Ch 6 Flashcards
(98 cards)
1
Q
What are the functions of the perichondrium?
A
Resists outward expansion, contains no blood vessels for nutrient delivery
2
Q
What cartilage is found at joints?
A
Articular cartilage (hyaline)
3
Q
What cartilage is found at the ribs?
A
Costal cartilage (hyaline)
4
Q
What is appositional growth?
A
when the new matrix is laid down ON surface of cartilage
5
Q
What is interstitial growth?
A
Chondrocytes in lacunae divide and secrete new matric = cartilage expands from WITHIN
6
Q
Support in reference to bones
A
bones provide support for body and soft organs
7
Q
Protection in reference to bones
A
Muscles use bones as levers
8
Q
Mineral storage in reference to bones
A
Bones store calcium and phosophate
9
Q
Blood cell formation in reference to bones
A
In red bone marrow
10
Q
Triglyceride Storage in reference to bones
A
In yellow bone marrow
11
Q
Axial skeleton =
A
skull, vertebral column, rib cage
12
Q
Appendicular skeleton =
A
bones of limbs, girdles attaching limbs to axial skeleton
13
Q
Compact bone
A
dense, hard outer layer
14
Q
Spongy bone
A
light, porous inner layer
15
Q
Is made of trabeculae…
A
Spongy bone
16
Q
What fills the space between trabeculae?
A
Bone marrow
17
Q
What has osteons as its structural unit?
A
Compact bone
18
Q
Diaphysis (LB) =
A
tubular shaft forming long axis
19
Q
Medullary Cavity (LB) =
A
(is surrounded by diaphysis) contains bone marrow
20
Q
Articular cartilage (LB) =
A
Covers ends of bones where bones meet to form joints
20
Q
Epiphyses (LB) =
A
Bone ends (covered with articular cartilage)
21
Q
Periosteum (LB) =
A
Fibrous membrane, covers outer bone surface
22
Q
Endosteum (LB) =
A
Delicate membrane, covers internal bone surfaces
23
Q
What is the function of red marrow?
A
Site of cell production
24
What is the function of yellow marrow?
Storing fat
25
Where would you find red bone marrow in an infant?
In all medullary cavities and spongy bone
26
Where would you find red bone marrow in an adult?
Axial skeleton and heads of humerus and femur
27
Where would you find yellow marrow?
Medullary cavities of adult long bones
28
Osteoprogenitor Cells
stem cells, same develop into osteoblasts
29
Osteoblasts
forms new bone
30
Osteocytes
maintain bone matrix
31
Osteoclasts
break down bone (=bone resorption)
32
Osteon
structural unit, resists bending or twisting
33
Lamallae
rings of bone matrix
34
central canal
contains blood vessels in nerve fibers
35
Perforating canals
occurs at right angles to central canals
36
Lacunae
Osteocytes reside inside
37
Canaliculi
connects lacunae and central canal
38
____________ connects the central canals to the blood supply of the periosteum and medullary cavity
Perforating canals
39
What is the structure of spongy bone?
no osteons, osteocytes in lacunae are found in trabeculae, trabeculae form along lines of stress
40
What are the organic components of bones?
bone cells, osteoid, collagen fibers, ground substance
41
What are the inorganic components of bones?
mineral salts, calcium phosphate crystals (hydroxyapatite)
42
Accounts for 65% of bone mass
Inorganic components
43
What makes bone hard and able to resist compression?
Mineral salts (inorganic)
44
What gives bone flexibility and tensile strength?
Collagen (organic)
45
What would happen if collagen fibers were removed?
bone becomes brittle
46
What would happen if mineral salts were removed?
bone becomes flexible
47
What is intramembranous ossification?
Bone develops directly from fibrous membrane
48
What bones are formed by intramembranous ossification?
Cranial bones and clavicles
49
In intramembranous ossification, where do ossification centers develop?
Mesenchymal cells cluster and become osteoblasts
50
What is endochondral ossification?
Bone develops by replacing hyaline cartilage (starts as hyaline cartilage)
51
What bones are formed by endochondral ossification?
all bones inferior to the base of the skull (except clavicles)
52
Osteomalacia
the lack of calcium and mineral salts, soft bendy bones
53
What is it called when osteomalacia shows in children?
Rickets
54
What causes osteomalacia and rickets?
Vitamen D deficency
55
Osteoporosis
lack of collagen AKA brittle bone disease
56
What is stage 1 of healing of bone fracture?
Hematoma Formation
-blood vessels tear and hemorrhage
-forms mass of clotted blood (a hematoma)
57
What is stage 2 of healing of bone fracture?
Fibrocartilaginous Callus Formation
-mass repair tissue formed by fibroblasts and chondroblasts
-2-6 weeks after fracture occurs
58
What is stage 3 of healing of bone fracture?
Bony Callus Formation
-Fibrocartilaginous callus replaced by bony callus of spongy bone
~2 months
59
What is stage 4 of healing of bone fracture?
Bone Remodeling
-excess material is removed
-compact bone replaces spongy bone
-can last months-years
60
What happens in the first major step of endochondral ossification?
Bone collar forms around the diaphysis of the hyaline cartilage model
61
What happens in the second major step of endochondral ossification?
Cartilage calcifies in the center of th diaphysis and then develops cavities
62
What happens in the third major step of endochondral ossification?
Periosteal bud invades the internal caities and spongy bone forms
63
What happens in the fourth major step of endochondral ossification?
The diaphysis elongates and a medullary cavity forms
*secondary ossification centers appear in the epiphyses
64
What happens in the fifth major step of endochondral ossification?
The epiphyses ossify when completed, hyaline cartilage remains only in the epiphyseal plates and articular cartilage
65
Where is the primary ossification center located?
In the center of the diaphysis
66
Where are the secondary ossification centers located?
In epiphyses (usually after birth)
67
After epiphyses are fully ossified where does hyaline cartilage remain?
In articular cartilage and the epiphyseal plate
68
What is the epiphyseal plate, and where is it located?
Its a disc of cartlage that allows long bones to grow (in length), its found between the epiphysis and diaphysis
69
What is epiphyseal plate closure?
-long bones stop growing in length
-cartilage cells stop dividing
(happens age 18 in females - 21 in males)
70
What is the epiphyseal line?
Fomrs after the epiphyseal plate closure and replaces plate with bone
71
What is the process by which bones grow in width?
Appositional growth
72
Describe appositional growth
-Osteo-CLASTS resorb the bone lining the medullary cavity
-Osteo-BLASTS add new bone underneath
73
How do long bones grow in length?
By the division of carilage cells in the epiphyseal plate (endochondral ossification)
74
What is bone remodeling?
A lifelong process where old bone is replaced by new bone
75
The addition of new bone is called ____
Bone deposit
76
What cells are responsible for bone deposit (the addition of bone)?
Osteo-BLASTS
77
The breakdown or removal of bone is called ______
Bone resorption
78
What cells are responsible for bone resorption (the removal of bone)?
Osteo-CLASTS
79
If osteo-CLASTS are more active than osteo-BLASTS, will bone mass increase or decrease?
Decrease
80
What stimulates the release of PTH?
Low blood calcium levels
81
What is the effect of PTH on osteo-CLASTS?
Stimulates osteo-CLASTS to resorb bone
82
What is the effect of osteo-CLAST activity on blood Ca2+ levels?
Calcium is released into blood, and raises Ca2+ levels
83
How do bones respond to mechanical stress?
Bones grow or remodel in response to demands placed on them
84
Long bones develop by replacing which tissue?
Hyaline cartilage
85
Concentric layers of bone matrix surrounding the central canal of an osteon are called __________
Lamellae
86
The term diploë refers to the ________
inner spongy bone layer in a flat bone
87
The central canal that runs through the core of each osteon contains ________
Blood vessels
88
A bone that has essentially the same width, length, and height is most likely to be a/an ________ bone
Short
89
Bone tissue that is composed mostly of trabeculae is classified as ________
Spongy bone
90
Passageways that connect blood vessels in the periosteum to those in the central canals are called __________
Perforating canals
91
Which of the following are present in both cartilage and bone?
Lacunae
92
Osteocytes __________
monitor the mature bone matrix
93
Yellow marrow is ________
Mostly fat
94
The primary function of osteoclasts is to ________
break down bone
95
A fracture in the shaft of a bone would be a break in the ________
diaphysis
96
Which of the following is an effect of parathyroid hormone (PTH)?
stimulates osteoclasts to break down bone
97
The flat bones forming the braincase of the skull develop ________
within fibrous membranes
