Normal structure of bone and bone cells Flashcards
What type of tissue is bone?
Specialised form of living connective tissue
How does the fibrous matrix in bone give it strength?
Allows bone to withstand high compressive loads
What is stored in bone?
Mineral ions
What is the most abundant mineral ion found in bone?
Calcium
What are the 2 types of bone?
Cortical/compact bone
Cancellous/trabecular/spongy bone
In cortical/compact bone, what is the proportion of bone compared to spaces?
High proportion of bone so there are few spaces
In cancellous/trabecular/spongy bone, what is the proportion of bone compared to spaces?
Low proportion of bone so there are lots of spaces
What type of bone causes a more severe bone fracture?
Cortical/compact
Why is a cortical/compact bone fracture more severe in post-pubescents than children?
Children can still change and regenerate cortical bone, but post-pubescents can’t
What is the trabeculae, that is found in trabecular bone?
Network of rods and plates
How can the substance bone matrix be described?
Non-living, intercellular
What component of bone makes up most of the bone mass?
Bone matrix
What collagenous protein is present in the bone matrix?
Type 1 collagen
What 3 non-collagenous proteins are present in the bone matrix?
Proteoglycan, osteocalcin, osteonectin
What is the function of type 1 collagen in the bone matrix?
Assembles into triple-stranded fibres that form 3D scaffold for bone cells and tissues to develop from
What are the 3 functions of proteoglycan in the bone matrix?
Aids regulation of collagen fibrogenesis, ion movement and forms compression-resistant networks between fibres
What are the 2 functions of osteocalcin in the bone matrix?
Binds to calcium, aids bone endocrine function (that can also affect other organs)
What is the function of osteonectin in the bone matrix?
Helps to influence bone mineralisation during formation as it binds HA and collagen so regulates calcium release (from HA)
In woven bone, what are 3 characteristics of the collagen pattern?
Random fibre orientation, immature form as cross-links haven’t formed between collagen fibrils to produce tight fibres, large and numerous osteocytes
What condition causes collagen to be laid down in an irregular way in woven bone?
Rapid new bone formation, such as in repair of a fracture
What are the 2 types of mature lamellar bone?
Cortical or spongy bone
Where is lamellar bone found in the body?
Almost whole of adult skeleton
What units is lamellar bone made up of?
Lamellae
In lamellae bone, is the collagen pattern in a distinct or random orientation?
Distinct
In a long bone, what is the cortex made of?
Compact bone ‘shell’