Bone (lesson 3) Flashcards
what can bone tissue also be known as?
osseous tissue
Bone tissue is a ____and ____, ____ tissue.
dense, supportive, connective
bone tissue contains ______ cells.
specialised
what does bone tissue produce?
solid matrix of calcium deposits
what fibres will you find bone tissue around?
collagen
how many types of cells do bones contain?
4
Name an organic compound in bone
collagen
bone is a ____ tissue
connective
What does the bone’s matrix consist of?
collagen fibres for flexibility and tensile strength
calcium for rigidity
hydroxyapatite Ca5(PO4)3 OH
Define ossification
The natural process of bone formation and the hardening of muscular tissue into a bony substance.
what can bone formation also be called?
osteogenesis
What is the first process in osteogenesis?
the development of hyaline cartilage
in the second stage of osteogenesis the hyaline cartilage ______ and the matrix is formed, then some of the matrix is _____.
grows, calcified
What is stage 3 in osteogenesis?
the development of the primary ossification centre
the primary ossification centre has a _____ bud and ______/____ cavity.
periosteal, medullary/marrow
in stage 4 of osteogenesis the development of the _______ _________ ______ in the ______ occurs.
secondary ossification centre, epiphysis
in the last stage of bone formation what two things are formed?
the articular cartilage and epiphyseal plate
where do bones lengthen?
the epiphyseal plate
bones grow from _____.
cartilage
When bone growing is complete what forms?
the epiphyseal line
Bones undergo constant remodelling from ___ __ ____ and _____.
adaption to stress and healing
What is dense/compact bone also known as?
cortical bone
what percent of bone in our bodies is cortical bone?
85%
name some components of compact/cortical bone
osteon/haversian system central/haversian canal lamellae lacunae with osteocytes canaliculi
what is spongy/cancellous bone known as?
trabecular bone
What percent of spongy bone do we have in our body (out of all the bones in our body)?
15%
what is trabecular bone made up of?
trabeculae
The outer layer of the periosteum is ____ and has an _____ network of _____ and ____ _____.
dense, irregular, nerves and blood vessels
what cells does the inner layer of the periosteum contain?
osteoblasts
How is the inner layer of the periosteum anchored to the bone?
by collagen fibres that penetrate into the bone
What canals connect the Haversian canals and also assist blood supply from the periosteum to the harversian canals?
Volkmann’s canals
What happens if calcium ion concentration increases by 30%?
neurons and muscle cells become unresponsive
What happens if calcium ion concentration decreases by 35%?
convulsions
Death may occur if the calcium ion concentration decreases by _____%.
50
calcium levels are closely regulated by ____ _________.
calcium homeostasis
What does PTH do to the kidneys?
It decreases the rate of excretion of calcium ions
When calcium ion concentration in the blood increases, _______ is released into the blood stream.
calcitonin
what does calcitonin inhibit?
calcitonin inhibits osteoclast activity
How does the release of calcitonin affect the kidneys?
It increases the rate of excretion of calcium ions
Name a nutritional bone disorder
rickets
As x-rays pass through the body, they are partially _____.
absorbed
The _____ the tissue, the greater the fraction of radiation that is _____.
denser, absorbed
What is osteopenia?
inadequate ossification
The prevalence and severity of osteopenia typically increases with _____.
age
What body parts are most affected by osteopenia?
epiphyses (end of long bones), vertebrae and jaw.
What is osteoporosis?
The reduction in bone mass sufficient to compromise bone function
What can osteoporosis typically lead to?
Bone fracture, leads to loss of independence and immobility
what gender is osteoporosis most common in (due to hormones)?
females
What happens immediately after a bone fracture? (stage 1 of fracture healing)
Extensive bleeding occurs, over a period of several hours, a large blood clot or fracture hematoma, develops.
what is stage 1 of fracture healing known as?
Fracture hematoma
What is stage 2 of fracture healing?
A callus forms
In stage 3 _____ occurs, this mean that the external callus becomes replaced by ___.
ossification, bone
In stage 3 what happens to fragments of dead bone and the areas of bone closest to the break?
They are removed and replaced
what is the final stage in fracture healing?
Remodelling, a swelling initially marks the location of the fracture, over time this region will be remodelled and little evidence of the fracture will remain.
