Chap 5: Bone (Cells) (exam 2) Flashcards
What are the cell types in bone?
- Osteoprogenitor
- Osteoblasts
- osteocytes
- bone lining cells
- osteoclasts
what is the appearance of osteoprogenitor cells?
Flat
where are osteoprogenitor cells located
endosteum and periosteum
osteoprogenitor cells are derived from where?
usually- mesenchyme cells
possibly- chondrogenic cells
what is the function of osteoprogenitor cells
usually to change into another bone cell type aka osteoblasts
can osteoprogenitor cells can or can not under go mitosis
yes they can
Osteoblasts appearance is what?
cuboid to columnar
what is the location of osteoblasts
endosteum and periosteum
osteoblasts are derived from what cell
osteoprogenitor cells
What are the functions of osteoblasts
produce osteoid,
produce materials (matrix vesicles),
respond to PTH directly
in response to PTH osteoblast will do what?
they will produce a factor OPG (that cause the creation of new osteoclasts),
secrete osteoclast stimulating factor (reabsorb bone),
cause them to produce enzymes to condition bone for osteoclasts
can osteoblast undergo mitosis
no
Osteocytes have what appearance
conforms to lacuna
what is the location of an osteocyte?
surrounded by bony matrix
What is the function of osteocytes?
- maintain the matrix and monitor the matrix
- release factors to influence osteoblast activity
- release factors to cause the creation of new osteoclasts
can osteocytes undergo mitosis
no
Bone lining cells appear to be what shape?
flat
what is the location of Bone lining cells
in the endosteum
bone lining cells are derived from what?
usually-osteoblast
possibly-osteocytes
what is the function of bone lining cells
primarily to wait to become an osteoblast again
do bone lining cells go through mitosis?
no way
Osteoclast appear how?
large and multi-nucleated
osteoblasts are located where
endosteum and periosteum
osteoclasts are derived from what
Peri-osteoclasts (related to monocytes)
what is the function to osteoclasts
to reabsorb bone
bone reabsorption occurs where
in the subosteoclastic compartment
What are the steps at reabsorbing bone?
inorganic matrix dissolves first then the organic matrix goes next
Inorganics dissolve using what
strong acids (primarily carbonic acid)
The organic will break down fast due to what?
the low pH from the inorganics dissolving first
The organics are broken down by what
lysosomal enzymes
at the end of the organics breaking down what will be about original to not damage surrounding cells
the pH will be about normal
What are the two hormones that regular osteoclasts
PTH and Calcitonin
PTH will do what to osteoclasts
it will increase osteoclast activity view causing osteoblasts to secrete osteoclast-stimulating factor
Calcitonin does what to osteoclasts
will decrease osteoclast activity (off switch)
