1
Q
the entire framework of bones and cartilage
A
The skeletal system
2
Q
a detailed study of the structure of bones, skeletal elements, teeth, morphology, function, disease, pathology, and the process of ossification of the bones
A
Osteology
3
Q
Functions of the skeletal system
A
- support
- protection
- assistance in movement
- mineral homeostasis
4
Q
Site of attachment for tendon and ligament
A
Support
5
Q
Encloses the organs of the cranial and thoracic cavities
A
Protection
6
Q
Allows for a range of movement over certain joints
A
Assistance in movements
7
Q
stores minerals like calcium and phosphate (in extracellular matrix)
A
mineral homeostasis
8
Q
red bone marrow helps make:
A
red and white blood cells
9
Q
- in the medullary cavity
- contained in yellow bone marrow
A
triglyceride storage
10
Q
long bone
A
humerus
11
Q
flat bone
A
sternum
12
Q
short bone
A
triquetrol
13
Q
irregular bone
A
vertebra
14
Q
Parts of the long bone
A
- Diaphysis
- Epiphysis
- Articular Cartilage
- Periosteum
- Medullary Cavity
- Endosteum
15
Q
lining the cavities inside the bone
A
endosteum
16
Q
lining that wraps around the bond
A
periosteum
17
Q
Four types of cells in bone tissues:
A
- Osteogenic cells
- Osteoblasts
- Osteocytes
- Osteoclasts
18
Q
- Found on the surface of a bone and in the periosteum
- Capable of mitotic division
A
Osteogenic Cells
19
Q
- Bone forming cells
- Found in the margins of bone
A
Osteoblasts
20
Q
- mature bone cells
- found in the lacunae
A
Osteocytes
*Have gaps that allow them to communicate with each other
21
Q
- bone dissolving cells
- contain many nuclei (fusion of many mesodermal cells)
A
Osteoclasts
22
Q
When the body is low on calcium, osteoclast levels do what?
A
Increase
23
Q
What makes up the composition of bone’s matrix?
A
- Collagen fibers
- Hydroxyapatite (Calcium and Phosphate)
24
Q
Hydroxyapitate
A
Calcium and Phosphate
25
Bone matrix has _____ water and _____ salts
less water and more salts
26
Percent composition of bone:
- 25% water
- 50% salt
- 25% fibrous protein
27
Few spaces between the hard components
Compact Bone
28
makes the external layer of all bones
Compact Bone
29
80% of bones are ____, the rest is _____
compact bone; spongy bone
30
Compact bone provides:
- Strength
| - Site of attachment for tendons and ligaments
31
site of attachment for tendons and ligaments
compact bone
32
Parts of compact bone matrix:
- osteon
- central canal
- perforating canal
- osteocyte
- lacuna
- bone matrix
- canaliculus
33
extensions of membrane between osteocyte
canaliculus
34
What is another word for osteons?
Haversian Systems
35
Bones are arranged in:
Haversian Systems
36
Bone that does not contain true osteons
Spongy Bone
37
Spongy bone is made up of:
lamellae that are arranged in a lattice of thin columns of bones
38
spaces between them filled with red bone marrow
Trabeculae
39
Arranged to resist stress from many directions
Trabeculae
40
What occurs in the spongy bone of the long bones?
Hematopoiesis
41
Hormone that stimulates blood cell production
Hematoprotein
42
Formation of bone on a connective tissue base
Ossification/osteogenesis
43
- mostly cartilage
| - slowly replaced by bone
Embryo Skeleton
44
There are two possible ways for ossification:
- Intramembraneous ossification
| - Endochondral ossification
45
type of ossification where bones begin with sheet-like layers of connective tissues
- Broad, flat bones
- Intramembraneous bone
Intramembraneous Ossification
*Skull bones (except mandible)
46
Type of ossification where bones begin as hyaline cartilage, form models for future bones
-most bones of the skelton
Endochondral Ossification
*Chond= "Cartilage"
47
Center of ossification
osteoblasts
48
Osteocytes develop in the spaces of the _____
bone matrix
49
Bone matrix develops into:
trabeculae to form spongy bones
50
Mesenchyme (on the outside):
condense to make the periosteum
51
Endochondral Ossification beings:
in the second month of development
52
Uses hyaline catilage "bones" as models for bone construction
Endochondral Ossification
53
Requires breakdown of hyaline cartilage prior to ossification
Endochondral ossification
54
Stages of Endochondral Ossification:
1. Formation of bone collar
2. Caviation of hyaline cartilage
3. Invasion of internal cavities by the periosteal bud, and spongy bone formation
4. Formation of the medullary cavity; appearance of secondary ossification centers in the epiphyses
5. Ossification of the epiphyses, with hyaline cartilage remaining only in the epiphyseal (growth) plates
55
- Cartilage cells undergo mitosis, pushing the epiphysis away from the diaphysis
- Followed by a hypertrophic zone
Growth Zone
56
where older cartilage cells enlarge
hypertrophic zone
57
In a transformation zone, the matrix becomes
calcified
58
-the matrix becomes calcified, cartilage cells die and the matrix begins to deteriorate
Transformation (calcification) zone
59
new bone formation occurs
Ossification (osteogenic) zone
60
Cartilage continually grows and is replaced by bone
Growth in legnth
61
Bone is reabsorbed and added by appositional growth
Remodeling
62
During infancy and childhood, epiphyseal plate activity is stimulated by:
growth hormone
63
During puberty, testosterone and estrogen:
- initially promote adolescent growth spurts
| - Cause: masculinization and feminization of specific parts of the skeleton
64
Later, hormones induce epiphyseal plate closure:
ending longitudinal bone growth
65
What causes masculinization and feminization of specific parts of the skeleton?
Testosterone and Estrogen
66
Adjacent osteoblasts and osteoclasts that deposit and reabsorb periosteal and endosteal surfaces
Remodling units
67
Occurs where bone is injured or added strength is needed
Bone Deposition
68
Bone Deposition requires a diet that is rich in:
- Proteins
- Vitamins A, C, and D
- Calcium, phosphorus, magnesium, and manganese
69
Production of collagen fibers
Vitamin C
70
Help promote activity associated with osteoblasts/osteoclasts
Vitamin A
71
Helps body absorb Calcium
Vitamin D
72
What do bones store Calcium for:
- transmission of nerve impulses
- muscle contractions
- blood coagulation
- secretion by: glands and nerve cells
- cell division
73
What does the Parathyroid do?
4 masses release PTH (Parathyroid Hormone) is released when blood calcium levels are too low. Hormone stimulates osteoclast activity to break down the bone's matrix and puts the Ca++ back into the blood
74
Thyroid releases _____ when blood calcium is too high. Stimulates osteoblasts to take Ca++ out of the blood and add to the bone matrix
Calcitonin
75
Bone fractures are classified by:
- the position of the bone ends after fracture
- the completeness of the break
- the orientation of the bone to the long axis
- whether or not the bone ends penetrate the skin
76
A break in any bone
Fracture
77
- Compound Fracture
| - Bone breaks through soft tissues
Open fracture
78
- Simple fracture
| - Bone does not break through the soft tissue
Closed fracture
79
- bone fragments into three or more pieces
| - common in the elderly
Comminuted fracture
80
- incomplete fracture where one side of the bone breaks and the other side bends
- common in children, because children still have a lot of cartilage
Greenstick fracture
81
One part of the bone is crushed into another part of the bone
Impacted Fracture
82
Epiphysis separates from diaphysis along the epiphyseal line
| -occurs where cartilage cells are dying
Epipheseal Fracture
83
A fracture that occurs at the distal end of the radius
Colle's Fracture
84
- Hairline Fracture
- Type of incomplete fracture
- Caused by: repeated or unusual stress often to a weight bearing bone
Stress Fracture
85
Steps in bone repair:
- Form a fracture hematoma
- Fibrocartilagenous callus formation
- Bony callus formation
- Bone remodling
86
What happens to the shape of bones when they repair themselves?
Width is greater than it was at the beginning and this will persist for the rest of their lives
87
Decreases in sex steroids causes a:
decrease in bone mass
88
Bones grow:
from birth through adolescense
89
Group of diseases in which bone reabsorption outpaces bone deposit
osteoporosis
90
During osteoporosis, ____ is most vulnerable
spongy bone of the spine
91
Osteoporosis occurs most often in:
Post-menopausal women
92
Bones become so fragile that sneezing or stepping off a curb can cause fracture:
osteoporosis
93
Treatments for osteoporosis:
- Calcium and Vitamin D supplements
- Increase weight-bearing exercise
- Hormone (estrogen) replacement therapy (HRT) slows bone loss
- Natural progesterone cream prompts new bone growth
- Statins increase born mineral density
94
- Bones are inadequately mineralized, causing softened, weakened bones
- Main symptom is: pain when weight is put on the affected bone
- Caused by insufficient: Calcium in diet, or Vitamin D deficiency
*In adults
Osteomalacia
95
- Bones of children are inadequately mineralized, causing softened, weakened bones
- Bowed legs and deformities of pelvis, skull, and rib cage are common
- Caused by insufficient calcium in the diet, or by vitamin D deficiency
Rickets
96
Why do isolated cases of Rickets occur?
Infants of breastfeeding mothers who are deficient in Vitamin D will also be deficient in Vitamin D and develop rickets
97
- characterized by excessive bone formation and breakdown
- bone with an excessively high ratio of woven bone to compact bone is formed
- Causes spotty weakening of bones
- Osteoclast activity wanes, but osteoblast activity continues to work
Paget's Disease
98
Where is Paget's disease localized?
spine, pelvis, femur, and skull
99
What is the treatment for Paget's disease?
the drugs Didronate and Fosamax
100
- Person is very short but has normal body proportions
| - Human growth hormone stimulates growth along the epiphyseal plates (without this hormones, this disease occurs)
Pituitary Dwarfism
101
- An excess of human growth hormone is released
| - Before epiphyseal plates seal, height may be up to 8 feet
Pituitary Gigantism
102
- Excess secretion of human growth hormone in adults
| - Causes enlargement of hands, feet, and jaw
Acromegaly
103
Produce membranes and cartilages that form the embryonic skeleton
embryonic mesenchymal cells
104
____ cells give rise to embryonic mesenchymal cells
Mesoderm
105
The _____ ossifies at a known rate
embryonic skeleton
106
fetal age is easily determined from ____
sonograms
107
At birth, most long bones are ____
ossified
*except at the epiphyseal plate
108
By age ____, nearly all bones are completely ossified
25
109
A single gene codes for:
- the tendency to accumulate bone mass early in life
| - the risk for osteoporosis later in life
110
in old age, bone absorption
outpaces bone growth
