Lecture 13- Skeletal System Pt 2 Flashcards
What is the area of growth called in a long bone?
Epiphyseal plate
On the _____ side, cartilage is formed
Epiphyseal
On the ____ side, cartilage is ossified (replaced with bone tissue)
Diaphyseal
What is the function of the reserve zone?
Anchor epiphyseal plate to osseous tissue of epiphysis
Contains small chondrocytes within matrix
What is the function of the proliferative zone?
Makes new chondrocytes
Contains stacks of slightly larger chondrocytes
What is the function of the maturation and hypertrophy zone?
Chondrocytes mature and grow
Chondrocytes are older and larger
What is the function of. the calcified matrix zone?
Chondrocytes become calcified and die
Contains mostly dead chondrocytes
What is the function of the ossification zone?
Calcified matrix connects epiphyseal plate to diaphysis
Bone grows in length when osseous tissue is added to diaphysis
What has to happen for bone to stop growing?
Chondrocytes in the epiphyseal plate stop proliferating AND bone replaces the cartilage
What process is responsible for longitudinal growth of long bone due to cartilage being ossified?
Endochondral ossification
What is appositional growth?
The increase in the diameter of bones by the addition of bone tissue at the surface of bones
What two things must happen for bone to increase in diameter
- Osteoclasts resorb old bone
- Osteoblasts produce new bone tissue through intramembranous ossification
Which cell type below has the longest life span
Osteoblast
Osteoclast
Osteocyte
Osteogenic cells
Osteocytes
Trapped in bone matrix and can survive entire lifetime
Which is not a function of the skeleton system?
Support
Movement
Mineral and energy storage
Digestion
Hematopoiesis
Digestion
Where does bone remodeling take place?
Basic multicellular unit (BMU)
What are the 5 steps in bone remodeling? What is the function?
- Origination- some injury to bone
- Activation-pre osteoclasts form osteoclasts
- Resorption- osteoclasts bind to bone tissue and release acidic contents
- Formation- osteoblasts form bone matrix/osteoid
- Mineralization- osteoid gets calcified and osteoblasts become osteocytes
Only Active Rats Find Mates
______ is the master regulator of bone remodeling
Osteoblast
Osteoclast
Osteocyte
Osteogenic cells
Osteocyte
Gives signals to osteoblasts and osteoclasts to coordinate their activity
Which part of the RANK-RANK-L-OPG system is solely used for bone formation?
OPG
Which part of the RANK-RANK-L-OPG-SOST system is used to clear bone tissue away?
RANK
RANK-L
SOST
RANK-L binding to RANK triggers the synthesis of _______
Osteoclasts
Promotes osteoclastogenesis
What does OPG inhibit?
RANK-L from binding to RANK receptor to form bone
What does SOST inhibit?
Osteoblasts/bone formation
Activates bone resorption
What is bone resorption?
The osteoclasts remove bone by dissolving the mineral and breaking down the matrix
What is a consequence of high bone density?
Difficulty staying afloat while swimming
