is bone mass so severe that is compromises normal function
132
What is the vicious cycle
bones broken are typically hip bones, reduction in activity, further bone loss, bones even more easily broken
