Bone Flashcards
What are the primary functions of bone tissue?
- Support the body
- Storage of minerals
- Protection of visceral structures
- Locomotion
- Hematopoeisis
The area between the epiphysis and diaphysis is called?
Metaphysis
What are the primary growth centers of a long bone?
Diaphysis & metaphysis
What are the secondary growth centers of a long bone?
Epiphysis & apophysis
What is the MOST metabolically active part of a long bone?
metaphysis
The diaphysis of a long bone is metabolically ____
inactive
The epiphysis of a long bone is metabolically ____
active (less)
The hard, dense, strong bone that forms the outer layer of bone is called?
Cortical bone
The inner, spongy layer of bone is called?
Trabecular bone (AKA cancellous bone)
The cavity within the shaft of the long bones filled with bone marrow is called?
Medullary cavity
A dense fibrous membrane covering the surface of bones (except at their extremities) and serving as an attachment for tendons and muscles.
Periosteum
The inner membrane layer separating the marrow cavity and the cortical bone is called?
Endosteum
What percentage of bone is composed of organic material?
30%
What percentage of bone is composed of inorganic material?
60%
What is the primary organic component in bone tissue?
Type I collagen
What is the function of the organic material in bone tissue?
Adds tensile strength to bone tissue (makes it more elastic)
What is the primary inorganic component in bone tissue?
Hydroxyapatite
What is the function of the inorganic material in bone?
Adds more rigidity to bone tissue (allows for more compressive strength)
What byproducts are made from osteoblastic activity?
Alkaline phosphatase and osteocalcin
What bone cell is found in the marrow and periosteum and can develop into osteocytes or osteoblasts?
osteoprogenitor cell
What bone cell is an osteoblast embedded in bone matrix (lacunae) that maintains bone tissues?
osteocyte
What type of bone cell is responsible for producing and mineralizing bone tissue?
Osteoblasts
What bone cell ultimately controls the differentiation and maturation of osteoclasts?
osteoblast (production of RANKL)
What type of bone cell is responsible for the resorption of bone?
Osteoclasts
What bone cell comes from the monocyte/macrophage cell family?
osteoclast
What is the ratio of organic to inorganic material of bone in children? What are the properties of this bone?
1:1
plastic, flexible
What is the ratio of organic to inorganic material of bone in adults? What are the properties of this bone?
1:4
rigid
What is the ratio of organic to inorganic material of bone in elderly? What are the properties of this bone?
1:7
^rigid, fragile
What part of the stress-strain curve is characterized by bone being able to deform in response to stress and returning to original shape when the stress is removed?
Elastic Phase
What part of the stress-strain curve is characterized by the deformation of bone in response to stress, but will retain the permanent shape of deformation?
Plastic Phase
What part of the stress-strain curve is where the elastic phase changes to the plastic phase?
Yield Point
What part of the stress-strain curve is characterized by the failure of bone under stress?
Ultimate Yield Point
How do the stress strain curves of compact versus spongy bone compare?
- spongy (trabecular) bone has a greater plastic phase, more gradual slope
- compact (cortical) bone has a very steep slope, small plastic phase
Compared to normal adult bone, what bones would have a more gradual slope, with a longer plastic phase?
bones of children
Compared to normal adult bone, what bones would have a more gradual slope, with a shorter plastic phase?
bones with osteoporosis
What term describes unmineralized (organic component of) bone?
Osteoid
What are the 2 main components of lamellar bone?
- compact/cortical bone
- spongy/trabecular/cancellous bone
What are the major passageways running in the direction of the length of long bones, providing paths for blood vessels called?
Haversian canals
What term describes the connection between Haversian canals that runs in a perpendicular fashion?
Volkmann’s canals
What type of bone development involves the direct transition of mesenchyme to bone?
Intramembranous ossification
(eg., closure of fontanels)
What type of bone development involves the ossification of a cartilage model that was formed from mesenchyme?
Endochondral ossification
In endochondral bone development, what is necessary for the ossification of cartilage to occur?
Vascularization
Bone ____ describes the process of original bone development
modeling
Bone ____ describes the continual process of bone turnover
remodeling
Bone remodeling is guided by ____
Wolff’s law
Per Wolff’s law, ____ force will increase bone resorption.
Increased tensile (decreased compressive)
Per Wolff’s law, ____ force will increase bone deposition.
Increased compressive
Which cells produce alkaline phosphatase as a byproduct of their normal function?
osteoblasts
What is the remodeling unit of bone?
cutting cone
Bone remodeling is initiated by ____ activity
osteoclastic
