Bone structure and function Part 1 Flashcards
- Where does connective tissue originate from?
embryonic mesoderm
- How is connective tissue characterised?
Characterised by abundance of matrix with few cells when mature
- What is the extracellular matrix composed of
composed of:
- Collagen and elastin fibres
- Ground substance
Name 5 types of connective tissue cells
Fibroblast
Chondrocyte
Osteoblast
Myofibroblast
Adipocyte
- What is the function of a fibroblast?
secretes collagen and elastin for the ECM of most tissues
- What is the function of a chondrocyte?
secretes collagen II for the ECM of cartilage
- What is the function of a osteoblast?
secretes collagen I for the ECM of bone
- What is the function of an adipocyte?
storage and metabolism of fat
- What is the function of a myofibroblast?
secrete ECM and have contractile function
- What does reduced tensile strength from collagen disorders cause?
causes:
- tissue laxity
- joint hyper mobility
- susceptibility to injury
- What is bone?
Specialised connective tissue
- What 2 things does the structural strength of bone provide for the body?
-mechanical support
-protection
- What is bone a reservoir for?
Reservoir for calcium and phosphate in the body
- What role does bone play in regards to calcium?
role in calcium homeostasis
- What is the outside lining of a bone known as?
Periosteum
- Give 3 features of the periosteum
- Fibrous CT layer, limiting bone growth
- Carries blood supply and osteoprogenitor cells
- Not present at the joint ends of long bones
- What is the inner lining of a bone known as?
Endosteum
- Give a feature of the endosteum
Lines the interior of bones
- Where is bone marrow found in a bone?
medullary cavity
- What is compact bone arranged into?
osteons
- What is the dense outer shell of bone called?
compact bone
- What is compact bone parallel to?
parallel to the long axis
- What is 2 things is spongy bone also known as?
Trabecula bone
inner cancellous bone
- What is inner cancellous bone arranged into?
interconnecting trabeculae with spaces for bone marrow
- What are the spaces in trabeculae bone for?
spaces for bone marrow
- Give 3 features of woven bone
Immature
Haphazard fibre arrangement
Mechanically weak
- What is woven bone remodelled into after foetal development/fracture repair?
lamellar bone
- Give 3 features of lamellar bone
. regular parallel collagen arrangement
. strong
. all adult bone is lamellar bone
- What percentage of the bone matrix is organic?
25% organic
- What percentage of the bone matrix is inorganic?
66% inorganic
- What is the organic portion of bone called?
osteoid
- What are the 2 non-collagenous proteins in the organic bone matrix that we need to know about?
osteocalcin and osteonectin
- What is the function of osteocalcin
binds calcium together, increasing its local concentration
- What is the function of osteonectin?
binds calcium to collagen
- What is the name of the inorganic component of the bone matrix?
calcium salt-hydroxyapatite
- Give 3 features of the inorganic component of the bone matrix
66% of dry weight of bone
Calcium phosphate with some carbonate and fluoride
Deposited in collagen hole zones