The Perichondrium is a thin covering over the main body of the cartilage.
10. Why is hyaline cartilage called articular cartilage?
because it covers the ends of bones.
11. What is appositional growth in cartilage?
on the outside
What is interstitial growth in cartilage?
within the cells
12. Know examples of long bones, short bones, flat bones, and irregular bones
Long bones include the femur, the humerus, the tibia and several other bones. Short bones are carpals and tarsals. Flat bones include bones like the sternum and the scapula. Irregular bones are vertebrae.
13. What is the difference between a bone diaphysis and a bone epiphysis?
The Diaphysis is the middle section of a bone. • The Epiphysis refers to the ends of a bone.
14. What is the difference between an epiphyseal plate and an epiphyseal line?
The Epiphyseal plate contains cartilage used for producing bone. • The Epiphyseal line is formed after the epiphyseal plate has stopped producing bone).
15. Where is the medullary cavity and what is contained in it?
The Medullary cavity is the cavity inside the diaphysis that contains yellow marrow.
16. Where is the periosteum and what does it contain?
The Periosteum is the covering of a bone. It contains nerves and blood vessels.
17. What are Sharpey's fibers?
Sharpey's fibers attach the periosteum to the bone as well as serving as attachments for ligaments and tendons.
18. What is the function of endosteum?
Endosteum lines the internal cavities of a bone.
19. What substance makes up the organic portion of bone?
collagen, contains carbon
What substance make up the inorganic portion of bone?
hydroxyapitite (calcium salts)
20. What is the function of an osteoblast? Osteocyte? Osteoclast?
Osteoblast - Bone building Osteocyte - Bone maintance Osteoclast - Bone destroying (Breakdown releases Calcium)
21. What are osteochondral progenitor cells?
Osteochondral Progenitor cells are stem cells that can be used to form more bone cells if needed.
22. How is woven bone related to lamellar or cancellous bone?
Woven bone is a form of bone that changes into either lamellar bone or cancellous bone. (Dense bone forms)
23. What mineral gives bone its strength for weight bearing?
Hydroxyapatite (Calcium and Phosphorus mineral) gives a bone strength.
24. What protein material gives bone its flexibility?
Collagen protein gives a bone flexibility.
25. What is the proportion of collagen protein to mineral matter in a bone?
A bone is normally 1/3 collagen and 2/3 hydroxyapatite.
26. When does an osteoblast become an osteocyte?
after mineral matter has surrounded it
27. What are canaliculi? ****
inner connection between osteocytes ****
28. During what two conditions would woven bone be formed?
fetal development and fracture repair
29. What occurs when a bone is remodeled?
removing old bone material and adding new bone material
30. What are lamellae?
layers of lamellar bone
What property is given to bone by lamellae?
31. What are trabeculae?
the support structures of cancellous bone
How do trabeculae arrange in a bone?
along the lines of stress
32. Under what conditions would the trabeculae change orientation?
stress lines change if a person gains weight or has a bone injury
The Haversian (central) canal? (Function)
transport material into and out of bone
The Lamellae? (Function)
layers of bone that form around the haversian canal giving the bone strength
The Osteocytes? (Function)
maintain bone tissue
The Canaliculi? (Function)
connects osteocytes together for cellular sharing and communication ****
Concentric lamellae? (Location)
circle around the haversian canal
Circumferential lamellae? (Location)
are found around the outer edge of the compact bone beneath the periostium
Interstitial lamellae? (Location)
form between the haversian systems
35. Define ossification.
converting tissue to bone
36. Bone is formed from what three kinds of tissues?
regular and irregular collagenous tissue, and hyaline cartilage
37. Define calcification.
depositing calcium salts in bone tissue to make the bones strong
38. What bones are formed during intramembranous ossification?
the bones of the cranium, the roof of the skull, part of the manible, and the clavical
39. During what week of embryonic development does ossification begin?
When is ossification completed?
females 17; males 20 or adulthood
40. What is the first event in intramembranous ossification?
osteoblasts forming bone within a membrane
Intramembranous bones are formed from what two kinds of tissues?
dense irregular and regular collagenous tissue
41. Flat skull bones form from what kind of tissue membrane?
fibrous connective tissue
42. What is the center of ossification?
where bone is forming in membrane
Where does ossification begin?
starts in the middle of the membrane and bone forms outward from there
Where is the oldest bone and the youngest bone in a bone fragment? ***
oldest is in the center, youngest is on the outside ****
43. What are fontanelles? How do they form? When do they close?
membrane covered spaces between skull bones, they form because the bone develops from the center outward, they close by age 2
44. Fontanelles allow for two events to occur. What are they?
continued growth of the brain for a short time after birth, pelvic vaginal birth
45. What is "head molding" in an infant?
as the head comes out it forms to the birth canal for easier passage
46. In endochondral ossification, what is the cartilage model?
47. Where is the primary ossification center in endochondral ossification?
What is a bone collar?
compact bone on the surface of the cartilage model
48. How does ossification proceed from the primary ossification center?
bone development proceeds toward the epiphyses
Where does the secondary ossification center begin?
from in the epiphyses
What is the last event of endochondral ossification?
two secondary ossification centers form in the epiphyses
49. What is the relationship of the location of the epiphyseal plate and the primary and secondary ossification centers?
it is a layer of cartilage between the two
50. What kind of growth occurs from the epiphyseal plate? How long does this growth persist?
bone length occurs, through the teen years for most individuals
51. What are the 5 major events of endochondral ossification?
1. forming cartilage model 2. forming the bone collar 3. bone development toward epiphysis 4. 2nd ossification centers 5. forming of the epiphyseal plate
52. When does the epiphyseal plate become nonfunctional in females? Males?
53. What role does estrogen play in female growth in height?
responsible for growth spurt and closing of epiphyseal plate
54. What is the difference between an epiphyseal plate and an epiphyseal line?
the plate becomes the line after the plate becomes nonfunctional
55. Bone growth in length is (appositional; interstitial) ___ growth.
56. Name the 4 epiphyseal plate zones.
resting cartilage, the proliferation zone, hypertrophy zone, calcification zone
57. Name the zone in which the cartilage cells divide.
58. Name the zone in which the plate is pushed forward and the bone grows in length.
59. Name the zone in which the cartilage is changed into bone.
60. Describe the 6 growth events that occur at the epiphyseal plate.
1. cellular proliferation (division), 2. cellular hypertrophy (enlargement) 3. calcification of cells (mineral deposition) 4. cellular death (cartilage is replaced by bone) 5. ossification 6. remodeling
61. Why does a person stop growing in height?
bone growth in length stops when the epiphyseal plate is completely replaced by bone
62. At what age does the growth spurt occur in girls? Boys?
Between 8 and 13 years in Girls and between 10 and15 in boys
63. Describe the events that lead to a bone growing in width.
1. osteoblasts in the periosteum form ridges that gradually grow together 2. each ridge develops concentric rings by the addition of matrix (bone becomes wider) 3. the increases in diameter are accompanied by increases in the diameter of the medullary canal (bone walls become thinner)
64. What is a consequence of a bone growing in width?
bone becomes wider
65. What minerals are needed for effective bone growth?
calcium and phosphate
66. How are vitamins A, C, and D needed for bone growth?
A - osteoblast and osteoclast activity, D - calcium transfer, C - collagen formation
67. What different hormones are needed for effective bone growth?
sex hormones and the thyroid and parthyroid hormones and growth hormone
68. What three stressors may cause bone remodeling?
weight and activity changes as well as disease/injury processes
69. What occurs during bone remodeling?
bone is torn down by osteoclasts and rebuilt by osteoblasts
70. The success of remodeling depends on the availability of what mineral?
71. What occurs in osteoporosis?
It's a loss of bone mass due to the lack of calcium or the means to replace that calcium into the bone.
72. What are the 4 steps in bone repair?
1. hematoma (blood clot) formation, 2. callus (soft clot) formation 3. callus ossification occurs to harden the tissues formed around the broken ends of the bone 4. remodeling of bone occurs to compensate for the body's response to the break in the bone
73. For what reason is a bone placed in a cast?
maintain the integrity of the callus
74. What occurs if calcium in the blood is high?
It goes into the bone as osteoblasts to build new bone
What occurs if blood calcium is low?
it moves out of the bone as osteoclasts to break down bone
75. What is the function of parathormone?
increase osteoclast activity and increases the break-down of bone so more calcium is carried in the blood
76. What is the function of calcitonin?
inhibits osteoclast activity, letting more calcium be taken into the bones, thus lowering the level of calcium in the blood.