3. • Cartilage is a specialized form of connective tissue
containing chondrocytes which secrete, and are
surrounded by, an extensive intercellular matrix.
Chondrocytes occur singly or in isogenous
groups, composed of 2-8 cells derived by mitosis from a
single chondrocyte. The cells are in the lacunae (cavities)
within the matrix. Matrix stains more intensely
immediately adjacent to the lacunae and the dark
staining zone is called the capsule. The strength and
durability of cartilage are properties of the matrix, which
is an interlaced network of collagenous and/or elastic
fibers in a ground substance, a gel of complex
proteoglycans.
4. • Hyaline cartilage is found lining
articular surfaces, and in the nasal
septum, tracheal rings, costal
cartilages, and the epiphyseal cartilage
of growing bone
• Elastic cartilage is found in the ear
and epiglottis, where it provides a rigid
but elastic, framework. Its principal
components are elastic fibers but type
II collagen is also present. Some
elastic fibers may be present in the
tracheal cartilage.
• Fibrocartilage is found in
intervertebral discs, the pubic
symphysis, in menisci of joints, and
often occurs where tendon and
ligament are joined to bones. Its
appearance varies with its location.
The major and characteristic
5. Bone Cartilage
• Bones grow longer over time • Cartilage forms from initial
but they also get thicker. condensation directly from
There are mechanism that mesenchyme and then grows by a
allow for bones to grow in combination of apositional growth
both length and width. • Interstitial growth - Chondroblasts
• To make a bone longer just within the existing cartilage divide
add bone tissue to the ends. and form small groups of cells,
If tissue is added at the end of isogenous groups, which produce
the bone the skeleton could matrix to become separated from
not move properly. It's like each other by a thin partition of
closing both lanes on an matrix. Interstitial growth occurs
interstate until the bridge is mainly in immature cartilage.
repaired. • Appositional growth - Mesenchymal
• Bone tissue must be added cells surrounding the cartilage in
below the joint somewhere the deep part of the perichondrium
along the length of the bone. (or the chondrogenic layer)
This occurs at the epiphyseal differentiate into chondroblasts.
plate, or growth plate. Here Appositional growth occurs also in
chondrocytes first produce mature cartilage.
14. • Osteoporosis is when bone density is decreased,
normally the process of matrix remodeling keeps bones
at the correct density but Osteoporosis slows this down.
15. • Cancer treatment can destroy bone marrow which is
where red blood cells are naturally replaced. Without the
bone marrow patients are more susceptible to sickness.
Bone marrow transplants replace the bone marrow with
healthy normal marrow.
16. Intramembranous ossification: when cells of an embryo
transforms into bone. In early development, the embryo has
three cell layers: the ectoderm which is on the outside,
mesoderm in the middle, and endoderm on the inside of the
embryo. Bones of the skull come directly from the mesenchyme
cells by intramembranous ossification.
Endochondral ossification: this is the gradual replacement of
cartilage by the bone. This process is responsible for forming
most of the skeleton of vertebrates. Osteoblasts arise in
regions of cartilage called ossification centers. (9)
17. 1. Inflammation: in a bone fracture, white blood cells move in to the area to
clean up debris created by the break. Inflammation triggers the growth new
blood cells.
2. Soft callus: as the blood cells divide and multiply near the break, the new
blood vessels develop to fuel the repair process; the body also creates
simply fibrous tissue cartilage around the bone fracture to bridge the gap.
3. Hard callus: later on, the body replaces the soft callus with a hard callus,
connecting the fragments of the bone more solidly. It creates a bulge at the
site of the fracture.
4. Remodeling: the body replaces the old bone with a new bone in a
continual process called remodeling; it makes the bone stronger and
compact and blood circulation in the bone improves.(8)
19. Bone: the types of bones are divided into long, short, irregular, flat,
sesamoid and sutural bones. Their function is to protect the body from
mechanical damage, to provide support, assist in movement, to store
minerals, produce red blood and white blood cells, and to be the
framework and shape for the body. The bones are made up of
osteoblasts, osteocytes, osteoclasts, and bone lining cells.
Cartilage: the types of cartilage are hyaline cartilage, fibrocartilage and
elastic cartilage. The main functions is to reduce the friction at the
joints, support tracheal and bronchial tubes, they act as shock
absorbers between the vertebrae, also maintaining the shape and
flexibility of ear, nose, along with others. Cartilage is made up of
chondroblasts, chondrocytes, and dense matrix that is composed of
collagen and elastic fibres. (10)
21. • Osteoblasts- These are bone forming cells within the bone.
• Osteocytes- These are involved in the formation of the bone, maintenance of
the matrix, and homeostasis of the calcium.
• Osteoclasts- The cells are responsible for bone resorption and remodeling.
22. • Maintain shape and structure of the bone.
• Strengthening the bone and adding tissue.
• Remodeling broken bones.
• Calcium from bones being used in other parts of body.
• Mineral reservoir, contains many minerals that the body
can use.
30. • Is made up of concentric rings of matrix that surround
central canals which contain blood vessels.
• Embedded in this bone tissue are small cave-like spaces
called lacunae, which are connected to each other
through small tunnels called canalicula.
• The lacunae contain osteocytes cells. As just discussed,
osteocytes help maintain healthy bone tissue and are
involved in the bone remodeling process that will be
outlined later in this lesson.
31. • Looks like an irregular latticework (or sponge) with lots of
spaces throughout.
• These spaces are filled with red bone marrow which is
the site of hemopoesis or formation of blood cells
32. • During the aging process, adults face the issue of a
changing skeletal framework.
• As humans age, the force-generating capacity (strength)
of their skeletal muscles is reduced. As a result, many
older people experience difficulty in performing their
activities of daily living. The loss of force production in
older people is primarily to the result of muscle atrophy
and alterations in the percentage of contractile tissue
within muscle rather than deficits in muscle.
33. Growth plate In growing children,
sprains and strains often
fractures result in potentially
serious growth plate
fractures and physeal
fractures. These same
sprains and strains in
active adults are
relatively benign injuries.
This article discusses
some of the important
orthopedic history
relative to the physes,
relevant anatomy,
classification systems,
and some details of
physeal fractures in
specific areas of the
An image depicting growth plate fractures can be seen below.
body.
34. • Growth plate (physeal)
fractures. Clinical appearance
of the knee of a patient with a
minimally displaced Salter-
Harris I fracture of the distal
femur. Impressive swelling
was noted adjacent to the
joint, but no evidence of intra-
articular swelling was
present. The patient was
markedly tender to palpation
about the distal femoral
physis.
