BONE Flashcards
What are ostoblasts and where are they located?
bone forming cells. always on the surface.
What is the function of osteocytes?
to maintain the bone matrix in mature bone
What color does the bone matrix stain with H&E?
acidophilic
What is the function of osteoclasts?
bone resorbing/digesting cells
What is the general process of intramembranous ossification?
mesenchymal cells –> osteoblasts –> osteoblasts form bone
What is the general process of endochondral ossification?
mesenchymal cells –> chondroblasts/chondrocytes –> calcification and death of chondrocytes –> osteoblasts form new bone on calcified matrix
Is cartilage tissue vascular or avascular?
avascular
how do cartilage cells recieve nutrients?
diffusion through the hydrated matrix (lots of proteoglycans!)
What is the best indicator that a long bone has attained its full length?
the disappearance/ossification of the growth plate
What are the 3 steps of an increase in the length of bone?
- Intersitial growth (new chondrocytes)
- calcification/death of newly made chondrocytes. Dead cartilage pushed into metaphysis
- Ossification of calcified cartilage in metaphysis
What are the zones of changes in the growth plate?
- Zone of resting cartilage cells
- Zone of proliferation
- Zone of hypertrophy
- Zone of calcification
- Zone of ossification
Explain the zone of resting cartilage cells
no morphologic changes in chonrodytes. Some cells proliferate and provide new cells below.
Explain the zone of proliferation
proliferation = pancakes!
prolfierated chondrocytes form columns of stacked cells
Explain the zone of hypertrophy
contains large chondrocytes. Nuclei within cells.
Explain the zone of calcification
Chondrocytes die, nuclei gone. provide scaffolding.
Explain the zone of ossification
mesenchymal cells differentiate into osteoblasts. newly formed osteoblasts begin to deposit bone on calcified cartilage
What is another word for the zone of ossification?
metaphysis
What is appositional growth of bones?
increase in width of bones
How do bones achieve appositional growth?
mesenchymal cells present in the inner layer of periosteum multiply and differentiate into osteoblasts
List the steps involved in an increase in the width of long bones
Periosteum –> differentitation of mesenchymal cells into osteoblasts –> osteoblasts form bone on surface –> osteoclasts remodel bone
Identify the cell
osteocyte
A. Identify the cell within the dotted area.
B. List one function associated with this cell.
C. Identify the cell indicated by the arrows.
A. Osteoclast.
B. Bone resorption.
C. Osteocyte (it is within the bone)
A. Identify the structure
B. identify the tissue
A. Periosteum
B. Bone
A. Identify the cell
B. Identify the cell
A. Osteoblast
B. Osteocyte
