Hierarchical Bone

Hierarchical Bone
Hierarchical architecture and mechanical properties of the various constituents of the bone are
important to understand the origin of toughness and stiffness and their alterations with age and
disease.
3.1. Macrostructure: cortical and cancellous bone
At the macrostructural level, bone is divided into the cortical (or compact) and cancellous (or
trabecular) types based upon their degree of porosity or density. Histologically, it is composed of a
cortical bone wrapped around older cancellous bone having irregular, sinuous convolutions of
lamellae. It is still not clear whether cortical and cancellous bone matrices consist of the same
material or have intrinsically different mechanical properties. Based upon the nanoindentation
studies, on an ... Show more content on Helpwriting.net ...
However, cancellous bone material being much more active metabolically, is remodelled more often
than cortical bone, and hence, it is "younger" usually than cortical bone. Based upon the mechanical
measurements at the macroscale, cancellous bone tissue were found to have slightly lower values of
moduli as compared to the cortical bone. Cancellous bone, can be described in terms of structural as
the extrinsic properties of trabeculae and pores. The description of cancellous bone in terms of
material properties defines the trabecular struts and plates. Mechanical properties of both cortical as
well as cancellous bone at the macrostructural level usually vary from bone to bone and within
different regions of the same bone due to variation in mineralization level and apparent density
values.
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Skeletal Bone Research Paper
Bone Lit Review
Introduction
– Skeletal bone is a dynamic tissue structure that constantly undergoes changes and remodeling
throughout someone's lifespan. Skeletal bones is a mechanical support for locomotion and
protecting the organs. Muscle tendons and ligaments insert onto the bone. It is only present in
vertebrates.
– Bone tissue is made up mainly of fibrous collagen connective tissue surrounded by a calcium
phosphate–like mineral. It is hollow shaped structured that cannot swell or shrink. However, there
are living cells and blood vessels imbued within the bone tissue.
– This paper will discuss the composition and cells of bone, different types and organization of
bone, bone remodeling, bone development in children, and bone fractures ... Show more content on
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They undergo a mineralization process to calcify the bone into a harden material. First, the matrix of
the bone, a mixture of both collagen and water, plus other organic components are first laid down
first. Osteoblast cells secrete type 1 collagen, glycoproteins, proteoglycans, membrane–enclosed
vesicles with alkaline phosphatase and toehr associated enzymes as well as a product known as
osteoid into the matrix. The osteoblast secretions bind with calcium with high affinity and enzymes
hydrolyze phosphate ions from various macromolecules creating a high concentration of ions. The
high ion concetrations causes calcium phosphate crystals to form and grow to mineralize further into
a compound known as hydroxyapatite. Hydroxoapatie surround collagen fibers and merge into a
solid bony

A Brief Note On The Highland Beach Group
The Highland Beach group was a Paleo–Indian group, which means that they were most likely
hunter–gatherers. Hunter–gathers didn't cultivate nor herd animals so they almost certainly searched
around for plants and animals to consume. According to Arch of Coastal Palm Beach County article
states the bodies were buried in a sand mound (Wheeler, Kennedy, Pepe, 2002). This collection is
supposed to have a hundred twenty individual. Due to this kind of lifestyle they may have been
prone to diseases such as osteogentic sarcoma, osteomallacia, and lastly osteoporosis as a
consequence. For this study I must look at the femurs of individuals in F.A.U.'s Highland Beach
collection for any signs of osteoporosis and it's possible causes. If there are ... Show more content on
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An example would be infantile congenital hypothyroid is categorized with a notable lack of bone
ossification. Last is Osteoporosis, which forms part of the endocrine and metabolic diseases. It is a
skeletal condition that interferes with the captation of proteins and carbohydrates (Manual).
Figure 1.
Osteoporosis is a generalized, progressive diminution of bone tissue mass per unit volume, causing
skeletal weakness, even though the ratio of mineral to organic elements is unchanged in the
remaining morphologically normal bone. Histologically there is a reduction in cortical thickness and
in the number and size of the trabeculae of cancellous bone, normal width of the osteoid seams.
Bone reabsorption is increased, bone formation appears to be normal but be defective. The major
clinical manifestations of osteoporosis are bone fractures. The most common form of metabolic
bone disease is the idiopathic osteoporosis in sub–adults of both sexes with normal gonadal
functions. Post menopausal osteoporosis, of course between 50 & 70 years of age, and is six times
more common in women than men (pathologia). There is a much greater loss of trabecular bone
(cancellous) than cortical bone. It is largely responsible for vertebral crush fracture cooles' fractures.
Senile osteoporosis occurs mainly in individuals older than 70 years of age, is twice as common in
women compared to men. It affects both trabecular and cortical

Case Study Osteoporosis
Case Study 1. What is meant by a "complete, comminuted, intertrochanteric fracture of the right
hip"? A. Complete – refers to a fracture completely through the bone: B. Comminuted – refers to a
fracture in which the broken bone has shattered into several smaller pieces: C. Intertrochanteric –
refers to a fracture located between the greater trochanter and lesser trochanter of the femur: 2.
Draw a picture of what you think Margaret's fracture looks like. 3. The radiologist reported signs of
osteoporosis. Describe the characteristics of an osteoporotic femur as seen on an X–ray. (How does
it differ in appearance from a normal femur?) Osteoporosis is marked by a decreased bone volume.
Loss of spongy ("cancellous") bone is greater than ... Show more content on Helpwriting.net ...
cartilage–forming cells) and lay down a fibrocartilage splint (i.e. soft tissue callus) | C. bony
callus(starting 3 to 4 weeksafter the injury) | – osteoblasts begin to replace the fibrocartilage splint
with spongy and compact bone, forming a bulge that is initially wider than the original bony shaft |
D. bone remodeling | – as the patient starts to use (or bear weight on) the bone, the bone starts to
remodel along lines of maximal stress (this remodeling process requires the activity of both
osteoblasts and osteoclasts | 7. During her long recovery, Margaret is advised by her physician to
begin weight–bearing as soon as she can. How does weight–bearing influence the process you
described in question #6? (Be specific in your answer and describe what weight–bearing does to
bone at the microscopic level.) The most popular hypothesis regarding the effect of weight–bearing
on bone remodeling is called Wolff's law . Wolff's law states that bone grows and remodels in
response to the mechanical stresses placed upon it (e.g. from muscle pull or gravitational pull).
Thus, bone is laid down along lines of maximal stress. This is presumably why: A. long bones are
the thickest midway down the diaphysis, where the stresses are the greatest. B. curved bones are the
thickest where they are most likely to buckle (e.g. note the thick greater

Bone Loss Analysis Essay
In addition to DXA, quantitative computed tomography (QCT) has also been developed to quantify
bone mineral content and to assess bone loss (29). The main advantage of this technique is that
cancellous bone can be exam¬ined separately from cortical bone (30). In particular, in QCT a thin
transverse slice through the body is imaged: the image can be segmented to give a quantitative
mea¬sure of volumetric BMD (unlike DXA) of vertebrae, as¬sessing the cancellous bone
independently of surround¬ing cortical bone and possible aortic calcifications (31). QCT can be
performed to the spine (usually two to four vertebrae between T12 and L4 inclusive) on
conven¬tional whole body CT scanners, or to the appendicular skeleton at peripheral sites (radius,
tibia) using smaller, less expensive, dedicated peripheral CT scanners (pQCT). In QCT ... Show
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However, although this technique has important ad¬vantages over DXA, it has also disadvantages,
some of which are common to DXA. First, it has been shown that BMD values depend on the bone
marrow composi¬tion: this factor could provide an underestimation of bone mineral content values.
Second, the radiation dose induced by a QCT scan of a hip is significantly higher than that of DXA
(1 mSv vs 10 μSv), which limits the applicability of the technique not only for screening but also for
standard diagnostics (36). In addition, this technique has difficulties with quality control, high cost
compared with DXA, necessity of well–trained technicians for scan execution (37). For the clinical
use of QCT and pQCT in the man¬agement of osteoporosis, the International Society for Clinical
Densitometry (ISCD) published its official posi¬tion in 2008 stating that QCT of spine and pQCT of
radius predict vertebral and hip fractures, respectively, in post–menopausal women

A Description Of The Biology Of Bone
4
Chapter 2
Background
2.1 Introduction
Chapter 2 will describe the essential background information needed to understand this
thesis project. A description of the biology of bone will be provided first and its focus
will be limited to femurs and tibiae, since those are the structures we have used
throughout this project. As well, we will briefly describe the analysis techniques that are
currently used to evaluate bones. Furthermore the theory behind the used technique and
instrumentation will be addressed. Previous bone studies using transcutaneous in vivo
Raman spectroscopy will also be described, as well as the differences between them and
the present thesis project.
2.2 Bone Structure and Composition
Bones ... Show more content on Helpwriting.net ...
12 Both the cortical and
trabecular structures provide ions like calcium phosphate, phosphorous, sodium and
magnesium that are basic to maintain the homeostasis of the bone.
Figure 1. Hierarchical structure of bone. Cotical bone is made of osteons (10–500 µm). Osteons are
composed of concentric lamella (3–7 µm) and a Haversian cannal. A lamella is composed of
mineralized collagen fibers, which are made up of collagen fibrils (0.5 µm each). A fibril is made up

of collagen molecules and apatite nano–crystals.11
The three major components of bone tissues are: type I collagen, water and dahllite
crystals. 13 Dahllites are plate–shaped carbonated apatite crystals, which have "small but
significant amounts of impurities such as HPO4, Na, Mg, citrate, carbonate, K". 14,15 The
apatite crystal lattice is then responsible for the degree of mineralization in bone tissue.
Type I collagen is the primary matrix component and its molecules are secreted by
Cortical bone
Osteons
Haversian canal
Concentric lamella
Mineralized collagen fibrils
Collagen molecule
Apatite nanocrystals 6 osteoblasts, these molecules will then arrange into collagen fibrils and
subsequently to
collagen fibers, which are the basis to lamellae.
Type I collagen despite being the primary protein is not the only one present in
bone tissue, which also contains non–collagenous proteins.

Structure And Functions Of The Skeletal System
TASK 1– Skeletal system Produce an information project that can be displayed around a sports club
or for athletes to give information on the different structures and functions of the skeletal system. A.
Describe the main functions of the skeletal system (P1) Functions of the Skeleton Support– the
skeleton acts as frame for the body and keeps us upright, it provides shape and is the main structural
frame for the body. Protection– the skeleton provides the protection for the vital organs in the body.
For example, the rib cage protects the heart and lungs. Another example would be the cranium; it
protects the one of the most import vital organs in the body, the brain. Movement– the skeleton
enables movement. It provides a large surface area for muscle attachment. When skeletal muscles
contract, they pull on bones at a joint to produce movement. Produce Blood Cells– the skeleton
enables red and white blood cells to be produced in the marrow cavities of larger bones of the body.
Red blood cells make haemoglobin and transport oxygen and carbon dioxide around the body. White
blood cells help protect the body against infections. Bones such as the femur and the pelvic girdle
produce blood cells. Fat and Mineral storage– the bones in the skeleton store many minerals. The
main minerals they store are calcium and phosphorus which strengthen the bones. Leverage– the
bones in the skeleton provide the attachment for muscles. The muscles attached to the bones provide
the power

Techniques Used For Human Skeletal Development Of Bone And...
Introduction
The objective of the course and the first laboratory experiments were to familiarize with the
practical skills in physical anthropology. And enable the students of Analysis for human skeletal
remains to identify, locate, describe and analyze the types of cells, tissues and structure of bones as
well as the formation of enamel and dentine.
The first practical session dealt with the microscopic identification of different structure in growth
and development of bone and enamel as well as dentine formation. The other aims of the practical
class was to be conversant with the microscopic identification and description of the cells, tissues in
the bone development, and overall function of the bone.
Materials
The materials used for the present laboratory exercise was comprised of
 Optical light microscope
 Slides
Compact bone, ground preparation
Decalcified preparation
Developing bone
Early dental gum (Observe only)
Late dental gum (Observe only)
Dental cap
Later dentine formation
Enamel formation
Tooth ready to erupt (Observe only)
Out of these only four slides were required to draw for the lab exercise. Moreover, the practical class
aims at preparing the diagrams of the selected slides. This required colored crayons, pencils, and
drawing sheets. The slides for the examination were prepared by our lab assistant or Teaching
assistant (Ms. Emily Peschel).
Methods
Optical (light microscope) was used to study and examine bone materials i.e.

Fracture Case Study Jenny's Fracture
1a] A fracture refers to a bone or cartilage that has attained too much pressure and stress that causes
a break in the bone or cartilage. Diseases such as osteoporosis and brittle bones disease can be the
cause of a fracture as your bones are weaker and not as tough. Jenny's fracture on the left humerus at
the proximal diaphysis was caused by an overload of stress from the large object falling down. 1b]
The proximal refers to the point of attachment where the bone connects.
1c] Diaphysis is known as the main and mid–section of the long bone.
2] There are four main types of bones. Jenny's has fractured her long bone which is the left humerus
at the proximal diaphysis, her flat bone which is occipital bone and an irregular bone at the 3rd ...
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In brains context, due to the rapid increase in body temperature the skeletal muscles would try
regulate an internal body environment. The general anaesthetic caused the patient to experience
effects of malignant hyperthermia. Brian's temperature will increase because the contracting muscles
will alter the energy and turn it into heat.
2] The steps of events and cell location that leads to a release of calcium for muscle contraction, is
produced by an electrical impulse which was caused by a stimulus. The impulse causes the muscle
membrane to have a charge which then makes the calcium ions leave from the sarcoplasmic
reticulum. When calcium and troponin are attached to each other it makes tropomyosin which move
away from the actin filaments which allows the contractions to occur
3] The receptor of the anaesthetic is located in the sarcoplasmic reticulum. Due to the general
anaesthetic Brian experienced the symptoms of malignant hyperthermia which causes the skeletal
muscles to severely contract which affects the levels of calcium in the muscles. The ryanodine
receptors have an increase rate of metabolic activity caused by the build–up of calcium in the
skeletal muscles. Due to the increase rate of metabolic reactions Brian will have severe muscle
contractions and a rapid increase in body

The Structure Of The Skeletal System
The skeletal system, while appearing inert at first glance, is a dynamic organ responsible for a
number of vital functions in the body; including but not limited to providing protection and support
to other organ systems, as well as permitting movement through collaboration with the muscular
system. At the cellular level, bone provides a reservoir of growth factors and cytokines, maintains
the acid–base balance and mineral homeostasis, and is the site of hematopoeisis. Like other
connective tissue, bone has both a cellular and an extracellular matrix component. The matrix is
made up of collagen fibers and noncollagenous proteins, with type I collagen accounting for ~90%
of total protein, and the noncollagenous osteocalcin, osteopontin, and bone sialoprotein, and others
making up the other 10%. In contrast with other connective tissue, the extracellular matrix of bone is
mineralized physiologically, though the deposition of layers of carbonated hydroxyapatite. This
mineral component, making up 50–70% of bone, provides bone 's characteristic mechanical rigidity
and strength (Clarke 2008). Elasticity and flexibility are due to the organic matrix, which makes up
another 20–40%, lending bone incredible resilience without compromising its strength, and another
5–10% of bone is water.
There are two major types of bone; trabecular (also called cancellous or spongy), and cortical (also
called compact). Cortical bone is denser and hard, whereas trabecular bone is a honeycomb network

Osteocytes's Role In Bone Homeostasis
Osteocytes are the most abundant cell type in human bones and play a fundamental role in bone
homeostasis. Representing 95% of all mature bone cells and have the longest lifespan in all bone
cells, up to decades, osteocytes are the key to bone integrity1. They are initially derived from
osteoblasts, residing within bones and take part in bone metabolism through excessive
communication with other bone cell populations, including osteoblasts, osteoclasts and most
importantly, osteocyte progenitors. Osteocytes secrete soluble signalling factors that regulate both
bone formation and bone dissociation. Osteocytes have a stellate shape, with cell body of around 15
micrometers. In mature bones, osteocytes form circular structures termed osteons, ... Show more
content on Helpwriting.net ...
Intramembranous ossification mainly forms the flat bones of the face, the clavicles, and the bones of
the skull. In this pathway, the bones ossify directly from multipotent mesenchymal cells, or in other
words, the mesoderm (Fig 2). Compared to its counterpart, intramembranous ossification is not
currently well understood4.
Figure 2. Intramembranous Ossification. The mesenchymal cells give rise to a centre of ossification.
The bone cells in the ossification centres proliferate rapidly and move outward until the whole
structure slowly progresses into spongy and compact bones. This structure of spongy bone doesn't
arrange the cells into

Cancellous Bone Structure
STRUCTURE OF LONG BONES:
Hyaline cartilage: covers the end of the bone, smooth surface stops the bones and absorbs shock.
Epiphysis: this is the extremity name of the bones.
Cancellous bone: is known as spongy bone, its help to store red bone marrow in the blood cells.
Epiphyseal plate: is a line across the bone starting from where the bone grows in length.
Diaphysis: this is the shaft of the bone.
Compact bone: It surrounded by yellow bone marrow in the diaphysis and gives strength to the
hollow part of the bone.
Periosteum: This is absent of hyaline cartilage, but covers surface of the bone, ligaments and
tendons.
Medullary cavity: is the space inside the diaphysis that contains yellow bone marrow. THE
FUNCTIONS OF THE

Osteoporosis In The Body's Skeletal System
The skeleton is a very important part of the body and is separated into two sections: the
appendicular and axial skeleton. The appendicular is any part of the body that attaches to another
bone. Those include but not limited to the legs, arms, and hands. The axial bones are located within
the center of the body like the spine and ribs. Bones in these two regions are classified into different
shapes including long, short, irregular, and flat. Flat bones are found in the skull and ribs. The flat
bones in the human body are flat and thin often curved. Short bones are the same size length wise
and width wise. Those are found in the wrist and ankle. Irregular bone does not go into a category.
This bone can be found in the pelvis. Lastly, is the ... Show more content on Helpwriting.net ...
Osteoporosis is a disease affecting the bones and is found mostly in women. This occurs when one's
body either makes too much bone, makes too little bone, or even both resulting in the bones
becoming weak and breaking easily. This is causes by the bone having larger holes meaning the
bones "have lost density or mass and that the structure of 'one's' bone tissue has become abnormal"
(National Osteoporosis Foundation 1984). Detecting the disease is done by performing a bone
density test. This diagnoses osteoporosis and help to guess the amount of bone located throughout
the body. There is a lot one can do to prevent this disease or even slow down the growth. It is
important to eat a balanced diet, participate in exercise regularly, and consume foods that are
essential to bone health. An environmental factor that affects the skeletal developments is a disease
known as achondroplasia. This is "a rare genetic disorder characterized by an unusually large head
(macrocephaly) with a prominent forehead (frontal bossing) and flat (depressed) nasal bridge; short
upper arms and legs (rhizomelic dwarfism), unusually prominent abdomen and buttocks; and short
hands with fingers that assume a "trident" or three–pronged position during extension (NORD
2015). This is causes randomly and affects both males and females and has quite a few health
problems related to this. One gets a lower muscle tone or even water on the brain.

The Human Skeletal Structure Of Ligaments
The Human Skeletal System The human skeletal anatomy is a mesmerising and complex structure
of ligaments that attach all 206 bones together, along with tendons that attach muscles to the bones
and also cartilage. All of the components are involved with the fundamental functions that are
essential to how the human body works and reacts. The skeleton assists in protecting the body's
organs, provides attachment sites for the musculature system that allows locomotion, also other
upholding the physical shape of the body, and protects vital organs such as the brain, spinal cord,
and heart. Defined as being in two parts, the axial and appendicular skeleton. The axial skeleton ...
Long Bones
The femur, ulna and radius, tibia and fibula, humerus and phalanges (bones of the fingers) are all
long bones. The periosteum is the outer layer of the long bone that consists of three main parts:
Epiphysis: consists of compact (cortical) bone on the outer layer and cancellous (spongy) bone
located within the lower and upper areas of the inner layer.
Diaphysis: Is the shaft and middle part of the bone that is made up of tougher also denser cortical
bone.
Both diaphysis and epiphysis are separated by epiphysis cartilages that solidify when the growth of
a human is totally completed.
Overall all the long bones make up the majority of a person's weight, especially the femur. The
femur is the longest bone within the human body and bares most of a person's weight and also helps
to maintain balance of the skeleton.
Short Bones
Short bones are all practically equal in length and width of each other that all consist of the same
structure with the outer layer being cortical bone along with the inner layer of cancellous bone that
contains red bone marrow. The bones that are identified as short bone are as follows:
Carpals: Carpals make the wrist.
Tarsal: Make up the ankle.
Flat Bones
Flat bones consist of a layer of trabecular (spongy/cancellous) bone between two thin layers of
compact bone. The flat bones are of a flattened shape, not rounded. Examples of flat bones are as
follows, the skull and ribs. Flat bones do contain marrow, but are not a bone marrow

Explain The Structure And Development Of The Skeletal System
Explain the structure and development of the skeletal system.
The skeletal system is made up of 206 bones which protects, support and allows the human body to
move. The skeletal system also consists of tissues such as; tendons, ligaments and cartilage – these
components connect the bones together which results to the posture and framework of the body. The
skeletal system of a new born baby consists of more bones than an adult (roughly 300 bones); this is
because the bones have not been joined together by the tissues. As the human body grows, the
smaller bones are joined together to form larger bones in the body. Teeth are also a part of the
skeletal system – they are made of dentin and enamel. Enamel is the strongest substance in the body.
The structure of the skeletal system on a whole consists of ligaments, tendons, cartilage, joints,
sockets and bones which all interrelate and play a massive part in the functioning of the body by
protecting the internal organs and allowing the body to maintain balance and posture.
Ossification is the process whereby new bones are created and developed by cells named
osteoblasts. An example of ossification is when cartilage is transferred to bone however, factors
determine the transformation. Calcium and the consumption of vitamin D will allow the process of
ossification to occur efficiently so that the bones can harden and the chances of fractures and breaks
can be prevented.
Bones are sturdy to hold a person's body fat however, they

The Effects Of Osteoporosis On The Development Of The Disease
Osteoporosis is typically a silent disease characterized by low bone mass and decreased bone
density ending by fractures that occur following no or at least minimal trauma. Osteoporosis has
multiple pathophysiologic mechanisms that interact in the development of the disease (1, 2). The
disease simply results from the imbalance between bone resorption and bone formation. Increased
bone resorption or decreased bone formation may lead to osteoporosis. Bone is made of collagen
and mineral components. The former gives bone its flexibility and energy–absorbing capability,
while the later gives bone its stiffness and strength. Imbalances can impair bone quality and result in
reduced bone strength and subsequently fractures.
Bone mass increases ... Show more content on Helpwriting.net ...
So the bone mass in older adults equals the peak bone mass achieved by age 18–25 minus the
amount of bone subsequently lost.
The process of bone remodeling may be considered a preventive maintenance mechanism that
maintains a healthy skeleton because of continually removing older bone and replacing it with new
bone. When this balance is altered, resulting in greater bone removal than replacement, bone loss
occurs (5).
Menopause and advancing age play the main role in this imbalance. With the onset of menopause,
the rate of bone remodeling increases.
Oestrogen deficiency
Accelerated bone loss can be affected by hormonal status as occurs in perimenopausal women.
Gonadal deficiency can impact elderly men and women and can be secondary to various disease
states and medications. Bone loss in women accelerates rapidly in the first years after menopause.
Osteoblasts, osteocytes, and osteoclasts all express estrogen receptors.
Estrogen deficiency can affect bone density by(5):
1– Up–regulates osteoclast progenitor cells.
2– Cause increased recruitment of higher numbers of preosteoclasts.
3– Increased activity and lifespan of mature osteoclasts.
4– Estrogen affects bones indirectly through cytokines and local growth factors
Aging
Aging interacts mainly with bone deposition than bone resorption. The supply of osteoblasts, which
deposit bone, as compared to demand is progressively declining with aging. After the third decade
of life, bone

The Skeletal System ( Include Joints, Types Classification...
MAUREEN REID – STUDENT I.D: REIM0115; TASK M; CONFIRM PHYSICAL HEALTH
STATUS.
The Skeletal System (Include Joints, Types classification and ROM)
INTRODUCTION Human beings have an endoskeleton which means the structure or skeleton is
inside us and we grow around it as it accommodates growth.
Comprised of;
Bones (206)
Joints / Articulation
Connective Tissue
See Skeleton labelling Diagram attached
FUNCTIONS OF THE SKELETAL SYSTEM
Supports soft tissue and is the framework of the entire body (scaffolding)
It provides the attachment points for muscle and ligaments
Protects delicate vital organs such as the brain, heart, lungs, and spinal cord.
They are the levers for the movement created by muscles that are attached to them
They store minerals such as calcium phosphorus which they release to the body as needed
They store lipids in the bone marrow which is used as energy
They produce Blood Cells in the red marrow
Bone Structure
Bones are not only thick and hard, they are also slightly elastic. Without elasticity they would break
too easily. They are composed mainly of bone tissue or osseous tissue. The skeletal system is very
dynamic as the bones are changing all the time, they remodel themselves depending on usage or
functional demand therefore the structure and function of the skeletal system are

Scientific Discussion Paper on the Human Skeletal System
The Human Skeletal System
Introduction
The human skeletal system is comprised of both fused and individual bones; supported and
supplemented by ligaments, tendons, muscles and cartilage. The skeletons purpose is to protect and
support the delicate internal organs and provide a framework that allows the body to stand upright
and move. It also produces blood cells and stores minerals that our body needs to function
effectively.
The skeletal system is a very important part of the human body. Without the skeleton humans would
be immobile and even a small impact on the head or chest would cause serious injuries, to the
internal organs.
The skeletal system is very complex. It contains many elements that work in union together in order
for ... Show more content on Helpwriting.net ...
Some examples of flat bones are the scapula (shoulder blades), the sternum (breast bone), cranium
(skull), coxae (hip bone), pelvis and ribs.
The anterior and posterior surfaces of flat bone are formed of compact bone to provide strength for
protection, with the centre consisting of cancellous bone and various amounts of bone marrow. Flat
bones contain the largest amount of red marrow.
Irregular Bones– These are bones in the body which do not fall into any other category, due to there
non–uniform shape. Examples of this type of bone are the vertebrae, sacrum and mandible (lower
jaw). They primarily consist of cancellous bone, with a thin outer layer of compact bone.
Sesamoid bones– Sesamoid bones are usually short or irregular bones imbedded in a tendon. These
bones are usually present in a tendon where it passes over a joint. There main function is to protect
the tendon from damage. Examples of sesamoid bones are the patella (knee cap) and the pisiform
(smallest of the carpals).
Anatomy & Physiology– Ligaments, Cartilage & Tendons
Ligaments– These are strong bands which connect bones to bones at the joint. They are elasticised

to allow the movement of that joint, but are strong enough to stop movement outside the normal
range.
Cartilage– This is a soft cushioning substance which covers the ends of the bones. It acts as a shock
absorber and reduces the rubbing

Exploring the Skeletal System Essay
Exploring the Skeletal System
The precise number of bones in the adult human skeleton varies from one person to another, but on
average there are 206 bones varying shapes and sizes. The skeleton is divided into two main parts.
The central bones of the skull, ribs, spin (vertebral column) and breast bone (sternum) form the axial
skeleton. The bones of the arms and legs, along with the shoulder blade (scapula), collar bone
(clavicle) and pelvis make up the appendicular skeleton.
The cylindrical, linked vertebrae of the spinal column offer strong, bony protection for the spinal
cord. Aided by muscles and ligaments, the vertebrae support the skull and hols the body upright.
The spin has a ... Show more content on Helpwriting.net ...
Ribcage
A bony cage within the chest shields the heart, lungs and other organs. There are 12 pairs of ribs, all
attached to the spine. The upper seven pairs of "true ribs" link directly to the sternum by costal
cartilage. The next two to three pairs of "false ribs" attach indirectly to the sternum by means of the
cartilage linked to the ribs above; the remaining "floating ribs" have no links to the sternum. (the
lowest ribs are hidden by the liver and stomach).
Pelvic bones
The pelvis varies in shape according to sex. Overall, the structure has a similar appearance in both
sexes but takes a shallower and wider form in females to allow for the specialised function of
childbearing. Arranged in a ring, the fused pelvic bones provide a strong foundation for the upper
body and protection for parts of the reproductive systems.
Bones of the skull
Two separate sets of bones from the intricate structure of the skull. The eight bones enclosing and
protecting the brain are called the cranial vault. Another 14 bones make up the skeleton of the face.
In adults, all of the lower jaw, (mandible) are locked together by joints known as sutures. Theses
seams are visible on the surface of the skull as lines between the bones.
Viewed from the front, the most prominent skull bones are the

Intervertebral Triangle Bone Research Paper
Cranium
The cranium is the part of the skull that encloses the brain. (14)
Mandible
The mandible is the jaw or the jaw bone. (15)
Sternum
The sternum is a long flat bone located in the middle of the chest. (16)
Intervertebral Disk
An intervertebral disk is a pad of cartilage that fits between two vertebrae's. (17)
Ribs
Ribs are a series of curved bones that are connected with the vertebrae and take place in pairs,
humans have 12 on each side of the vertebrae body. Some of the pair are connected to the sternum
and form the thoracic wall. (18)
Sacrum
The sacrum is a triangular bone that lies just beneath the spine. The sacrum has five sections that are
joined together into one large bone. The coccyx joins to the bottom of the sacrum. The sacrum ...
(39)
Spongy/Compact Bone
Compact bone is the hard external layer of all bones that protects and surrounds the medullary
cavity filled with marrow.
Spongy or cancellous bone tissue consists of trabeculae that are arranged as rods or plates with red
bone marrow in between. (40)
Bone Marrow
Bone marrow is a soft substance that fills bones and it comes in two types. Type A is yellowish bone
marrow that consists chiefly of fat cells and is found especially in the cavities of the long bones.
Type B is a reddish bone marrow that contains little fat, is the chief site of red blood cell and blood
granulocyte formation, and occurs in the normal adult in cancellous tissue especially of certain flat
bones.(41)
Major Joint Types Description Location in the Body Diagram
Gliding Gliding joints are formed between two bones that meet at flat surfaces. They allow bones to
glide past one another in any direction. (42) Wrists, Ankles and Spines. (43)

Condyloid The end of one bone is shaped like an oval that fits into the other that is shaped like an
elliptical cavity. Condyloid joints allow movement in every direction except axial. (45) Wrist,
Forearm and the Hand.

Simple Epithelial Tissues
Epithelial Tissue:
Epithelial tissues line and cover the organs, capillaries and body cavities within the body. Epithelial
tissues can be broken down into four types: Simple Squamous, Simple Cuboidal, Transitional and
Stratified Squamous. Epithelial tissues are named first by their amount of layers they have, and
second by the cell shape.
Simple Epithelial tissues are composed of only one layer of cells, while stratified tissues are
composed of more than one layer of cells. Squamous tissues are flat as compared to cuboidal or
cube shaped tissues. The final tissue is called columnar, and these cells have a column like shape.
Simple Squamous:
Simple squamous tissues are composed of one flat layer of cells. Simple squamous cells line air
sacs, kidneys and ... Show more content on Helpwriting.net ...
Epithelial tissue can be broken down into four types of tissues: simple squamous, simple cuboidal,
transitional and stratifies squamous. While these tissues differ in structure, they work together to
complete the main function of protecting the organs of the body. Connective tissue supports,
insulates, and stores energy for the body. Theses tissues can be broken into four types of tissues:
adipose, hyaline cartilage, areolar and bone. These four tissues collaborate to ensure the proper
protection, insulation and energy storage for the organs, bones and muscles of the human body.
Muscle tissue provides the body with movement through the contraction and relaxation of muscles.
These tissues can be further divided into three types of tissues: smooth muscle, skeletal muscle, and
cardiac muscle. Each type of muscle provides movement for the different parts of the body,
including the heart, muscles, bones and the movement of food and liquids in the digestive tract.
Finally, the nervous tissue controls the messages that are sent throughout the body and forming the
nervous

Essay On Weight Of The Rats
The researchers obtained 36 female rats that were 5 weeks old. These mice were randomly divided
into three diet groups, low sodium (LS), normal sodium (NS) and high sodium (HS). The rats were
weighed on a weekly basis for a total of 60 days. By weighing the rats on a weekly basis, the
researchers were able to determine that there was no significant difference in weight between the
three dietary groups, (figure 1). The main conclusion that one can get from this data is that sodium
does not have a large effect on the weight of the rats. Since sodium does not cause the rats to gain a
significant amount of weight it can be concluded that the bones of the rats will not develop
differently due to them weighing more than normal.
The rats ... Show more content on Helpwriting.net ...
Since the area and thickness of the trabecular bone were increased in the rats fed the low sodium
diet, it can be inferred that there would also be an increase in osteoblasts. This same
histomorphometry test was also performed on the fifth lumbar vertebra (LV5). The researchers
discovered, similar to the PTM test, that the low sodium group of rats had an increase in trabecular
bone area. In addition to an increase in the trabecular bone area, the researchers also witnessed an
enhanced bone formation through an increase in osteoblast number and activity in the low sodium
group, (Table 5). The third bone that had the histomorphometry analysis performed on was the
cortical bone in the middle part of tibia shaft (TX). Unlike the other two bones, the researchers
determined that there was no statistical significant change in the parameters of this bone in any of
the three diet groups, (Table 6).
Furthermore, the researchers also conducted a RT– PCR test. The RT–PCR test was conducted to
determine the expressions of osteogenesis genes mRNA. In this experiment, the run–related
transcription factor 2 (Runx2), osteocalcin and osteopontin, were all tested with the amplification of
housekeeping β – actin as the control. After, the products of the PCR were analyzed with 2%
agarose gel electrophoresis. The Runx2 transcription factor was the first to be tested. The results
showed

Cortical Bone Fusion
Due to a powerful corrective force in the 3–dimensional plane and improvement the stability of
spinal fusion constructs[1–3], the pedicle screw has been trusted and applied by majority of the
orthopedic and neurosurgeons. But the diameter of the thoracic pedicle is small, the thoracic spinal
cord and large vessels are adjacent to the pedicle, so the screw misplacement in thoracic has the
potential for serious complications, such as spinal cord or nerve root injury, and the inferior vena
cava, the thoracic duct, the lungs, the sympathetic chain endanger[2, 4, 5]. In an attempt to minimize
these risks, multiple techniques and difference start points have been described for placement of
these implants, for example, the freehand technique[5–9], Funnel Technique[10], open–lamina
technique[11], in–out–in technique[12], minilaminotomy technique[13], and percutaneous pedicle
screw technique[14].
Sterba et al[15] found that the screw inserted vertically without convergence showed greater pullout
load than traditionally technique. Santoni et al[16] report the cortical bone trajectory (CBT) in 2009,
which meant a more medial–to–lateral directed. The cortical bone trajectory (CBT) technique is a
theoretical benefit to the fixation of osteoporotic vertebrae which involves maximizing the thread
contact with ... Show more content on Helpwriting.net ...
CBT screw that is inserted through a more medial starting point by following a more vertical
trajectory showed greater pullout load[30] and similar ROM to traditional pedicle trajectory
screw[18]. CBT technique has four major advantages: 1. Direction with caudocephalad path
sagittally and laterally directed path in the transverse plane protects the screw away from the nerve
tissue. 2. It needs less tissue trauma and less recovery time.3. Osteopenic or osteoporotic patients
will earn more advantage[18–20, 31, 32], 4. The incidence of postoperative radiculitis[33]

Periodontal Therapy Essay
The goal of periodontal therapy is to provide the patients with a dentition that functions in health
and comfort for the remainder of their lives. Ideally, periodontal therapy should resolve
inflammation, arrest progression of disease, maximize patient comfort, maintain aesthetics, and
regenerate lost periodontal support1.
Periodontal regeneration is defined histologically as regeneration of the tooth's supporting tissues,
including alveolar bone, periodontal ligament and cementum over a previously diseased root
surface2. Great strides are being made to achieve this goal using bone grafts and various other
regenerative procedures3. With the exception of blood, bone is the most frequently transplanted
tissue in the human body. Virtually every operative day, orthopaedic surgeons, neurosurgeons,
craniofacial surgeons and periodontists need to fill bony defects or augment deficient bone. The
major types of commonly used bone graft materials include autografts, allografts and alloplasts. ...
Alloplasts are osteoconductive; i.e., they act as a scaffold and support new bone growth. But, they
neither generate new bone nor induce new bone formation. Later, studies reported that the ceramic
alloplast, bioactive glass, in addition to being osteoconductive, bonds directly to bone

The Ailment, Diagnosis, And Treatment Of 72 Year Old...
In the following case study I will discuss the ailment, diagnosis, and treatment of 72 year old
Margaret Donavan. In her case she was brought into the emergency room after suffering from a fall.
After the fall she was unable to get herself up but only suffered injury to her right hip. She was also
very alert and responsive at the scene. She had no previous history of any health issues besides
hypertension which she was taking medication for.
1. What is it meant by a "complete, comminuted, intertrochanteric fracture of the right hip"?
After being taken care of by physicians Margaret Donavan was diagnosed with a complete,
comminuted, intertrochanteric fracture of her right hip. In a complete fracture, it means that the bone
is broken ... Show more content on Helpwriting.net ...
When a femur becomes osteoporotic, it is the outer layer of the bone around the epiphyses and
diaphysis, which begins to thin. This is the compact bone. In the distal and proximal epiphyses there
would also be a loss of the cancellous bone. This is where the spongy bone is. When a bone is
osteoporotic, a person becomes more susceptible to suffering from a bone fracture. On an x–ray, an
osteoporotic femur doesn't look as dense as a normal femur x–ray. In some of them you can see the
larger spaces that are made in the trabeculae of the bone. This is the part that has a spongy
appearance. In a normal femur the spaces in the spongy bone are smaller and dense. In the
osteoporotic bone, the spaces are larger, which makes the bone more fragile. It doesn't have as
strong of a structure as a normal bone would.
4. Describe the microscopic features of osseous tissue that normally help long bones withstand
lateral stress without breaking.
When lateral stress is placed on the femur there are two different types of impact. The first one
causes compression of the bone on the side of the bone during impact. The second one causes
stretching on the opposite side of the bone during impact. When these two actions work together
they actually cancel each other out which takes away the need for compact bone in the middle area
of the femur. With this action, the middle area of bone

Task 1: Bones And Connective Tissue
Task 1 – Bones and Connective Tissue
1.1 Explain the structure and composition of bone tissue
A long bone is composed of 6 main parts. The diaphysis, epiphyses, metaphyses, articular cartliage,
the periosteum and medullary cavity. (Tortora and Derrickson, 2011).
The epiphyses are the proximal and distal ends of a bone that consists mainly of spongy bone.
(Tortora and Derrickson, 2011). Originally the epiphyses are separated from the diaphysis by a layer
of cartilage that later fuses together through ossification. (CollinsDictionary [online], 2012).
The articular cartilage is a connective tissue that covers the part of the epiphysis where the bone
comes together to form a joint, also known as an articulation. Articular cartilage allows bones to
glide over each other creating very little friction and also makes it easier for ... Show more content
on Helpwriting.net ...
When the bone has reached maturity the marrow is transformed into yellow bone marrow. (Jarmey,
2004).
Blood supply to the nutrient arteries of a long bone occur through the nutrient foramina, the nutrient
foramina aids in the growth and nutrition of bones. (Vinay and Arun, 2011).
The endosteum is a connective tissue that protects cavities in long bones. The endosteum covers the
surface of cancellous bone and the medullary cavity, unlike the periosteum the endosteum is not
dense irregular connective tissue. (Clark, 2005)
The periosteum is also a connective tissue composed of an outer fibrous layer of dense irregular
tissue and an inner osteogenic layer. The periosteum protects and repairs the bone while also
enabling tendons and ligaments to form an attachment with the underlying bone. (Tortora and
Derrickson, 2011).
1.2 Explain the functions of bone
The skeletal system has 6 main functions and makes up 18% of the overall weight of the human
body. (Tortora and Derrickson, 2011)

The Relationship Between Osteoporosis And Osteoporosis
Osteoporosis, also known as porous bone, is a disease characterized by low bone mass and structural
deterioration of bone tissue which leads to bone fragility and an increased risks of the hip, spine, and
wrist. Both men and women are affected by this (although it affects women more) but it can be
prevented and treated. In the United States, more than 40 million people either already have
osteoporosis or at a high risk because of low bone mass.
Sir Astley Paston Cooper was a famous English physician, anatomist, and surgeon who first
discovered the association between fractures and bone density reduction because of aging which
created the base for discovering Osteoporosis. Another person who helped with the discovery of
osteoporosis was Jean Lobstein. Around 1833, Lobstein was the first person to medically describe
the pathological condition and appearance of Osteoporosis. He described the condition as, "One
with holes in the bone associated with fragility". He was also the one who named the disease.
Another important discovery of the disease is the relationship between osteoporosis with the
postmenopausal state, which was discovered by Fuller Albright. Albright discovered that there is a
direct relationship between the lack of estrogen after menopause and the development of
osteoporosis. After menopause, bone breakdown outrun the building of new bone. Early menopause,
usually before the age of 45, and any prolonged period in which hormone levels are low and
menstrual

Essay on Muskosceletal Physiology
1. Define the following terms, used in the case and also in associated questions:
a. Hemorrhage
Associated with a large loss of blood. In the case it is the extreme amount of blood lost from her arm
wound. Hemorrhage's can be internal or external
b. Fracture
A fracture is a break, in this case a break in the patients humerus, occipital bone and 3rd Lumbar
vertebral body
c. Proximal
Closer to the origin of the body. In this case the fracture at the proximal diaphysis means the part of
the shaft closer to the origin of the humerus (the shoulder)
d. Diaphysis
The shaft of the bone which surrounds the medullary cavity. In this patients case the diaphysis
(shaft) of the humerus has been fractured 2. One way bones are classified is by ... Show more
content on Helpwriting.net ...
Compact bone contains Haversian Systems, which are in concentric circles called lamellae.
Haversian system contains a blood supply and the periosteum is located on the outside
5. Most connective tissue, including bone, is highly vascular. Which anatomical structures in Mrs.
Morgan's compact bone house blood vessels? What sign or symptom in Mrs. Morgan's case is
directly related to disruption of these structures by her bone fractures? How is the sign or symptom
related to these anatomical structures?
The Haversian system houses the blood vessels in Mrs. Morgan's compact bone. The bone tissue
sticking out the skin, the bruising and the extensive bleeding from the arm are the signs and
symptoms related to the disruption of these structures by her bone fractures. The bleeding and the
bone tissue sticking out of the skin shows how the blood vessels within the Haversian system, such
as the periosteal arteries supplying the outer area and the nutrient artery which supplies the inner
part of bone have been disrupted. The disruption of these arteries within the Haversian system will
then make Mrs Morgan's humerus susceptible to avascular necrosis.
6. Within days after a fracture, a "soft callus" of fibrocartilage forms. What fibers are found in this
type of cartilage? Identify the cells required for fibrocartilaginous callus formation and list their
functions.
Soft Callus cartilage is formed 1–3 weeks after a

The Structure Of The Hip Joint
The hip joint is involved in movement and support of the body. Describe how the structure of the
tissues associated with the joint enable it to function effectively.
Analysing the structure of the hip joint will discover the importance of the joint and the way it helps
to support, stabilise, strengthen and create movement. Areas that will be explored are the skeletal
system, different types of joints and all the tissues involved at the hip joint.
The skeletal system has five main functions which consist of support, movement, protection of
organs, blood cell production and mineral release and storage. The skeletal system is made up of
two parts, the Axial skeleton and the Appendicular skeleton. The Axial skeleton includes of the
skull, spine and ribcage. The Appendicular is made up of the arms, legs, pelvic girdle and pectoral
girdle. The human skeleton is composed of bones and joints. A joint is where two bones meet to
enable movement. Hinge, pivot, gliding, saddle, ellipsoid and the ball and socket are all different
types of joints which can be found in the human body.
Joints are classified by their structure; the hip joint is classified as a synovial joint. As shown in
image 1 the synovial joint has a joint cavity which lies between the two bones. This contains the
synovial fluid that lubricates the joint. The fluid is produced by the membrane which lines the
cartilage called the synovial membrane. In certain joints small sack structures called bursas hold the
synovial

Structure Of Skeletal System Of The Human Body
Structure of Skeletal System
The human body is made up of 206 bones held together by ligaments, whilst joints provide mobility.
Ligaments are a band of tough, flexible connective tissue which connects two bones. The skeleton
forms a frame at which the internal organs rest and over which muscles and skin is layered over.
The bones of the human skeleton are divided into 2 groups: axial and appendicular skeletons. The
axial skeleton forms the axis of the body and it includes the bones of the skull, ribcage and the
spine. These bones are there to support, protect and carry other body. For example, the spine is a
part of the axial skeleton and it protects the spinal cord.
The appendicular skeleton is made up of the bones of the upper and ... Show more content on
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Flat bones– Thin, flattened and slightly curved. They have 2 outer layers of compact bone with
cancellous tissue between them. The sternum and scapula are flat bones.
Irregular bones– Complex shapes that fit none of the other categories of bone because of their odd
shape. The facial bone and vertebrae are some examples.
Sesamoid bones– Specialised function: they make joint movement easy and resist friction. They are
covered with a layer of cartilage as they are found where bones articulate. Although they look small,
sesamoid bones vary in size. The largest is the patella.
Location of major bones
The human skeleton consists of groups that contain one or more major bones.
Skull– the bony framework of the head consisting of facial and cranial bones which form the
cranium. The skull protects the brain.
Shoulder girdle– This consists of 4 bones, two clavicles and two scapulae. The clavicle connects the
humerus to the torso. An end of the clavicle is connected to the sternum and the other end is
connected to the shoulder blade.
Chest– The chest is made up by the ribs and sternum and it protects the heart and the lungs. The
sternum is a flat bone that is found in the middle of the chest. The ribs are thin and flat and there are
24 bones in total to make up the ribs (12 pairs). The first seven pairs are connected to the spine and
the sternum by cartilage. The next 3 pairs are attached to the

Endochondrial Ossification: Development Of New Bone
Endochondrial ossification is the term used for the development of new bone. Bone growth and
remodelling takes place on a continual basis, ossification lengthens and thickens bone and therefore
the process of ossification is used throughout life as well as during the period after bone fracture.
Endochondral ossification, this type of bone development involves cartilage models, which are then
replaced with bony tissue. This takes place at the embryonic stages; 8 weeks into development,
condroblast secret cartilaginous matrix which will from the hyaline cartilage for bone development.
The lacunae trap the condrablast and this is all surrounded by the perichondrium.
The next stage is when the condracytes enlarge it begins to calcify and form

Periosteum
Periosteum
Periosteum is a dense layer of connective tissue. It is very thin and is on the outside of the bone. It
plays a vital role in growth and repair. It is divided into two sections, an outer layer and inner layer.
The inner layer contains osteoblasts which helps with the increase of the width and length of other
bone types. [13]
Compact Bone/ Spongy
Compact bones are also called cortical bone. Cortical bone is one of the two different bones found in
the body. It is covered by periosteum and is lined with endosteum. These bones make up eighty
percent of the human skeleton. The remainder is cancellous bone (spongy bone) it has a spongy
appearance and is shaped like a cylinder. It is so hard that surgeons would have to use a saw to cut

Spongy Bone Essay
Bone is made up of two types of structure which are the compact bone and the spongy bone.
Compact bone lies over spongy bone and makes up most of a bone's diaphysis, it consist of
compactly arranged osteons which is the Harvesian system. Compact bone able to protect, supports
and resist stress. Spongy bone makes up most of the mass short, flat and irregular bones and is also
found at the epiphyses of long bones. It stores marrow and provides some support. The size of the
bone grow throughout childhood and adolescence as our body produces more bone than it loses. At
some point in life, human will be at their peak bone mass density (BMD) which is the end of the
bone growth. For normal human being, the BMD usually stays constant as the break down and
regeneration of bone is equal. However, for certain people, the bone loses is more than the
regeneration and production which then cause osteoporosis. ... Show more content on
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Cancellous bone is more active and is broken down and regenerated more quickly than compact
bone. Because of this, cancellous bone is more likely to be affected when the break down and
regeneration of bone are out of balance in osteoporosis. The cells that are responsible for the BMD
to stay constant is osteoblasts and osteoclasts. The function of osteoblasts is that it produces new
bone matrix in a process called ossification while osteoclasts are cells that remove and recycle bone
matrix. For a normal bone, there is a balance between the action of osteoblasts and osteoclasts but in
osteoporotic bone, the activity of the osteoclasts in removing bone matrix is faster than the
osteoblasts can form a new bone matrix. This results in a net bone lose. Osteoporosis can also lead
to thinning of both the compact bone and cancellous bone which makes bone more fragile to

Surgical Sur Surgical Dislocation
Surgical dislocation of the hip gives a sheltered intends to treat FAI. It is conceivable to completely
assess the femoral head–neck junction, and to examine the labrum and adjacent acetabular cartilage .
An entire 360º perspective of the acetabulum can be obtained . With a blunt probe, the articular
cartilage assessed and the integrity of the labrum and the articular cartilage is determined. This
methodology gives access to perform osteochondroplasty and labral reattachment as required. By
restoring the congruency between the femoral head and the acetabulum, this approach might permit
the patient to come back to appeal exercises without encountering the manifestations and dynamic
joint obliteration seen with FAI. [22]

The Skeletal System Essay
The skeletal system includes the osseous tissues of the body and the connective tissues that stabilize
or interconnect the individual bones. The bone is a dynamic tissue. Throughout the lifespan, bone
adjusts to the physiologic and mechanical demands placed on it by the processes of growth and
remodeling. Bone serves the organism at multiple levels: As a system, bones permit the organism to
locomote effectively and to maintain posture by bearing loads without deformation, by providing
rigid attachment sites for muscles and acting as a system of levers to amplify small movements. As
an organ, bones protect the viscera and house the hemopoietic tissue (red marrow). As a tissue,
bones serve as a reservoir of readily mobilizable calcium, an ... Show more content on
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The calcium salts of bone represent a valuable mineral reserve that maintains normal concentrations
of calcium and phosphate ions in body fluids. In addition, fat cells within marrow cavities store
lipids that represent an important energy reserve. The bones of the skeleton function as levers that
direct and modify the forces generated by skeletal muscles. The movements produced range from
the delicate motion of a fingertip to powerful changes in the position of the entire body. Osseous
tissue contains specialized cells, cell products, and a fluid matrix. The distinctive solid, stony nature
of bone results from the deposition of calcium salts within the matrix. Crystals of calcium phosphate
account for almost two–thirds of the weight of the bone. The majority of bone mineral occurs in the
form of hydroxylated calcium phosphate crystals
(Ca 10 [PO 4 ] 6 [OH]2 ) referred to as hydroxyapatite. The remaining third is dominated by
collagen fibers, with osteocytes and proteoglycans contributing only around 2 percent.
Calcium phosphate crystals are very strong, but inflexible. They can withstand compression, but the
crystals are likely to shatter when exposed to bending, twisting, or sudden impacts. Collagen fibers
are extremely tough, but quite flexible. They can easily tolerate stretching, twisting, and bending,
but when compressed they simply bend out of the way. In bone, the collagen fibers

Case Study Of Osteoporosis
Osteoporosis is a disorder of bones that affects bones making them low in bone mass fragile and
will lead to bone fracture. Bone fracture will easily occur as this disease cause the matrix inside the
bone become weak and brittle.Bones can become so brittle due to activities such as coughing can
cause fractures.According to Macgill (2015) the origin of the word osteoporosis explain the
condition of 'osteo' is for bone and 'porosis' means porous that resulting in weakness. At this
condition, the bone tissue is mineralized normally, but the production is not enough to preserve the
normal skeletal architecture. 80% of women and 20% men of 28 million American are affected with
the osteoporosis. Approximately, women with the age of 50 will develop osteoporosis. Thin bones
are the cause of 1.5 million fractures a year. As in Malaysia, the statistic shows that osteoporosis
related to fractured is the common health problem especially in elderly.. ... Show more content on
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It also protect soft internal organs for an example brain and heart from injury. Skeleton with muscle
is strong bones that can enable the body to move freely. Individuals who is at increase risk for
fractures may be difficult to heal because of the weakened bones. This can lead to loss of mobility,
the inability to retain independent living and even death. Osteoporosis can gives a huge effect to
human skeletal due to decreased mineralization of the bone. Human skeletal consist of two types of
bones which is compact bones and spongy bones. Compact bones is a bone that has a solid outer
surface while spongy bone is inner bone that less dense than compact bone which has many holes
like sponge. A spongy bone does not have osteon.The matrix forms an open network of trabeculae.
Healthy bone is dense enough to support and protect body and to handle stresses of movement and
minor injuries while osteoporosis has abnormally thin bones with larger holes on spongy

A Brief Note On The Highland Beach Group
The Highland Beach group was a late southeastern prehistoric aboriginal Florida population (ca.
800–1200 AD) (Yaşar I. M., 1989). The Highland Beach group was a Paleo group, which means that
they were hunter–gatherers. Hunter–gathers didn't cultivate nor herd animals so they almost
certainly searched around for plants and animals to consume. According to Arch of Coastal Palm
Beach County article, the individual were buried in a sand mound (Wheeler, Kennedy, Pepe, 2002).
This collection is supposed to have a hundred twenty individual. Due to this kind of lifestyle they
may have been prone to diseases such as osteogentic sarcoma, osteomallacia, and lastly osteoporosis
as a consequence. For this study, I must look at the femurs of individuals ... Show more content on
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To get a better understanding of this disease the differences between at least three Osteo–related
diseases must be discussed. First is Osteomalacia, this is determined in the period of growth, due to
disorders in absorption, utilization or lack of vitamin D and calcium. The bone becomes bland, this
is a consequence of deficit of calcium and phosphate is eliminated via the renal system due to lack
of vitamin D (Dorland, 1982). Second is osteodystrophy, which is a type of bone atrophy with a lot
of osteoclastic (destruction of bone) activity and is a substitution of bone by fibrous tissue, typical of
hyperparathyroidism or osteofibrosis (Pedro–Pons 1972). Last is Osteoporosis, which forms part of
the endocrine and metabolic diseases. It is a skeletal condition that interferes with the captation of
proteins and carbohydrates (Caraballo A, Babaldon F. 1986).
Figure 1.
Osteoporosis is the most frequent skeletal alteration. It is categorized as an atrophy of the bone
tissue (Beskow 1997). It is a generalized, progressive diminution of bone tissue mass per unit
volume, causing skeletal weakness, even though the ratio of mineral to organic elements is
unchanged in the remaining morphologically normal bone. Histologically there is a reduction in
cortical thickness and in the number and size of the trabeculae of cancellous bone, normal width of
the osteoid seams. Bone reabsorption is increased; bone formation appears to be normal but
defective (Bullock, 1984).

Pdl Lab Report
PDL cells that induce coronally the periodontal regeneration coming from flap. It was said that they
came from progenitor cells from within.
In a study, a tooth was made with slits inside the chamber and was implanted into 5 mm tissue with
the dentinal wall remaining and an implant was insurted in to the root and collagen barrier was
added. The histological specimen after 3 months showed formation of cementum and PDL was
formed between the dentinal wall and implant.
So, projenitor cells in PDL are strongly associated in the regeneration of periodontal apparatus.
Role of epithelium in periodontal wound healing: It seems that as the tooth is merged into the
mucosa the epithelial lining is continuous apically inhibiting the periodontal ... Show more content
on Helpwriting.net ...
In an experiment, a Widman flap was made and after each two consecutive month professional
cleaning was made it was noticed that we have new bone formation either 2 walled or 3 walled but it
was said it's due to the new CT attachment.
Grafting procedure:
In multiple experiments where bone grafts or implant bone substitutes where made with either:
1. Autogeneous graft: from same person
2. Allogenic graft: frozen red bone marrow and calcellous bone from genetic dissimilar members
3. Xenograft: from another species
4. Alloplastic graft: synthetic material with bone substitute
These contained:
1. Osteo–induction: Bone inducing substances
2. Osteo–genesis Bone forming cells
3. Osteo–conduction: Scaffold for bone formation
It has showed promising results but the documentation varried due different:
1. Attachment levels
2. Location
3. Xrays
4. Re–entery procedure.
A new cementum was made and collagen fibers bonded to it making new periodontal attachment.
3. Nonresorbable membranes:
Usage of membranes as cellulose acetate filters and EPTFE (EXPANDED polytetraflouro ethylene)
as GRT barriers as they has these properties: a– Manageable clinically b– Make space for tissue

healing c– Allow tissue integration d– Biocompatible e– Cellular barrier
With the use of ePTFE, THE THICK KERATINIZED attached gingiva must be

broken hip with answer 4
Chief Complaint: 72–year–old woman who fell on her right hip.
History: Margaret Donovan, a 72–year–old white female, was brought to the emergency room by
her son–in–law after falling in her bathtub. She was previously in good health, despite leading a
relatively sedentary lifestyle and having a 30–pack–year history of cigarette smoking. The only
medication she currently takes is Inderal (propranolol) for mild hypertension. She fell upon entering
the bathtub when her right leg slipped out from under her; she landed on her right hip. There was no
trauma to her head, nor does she complain of right or left wrist pain. However, she reports severe
pain in the right hip and upper thigh, and was unable to get up after her fall. An injection ... Show
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Given the above considerations, Margaret's osteoporotic femurs are vulnerable to fracture because
of (A) the loss of spongy bone in the epiphyses and (B) the thinning of the bony collar in the
diaphysis.
6. Describe the changes that a broken bone undergoes as it is healing. The bony collar of long bones
helps them withstand compressive stress by the mechanism described in #4A above (i.e.
hydroxyapatite, weight–bearing pillars). In addition, long bones also withstand compressive forces
by virtue of the spongy ("cancellous") bone in the epiphyses. The interlocking network of bony
plates (called "trabeculae") found in spongy bone help to distribute the weight of the body out to the
tough bony collar of the diaphysis. In this way, bony plates act much like the trusses or struts in old–
time railroad bridges which distribute the weight of the train evenly over the entire bridge.
7. During her long recovery, Margaret is advised by her physician to begin weight–bearing as soon
as she can. How does weight–bearing influence the process you described in question #6? (Be
specific in your answer and describe what weight–bearing does to bone at the microscopic level.)
The most popular hypothesis regarding the effect of weight–bearing on bone remodeling is called
Wolff's law . Wolff's law states that bone grows and remodels in response to the mechanical stresses
placed upon it (e.g. from muscle pull or gravitational

Hierarchical Bone

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