Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
108 Cards in this Set
- Front
- Back
|
Functions of Skeleton
|
supports body, protects delicate parts, produce blood cells, storage of minerals, leverage for body movement
|
|
|
Chemical composition
|
organic and inorganic components
|
|
|
What are the different bone cells?
|
osteoprogenitor cells, osteoblasts, osteocytes, osteoclasts
|
|
|
Osteoprogenitor Cells
|
stem cells derived from mesenchyme which will become osteoblasts; found in the endosteum and periosteum
|
|
|
Osteoblasts
|
immature bone cells, will develop into osteocytes; make bone matrix around themselves; produce new bone (osteogenesis)
|
|
|
Osteocytes
|
mature bone cells surrounded by bone matrix; live in lacunae; maintain & repair hard matrix
|
|
|
Osteoclasts
|
demolition team of bone tissue; break down and remove matrix for remodeling and growth, or when body needs calcium or phosphorus
|
|
|
Collagen Fibers
|
found in bone matrix; made by osteoblasts and osteocytes
|
|
|
Inorganic Components
|
65% of bone weight; mineral salts crystallize and harden around collagen fibers in the matrix
|
|
|
Examples of mineral salts
|
calcium phosphate, calcium hydroxide, calcium carbonate
|
|
|
Types of bone tissue
|
compact bone and spongy bone
|
|
|
Classification of bones by shape
|
long, short, flat, irregular
|
|
|
Structure of long bone
|
epiphyhsis, epiphyseal line, diaphysis, medullary cavity, endosteum, periosteum, articular cartilage
|
|
|
Epiphysis
|
proximal and distal edns of a long bone; composed of spongy bone surrounded by a thin layer of compact bone
|
|
|
Epiphyseal line
|
junction between epiphysis and diaphysis
|
|
|
Diaphysis
|
(shaft) composed of compact bone surrounding
|
|
|
Medullary (marrow) cavity
|
contains yellow marrow (fat) in adults; lightens weight
|
|
|
Endosteum
|
single cellular layer around medullary cavity
|
|
|
What has a thin membrane lining medullary cavity and all other internal bone spaces and canals; cellular layer of osteoprogenitor cells, osteoblasts and osteoclasts
|
endosteum
|
|
|
Periosteum
|
tough sheath on the outside of bone- boundary of bone; nourishes and repairs
|
|
|
What are the two layers of periosteum?
|
deep layers and superficial layer
|
|
|
Describe a deep layer of periosteum
|
cellular; has osteoprogenitor cells, osteoblasts and osteoclasts; in contact w/ the compact bone
|
|
|
Describe superficial layer of periosteum
|
dense irregular connective tissue; very tough; provides an anchoring point for tendons and ligaments (fibers merge)
|
|
|
Where is ots of blood vessels and nerves are present that penetrate and nourish interior of bone?
|
periosteum
|
|
|
What is at the ends of long bone?
|
articular cartilage
|
|
|
Articular Cartilage
|
hyaline cartilage and cushion
|
|
|
What are the two types of bone?
|
compact bone and spongy bone
|
|
|
Where is compact bone located?
|
on outside of all bones and is thicker in diaphyses than epiphyses
|
|
|
What is the function of compact bone?
|
very strong and dense; resists stress
|
|
|
What is compact bone composed of?
|
osteons or Haversian systems
|
|
|
What are the 7 components of compact bone structure?
|
central canal, lamellae, lacunae, osteocytes, canaliculi, lots of osteons crowd together to form compact bone, perforating (Volkmann's) canals
|
|
|
Central Canal
|
runs longitudinally in long bone, lined by endosteum, contains blood vessels and nerves
|
|
|
Lamellae
|
concentric rings of hard, calcified matrix around canal
|
|
|
Lacunae
|
spaces which house bone cells
|
|
|
Osteocytes
|
in lacunae
|
|
|
Canaliculi
|
connect lacunae; 'little canals,' also connect to central canals; nutrients and waste diffuse through canaliculi between osteocytes and blood vessels
|
|
|
Perfortating (Volkmann's) canal
|
run perpendicular to bone's long axis; have blood cells; connect periosteum to central canals to medullary cavity
|
|
|
Spongy (cancellous) bone tissue
|
unorganized, porous appearance
|
|
|
Locations of spongy bone
|
1. interior of bones (covered by compact) 2. in long bones, spongy bone is found in epiphyses
|
|
|
Function of spongy bone
|
light weigh; withstands stress in different directions; may contain red marrow (for hematopoiesis)
|
|
|
Structure of spongy bone
|
no osteons, irregular lattice of thin plates of bone=trabeculae; spaces between trabeculae contain osteocytes, marrow and blood vessels
|
|
|
Where is articular cartilage found?
|
At the ends of bones, and between bones.
|
|
|
Bone is porous with channels for what two things?
|
Blood Vessels and Nerves
|
|
|
Where is compact bone found?
|
On the outside of all bones (It's thincker in the diaphyses than the epiphyses)
|
|
|
What is the function of Compact Bone?
|
It is strong and dense and resists stress.
|
|
|
What is compact bone composed of?
|
Osteons or Haversian Systems
|
|
|
What is the Central Canal?
|
It runs the lenght of the bone, is lined by endosteum, and contains blood vessels and nerves.
|
|
|
What are Lamellae?
|
Concentric rings of hard, calcified matrix around canal.
|
|
|
What are lacunae?
|
The spaces that house bone cells.
|
|
|
Where are osteocytes (bone cells) found?
|
in the lacunae
|
|
|
How are the Lacunae connected?
|
By canaliculi
|
|
|
What are canaliculi?
|
"Little canals" that connect lacunae, they also connect to central canals. Nutrients and waste diffuse through canaliculi between osteocytes and blood vessels.
|
|
|
What are Perforating (Volkmann's) Canals?
|
Canals the run perpendicular to bone's long axis, they have blood vessels, and connect periosteum to central canals to medullary cavity.
|
|
|
What does spongy (cancellous) bone look like?
|
It has an unorganized, porous appearance.
|
|
|
Where is spongy bone located?
|
The interior of bones, it is covered by compact bone. In long bones, it is found in the epiphyses.
|
|
|
What is the function of spongy bone?
|
It is lightweight, withstands stress in different directions, and may contain red marrow for Hematopoieses.
|
|
|
What is the structure of spongy bone?
|
There are no osteons, have trabeculae, and the spaces between trabeculae have osteocytes, marrow and blood vessels.
|
|
|
What are the different places where marrow located in adults and infants ?
|
Infants have marrow in spongy bone AND in medullary cavity. Adults have marrow in the head of the Femur & Humerus, some flat bones (sternum) and some irregular bones (Os coxa).
|
|
|
Where are marrow transplants drawn from?
|
Sternum and os coxa
|
|
|
What is the other type of bone marrow?
|
Yellor Marrow
|
|
|
Where is yellow marrow located?
|
All of the bone cavities where red is not located.
|
|
|
What is ossification?
|
replacing of other tissues with bone.
|
|
|
What are the skeletons of embryos composed of?
|
Hyaline cartilage and fiberous membranes. (They are shaped like future bones.)
|
|
|
When does ossification begin?
|
In the 6th week of embryonic development. (It never really stops)
|
|
|
What are the 2 types of ossification?
|
Intramembraneous and Endochondral
|
|
|
Where do Intramembraneous & Endochondral Ossification each occur?
|
Intramembraneous occurs in flat bones.
Endochondral occurs in almost all bones. |
|
|
What does Intramembranous Ossification begin with?
|
Fibrous connective tissue in membrane of Mesenchyme.
|
|
|
How is bone matrix formed in Intramembraneous Ossification?
|
Mesenchymal cells become osteoprogenitor cells and then osteoblasts. They form ossification centers, form bone matrix and then calcify.
|
|
|
What is an ossification center?
|
A cluster of osteoblasts.
|
|
|
What is an osteoid?
|
The part of the bone matrix made by osteoblasts.
|
|
|
What is calcification?
|
When calcium salts deposit around fibers.
|
|
|
How are spongy bone and periosteum formed?
|
Trabeculae (thin plates of bone) form and fuse together, spaces between fill with marrow and periosteum forms from more mesenchyme.
|
|
|
How is compact bone formed?
|
Periosteum remodels the surfaces of spongy bone into compact bone. The middle may be modeled into marrow cavity.
|
|
|
What direction to intramembranous ossification take place?
|
From the center of a bone out.
|
|
|
What are Fontanelles?
|
The spaces between the bones of the skull.
|
|
|
What are all the fontanelles?
|
Anterior, Posterior, Sphenoidal, Mastoid.
|
|
|
When do the fontanelles usually fuse?
|
By the 2nd year.
|
|
|
What is a suture?
|
The fustion site of any two bones.
|
|
|
What does Endochondral Ossification begin with?
|
Hyaline cartilage (the model or pattern present in the embryo).
|
|
|
What are the steps of Endochondral Ossification?
|
Hyaline cartilage is covered by perichondrium, it becomes converted into periosteum.
|
|
|
By age 5, where does cartilage remain?
|
Articular cartilage and epiphyseal plates (growth plates)
|
|
|
What is interstitial growth?
|
bone growth in length.
|
|
|
What occurs in interstitial growth?
|
New cartilage os formed at epiphyseal plates, old cartilage is converted to bone.
|
|
|
How much will long bones lengthen per year?
|
About 2-3 inches.
|
|
|
When does interstitial growth stop for Males and Females?
|
Females about 18, Males about 21
|
|
|
What is required for Interstital growth to occur?
|
You need the Growth homone, thyroid hormone (& other hormones), adequate nutrition, and sex hormones can speed things up.
|
|
|
What eventually will make the epiphyseal plate become the epiphyseal line?
|
A surge of sex hormone.
|
|
|
What is Appositional Growth?
|
Bone growth in diameter.
|
|
|
How does appositional growth occur?
|
Osteoblasts form new bone in periosteum (outside) while osteoclasts erode bone in endosteum (inside) and the bone and marrow cavity both increase in size.
|
|
|
What do osteoclasts do?
|
Destroy old bone (reabsorption)
|
|
|
What do osteoblasts do?
|
Make new bone.
|
|
|
How is bone growth controlled?
|
By hormones, nutrition, mechanical stress and gravity.
|
|
|
How do mechanical stress and gravity effect bone growth?
|
Stress on bones causes them to become thicker and heavier. Bones that are not used or stressed will atrophy because the body will use the nutrition elsewhere.
|
|
|
How are fractures in bones reparied?
|
Hematoma forms between broken ends, fibrocartillage callus forms, bony callus forms and then remodels back into bone (same as bone around it.)
|
|
|
What is a hematoma and where does it form?
|
A blood clot that fills space between broken ends of bones.
|
|
|
What occurs when the fibrocartillage callus forms?
|
Granulation tissue forms (fragile tissue) from capillaries and fibroblasts that secrete collagen and cartilage matrix, the callus protrudes and bulges beyond outer bone surface. (Usually takes 3-4 weeks)
|
|
|
What occurs during the Bony callus fomation?
|
Osteoblasts and osteoclasts migrate into callus and replace it with spongy bone. It still protrudes. (Usually takes 6-8 weeks if immobilized and circualtion is good)
|
|
|
What occurs during remodeling of bone?
|
Some spongy bone is converted to compact bone, excess bone on outside is removed, Medullary cavity is restored and this area may be slightly stronger than the surrounding area.
|
|
|
What is osteopenia and osteoporosis?
|
When the bone is reabsorbed faster than it is rebuilt.
|
|
|
What is Osteopenia?
|
The loss of bone due to aging.
|
|
|
What is osteoporosis?
|
The loss of bone mass to the point that it compormises normal function.
|
|
|
What are the symptoms of Ostoporosis?
|
Fragile easily fractured bones, lost height or teeth, a humpbacked appearance.
|
|
|
Who is affected by osteoporosis?
|
Everyone in old age can be affected, women are more common than men due to the loss of estrogen at menopause. Caucasian women are effected more often, and smaller women more than larger women.
|
|
|
When does bone mass loss begin to occur?
|
Usually between 30-40 years
|
|
|
How much do men and women usually lose?
|
Women lose 8% per decade, Men lose 3% per decade.
|
|
|
How can osteoporosis be prevented?
|
Exercise to stress bones, good nutrition (adequate Calcium, Vitamins C & D, and protein.
|
|
|
How can osteoporosis be treated?
|
Hormone replacement therapy, or Sodium Flouride, calcitonin or alendronate.
|
|
|
Name all the cranial sutures.
|
Squamous, Lambdoid, Coronal, Sagittal, and
Metopic (disappears by age 2). |
