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Associated tissues

Bones

  • Provide the framework and internal core structure for the attachment of muscles
  • Bone is a living rigid tissue which forms the support structures for the rest of the body. The process of bone formation is called ossification.
  • The matrix of bone contains a dense arrangement of collagen fibres together with mineral salts of calcium, magnesium and phosphates.
  • The calcium salts give bone its hardness and rigidity while collagen fibres give bones its flexibility and strength.

Functions of bone

  • To serve as a firm support framework for the whole body.
  • To protect such delicate structures as the brain and spinal cord
  • To serve as levers, working with attached muscles to produce movement.
  • To serve as a storehouse for calcium salts , which may be reabsorbed into the blood if there is not enough calcium in the diet,
  • To produce blood cells in the red marrow.

Microscopic structure of a long bone

  • Numerous hollow tunnels called Haversian canals occur within the matrix of bone tissue and run parallel with the length of the bone. Under the microscope they appear as black circles against a lighterbackground.
  • Each Haversian canal is surrounded by concentric rings of compact bone called lamellae
  • Each of these layers contains a ring of fluid-filled cavities called lacunae. Each of these lacuna will contain a number of bone cells called osteocytes.
  • The lacunae are linked to each other and to the Haversian canal by a system of very tiny interconnecting canals called canaliculi. Strands of cytoplasm extend through these canals which supply the osteocytes with oxygen and nutrients and remove waste products
  • The Haversian canals, lacunae, osteocytes and canaliculi together form a unit called a Haversion System and a number of these systems make up compact bone.
  • Apart from osteocytes which are embedded in the lacunae of bone there are two other types of bone cells

Osteoblasts : Bone forming cells. These cells allow the bone to change and remodel its shape as the organism grows and responds to stresses. If a bone is broken or if strengthening is needed, bone cells lay down new tissue and repair damaged tissue

Osteoclasts: Special bone cells for destroying and reabsorbing bone tissue.

Cartilage

Main features

  • cartilage is a tough semi-transparent flexible tissue
  • it is enclosed by a fibrous capsule called the perichondrium
  • consists of living cells called chondrocytes which secrete a rubbery protein matrix called chondrin
  • chondrocytes occur in small fluid-filled spaces called lacunae which are scattered throughout the matrix.
  • There are no blood vessels or nerves in the matrix.

Cartilage and bone

Infant and young children do not have bones like those of adults. Their bones are made mostly of cartilage, a firm elastic fibrous material.

As the individual grows and matures, the cartilage is gradually replaced by bone cells which deposit crystals of calcium carbonate and calcium phosphate.

This process called ossification greatly increases the strength of the bone.

Bones usually continue to grow through adolescence. During this time a layer of cartilage still exists between the head and shaft at either end of thebone. The growth of the bone does not interfere with the way joints fit together.Eventually once all the cartilage has become ossified bone growth will stop

Types of cartilage

Hyaline Cartilage:

Appearance: glass-like, bluish-white in colour, few fibres present

Location:

  • at the ends of bones as articular cartilage
  • where the ribs are joined to the sternum
  • forms rings in the trachea
  • larynx and tip of nose
  • as temporary cartilage in bones.

Functions:

  • reduces friction at the joints.
  • allows a degree of movement during breathing
  • keeps the trachea open.
  • Forms permanent structures
  • Allows for bones to increase in length.

Fibrocartilage

Appearance: has numerous white collagen fibres in the matrix.

Location:

  • as cartilaginous discs between the vertabrae
  • in the rim of sockets of ball and socket joints
  • between the pubic bones

Functions:

  • act as shock absorbers
  • make the cavity deeper without hampering movement
  • allows for limited movement

Elastic cartilage

Appearance: has a network of yellow elastic fibres in the matrix.

Location:

  • in the pinna of the ear
  • in the epiglottis

Functions:

  • maintains the shape of the ear but also allows for changes in shape.
  • strengthens the epiglottis which prevents food from entering the trachea.

Ligaments

  • Ligaments consist of white collagen fibres and a network of yellow elastic fibres.
  • The collagen fibres are less orderly and more randomly arranged than in tendons and ligaments have varying amounts of elastic fibres.
  • Ligaments join bone to bone and they also control the degree of movement allowed between the two bones. This is achieved by the amount of elasticity in aligament i.e. a ligament will only stretch enough to allow a particular movement to happen.
  • The more elastic fibres in the ligament the greater the articulation between two bones. Thus the attachment of ligaments between bones keep the bones of a jointin position.
  • By restricting bone movement ligaments will prevent any dislocation during normal actions.

Tendons

Attach muscles to bones and facilitate the various positions of the body related to movement and balance.

  • Tendons consist of non elastic collagen fibres only.
  • These are densely packed, arranged in parallel bundles and are extremely strong, less flexible and more resistant to stress
  • The fibres give tendons a white shiny appearance.
  • There is a minimal amount of matrix present.

Questions & Answers

how do they get the third part x = (32)5/4
kinnecy Reply
can someone help me with some logarithmic and exponential equations.
Jeffrey Reply
sure. what is your question?
ninjadapaul
20/(×-6^2)
Salomon
okay, so you have 6 raised to the power of 2. what is that part of your answer
ninjadapaul
I don't understand what the A with approx sign and the boxed x mean
ninjadapaul
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
Salomon
I'm not sure why it wrote it the other way
Salomon
I got X =-6
Salomon
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
ninjadapaul
oops. ignore that.
ninjadapaul
so you not have an equal sign anywhere in the original equation?
ninjadapaul
Commplementary angles
Idrissa Reply
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Sherica
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Sherica
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Tamia
what is a good calculator for all algebra; would a Casio fx 260 work with all algebra equations? please name the cheapest, thanks.
Kevin Reply
a perfect square v²+2v+_
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Abdirahman Reply
algebra 2 Inequalities:If equation 2 = 0 it is an open set?
Kim Reply
or infinite solutions?
Kim
The answer is neither. The function, 2 = 0 cannot exist. Hence, the function is undefined.
Al
y=10×
Embra Reply
if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
Nancy Reply
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ramon Reply
Kristine 2*2*2=8
Bridget Reply
Differences Between Laspeyres and Paasche Indices
Emedobi Reply
No. 7x -4y is simplified from 4x + (3y + 3x) -7y
Mary Reply
is it 3×y ?
Joan Reply
J, combine like terms 7x-4y
Bridget Reply
how do you translate this in Algebraic Expressions
linda Reply
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
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. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
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Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
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Yasmin
what is the function of carbon nanotubes?
Cesar
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
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what is system testing?
AMJAD
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
AMJAD
what is system testing
AMJAD
what is the application of nanotechnology?
Stotaw
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
bamidele Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
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Source:  OpenStax, Siyavula: life sciences grade 10. OpenStax CNX. Apr 11, 2012 Download for free at http://cnx.org/content/col11410/1.3
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