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Unit 3: Bone and Cartilage
& Bone Development
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Introduction and objectives
Cartilage is a specialized connective tissue composed of cells, fibers and ground substance. The
unique properties of cartilage play an important role in the structure and function of movable
joints such as the glenohumeral joint. The growth in length of long bones is totally dependent
upon the unique properties of cartilage. With the exception of certain membranous bones, the
entire skeletal system develops first as a cartilaginous model, which is later replaced by bone.
One of the most incapacitating and painful diseases man is subjected to, osteoarthritis, involves a
degenerative change in the ground substance of articular cartilage such that collagen fibrils are
unmasked and freely exposed on the joint surfaces. The importance of rigid calcified tissue
(bone) as a support for the body and limbs should be obvious. Not so obvious is its role as a
reservoir of calcium ions. Calcium ions are exchanged between the blood and bone
compartments of the body under the influence of parathyroid hormone and calcitonin on various
bone cells such as osteoblasts, osteocytes and osteoclasts.
Cartilage & Bone Tissue with WebMic
There are five specimens each for the study of cartilage and bone tissue. Hyaline cartilage,
elastic cartilage and fibrous cartilage are demonstrated from the overall organization down to the
individual cells, the chondrocytes, which form and maintain cartilage as a viable tissue. Adult
compact and cancellous lamellar bone are demonstrated in two specimens. Finally, the two types
of ossification are demonstrated, endochondral and intramembranous ossification.
After completing this unit, you should be able to identify and distinguish between the following:
1.
2.
3.
4.
5.
6.
7.
8.
9.
4.
5.
6.
7.
the three types of cartilage: hyaline, elastic, and fibro-cartilage
chondroblasts
chondrocytes
perichondrium
bone
lamella
canaliculi
Haversian system (osteon)
Haversian canal
osteoblasts
osteocytes
osteoclasts
periosteum
Also, after completing this unit in conjunction with reading a chapter on connective tissue in a
histology textbook and/or hearing a lecture on connective tissue, you should understand:
1.
2.
3.
4.
5.
how cartilage grows
the differences between cartilage and bone
the remodeling of bone
the process of intramembranous bone formation
the process of endochondral bone formation
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Cartilage
Before we begin a study of the histology of cartilage it will be helpful to know some features that
cartilage and bone have in common. The cells of cartilage and bone are found in spaces called
lacunae (small pits) and thus are separated from the surrounding extracellular material. The
extracellular matrix (matrix is composed of fibers and ground substance) of both bone and
cartilage is composed of collagen fibers and glycosaminoglycans. Cartilage collagen is type II
and bone collagen is type I. Cartilage ground substance (glycosaminoglycans) is not calcified as
compared to bone which is calcified. Bone can grow in the adult by one method and that is
appositional growth which is the deposition of bone matrix by osteoblasts in the periosteum onto
the old bone matrix. Cartilage can grow by two methods, appositional and interstitial which is
the process whereby cartilage cells within the cartilage matrix can divide resulting in growth of
cartilage within itself.
Hyaline Cartilage
To begin our study of cartilage go to the general histology section and, under cartilage, choose:
Hyaline Cartilage (Rib)-Hematoxylin-Eosin
Scan the 5x image noting that the overall staining reaction is blue. Can you observe the many
small spaces? These are the lacunae and, in each one, is a chondrocyte. Find the label
perichondrium at the edge of the cartilage. The perichondrium as its name suggests surrounds
cartilage. It is composed of a dense connective tissue. The innermost layer of that surrounding
connective tissue has stem cells that can divide and provide a reservoir of cells that can secrete
cartilage matrix. This is called the chondrogenic layer. The line emerging from the label ends
right at the point where new cartilage cells are being formed. On the cartilage side the stained
matrix is blue because of the highly sulfated glycosaminoglycans being produced in contrast to
the pink stained outer perichondrium (called the fibrous perichondrium) which has a matrix
composed predominately of collagen type I with little ground substance. Within the cartilage in
addition to the glycosaminoglycans the matrix contains type II collagen in the form of fine fibers
often referred to as fibrils. Hyaline cartilage as is present in this specimen of a rib appears rather
smooth because of the small dimension of its collagen fibers (ground substance masks the
fibers). Hence the term hyaline which means glass-like. Now scan into the center of the image
and find the label interterritorial matrix. There are two named regions of the matrix. The other
named region is territorial. Territorial matrix is the matrix that is closely associated with each
lacunae containing a chondrocyte. Interterritorial matrix is the remaining matrix. Select the 20x
image. Find the interterritorial label and read the text related to it. In this specimen the contrast
in staining between the territorial and interterritorial matrix is not very obvious. There is more
ground substance in territorial matrix hence it will stain more blue than interterritorial which
contains a higher percentage of collagen which is responsible for it staining more pink. This
difference will be better demonstrated in the specimen we use to study elastic cartilage.
The other feature important to learn in this specimen is the morphological feature related to
interstitial growth of cartilage: the isogenous group. Find the label isogenous group and read the
related text. Observe that there are two chondrocytes that look like they came from a dividing
cell. Isogenous groups are groups of daughter cells resulting from mitosis. This is the way the
cartilage grows interstitially. This method of cartilage growth can occur in the adult to a limited
degree, but is one of the main growing mechanisms in the developing embryo and fetus.
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Elastic Cartilage
In the general histology section under cartilage choose:
Elastic Cartilage (Epiglottis) – Elastin (Verhoeff’s)-Nuclear Red-Picroindigo
In this specimen nuclei stain light red, cytoplasm stains red, collagen fibers stain yellow, and
elastic fibers stain brown-black. Unlike the rib, the cartilage of the epiglottis is elastic. When
food is swallowed the epiglottis is forced downward covering the glottis resulting in food being
directed into the esophagus. When food passes the epiglottis it rebounds to its resting form
because of its elastic nature. The predominant fiber in the interterritorial matrix of cartilage is
composed of elastin (the elastic fiber). Scan the 5x image noting the cartilage, its perichondrium
and the elastic cartilage. Again, as in hyaline cartilage, the spaces are the lacunae each of which
contains a chondrocyte. The line in the image that indicates the perichondrium ends at precisely
the point at which there is a transition from fibrous to chondrogenic perichondrium. Stem cells
located in the chondrogenic perichondrium give rise to chondroblasts. Chondroblasts then
secrete matrix. As soon as the chondroblasts surround themselves with matrix they are then
called chondrocytes. The outer layer, the fibrous perichondrium is yellow indicating a
dominance of collagen fibers. This layer functions like a capsule which defines the outer limit of
the cartilage. From the chondrogenic region inward the staining of the matrix becomes darker.
The dark staining reaction is because of the presence of elastic fibers. As the new chondrocytes
mature, they secrete more elastic fibers until finally the matrix is very rich in elastic fibers.
Select the 20x image. Scan it noting the labels perichondrium, chondrocyte, isogenous group,
and interterritorial matrix. As you scan from the perichondrium inward observe the increase in
density of elastic fibers. Read the text related to the interterritorial matrix. This is the matrix
containing the highest density of elastic fibers. Similarly, in hyaline cartilage, this is the region
that contains the highest density of type II collagen fibers. Although not labeled in this
specimen, observe the matrix immediately surrounding the labeled chondrocyte and the
chondrocyte below the ‘interterritorial matrix label’. This matrix, called the territorial matrix,
stains lighter because it has more ground substance than elastic fibers. Now choose the specimen
of elastic cartilage stained with hematoxylin and eosin:
Elastic Cartilage (Epiglottis) – Hematoxylin-Eosin
In the 5x image note the perichondrium and the main mass of elastic cartilage. If you look
closely in the region of the perichondrium you can see how the cells get larger as they are located
deeper in the cartilage. This is because they are maturing from chondroblasts to chondrocytes
where finally the chondrocyte is surrounded by a clear region (the lacuna). Scan the 20x image
and study the perichondrium label region to see this more clearly demonstrated. Also in this
image, note and read the text related to the labels interterritorial matrix and territorial matrix.
Note that the territorial matrix stains bluish whereas the interterritorial matrix stains pink due to
the higher density of elastic fibers. Note that the matrix of this elastic cartilage is less
homogeneous (glassy like) than the hyaline cartilage due to the larger and more refractile elastic
fibers. However, when you compare the appearance of the matrix of this specimen with the
previous one you studied stained with a special elastic fiber stain, the elastic fibers do not appear
obvious. To complete your study of this specimen select the 40x image and note the two regions
of the matrix and the labeled chondrocyte. Read the text label related to the chondrocyte.
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Fibrocartilage
Fibrocartilage is the tissue that makes up the structure of menisci in joints, tendons as they
approach their insertions into bone, and the capsule surrounding the intervertebral discs. Begin
your study with the specimen stained with a special stain. In the general histology section under
cartilage choose:
Fibrocartilage (Meniscus) – Hematoxylin-Eosin-Metanil Yellow
Nuclei stain blue-black, collagen stains yellow, and ground substance stains light blue. Scan the
5x image. Note the labeled collagenous fibers (made up of collagen type I) that stain yellow.
Look between the collagen fibers, especially in the upper half of this image, and see if you can
make out the darkly stained strands. These are a series of isogenous groups of chondrocytes.
This is the main characteristic diagnostic feature of fibrocartilage. Recall that you did not
observe such a physical arrangement of chondrocytes in either hyaline or elastic cartilage. The
chondrocytes and collagen fibers are organized in a fashion parallel to the line of force.
Fibrocartilage in tendons, for example, has its collagen continue in the same orientation as the
tendon, parallel to the line of force. To observe this more closely, select the 20x image and find
the labeled chondrocyte and collagenous fiber located in the middle just to the left of the center
of the image. Now you can observe several strands of chondrocytes (isogenous groups) running
parallel between collagen fibers. The longitudinal strands of chondrocytes making up the
isogenous groups got that way because the parent cells divided in one direction. Note the bluish
stain immediately surrounding the chondrocytes. This is the territorial matrix that has very little
to no collagen. Read the text related to the labels. Select and scan the 100x image where you
can observe the chondrocytes and matrix in more detail.
This now concludes your study of cartilage. You have learned that there are three types. You
have learned that the difference between the three types mainly lies in the difference in the type
of fibers present and how those fibers are oriented. In hyaline cartilage the fibers are collagen
type II and they are oriented in all directions. In elastic cartilage, the fibers are elastic and they
too are oriented in all directions. In fibrocartilage, the collagen fibers are made up of type I
collagen, the fibers are oriented in one direction, parallel to the line of force generation. You
have learned that cartilage can grow in two ways, appositional and interstitial. Finally, you have
learned that the perichondrium serves both as a capsule enclosing the cartilage and as a reservoir
of stem cells. New cartilage cells, chondroblasts, are formed by mitosis which then differentiate
to secrete the matrix of cartilage. Now let’s study the histology of bone and see how it differs
from cartilage.
Bone
From its earliest beginnings bone is more rigid than cartilage. Its matrix becomes calcified and
therefore it cannot expand from within, as is the case of interstitial growth in cartilage. Bone can
only grow by deposition of cells and matrix upon its surface, appositional growth. Bone is
similar to cartilage in that its forming cells, the osteoblasts, are quickly surrounded by matrix
(secreted by osteoblasts) and then the name of the cells changes to osteocytes which are
contained in lacunae. There are several different types of bone. Bone which is composed of
interconnecting strands (called spicules or trabeculae) is known as cancellous (also called
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trabeculated) bone. This kind of bone has a spongy appearance and is present in the center of
bone, the medullary region, which is where the bone marrow is also located. Another kind of
bone is compact bone. In this type of bone, the matrix is not arranged in trabeculae but is solid
being penetrated throughout by blood vessels running in structures called Haversian canals. This
is the kind of bone that is present in the outer part of long bones (the cortex region of a bone).
Let’s begin our study of adult bone with one that is stained with a special stain to demonstrate all
the features. Go to the general histology section, and under bone choose:
Lamellar Bone (Femur) – Thionin-Picric Acid
This specimen has been prepared by taking a rather thick section of undecalcified bone and
grinding it until it is very thin, about 50 microns (compared to a histology section which is on the
order of 5-10 microns thick). Nuclei and cytoplasm stain red. Collagen stains yellow. Small
canals in the bone, canaliculi, appear dark due to refraction of the light as it passes from matrix
into the empty space of the small canals.
Lamellar bone is so named because the collagen fibers are arranged in layers between which
there are rows of osteocytes in lacunae. Scan the 5x image of this specimen with the labels
turned on. As you scan the image note that there are dark round stained areas and circular areas
that have no stain. These are the Haversian canals that normally contain blood vessels. The
empty circular areas are Haversian canals from which the blood vessels have been lost in the
preparation of this tissue. Find the labels Haversian canal and osteon. The osteon is a name
given to the structure made up of concentrically arranged lamellae and osteocytes arranged
around a center, the Haversian canal. Another term equal to osteon is Haversian system. Even at
this magnification, if you look carefully, you should be able to observe the concentric appearance
of the layers around the Haversian canals. The lamellae, which surround the Haversian canals,
are called concentric lamellae. Now scan to the upper edge of the image and find the label ‘outer
circumferential lamellae’. This is the outer most part of the bone cortex where the lamella is
running in parallel with the surface of the bone rather than around Haversian canals. This is
typical of all major bones in the body. Now we shall see this in more detail. Scan the first 20x
image and find the labeled osteon. Note that it is a discrete unit of bone matrix oriented around a
Haversian canal. Examine the osteon to the right of this one where you can find one of the
lamella labeled. Now you can see the layered arrangement including the dark small areas which
are the lacunae containing osteocytes. Can you see the fine dark lines that are mostly oriented
across the lamellae from the Haversian canal outward? These are the small channels in matrix
that contain the processes of osteocytes and where fluid can move from the Haversian canal
outward into the outermost perimeter of the osteon. These small channels are called canaliculi.
Before you leave this image, find the two regions labeled ‘cementing substance’. Cementing
substance is deposited at the very beginning of the formation of an osteon. Note that the
cementing substance forms a boundary between an osteon and interstitial lamellae. Interstitial
lamellae are either primitive lamellae formed before osteons, or represent in the adult, portions of
osteons left in the process of bone remodeling (bone remodeling should be studied by consulting
your lecture notes and textbook). An osteon is formed by osteoblasts secreting matrix that is rich
in ground substance initially to form the cement line and then secreting matrix rich in collagen
entrapping osteoblasts which are then called osteocytes. More osteoblasts are generated by
mitosis of osteoprogenitor cells between the blood vessels in the forming Haversian canal then
secreting another layer of matrix in which they are trapped. Next study the second 20x image.
Observe the difference between the periosteum (similar to cartilage in that it has a fibrous
portion surrounding an osteogenic portion in which osteoprogenitor cells are located), the outer
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circumferential lamellae, and the osteon in which an osteocyte and Haversian canal are labeled.
Now select the 100x image where you can study the components of an osteon in detail. Note the
osteocyte processes in the canaliculi and read the text related to the label, locate the Haversian
canal, observe the two labeled lamellae, and note the osteocytes in lacunae. To conclude your
study of compact bone in the adult under bone choose:
Lamellar Bone (Femur) – Hematoxylin-Eosin
This specimen was prepared by removing the calcium using a process called decalcification.
After removing a sample of bone and placing it in a fixative, the tissue is decalcified by
immersion in weak acid over a period of days. Finally the sample is embedded in paraffin and
sectioned routinely at 5 – 10 microns in thickness. One difference is striking between this
sample and the ground section. You will not be able to make out the osteons and lamella as
clearly in this specimen. You can observe lacunae but you will not be able to observe the
canaliculi because the refractive index of the canaliculi containing the osteocyte cell process is
very similar to the refractive index of the surrounding matrix. In the ground section the air in the
canaliculi was responsible for the change in refractive index from the matrix rendering them
readily visible. Scan all three images noting the structures and recalling what you learned in the
previous specimen. Now we will turn out attention to learning about how bone develops.
Bone Development
Bone develops in the embryo and fetus in two ways. One involves a cartilaginous precursor and
is called endochondral bone formation. The other has no cartilage precursor with the bone
forming directly in mesenchyme and is called intramembranous bone formation. Both means of
bone formation continue into the adult, but endochondral bone formation is more extensive and
prominent in the adult throughout the growth in length of long bones until the end of puberty,
even into the early 20’s of postnatal life. Intramembranous bone formation involves growth of
flat bones like the bones making up the calvarium. For example, the temporal, frontal and
parietal bones form first by intramembranous formation in the embryo and fetus and continue to
growth in size and thickness in the adult. First we will study the histology of intramembranous
bone formation.
Intramembranous Bone Formation
Begin by choosing a specimen in the general histology section under bone. Choose:
Intramembranous Ossification (Skull) – Hematoxylin-Eosin-Methylene Blue
Nuclei are stained blue, cytoplasm is stained red, collagen is stained blue and calcified matrix is
stained red. Beginning with this special stain will permit us to readily observe the features of
intramembranous bone formation.
Scan the 5x image noting the label bone spicules and the surrounding connective tissue. Note
that most of the bone matrix stains red indicating that it is mineralized. Examine carefully the
lower surface of either labeled bone spicule. Can you make out the row of circular objects
(small) just below the red stained spicule? These are osteoblasts lined up on the surface of the
bone. If you take note of the left bone spicule that is labeled and look directly below it you can
see a much smaller spicule and to the left of it is a linear region where you can also see
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osteoblasts. This is how intramembranous bone formation begins: differentiation of
mesenchymal cells into osteoblasts secretion of bone matrix by osteoblasts, osteoblasts then
surrounded by the matrix and now called osteocytes, etc. You will see this in greater detail by
examining the 20x image. In this image you can easily see osteocytes entrapped in the lacunae
in bone matrix. Observe the osteoid, osteoblasts, osteoclasts reading all of the text related to the
labels. Note how the osteoid stains blue due to the presence of more collagen than calcified
ground substance. Note that the bone spicule is labeled as woven bone. Woven bone is not
arranged in strict layers (lamellae). As it matures it becomes lamellated and will eventually be
lamellar bone. Woven bone can be remodeled into circumferential bone as in the cortex of the
femur (outer circumferential lamella) or into compact bone as in the main mass of the cortex of
long bones. Note also the osteoclasts which are important in the remodeling and shaping of adult
bone.
Now select the first 100x image and scan it to observe the osteoclast, the lacuna in which it
resides, Howships’s lacuna, bone matrix, and an osteocyte in a lacuna. Note the multinucleated
osteocyte. These are large cells that always reside on the surface of bone. The lacuna in which
an osteoclast resides is merely a depression on the surface of bone formed by the bone resorbing
action of the osteoclast itself. The osteoclast on the right is separated from its lacuna by a large
space which is an artifactual displacement. Read the text related to the labeled osteoclast and
Howship’s lacuna to learn more. Note the osteocyte within the lacuna in the bone matrix.
In the second 100x image you will be able to observe in more detail osteoblasts, osteoclasts, a
lacuna with two canaliculi projecting from it, and the bone matrix. Find the two osteoid labels
and read one of them. Then look for the osteocyte between the two labeled osteoid areas. This
osteocyte has just become surrounded with matrix it has secreted. Now find the labeled
osteocyte just above the right region of osteoid that is labeled. You can observe two canaliculi
projecting from the lacuna in which this osteocyte is entrapped. Now read all of the text related
to the labels. Conclude your study of intramembranous bone formation by choosing:
Intramembranous Ossification (Skull) – Hematoxylin-Eosin
In this hematoxylin – eosin stained specimen the features of intramembranous bone formation
are represented and labeled but you will find that they are not as easily contrasted as in the
special stained specimen you just studied. However, using what you learned in studying the
previous specimen you should be able to recognize the features of intramembranous bone
formation.
Endochondral Bone Formation
You have one specimen to study the histology of endochondral bone formation. In the general
histology section under bone choose:
Chondral Ossification (Finger) – Hematoxylin – Eosin
Nuclei are stained blue. Cytoplasm and other acidophilic regions are stained red. Basophilic
regions are stained blue. By inspecting and observing the rectangular boxes in the 5x image you
can see that the higher magnified images will be showing you the details of regions going from
left to right. This is a specimen of a developing finger, as it would appear in a fetus. Scan this
image from left to right across the middle and note that the staining is intense blue on the left
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extreme with numerous spaces. This is hyaline cartilage. In the middle of this image you will
note that the solid blue staining ceases and is replaced by strands and islands of blue stain
surrounded by light pink staining tissue. The strands and islands are composed of calcified
cartilage surrounded by bone marrow. Finally if you scan to the extreme right you will observe
strands of blue staining surrounded by a pink layer of tissue outside of which is the highly
cellular (observe the nuclei) bone marrow. The pink layer of tissue on the calcified cartilage is
the newly formed matrix (osteoid) formed by the osteoblasts. Now return to the left side and
slowly scan from left to right again. At the extreme left part of the image you are looking at the
last bit of the zone of reserve non-proliferating cartilage that resembles ordinary hyaline
cartilage. As you slowly scan to the right notice how the cartilage cells are now lined up in
parallel, particularly in the region where you find the label ‘proliferating chondrocytes’. Notice
next how the cartilage cells are enlarged. This is where the cartilage cells are beginning to die
and the matrix of the cartilage is becoming calcified. Next you see the strands of calcified
cartilage upon which osteoblasts are depositing bone. Can you now understand that, in
endochondral bone formation, it begins with cartilage, which is calcified and partially resorbed?
The remaining strands of calcified cartilage serve as a template upon which bone is deposited to
form the bond spicules (trabeculae) that are seen in the adult. In this finger the growth in length
is achieved by the proliferation of chondrocytes in a linear fashion in the zone of proliferation.
In the higher magnified images you will inspect the zone of proliferation, zone of hypertrophied
and calcified cartilage, and the zone of bone deposition. The first 20x image is the zone of
proliferation. Note how the isogenous groups of chondrocytes are arranged in linear arrays. The
second 20x image illustrates in more detail the zone of hypertrophic cartilage. The next 20x
image illustrates the zone of calcified cartilage which is being shaped by the action of
chondroclasts (same as osteoclasts but resorb cartilage) to prepare the templates for forming the
bone spicules. The last 20x image illustrates the zone of bone deposition where you can observe
and study osteoblasts which have recently deposited bone matrix (osteoid because it is pink
indicating collagen and ground substance that has not yet become calcified), an osteoclast
(chondroclast) participating in the modeling of the calcified cartilage into appropriate sized and
shaped templates for spicule formation, osteocytes, and bone marrow.
This now concludes your study of bone formation. You have learned that there are two ways in
which bone forms. The formation of bone in mesenchyme from mesenchymal cell derived
osteoblasts is intramembranous bone formation. This occurs without any involvement or
presence of cartilage. The formation of bone that does involve cartilage is endochondral bone
formation. This is the way that most long bones form. The cartilage involvement provides two
important steps in bone formation by this method. First the proliferating cartilage is the means
whereby bone grows in length. As long as cartilage is proliferating, the bone is growing in
length. When the proliferation stops due to the decrease of growth hormone at the end of
puberty, bone cannot grow in length anymore. The other way in which cartilage is important is
that it provides first the model of the bone and then the templates for the formation of bone
trabeculae.
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Sample Practical Questions
In the image above the structure labeled 1 is which of the following?
A. osteoblast
B. osteocyte
C. osteoclast
D. osteoid
E. canaliculus
In the image above the structure labeled 2 is which of the following?
A. osteoid
B. interstitial lamellae
C. osteon
D. Haversian canal
E. bond spicule
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Connective Tissue Section Labeled Structures
The tables below are arranged by sections listing the specimens in the bone tissue collection with
the labeled structures by magnification. In reviewing you will find it easy to find a structure by
consulting these tables.
Intramembranous Ossification (Skull)-Staining: Hematoxylin-Eosin-Methylene Blue
20X
Connective Tissue
Bone Spicule
80X
Osteocyte
Osteoblast
Osteoclast
Woven bone
Osteoid
Blood vessel
Connective tissue
400X-A
Nucleus
Osteocyte
Bone matrix
Osteoclast
Howship’s lacuna
400X-B
Osteoid
Osteoblast
Bone matrix
Osteocyte
Osteoid
Lacuna
Intramembranious Ossification (Skull)-Staining: Hematoxylin-Eosin
20X
Bone spicule
Connective tissue
80X
Osteoclast
OsteocyteOsteoblast
Woven bone
Osteoid
Blood vessel
Connective tissue
160X
Osteoblast
Osteocyte
Osteoid
Bone matrix
Osteoclast
Blood vessel
Chondral Ossification (Finger)-Staining: Hematoxylin-Eosin
20X
80X-A
80X-B
80X-C
80X-D
Proliferating chondrocytes Interterritorial matrix Hypertrophic chondrocyte Calcified interterritorial matrix Bone matrix
Hypertrophic chondrocytes Chondrocyte
Interterritorial matrix
Bone marrow
Osteocyte
Bone spicule
Hypertrophic chondrocyte
Osteoblasts
Osteoclast
Interterritorial matrix
Bone marrow
Lamellar Bone (Femur)-Staining: Thionin-Picric Acid
20X
Osteon
Haversian canal
Periosteum
Outer circumferential lamellae
80X-A
Haversian canal
Interstitial lamellae
Osteon
Lamella
Osteocyte
Cementing substance
80X-B
Outer circumferential lamellae
Osteocyte
Haversian canal
Periosteum
400X
Haversian canal
Osteocyte
Osteocyte process
Lamella
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Lamellar Bone (Femur)-Staining: Hematoxylin-Eosin
20X
Osteon
Haversian canal
80X
Osteon
Haversian canal
Osteocyte in lacuna
Lamella
160X
Haversian canal
Blood vessel
Lacuna
Lamella
Hyaline Cartilage (Rib)-Staining: Hematoxylin-Eosin
20X
Chondrocytes
Interterritorial matrix
Perichondrium
80X
Isogenous group
Chondrocyte
Interterritorial matrix
Elastic Cartilage (Epiglottis)-Staining: Elastin (Verhoeff's)-Nuclear Red-Picroindigo
20X
Epiglottis - elastic cartilage
Epithelium
Perichondrium - connective Tissue
Glandular tissue
80X
Perichondrium
Isogenous group
Interterritorial matrix
Chondrocyte
160X
Interterritorial matrix
Chondrocyte
Elastic fibers
Isogenous group
Elastic Cartilage (Epiglottis)-Staining: Hematoxylin-Eosin
20X
Perichondrium
Elastic cartilage
Glandular tissue
80X
Perichondrium
Interterritorial matrix
Chondrocyte
Isogenous group
160X
Interterritorial matrix
Chondrocyte
Territorial matrix
Fibrocartilage (Meniscus)-Staining: Hematoxylin-Metanil Yellow
20X
Chondrocyte
Collagenous fiber
80X
Collagenous fiber
Chondrocyte
400X
Isogenous group
Chondrocyte
Nucleus
Collagenous fiber
Fibrocartilage (Meniscus)-Staining: Hematoxylin-Eosin
20X
Collagen
80X
Collagenous fiber
Chondrocytes
160X
Collagenous fiber
Chondrocytes
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