CH 6 Flashcards
Skeletal system
1
Q
The skeletal system includes what?
A
Bones and articulations
2
Q
Another word for articulations
A
Joints
3
Q
Adult humans typically have ______ bones
A
206
4
Q
Functions of the skeletal system
A
- Framework/ support
- Protection
- Muscle attachment
- Hemopoiesis/hematopoiesis
- Mineral storage
- Energy storage
5
Q
poiesis
A
formation of
6
Q
The skeletal system acts as framework and support for ___________
A
tissue
7
Q
Protection
A
hard casing
e.g. skull, spine (vertebral column), ribcage, pelvis
8
Q
Hemopoiesis/ hematopoiesis
A
formation of ALL blood cells (red and white blood cells, platelets)
9
Q
Where does hemopoiesis occur?
A
Red bone marrow
10
Q
Mineral storage
A
Bone acts as a reservoir for calcium when blood calcium levels get too low
11
Q
__________ control calcium levels
A
Hormones
12
Q
Muscle attachment
A
Bone is an attachment site for skeletal muscle
Movement occur when muscles contract by pulling on bone
13
Q
Energy storage
A
Yellow bone marrow is adipose tissue
14
Q
Two types of skeletal tissue
A
- Cartilage
- Bone
15
Q
Cartilage cells
A
- Chondrocytes
- Chondroblasts
16
Q
Chondro
A
cartilage
17
Q
blast
A
to form
18
Q
Chondrocytes
A
Mature cartilage cells
19
Q
Where are chondrocytes located?
A
Lacunae
“little lake”
20
Q
Lacunae
A
Small spaces filled with extracellular fluid
21
Q
chondroblast
A
secrete cartilage matrix
22
Q
Cartilage matrix
A
- Fibers
- Ground substance (semi-solid)
23
Q
Cartilage ground substance contain ___________ molecules
A
proteoglycan
24
Q
Proteoglycan molecules
A
Absorbs water into the matrix
25
Proteoglycan molecules are the reason why bones are a good ____________
shock absorber
26
3 types of cartilage
- Hyaline cartilage
- Fibrocartilage
- Elastic cartilage
27
Hyaline is the ___________ cartilage
stiffest
Without it, bones would break with enough pressure
28
Defining characteristic of hyaline cartilage
No fibers in the matrix
29
Hyaline cartilage location
Covers ends of bones, costal cartilage, nose, larynx, trachea, bronchial passageways, fetal skeleton
30
Costal
ribs
31
Larynx
Adam's apple-- opening to the trachea
32
Elastic cartilage is the most ____________
flexible
33
Elastic cartilage
Many elastic fibers in matrix
34
Elastic cartilage locations
Outer ear, larynx, wall of auditory tube
35
Fibrocartilage is the best ______________
shock absorber
36
Fiber(s) of the fibrocartilage
collagen
37
Fibrocartilage location
intervertebral discs, pubic symphysis, meniscus of the knee
38
How do chondrocytes tend to arrange themselves?
Lined up in rows
39
Bone cells
- osteoprogenitor cells
- osteoblasts
- osteocytes
- osteoclasts
40
___________ become osteoblasts
osteoprogenitor
41
osteoblast
forms bone matrix, mature into osteocytes
42
osteocytes
mature bone cells that maintain matrix
located in lacunae
43
____________ have arms to connect each other
osteocytes
44
osteoclasts
reabsorbs old bone matrix
45
Which bone cells become more active and remove bone to increase blood calcium levels?
osteoclasts
46
Bone matrix contains what fiber(s)?
Collagen
47
Collagen fibers of the bone matrix provide it a certain degree of __________
flexibility
Without, bones would break under body weight
48
The ground substance of bone contains _______________ that provides __________
hydroxyapatite crystals, hardness and rigidity
49
Types of bone
- Compact
- Spongey
50
Compact
Hard bone that supports body weight
51
Haversian system is AKA as a _________
osteon
52
Haversian system/ osteon
Basic structural and functional unit of mature compact bone
Cylindrical
53
Central canal/ Haversian canal
Cylindrical channel that lies in the middle of the osteon
54
What travels within the central canal?
Blood vessel and nerves that supply the bone
55
Concentric lamellae
Rings of CT that surround the central canal and form the bulk of the osteon
56
Lamellae
Layers
57
Each lamellae contains what?
Collagen fibers
Alternating direction of fibers gives bone its strength and resilience
58
Interstitial lamellae
Leftover parts of the osteon that have been partially resorbed (not full circle like concentric lamellae)
Interstitial - in between
59
Canaliculi
Tiny channels that connect neighboring osteocytes
60
Perforating/ Volkmann's canal
Central canals that contain blood and nerves that run perpendicular to the central canals
Helps connect multiple Haversian canals
61
Circumferential lamellae
Rings of bone that runs the entire circumference of the bone
62
Cancellous/ spongey bone
Lighter bone that forms the bone marrow
63
Spongey bone components
- Trabeculae
- Cancellous cavities
64
Trabeculae
Tiny pieces of bone that interconnect with each other; open lattice of narrow plates of bone
65
Cancellous cavities
Store bone marrow
Located between trabeculae
66
Classifications of bone by shape
- Long
- Short
- Flat
- Irregular
67
T or F: every bone has compact and spongey bone
True
Typically compact bone on outer surface, spongey bone on surface
68
Spongey bone of flat bone
Diploe
69
What characteristic does the diploe give bone?
Strength to withstand lots of pressure
70
Long bone anatomy
- Epiphyses
- Metaphyses
- Diaphysis
71
Epiphyses
Ends of long bone
72
Purpose of the epiphyses
Gives more surface area for articulation
73
Metaphyses
Flared part of long bone
74
__________ is referred as the neck of the bone
Metaphyses
75
__________ is referred as the shaft of the long bone
Diaphysis
76
Only part of bone that does not ossify
Hyaline cartilage
77
Articulation cartilage
Hyaline cartilage located at the end of bones for protection
78
In which part of the long bone is the spongy bone located?
Epiphyses
79
In which part of the long bone is compact bone located?
Diaphysis
80
Empty cavity located at the center of long bone
Medullary/ marrow cavity
81
What fills the medullary cavity in children? Adults?
Red bone marrow; yellow bone marrow
82
Bone coverings
- Periosteum
- Endosteum
83
Layer(s) of the periosteum
Inner osteogenic/ cellular layer
Outer fibrous layer
84
Inner osteogenic/ cellular layer
Can form new bone, layer of osteoblasts and some osteoprogenitor cells
85
Which tissue forms the outer fibrous layer of the periosteum?
Dense irregular (NOT bone)
86
Peri
Outside
87
Endo
Inside
88
Endosteum
Layer of osteoblasts and osteoprogenitor cells
89
Locations of the endosteum
Trabeculae of spongy bone
Lines the medullary cavity
90
Ossification is AKA as
osteogenesis
91
Ossification
Formation of bone
92
When does ossification begin? End?
By 8th week of gestation until adulthood
93
Two types of ossification
- Intramembranous
- Endochondral
94
Intramembranous ossification
Bone forms from mesenchyme
95
Mesenchyme
Embryonic CT
96
Where does intramembranous ossification occur?
In portions of skull and clavicles
97
Stages of Intramembranous Ossification
1) Ossification centers form within thickened regions of mesenchyme. Osteoblasts secrete osteoid at ossification center
2) Osteoid undergoes calcification
3) Woven bone and the surrounding periosteum form
4) Lamellar bone replaces woven bone as compact and spongey bone form
98
Woven bone
AKA primary bone
Immature bone
99
Lamellar bone
AKA secondary bone
Mature bone
Forms in layers (lamellae form in layers)
100
Osteoid
Unmineralized bone matrix; precursor to solid bone matrix
Has no calcium in it
101
-oid
"like"
102
Endochondral ossification
Bone forms from hyaline cartilage
103
Where does endochondral ossification occur?
In all other bones of the skeleton except portions of the skull and clavicles
104
Stages of endochondral ossification
1) Fetal hyaline cartilage model develops
2) Cartilage calcifies and dies. A periosteal bone collar forms around the diaphysis
3) Primary ossification center forms in the diaphysis
4) Secondary ossification centers form in the epiphyses
5) Bone replaces cartilage, except for articular cartilage and epiphyseal plates
6) Epiphyseal plates ossify and form epiphyseal lines
3 and 4 essentially woven bone forms and is replaced with lamellar bone
105
Hypertrophy occurs in chondrocytes when the cartilage calcifies and dies. What is hypertrophy?
Enlargens
106
A periosteal bone collar forms around the diaphysis. This happens by periosteal buds invading the dying cartilage. What are periosteal buds?
- Blood vessel- supplies nutrients
- Osteoclast- resorb bone matrix
- Osteoblast- form new bone
107
Epiphyseal plate AKA growth plate
A layer of hyaline cartilage at the boundary of the epiphysis and diaphysis
108
Interstitial bone growth
Lengthens bone by layer of cartilage, new bone, repeat
109
How many microscopic zones of interstitial bone growth at the epiphyseal plate are there?
5
110
5 zones of growth at the epiphyseal plate
1) Resting cartilage: randomly scattered chondrocytes. Regular old hyaline cartilage
2) Proliferating cartilage: chondrocytes divide (compact, stacked appearance)
3) Hypertrophic cartilage: chondrocytes hypertrophy and die
4) Calcified cartilage: empty lacunae
5) Ossification: new bone
111
