Chapter 6 Lecture Flashcards
(130 cards)
1
Q
What is the study of bones?
A
Osteology
2
Q
_______ is a organ containing several tissue types in the body.
A
Bone
3
Q
Osseous tissue is bone tissue true or false?
A
True
4
Q
What type of tissue is osseous tissue?
A
Supportive connective
5
Q
Bone are an integral part of which system?
A
Skeletal
6
Q
The skeletal system is made up of what three things?
A
Bones, Cartilages, Ligaments.
7
Q
Are bones very metabolically active organs?
A
Yes.
8
Q
What kind of tissue are ligaments made up of?
A
Dense regular connective.
9
Q
What joins bone to bone?
A
Ligaments
10
Q
What are the two supporting connective tissue in the body?
A
Osseous Tissue, Cartilage
11
Q
Name all the places cartilage can come from.
A
Mesoderm, Embryonic mesenchyme tissue (stem cells), Chondroblasts, Chondrocytes.
12
Q
Where can hyaline cartilage be found?
A
The superior ten pairs of ribs in the sternum. (called coastal cartilage)
Articulating sites of many bones. (called articular cartilage)
Rings of the trachea.
13
Q
Where can elastic cartilage be found?
A
The skeletal structure of the ouster ear.
The epiglottis in the respiratory system.
14
Q
Which cartilage is the strongest?
A
Fibrocartilage
15
Q
Where can fibrocartilage be found?
A
Meniscus of the knee joint.
Intervertebral discs.
Pubic symphysis.
(this is not all the locations)
16
Q
What are the 5 primary functions of the skeletal system?
A
Support
Storage of minerals (calcium) and lipids (yellow marrow)
Blood cell product, or hematopoiesis (red marrow)
Protection
Leverage (force of motion for movement)
17
Q
What are the 6 bone shapes?
A
Long bones, Flat bones, Short bones, Irregular bones, Sutural (wormian) bones, Sesamoid bones
18
Q
_____________ are longer than wide, with somewhat cylindrical axis. They are found in the arms, legs, hands, feet, fingers and toes.
A
Long bones
19
Q
__________ are thin with parallel surfaces. They are found in the skull, sternum, ribs, and scapula.
A
Flat bones
20
Q
_________ are small and thick, including ankle and wrist bones.
A
Short bones
21
Q
____________ are complex shapes such as spinal vertebrae and pelvic bones.
A
Irregular bones
22
Q
____________ are small, irregular bones between the flat bones of the skull; typically found in the lambdoid suture.
A
Sutural bones
23
Q
____________ are small, flat bones that develop embedded in tendons near joints of the knees, hands, and feet.
A
Sesamoid bones
24
Q
All bone is classified as _______ bone or ________ bone?
A
spongy or compact
25
What is another name for spongy bone?
Cancellous bone.
26
Does spongy does always look spongy?
Yes
27
Is spongy bone always internal?
Yes
28
What is goes down/ is inside of spongy bone?
Red marrow - Hematopoiesis.
29
Does spongy bone have osteons?
No
30
_______ is dense in makeup and has osteons!
Compact bone
31
True or false compact bones is not alway external?
False, it is always external.
32
What does compact bone provide?
Protection and support.
33
What is the general overview of macroscopic structure of flat bone?
1. "bone sandwich"
2. No marrow cavity
3. No osteons.
4. Spongy bone "sandwiched" between compact bone in cranium.
34
Spongy bone "sandwiched" between compact bone in the cranium is called?
Diploe
35
________ is dense supportive connective tissue containing specialized cells.
Osseous tissue
36
The matrix of bone tissue is solid because?
inorganic calcium salts make up its ground substance.
37
What represents the organic portion of the bone matrix?
```
protein fibers (collagen)
Note to self: (they are dispersed though the ground substance)
```
38
What are the characteristics of bone tissue?
1. Dense matrix containing deposits of calcium salts.
2. The matrix contains bone cells within lacunae
3. Canaliculi
2. Periosteum
5. High vascular and innervated
39
Canaliculi are?
tunnels through the bone extending from lacuna to lacuna through the matrix that allow osteocytes to connect.
40
What is the matrix of the bone made of?
- Two-thirds is made up of calcium phosphate, which reacts with calcium hydroxide, to form crystals of hydroxyapatite, which incorporates other calcium salts and ions as it crystallizes.
- About 1/3 of bone is protein fibers (collagen).
- Bone cells are only about 2% of bone mass.
41
What are the cells of bones?
Osteoprogenitor cells.
Osteoblasts.
Osteocytes.
Osteoclasts.
42
What is an osteoprogenitor cell?
they are stem cells that differentiate to produce osteoblasts. ( only source of new osteoblasts )
43
Where are osteoprogenitor cells located?
they are primarily located in the matrix of the inner layer of the periosteum and in the endosteum.
44
What do osteoprogenitor cells active in?
fracture repair.
45
Another name for osteoblasts?
bone makers.
46
What are immature bones cells that secrete the matrix by the process of osteogenesis or ossification?
Osteoblasts.
47
When osteoblasts are surrounded by cone (lacuna), the complete their differentiation. What do they then become?
Osteocytes.
48
Can osteoblasts divide?
No
49
What are osteocytes?
mature bone cells that maintain the bone matrix.
50
Where to osteocytes live?
in lacuna.
51
Can osteocytes divide?
No
52
What are the main functions of osteocytes?
1. To produce protein and mineral content of the matrix, thus maintaining the matrix.
2. Help repair damaged bone.
53
What is another name for osteoclasts?
Bone destroyers
54
Osteoclasts are?
giant, multinucleate cells that secrete acids and protein-digesting enzymes which dissolve bone matrix and release calcium into body fluids. ( this is the process of osteolysis or bone resorption )
55
_______ are NOT differentiated from osteoprogenitor cells.
Osteoclasts
56
Where do osteoclasts differentiate?
in red bone marrow in hematopoietic tissue into mature osteoclast cells.
57
When osteoclasts break down bone faster than osteoblasts build bone, bones become ______?
weak
58
Bones get stronger with exercise, which causes oestoblasts to _______?
build bone
59
What is Wolff's law?
bones respond to exercise and stress.
60
Good diet + Exercise =
Healthier bones.
61
What is the structure of compact bone?
a longitudinal unit called the osteon.
62
All ______ in long bones run the length of the bone, strengthening the bone in that direction.
osteon
63
Do compact long bones have blood vessels? If so where are they located?
Yes, they are located in the perforating canals.
64
What is the structure of spongy bone? Is it arranged in it arranged in osteons?
No, it is not arranged in osteons. It's matrix forms as open network of strut-like structures called trabeculae.
65
Does spongy bone have blood vessels? If so where?
No, they do not have blood vessels.
66
What is located in spongy bones trabeculae?
It is filled with red bone marrow, which has blood vessels and supplies nutrients to the osteocytes and removes wastes by diffusion.
67
In spongy bone the cross-bridging structure of the __________ allows for handling of stress in many different directions.
trabeculae
68
What bone is heavier compact bone or spongy?
compact bone
69
In long bones there is a _________ cavity or ________ cavity in which there is yellow marrow in healthy adults. ________ is mostly ________ tissue, a good site of energy storage.
medullary
marrow
yellow marrow
adipose
70
What is periosteum?
a membrane that covers outer surfaces of bones except the parts of bone where they join with other bones.
71
What is the structure of periosteum?
It has an outer fibrous layer (dense irregular tissue) and an inner cellular layer (osteprogenitor cells, osteoblasts, osteoclasts).
72
What are periosteum's three functions?
1. isolates bone from surrounding tissues.
2. provides a route for circulatory and nervous supply.
3. participates in bone growth and supply.
73
What is endosteum?
a cellular layer that lines the inner surfaces of bone, such as the medullary cavity and central canals.
74
Does endosteum have a touch fibrous layer? If not why not?
No, because of its location there is no need for the touch fibrous layer.
75
What does endosteum contain?
It contains osteoblasts and osteoprogenitor cells and not to many osteoclasts.
76
Is endosteum active in bone growth and repair? Why or why not?
Yes, because of the osteoprogenitor cells and the osteoblasts.
77
Is an embryonic skeleton (fertilization - 8 weeks) made of real bones? If not what is it made out of?
No it is not. It is made out of two other types of tissue that then differentiate into osseous tissue.
78
What are the two tissues types that make up the embryonic skeleton between fertilization - 8 weeks?
1. fibrous connective tissue membrane
| 2. hyaline cartilage
79
Which bones begin as fibrous connective tissue?
The flat bones in the cranium, and the clavicles. Mature bones that are formed this way are often called membrane bones.
80
Which bones begin as hyaline cartilage?
Almost all bones begin as hyaline cartilage. This type of mature bone is often called endochondral bone.
81
Does all cartilage differentiate in bone tissue?
No.
82
The process of bone formation is called?
osteogenesis or ossification.
83
The process of depositing ________ _____ occurs during ossification and also may occur in other tissues.
(this is not a part of bone formation)
calcium salts
84
What are the two main forms of ossification?
intramembranous ossification
| endochondral ossification
85
What undergoes intramembranous ossification? When does it begin?
embryonic mesenchymal stem cells in a fibrous membrane. the flat bones of the cranium, and the mandible, and the clavicles.
it begins 6-8 weeks of embryonic development.
86
What are the three main steps in intramembranous ossification.
1. Mesenchymal cells aggregate and differentiate into osteoblasts, which begins ossification.
2. Blood vessels grow into the area to supply the osteoblasts with nutrients, oxygen etc. Bone tissue forms, trapping blood vessels inside bone and ossification proceeds.
3. Then spongy bone develops first, then compact bone develops as spongy bone undergoes remodeling.
87
Where does intramembranous ossification begin?
at a site out in the fibrous tissue called an ossification center.
88
What undergoes endochondral ossification? When does it begin?
most bones originate as hyaline cartilage which becomes ossified through this process.
6-8 weeks of embryonic development, the bones of the body are formed as miniature hyaline cartilage template bones.
89
What is more complex endochondral ossification or intramembranous ossification?
endochondral
90
What are the 5 steps in endochondral ossification?
- The template bone is hyaline cartilage, so the cells are chondrocytes, and the connective tissue surround the cartilage bone is a perichondrium at this point not a periosteum.
1. Threefold:
- Chondrocytes in the perichondrium differentiate into osteoblasts, thus turning the perichondrium into the periosteum.
- Chondrocytes in the center of the bone die, leaving a space that will become the medullary cavity.
- Osteoprogenitor cells move in and differentiate into osteoblasts, and osteoclasts migrate in as well.
2. Blood vessels enter the developing bone, bring in nutrients.
3. Remodeling creates marrow cavity.
4. The epiphysis fill with spongy bone. The hyaline cartilage remaining at the end of the bone become articular cartilage. Cartilage remains at the metaphysis and becomes the epiphysis plate.
5. When the long bone stops growing, the epiphysis plate cartilage ossifies and becomes the epiphyseal line.
91
Postnatal growth of long bones is called?
interstitial growth
92
Define interstitial growth.
Growth of a long bone in length.
93
Where does "actual" interstitial growth occur?
in the cartilage, cartilage cells are dividing and then changing into bone cells.
94
Do mature bones demonstrate interstitial growth once they go for a plate to a line?
No, only plates show interstitial growth.
95
What is appositional growth?
growth in diameter of long bones.
96
Does appositional growth occur after long bones are mature?
Yes.
97
What are the major factors affecting bone growth?
1. genetic predisposition certainly affects bone size and health.
2. normal bone growth and maintenance requires some nutritional and hormonal factors.
- Dietary source of calcium and phosphate salts, plus small amounts of magnesium, fluoride, iron, and manganese.
- The hormone calcitriol, made in the kidneys, is essential for proper absorption of calcium and phosphorus by the digestive tract. Calcitriol synthesis requires vitamin D3.
- Vitamins: Vitamin C is required for collagen synthesis, and stimulates osteoblast differentiation. Vitamin A stimulates osteoblast activity. Vitamins K and B12 help synthesize bone proteins.
- Growth hormone ( one of the pituitary hormones) stimulates tissue growth in general... including interstitial cartilage growth, and appositional growth of bone tissue = pituitary gigantism or acromegaly occurs in adults as a result of hypersecretion of GH. It only affect the diameter and thickness. Pituitary dwarfism... hyposecretion of GH= small person... normal proportion.. contrast with achondroplasia.
- Sex hormones: testosterone in males and estrogen in women stimulate osteoblast activity... typical growth spurt at puberty.
- Calcitonin and parathyroid hormone: regulate calcium and phosphate homeostatic levels in bonds fluids.
98
Since osseous tissue in bone ages, or sometimes undergoes change it must be ______.
renovated.
99
Thoughtout our lives, the skeleton must maintain itself and replace _________ __________.
mineral reserves.
100
The process that recycles and renews the bone matrix is called?
remodeling.
101
Are bones dynamic organs?
Yes
102
What is responsible for the day-to-day maintenance of the bone matrix?
The mature bone cells! (osteocytes)
103
Osseous tissue is constantly undergoing change, what is this process called?
How long does it occur?
bone remodeling.
| your entire life span.
104
Bone remodeling involves an interplay primarily between ________ and ______.
Osteoblasts and osteoclasts.
105
Another name for osteoblasts?
bone makers
106
What do osteoblasts do?
They lay down bone matrix on bone surfaces, and become enclosed in lacunae.
Then they differentiate unto a non-dividing osteocyte that maintains the matrix in its surrounding area.
107
Another name for osteoclasts?
bone destroyers
108
What do osteoclasts do?
mineral resorption or osteolysis occurs when osteoclasts dissolve bone matrix, thus allowing Ca++ and PO4 - to enter body fluid and blood.
109
How to osteoclasts to what they do?
1. Osteoclasts release H ions into interstitial fluid, which attract chloride ions > HCl.... ionizes (dissolves) calcium salts (ground substance of bone tissue)
2. Osteoclasts also secret enzymes that breaks down the collagen fibers in the matrix.
110
What is bone remodeling involved in:
1. Bone growth
2. Changes in bone shape.
3. Bone repair
4. Ca++ regulation in body fluids and bone.
111
Bone are storage areas for many metabolically active mineral, but which one in particular?
Calcium.
112
Where is calcium stored?
In bones.
113
What is the most abundant mineral in the body?
Calcium.
114
Calcium ions are important for?
membranes and the intracellular activities of neurons and muscle cells.
115
Calcium ion homeostasis is maintained by?
the hormones calcitonin and parathyroid hormone, which control calcium in storage, absorption and excretion through two opposing negative feedback mechanisms.
116
What are the three sites controlled by calcium homeostasis?
1. bones, where calcium is stored.
2. digestive tract, where calcium is absorbed.
3. kidneys, where calcium is excreted.
117
What is hypocalcemia?
When Ca++ falls.
118
What is hypercalcemia?
When Ca++ rises.
119
What hormone raises the level of Ca++ and where is it produced?
Parathyroid hormone
| produced by: parathyroid glands
120
How does the parathyroid hormone increase the levels of Ca++?
1. stimulating osteoclasts (release calcium stored in bone)
2. increasing intestinal absorption of calcium ions (through its effect on calcitriol)
3. decreasing the rate of calcium excretion at the kidneys.
121
What decreases the level of Ca++? Where does it come from?
Calcitonin
| secreted by the thyroid!
122
How does calcitonin decrease the levels of Ca++?
1. inhibiting osteoclast activity.
| 2. increasing calcium ion excretion at the kidneys.
123
Calcium and phosphate ions circulating in the blood are constantly being lost in the urine. If they aren't reobtained from the diet, the will be released from storage in the skeleton, making bones weaker. What is necessary to keep bones strong?
Exercise and a diet with enough calcium.
124
What is calcium needed for?
muscle contractions, nerve impulses, bone matrix, blood clotting.
125
what is phosphorous needed for?
atp, phospholipids (plasma membrane), bone matrix
126
What is calcitriol?
It is actually a vitamin substance that behaves like a hormone.
127
What are calcitriols three functions?
1. Stimulates resorption of calcium & phosphorous from bone.
2. Some inhibition of Ca++ loss in urine from kidneys
3. Stimulates calcium and phosphorous absorption in small intestine.
128
What are fractures?
Cracks or breaks in bones cause by physical stress.
129
Fractures are repaired in four steps what are they?
| *****
1. Bleeding produces a clot called the fracture hematoma, establishing a fibrous network. Bone cells in the area die, and inflammation often occurs in the area around the injury.
2. Two types of calluses form at the sites of the fracture. Theses calluses stabilize the break: A collar of cartilage and fibers (external callus) surrounds the break, and an internal callus develops in the marrow cavity. During this time, the clot is dissolving, and macrophages are cleaning up the area.
3. Both calluses are ossified over a period of 4-6 weeks. The first boned formed in spongy bone.
4. Osteoblasts and osteocytes continue to remodel the fracture for up to a year, replacing the spongy bone with compact bone.
130
What are the major types of fractures?
```
Potts fracture
comminuted fracture
transverse fracture
linear fracture
Colles' fracture
greenstick fracture
epiphyseal fracture
impacted fracture
complete fracture
incomplete fracture
```
