Term
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Definition
very large, multinucleated bone-reabsorbing cells |
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Term
Where are osteoclasts found? |
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Definition
In indentations of the bone matrix that they make called resorption bays or Howship's lacunae |
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Term
What is the name of the cell that breaks down calcified cartilage? |
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Definition
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Term
What is the name of the cell that breaks down dentin? |
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Definition
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Term
What is the main organic component in the matrix of the bone? What does it do? |
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Definition
Collogen fibers, they help prevent breaking |
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Term
What inorganic component is known to give bones their hardness? |
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Definition
Calcium phosphate, also called Hydroyapatite |
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Term
This is known as a specialized connective tissue that contains cells and intercellular matrix |
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Definition
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Term
What are the three types of tissue bone contains? |
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Definition
Bone connective tissue, nervous tissue and blood CT, and cartilage in articular region of long bones |
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Term
The humerus is what type of bone |
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Definition
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Term
What type of bones make up the wrist |
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Definition
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Term
What kind of bone is the sternum |
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Definition
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Term
What types of bones are the skull and veterbra? |
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Definition
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Term
What type of bone is the patella (kneecap)? These bones develop within tendons. |
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Definition
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Term
What are the ends of long bones called? |
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Definition
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Term
What are the two names for the surface along the inner core of a long bone? |
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Definition
medullary cavity and marrow cavity |
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Term
The shaft of a long bone is called the...
a) epiphysis
b)odontoblast
c) growth plate
d) diaphysis |
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Definition
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Term
What is the difference between the endosteum and the marrow cavity? |
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Definition
The endosteum is the inner surface and the marrow cavity is the 3D area |
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Term
The outer surface of a long bone is called the what? |
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Definition
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Term
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Definition
the transition area between the epiphysis and diaphysis. There is columns of spongy bone in this region |
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Term
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Definition
epiphysis is the green portion |
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Term
Describe the lineage of cells that result in osteocytes. |
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Definition
Mesenchymal cells -> Osteoprogenitor cells -> Osteoblasts -> Osteocytes |
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Term
What is the function of osteoblasts? |
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Definition
build bone. They are involved in the mineralization of collogaen fibers and they synthesize and secrete organic bone matrix |
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Term
How do osteoblasts become osteoclasts? |
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Definition
as osteoblasts build the surrounding bone and become trapped in the bone, they differentiate into osteocytes |
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Term
What is the structure in the bone that osteocytes are housed in? |
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Definition
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Term
What are osteoclasts derived from? |
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Definition
hematopoietic stem cells -> macrophages -> osteoclasts |
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Term
After osteoclasts attach to a bone, what happens for the degradation of the bone to occur? |
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Definition
Osteoclasts attaches to "sealing zone" of bone matrix with ruffled border. Osteoclasts secrete HCL and protein digesting lysosomal enzymes from ruffled borders. Proteolytic enzymes stored in lysosomes of osteoclasts. |
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Term
What are the two architectural types of bone in adults? |
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Definition
Compact bone - dense outer layer, Spongy (cancellous) bone - internal network of bone. |
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Term
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Definition
Marrow that produces bloods cells |
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Term
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Definition
Marrow composed mostly of lipids and fats |
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Term
What anchors the periosteum to compact bone? |
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Definition
Transverse fibers known as Sharpey's Fibers |
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Term
Where is the periosteum not present? |
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Definition
Bone covered by articular cartilage, sesamoid bones found within tendons, and areas where tendons and muscle insert into bone. |
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Term
What is the network of the spongy bone called? |
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Definition
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Term
What is the tunnel running through the Osteon called? |
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Definition
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Term
What connects separate Haversian Canals? |
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Definition
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Term
What are the concentric circles in the Haversian System called? |
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Definition
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Term
How are osteocytes from different lamella connected? |
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Definition
Small tunnel-like structures called Canaliculus |
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Term
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Definition
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Term
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Definition
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Term
What are the symptoms of Acromegaly? |
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Definition
Increased bone formation in adults. Over production of somatotropin. Causes thickening of the bones, esp in the face. |
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Term
What is occuring during osteoporosis? |
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Definition
increased osteoclast activity in comparison to osteoblast activity |
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Term
Osteomalacia is an adult version of this disease and is caused by a lack of what? |
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Definition
Adult version of rickets, caused by deficiency of Vitamin D |
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Term
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Definition
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Term
What occurs in Paget's disease? |
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Definition
Excessive bone breakdown and formation which causes dense but fagile bone. |
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Term
Which part of the bone has fibrous and cellular layers like its cartiladge counterpart? |
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Definition
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Term
Why doesn't the periosteum cover the epiphysis regions in some bones? |
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Definition
Because the epiphysis could be covered in cartilage |
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Term
What is another term for the growth plate? |
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Definition
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Term
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Definition
The organic components of bone matrix. Unmineralized and composed of proteoglycans, GAGs, glycoproteins, and collagen |
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Term
Which of the bone cells does not divide? |
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Definition
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Term
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Definition
maintain protein and mineral content of matrix, help repair damaged bone, |
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Term
What is the space between the plasma membrane of an osteocyte and the wall of lacuna called? What is there? |
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Definition
This is the Periosteocytic space, filled with extracellular fuild rich in nutrients and exchageable Ca generated from bone during bone resorption by osteoclasts |
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Term
What does osteoclasts secrete when the are breaking bone? |
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Definition
HCL and lysosomal enzymes (Cathepsin K). HCL dissolves the inorganic matrix in the bone, Cathepsin K breaks down collagen and other matrix proteins |
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Term
Are osteoblasts enough for bone growth? |
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Definition
No, need a balance of osteoblasts and osteoclasts |
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Term
What are the main components of the bone matrix? |
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Definition
1/3 protein fibers (collagen type 1), 2/3 Calcium phosphate, and several glycoproteins. |
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Term
What glycoproteins are in the bone matrix? |
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Definition
osteocalcin, osteopontin, bone sialoproteins, and osteonectin |
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Term
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Definition
crystals that form in the bone. Made of calcium phosphate. |
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Term
What is the main organic component of bone and dentine? |
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Definition
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Term
What is (are) the main organic component(s) of enamel? |
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Definition
amelogenins and enamelins (no collagen) |
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Term
What is the difference between primary and secondary bones? |
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Definition
Primary form during fetal development and are seconday bones are found in adults. Primary have a low mineral content while secondary are more calcified and are stronger. |
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Term
What does the endosteum face? |
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Definition
medullary or marrow cavity |
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Term
What does the endosteum consist of? |
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Definition
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Term
Haversian canals are lined with what kind of cells? |
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Definition
osteoprogenitors and osteoblasts. Both are invovled in bone rebuilding |
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Term
Where does the spongy bone originate from? |
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Definition
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Term
What are other names for the spongy bone? |
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Definition
cancellous bone and trabecular bone |
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Term
What pathway do compact bone have than spongy bone don't have? |
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Definition
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