Skeletal System Flashcards
(98 cards)
what is the skeleton composed of?
- Bone
- Cartilage
What are the 2 types of bone?
- Compact
- Spongy
What are the features of bone?
- Matrix is solid
- 35-45% water and organic matter
- 55-65% crystallized minerals (calcium/phosphate)
- Vascular
- Innervated
what are the 3 types of cartilage in skeletal system?
- hyaline
- elastic
- fibro
what are the features of cartilage?
- matrix is flexible
- 75% water
- collagen/elastin fibres in gel like substance
- gel like substance = chondroitin sulphate
- avascular
- no nerves
what is connective tissue?
cells and fibres immersed in a ground substance (matrix)
what are the 4 cell types in bone?
1) ostogenic cells
2) osteoblasts
3) osteocytes
4) osteoclasts

what are ostogenic cells?
undifferentiated cells
- other cells arise from this cell (become osteoblasts)

what are osteoblasts?
forms the matrix and collagen fibres but can’t divide
- makes the matrix to make our bones
- osteoblasts turn into osteocytes

what are osteocytes?
mature cells that no longer make up the matrix
- do not divide/ secrete matrix

what are osteoclasts?
huge cells that function in bone resorption
- breaks down bone matrix
- does not originate from ostogenetic cell

where is compact bone located?
shaft of long bones and external layer of all bones
what are some compact bone facts?
- organized and strong
- contains yellow bone marrow that stores triglycerides (fats)
what is the structure of compact bone?
- osteon/haversian system
- haversian canal
- lacuna/lacunae
- concentric rings/ lamellae
- canaliculi
- osteocytes
what is the osteon/haversian system?
concentric rings of calcified matrix surrounding haversian canal

what is lamellae?
the concentric rings surrounding the osteon/haversian system
what are lacunae?
empty spaces in osteon containing osteocytes
where are osteocytes found in compact bone?
lacuna
what is canaliculi?
small canals that connects one cell to another to let in nutrients/oxygen to cells in lacuna
- how osteocytes communicate
what is canaliculi filled with?
extracellular fluid
what is the haversian canal?
canal in centre of osteon/haversian system that blood vessels, lymph vessles, and nerves run through
where is spongy bone located?
end of long bones and inside flat bones
what does spongy bone look like?
- less organized
- comprised of trabeculae and space for red bone marrow

what is trabeculae?
thin plates of bone in a fence like structure positioned along lines of stress











