Cartilage and Bone Flashcards
what are bone and cartilage an example of
skeletal connective tissue
where is cartilage found in the body
external ear
nose
intervertabral disc
articular cartillage in joints
costal
pubic symphysis
mensiscus
what are the bones of the skeleton
axial and appendicular skeleton
what are the different forms of cartilage
hyaline cartilage, elastic cartilage, and fibrocartilage
what features are common to all 3 cartilages
the ground substance, fibres and cells
what is the extracellular matrix
firm, solid, glassy gel
what do the physical properties of cartilage depend on
compositiono f the ECM and the type and arrangement of fibres
what is hyalin cartilage
the most common form of cartilage, and abundant ground substance. contains collagen fibres
what is lacunae
a small chamber in the matrix occupied by one or more chondrocytes
what are the features of elastic cartilage
highly flexible
found in outer ear/epiglottis
histologically similar to hyaline cartilage
elastic fibres are concentrated around the lacunae
collagen fibres are also present
what is hydroxyapatite
mineralised crystals of calcium and phosphate
are bones organs
yes
what do bones consist of
bone tissue
ct proper
adipose tissue
blood vessels
nervous tissue
articular cartilage
what are the different conformations of bone tissue
compact bone and spongy bone
what is cortical bone
compact bone
what is trabecular bone
spongy bone
what are the different cells of bone tissue
- osteogenic/ osteoprogenitor cell
- osteoblast
- osteocyte
- osteoclast
what are osteoprogenitor cells
bone cell precursors that give rise to osteoblasts
what are osteoblasts
cells that synthesis and secrete bone tissue known as osteoid. they also gives rise to osteocytes
what are osteocytes
cells that maintain mineralised bone tissue
what are osteoclasts
cells that resorb bone. they are derived from monocytes and macrophage lineage
what is the periosteum composed of
outer fibrous layer and an inner osteogenic layer
does spongy bone contain lamellar bone
yes
are there osteons in spongy bone
no
what are the spaces between trabeculae occupied by
red and yellow marrow, nerves, blood vessels and lymphatics
what is spongy bone lined by on the external surface
endosteum
what is osteoblastogenesis
bone formation
what is osteoclastogenesis
bone resorption
what are osteoclasts lineaged from
phagocytes
why may bones be remodelled
growth, mechanical stress, hormonal reasons and immunological reasons
what are some diseases in bones characterised by
unbalanced osteoclastogenic activity
what is periodontitis
a destructive inflammatory disease caused as a chronic immune response to oral bacteria which leads to the destruction of host tissues.
how does periodontitis lead to bone damage
there is immune mediated uncoupling of bone bone remodelling, increased osteoclastogenesis, and destruction of alveolar bone and subsequent tooth loss
what is osteomalacia
rickets
what causes rickets
failure of osteoid to mineralise adequately. dietary deficiencies like lack of calcium, phosohate and vitamin D can lead to the bones being weakened and prone to fracture.
which dental abnormalities is rickets associated with
enamel hypoplasia and delayed tooth eruption
what form of tissue is the skeleton formed from
skeletal connective tissue
what can the skeleton be divided into
the appendicular skeleton and the axial skeleton
which bones are involved in the appendicular skeleton
bones of limbs that provide attachment sites for muscles.
what is the function of the appendicular bones
facilitating movement
what is the function of hyalin cartilage in relation to bones
connecting the rib to the sternum
what are the cells found in cartilage called
chondroblasts and chondrocytes
what do chondroblasts do
secrete the extracellular matrix
what do chondrocytes do
maintain the extracellular matrix
what is the structure of cartilage extracellular matrix
firm, solid, and glassy
why is the extracellular matrix of cartilage firm
the presence of chondroitin sulphates
how can cartilage secrete waste
through diffusion
what is the perichondreum
a dense fibrous tissue surrounding the hyaline cartilage
what does the perichondreum attach cartilage to
various other tissues
is the outer layer of perichondreum present in articular cartilage
no
what is the difference between articular cartilage and hyaline cartilage
the presence of the outer layer of the perichondrium is not present in articular cartilage
what is the inner layer of the perichondreum
the cellular layers
what are chondrocytes
mature chondroblasts
where are elastin fibres found most densely
surrounding the lacunae
what does the ground substance of bone contain
chondroitin sulphate and hyaluronic acid
does the ground substance take up a large component of bone
no
what fibres are found in bone
type 1 collagen
what forms osteoid
ground substance and collagen
is osteoid mineralised
no
what percentage of bone is taken up by the osteoblasts, osteocytes and osteoclasts
2%
how is osteoid mineralised
deposition of hydroxyapatite
what is hydroxyapatite
mineralised crystals of calcium and phosphate
what is mineralised osteoid often likened to and why
reinforced concrete because of its hard and flexible nature - the collagen fibres give a framework to the brittle surface of the osteoid
where is red adipose tissue found in the bone
in the ends, known as the epiphysis
what is cortical bone
the dense, tough, smooth outer layer of bone
what is trabecular bone
inner part of the bone with a spongey/honeycomb build to it
why does bone have two different compositions
provides optimum strength for the least amount of weight
which bone cell has immune lineage
osteoclasts
what are the two distinct layes of periosteum
outer fibrous and inner osteogenic layer
what are the layers of bone tissue called
lamellae
what are lamellae
layers of bone tissue
what are trabeculae
the spikes within travecular bone
what are the spikes within trabecular bone called
trabeculae
what are osteons
cocentric layers of bone tissue
what are cocentric lamellae
the name given to each cocentric layer of bone tissue known as osteon
what do central canals contain
blood vessels, nerves and lymphatic vessels
how do osteocytess communicate with each other
canaliculi
what are interstitial lamellae
compact bones that lie betweeen osteons. they are remnats of old, remodelled osteons
why are osteocytes trapped in lacunae
to maintain the material they laid down as osteoblasts
what functional features found in corticol bone are not found in spongy bon
osteons and central canals
how is spongy bone arranged
in layers known as lamellae
what is each trabeculae lined externally by
endosteum
why is trabecular bone always being remodelled
to maintain the strength of the bone
what can bone remodelling be stimulated by
growth
mechanical stress
hormonal changes
immunlogical reasons
how can immunological reasons lead to remodelling of bones
inflammation in diseases like periodontitis can lead to an increase in osteoclastogenesis and then lead to destruction of bone
which component of cartilage is responsible for coferring signficant compression strength
chondroitin sulphate
are all cartilages avascular
yes
articular cartilage is a modification of which other type of cartilage
hyaline cartilage
what name is given to the outer fibrous connective tissue surrounding hyaline cartilage
perichondrium
what is the name for the small chamber in which chondrocytes are located
lucuane
elastic cartilage is histologically similar to which other type of cartilage
hyaline
which type of cartilage is dominated by dense bundles of collagen fibres
fibro
what are lacunae
small cavities where the chondrocytes are found
how are the scattered fibroblasts on fibrocartilage identified
by their elongated nuclei
what surrounds the tracheal hyaline cartilage
a perichondreum of connective tissue
give an outline on the histology of vertebral bone
contains both cortical and trabecular bone, however the latter takes up the majority.
what are haversion lamellae
concentric layers of mineralised bone matrix that radiate away from the haversion canal
what is the haversion canal
the central canal found in osteons that contain blood vessels and nerves. they also have osteoblasts on their surface
where is cortical bone located
near the surface of bone
that is lammellar bone
bone arranged in sheets. makes up 80% of compact bone and only 20% of trabecular bone
what are spicules
the small beam like structures found within trabecular bone that connect with each other to form a network of interconnecting spaces which contain bone marrow
where is woven bone found
mostly in trabecular bone that is developing, growing or healing. consists of randomly arranged collagen fibres
what kind of cytoplasm do osteoblasts have
basophilic
where is yellow adipose tissue found
in the shaft of the bone known as the diphysis
what tissues are found in the bone
- bone tissue
- connective tissue proper
- adipose tissue
- blood vessels
- nervous tissue
- articular cartilage
what is adipose tissue
red or yellow fatty marrow at the centre of the tissue, often found in the epiphysis and the diphysis of the bone
what is the function of fibrocartilage
to attach and connect vertebrae to each other and to limit the movement of the spine
what are lacunae
chambers where chondrocytes are found
why is hyaline useful for lubricating joints
the abundance of ground substance
what is hyaline useful for
lubricating joints
what feature do all the forms of cartilage share
they are avascular ie they do not have blood vessels
what does chondroitin mean
it is belonging or in relation to cartilage
what is the ground substance of cartilage predominantly made up of
chondroitin sulphate
what is the function of the elastic cartilage in relation to bones
can be found in the external ear
where can fibrocartilage be found in the skeleton
as pads that connect and protect individual vertebrae in the spine
what is the function of the bones in the axial skeleton
to protect organs
which bones are found in the axial skeleton
skull, vertebrae and ribs
what are lamellae
layers of bone tissue
what is fibrocartilage
an extrememly durable and tough form of cartilage with little ground substance. it is dominated by irregular dense collagen fibres
chondocytes are arranged in rows
pads of this cartilage lie between spinal vertebrae
what is the function of elastic cartilage
a flexible, avascular connective tissue that provides support and resistance to compression.
