Chapter Six: Skeletal System Flashcards
1
Q
What are the three components of the Skeletal System?
A
- Bone
- Cartilage
- Tendons and Ligaments
2
Q
What are the three types of Cartilage?
A
- Hyaline
- Fibrocartilage
- Elastic
3
Q
What are the five functions of the Skeletal System
A
- Support
- Protection
- Movement
- Storage
- Blood Cell Production
4
Q
What two things does the Skeletal System store?
A
Calcium and Phosphorus
5
Q
Where does blood cell production take place in the Skeletal System?
A
Red Bone marrow
6
Q
What are the two specialized cells that produce matrix in the Skeletal System?
A
Chondroblasts
Chondrocytes
7
Q
What specialized cell forms the matrix?
A
Chondroblasts
8
Q
What specialized cell is surrounded by matrix and is located in the lacunae?
A
Chondrocytes
9
Q
What is made of collagen fibers for strength and proteoglycans for resiliency in cartilage?
A
Matrix
10
Q
What is the double-layered connective tissue sheath that covers cartilage except at articulations?
A
Perichondrium
11
Q
What are the two types of Perichondrium?
A
Inner and Outer
12
Q
What kind of Perichondrium is more delicate, has fewer fibers, and contains chondroblasts?
A
Inner Perichondrium
13
Q
What kind of Perichondrium has dense irregular connective tissue containing fibroblasts; penetrated by blood vessels and nerves?
A
Outer Perichondrium
14
Q
What covers bones at joints; has no perichondrium, blood vessels, or nerves that is located in Cartilage?
A
Articulate Cartilage
15
Q
What are the two types of Cartilage Growth?
A
Appositional and Interstitial
16
Q
What type of cartilage growth: new chondrocytes and new matrix laid down at the periphery?
A
Appositional
17
Q
What type of cartilage growth: chondrocytes within the tissue divide and add more matrix between cells?
A
Interstitial
18
Q
The bone matrix is like reinforced….
A
concrete
19
Q
The bone matrix is like steel reinforcing “rods” are collagen fibers, “cement” is…
A
Hydroxyapatite
20
Q
What are the two organic components of the bone matrix?
A
Collagen and Proteoglycans
21
Q
What is the inorganic component of the bone matrix and what kind of crystals?
A
Hydroxyapatite (CaPO4 crystals)
22
Q
In Osteogenesis Imperfecta, the mildest types have a deficiency of…
A
Collagen
23
Q
In Osteogenesis Imperfecta, the more severe types have production of…
A
Defective Collagen
24
Q
In Osteogenesis Imperfecta, the most severe types have both…
A
defective collagen and are collagen deficient
25
Stem cells that develop into either chondroblasts or osteoblasts that are located in the periosteum
Osteochondral Progenitor Cells
26
What type of bone cell?
- formation of bone through ossification/osteogenesis
- collagen produced/processed by E.R. and Golgi, released by Exocytosis
- Matrix vesicles contain Ca2+ and PO43-
- Ossification forms bone by these bone cells
Osteoblasts
27
Matrix vesicles contain…
Ca2+ and PO43-
28
In Matrix Vesicles, hydroxyapatite crystals form, then are released by…
Exocytosis
29
Formation of bone by osteoblasts
Ossification
30
Osteoclasts are surrounded by the…
Matrix
31
What are the spaces occupied by osteocyte cell body?
Lacunae
32
What are the canals occupied by osteocyte cell processes which connect to other osteocytes
Canaliculi
33
Osteocytes: nutrients diffuse through tiny amount of liquid surrounding cell and filling __________ and __________
Lacunae and Canaliculi
34
Osteocytes can communicate and transfer nutrients from one cell to the next through…
Gap Junctions
35
Multi-nucleated and probably arise from fusion of multiple cells; involved in resorption of bone
Osteoclasts
36
Breakdown of bone into constituent parts
Resorption
37
Site at which cell membrane borders bone and resorption takes place
Ruffled Border
38
Osteoclast: H+ ions pumped across membrane, acidic environment causes _________________ of bone
Decalcification
39
Osteoclast: release enzymes that digest the __________ ___________ of bone
protein component
40
What type of bone?
- collagen fibers randomly oriented
- laid down during fetal development and during fracture repair
Woven Bone
41
What is the term associated with…
- removing old bone and adding new
- woven bone is ______ into lamellar bone
- changes bone structure to accommodate changes in mechanical stress
Remodeling
42
What type of bone?
- mature bone in sheets called lamellae
- within a layer, fibers are oriented in one direction
- fibers in one layer are usually oriented at a right angle to fibers in other layers - provides strength
Lamellar Bone
43
What part of Spongy Bone?
Interconnecting rods or plates of bone
- spaces filled with marrow
- oriented along stress lines
- consist of lamellae with osteocytes in lacunae
- blood vessels do not penetrate ______
Trabeculae
44
What part of Compact Bone: central canal, associated concentric lamellae and osteocytes?
Osteon
45
What part of Compact Bone: parallel to long axis?
Central Canals
46
What part of Compact Bone: cocentric, circumferential, interstitial?
Lamellae
47
What part of Compact Bone: perpendicular to length of bone?
Perforating Canal
48
What part of Compact Bone?
- blood vessel-filled central canal
- concentric lamellae of bone surrounded central canal
- lacunae and canaliculi contain osteocytes and fluid
Osteons
49
Circumferential Lamellae is on the ______________ of a bone
periphery
50
Interstitial lamellae is between….
Osteons
51
Remnants of Osteons are replaced through…
remodeling
52
Blood vessels from periosteum penetrate bone and connect vessels of the central canal
Perforating (Volkmann’s) Canals
53
Nutrients and wastes travel to and from osteocytes via ____________ _________ of lacunae and canaliculi
Interstitial Fluid
54
Nutrients and wastes travel from osteocyte to osteocyte by…
Gap Junctions
55
Examples of Long Bones are…
Upper and Lower limbs
56
Examples of Short Bones are…
Carpals and Tarsals
57
Examples of Flat Bones are…
Ribs, Sternum, Skull, and Scapulae
58
Examples of Irregular Bone…
Vertebrae and Facial
59
What type of bone?
- no diaphyses
- sandwich of spongy between compact bone
Flat Bone
60
What two types of bone?
- no diaphyses and not elongated
- compact bone that surrounds spongy bone center
Short and Irregular Bone
61
What structure of Long Bone?
- shaft
- compact bone
Diaphysis
62
What structure of Long Bone?
- end of the bone
- primarily spongy bone
Epiphysis
63
What structure of Long Bone?
- growth plate
- composed of hyaline cartilage; present until growth stops
Epiphyseal Plate
64
What structure of Long Bone?
- ossified remnant of epiphyseal plate
- no further lengthwise growth occurs at this point
Epiphyseal Line
65
What structure of Long Bone?
- hollow center of diaphysis of long bones
- contains bone marrow
Medullary Cavity
66
What structure of Long Bone?
- lines all internal spaces including spaces in spongy bone
Endosteum
67
What structure of Long Bone?
- outer layer is fibrous
- inner layer is single layer of bone cells including osteoblasts, osteoclasts and osteochondral progenitor cells
- fibers of tendon are continuous with fibers of periosteum
Periosteum
68
What type of ossification takes place in connective tissue membrane?
Intramembranous Ossification
69
What type of ossification forms from a pre-existing cartilage model?
Endochondral Ossification
70
Both Intramembranous and Endochondral ossification produce _________ bone that is then remodeled
Woven
71
After remodeling takes place, one cannot tell by what type of ________________ it formed
ossification
72
Intramembranous Ossification begins at the _________ week of embryonic development and ends around _______ years of age
Eighth
Two
73
Intramembranous Ossification takes place in _____________ ____________ ____________ formed from embryonic mesenchyme
Connective Tissue Membrane
74
Intramembranous Ossification forms what 4 things?
1. Skull Bones
2. Parts of Mandible
3. Diaphyses
4. Clavicles
75
locations in membrane where ossification begins
Centers of Ossification
76
Large membrane-covered spaces between developing skull bones; unossified
Fontanels
77
Most bones develop via…
Endochondral Ossification
78
Endochondral Ossification involves the formation of a ___________ _________ which is then gradually replaced with bone over time
Cartilage Model
79
Cartilage formation begins at the end of the _________ week of development
Fourth
80
Some ossification begins at about week eight; some does not begin until ____ - ____ years of age
18-20
81
Growth in length of the bone occurs at the….
Epiphyseal Plate
82
What does Interstitial Growth have to do with the formation of new cartilage?
Interstitial grows cartilage
83
Where does Appositional Growth form new cartilage?
On the surface of cartilage
84
Between what ages does the Epiphyseal Plate ossify?
12-25
85
What Zone of the Epiphyseal Plate?
New cartilage is produced on the epiphyseal side of the plate as the chondrocytes divide and form stacks of cells
Proliferation Zone
86
What Zone of the Epiphyseal Plate?
Chondrocytes mature and enlarge
Hypertrophic Zone
87
What Zone of the Epiphyseal Plate?
Matrix is calcified and chondrocytes die
Calcified Cartilage Zone
88
What Zone of the Epiphyseal Plate?
Cartilage on the Diaphyseal side of the plate is replaced by bone
Ossification Zone
89
What type of cartilage does not ossify, and persists through life?
Articular Cartilage
90
What type of Cartilage increases the size of bones with no epiphyses (short bones)?
Articular Cartilage
91
________________ near the surface of the articular cartilage proliferate and ossify
Chondrocytes
92
What type of growth in bone?
- Interstitial growth cannot occur because matrix is solid
- occurs on old bone and/or on cartilage surface
Appositional Growth
93
Size and shape of a bone are determined genetically but can be modified and influenced by __________ and ________
nutrition and hormones
94
Lack of what two things can heavily affect bone growth?
Calcium and Protein
95
What Vitamin is necessary for absorption of calcium from intestines and can be eaten or manufactured in the body?
Vitamin D
96
Lack of Vitamin D during childhood
Rickets
97
Lack of Vitamin D during adulthood leading to softening of bones
Osteomalacia
98
What type of Vitamin is necessary for collagen synthesis and the lack of this vitamin impairs wound healing and results in teeth falling out?
Vitamin C
99
Deficiency of Vitamin C
Scurvy
100
Bone remodeling is caused by the migration of ____________ and _____________ to the site of bone remodeling
Osteoclasts and Osteoblasts
101
Stress causes bone remodeling to do what two things?
1. Increase bone mass (density)
2. Align trabeculae with stress
102
Changes caused by osteoblast activity increase with…
stress
103
Decreased bone density which results from an imbalance between bone resorption and bone formation
Osteoporosis
104
What is the first step of bone repair in which:
- localized mass of blood released from blood vessels but confined within organ or space
- clot formation
Hematoma Formation
105
What is the second step in bone repair?
Callus Formation
106
Mass of tissue that forms at a fracture site and connects the broken ends of the bone
Callus
107
What type of callus?
- forms between the ends of the bones
Internal Callus
108
What type of Callus?
- collar (stabilizes two pieces of bone) around opposing ends
External Callus
109
______________ clean up debris in callus formation
Macrophages
110
_______________ break down dead tissue in callus formation
Osteoclasts
111
_____________ produce collagen in callus formation
Fibroblasts
112
What is step three in bone repair in which the callus is replaced by woven bone?
Callus Ossification
113
What is the fourth step of Bone Repair in which woven bone and damaged material is replaced by compact bone and there is a sculpting of site by osteoclasts?
Bone Remodeling
114
Bone is a major storage site for…
Calcium
115
The level of calcium in the blood depends upon the movement of calcium into or out of the…
Bone
116
Calcium ___________ bone when osteoblasts create new bone
enters
117
Calcium __________ bone when osteoclasts break down bone
leaves
118
What two hormones control blood calcium levels?
Parathyroid Hormone
Calcitonin
119
Parathyroid Hormone (PTH) is released when blood calcium levels are…
low
120
PTH stimulates __________ to resorb bone
Osteoclasts
121
PTH stimulates reabsorption of _______ in the kidneys
Ca2+
122
PTH stimulates ____________ ____ formation in kidneys -> increased calcium absorption in intestines
Vitamin D
123
Calcitonin is released when blood calcium levels are…
high
124
Calcitonin inhibits osteoclasts -> allows ___________ to take up calcium from the blood to use in bone formation
Osteoblasts
