2. INTRODUCTION
The skeletal system includes:
Bones
Cartilages
Joints
Ligaments
Other connective tissues
3. Composition of Bone (Extracellular) Matrix
Inorganic components
hydroxyapatites
calcium and phosphate deposits
65% of bone by mass
responsible for bone hardness
Fibers
collagen
provides an ability of bone to flex slightly without
fracturing
4. FUNCTIONS
Support
Movement: muscles attach by tendons and use bones as levers
to move body
Protection
Skull – brain
Vertebrae – spinal cord
Rib cage – thoracic organs
Mineral storage
Calcium and phosphorus
Released as ions into blood as needed
Blood cell formation and energy storage
Bone marrow: red makes blood, yellow stores fat
9. Vertebral Column
Sacrum (mid-line region of buttocks)
Coccyx (4 or 5 fused vertebrae of the tail bone)
7 Cervical Vertebrae (of the neck)
12 Thoracic Vertebrae (of the chest)
5 Lumbar Vertebrae (of the lower back)
Lumbar vertebra,
lateral view
Lumbar vertebra,
superior view
12. Sternum
Mid-line breast bone
The clavicles and ribs one to seven articulate with
the sternum
Sternum – comprised of
the manubrium, sternal
body and xiphoid process
13. Consists of:
1. The pectoral gridle (chest)
2. Pelvic girdle (hip)
3. The upper limbs
4. The lower limbs
Appendicular skeleton
14. 1.Pectoral Girdle
Consists of:
Scapula (shoulder blade)
Clavicle (collar bone)
Allows the upper limb great mobility
The sternoclavicular joint is the only point of
attachment between the axial skeleton and the
pectoral girdle
Scapula
Clavicle
15. 2. Pelvic Girdle
Formed by pair of os coxae (hip
bones)
supports the bladder and
abdominal contents
Attachment:
Posteriorly – join with the sacrum
Anteriorly - join to each other
anteriorly
Laterally – join to the head of thigh
bone through a cup-shaped
acetabulum
16. 3. Upper Limb
Humerus
The arm bone
shoulder to elbow
Radius and Ulna
The forearm bones
elbow to wrist
Humerus
Ulna
Radius
18. Upper Extremities
Humerus: upper arm
Radius: thumb side of forearm
Ulna: little finger side of forearm
Carpals (8): wrist bones
Metacarpals (5): hand bones
Phalanges (14): finger bones
19. 4. Lower Limb
Femur
thigh bone
from hip to knee
Patella
knee cap
sesamoid bone in the
tendon of the
quadriceps muscles
(thigh)
Femur
Patella
20. Lower Limb Cont’d
Tibia and Fibula
leg bones
From knee to ankle
Tibia is medial and fibula is
lateral
Medial malleolus and Lateral
malleolus
The distal ends of the tibia and
fibula, respectively
commonly referred to as the
"ankle bones"
can be easily palpated
Fibula
Tibia
Lat. malleolus
Med. malleolus
21. Lower Limb Cont’d
Tarsals
ankle bones
calcaneus or the heel bone
talus
Metatarsals
5 bones of the foot
unite with the toes
Phalanges
toe bones
three per toe except the big
toe - proximal, middle and
distal
Calcaneus
Talus
Phalanges
Metatarsals
Tarsals
22. Lower Extremities
Femur: thigh bone
Patella: kneecap
Tibia: shin bone
Fibula: lateral bone of lower leg
Tarsals (7): ankle bones; talus and calcaneus
Metatarsals (5): foot bones
Phalanges (14): toe bones; great toe = halux
31. 5.Pneumatic Bones
have air spaces within
them which makes
them lighter than more
solid bone. They are
only found in the skull.
An example of a
pneumatic bone is the
Sphenoid bone.
Maxilla
32. 6.Sesamoid bones
• Sesamoid bones are small
more or less rounded masses
embedded in certain tendons
and usually related to joint
surfaces.
• Their functions probably are to
modify pressure
• to diminish friction, and
• occasionally to alter the
direction of a muscle pull
• Example:patella,pisiform.fabella
33. 7.Accessory bones.
• They are not always
present.
• These may occur as
ununited epiphyses
developed from extra
centres of ossification.
• Example:sutural bone,os
trigonum,os vesalianum
34. 8.Heterotopic bones
irregular nodules of bone
may appear as the result
of intermittent pressure
in certain regions, e.g.,
the “rider’s bone,” which
is occasionally developed
in the Adductor muscles
of the thigh.
35.
36. Bone Classification(structural)
According to the degree of porosity,
bone can be classified into two general
categories:MACROSCOPICALLY
Cortical bone (low porosity)
Spongy or cancellous bone (high
porosity)
37. Bone is very strong for its
relatively light weight
The major components of
bone are:
Calcium carbonate
Calcium phosphate
Collagen
Water
Bone Composition Cortical Bone
Spongy Bone
Medullary (marrow) cavity
39. Developmental Classification
Membranous(dermal): ossify in
membrane(intramembranous or
mesenchymal
ossification)e.g.,facial bones.
Cartilaginous: ossify in
cartilage(intracartilaginous or
endochondral
ossification)e.g.,vertibral column
Membrano Cartilaginous: ossify
partly in membrane and partly in
cartilage.e.g.,clavicle,madible,occi
pital,temporal,sphenoid.
MOCST
Somatic bone
Visceral bone: They develop
from pharengeal
arches,example:Hyoid
bone,ear ossicles.
42. Diaphysis
It is the elongated
shaft of a long
bone which
ossifies from a
primary centre.
43. TYPES OF EPIPHYSIS
There are four types of epiphysis:
1.Pressure epiphysis:
Pressure epiphyses assist
in transmitting the weight
of the human body and
are the regions of the
bone that are under
pressure during
movement or locomotion.
Another example of a
pressure epiphysis is the
head of the humerus
which is part of the
shoulder complex
44. 2.Traction epiphysis:
the regions of the long bone which are
non-articular, i.e. not involved in joint
formation.
the supporting ligaments and tendons
attach to these areas of the bone.
Traction epiphyses ossify later than
pressure epiphyses.
Examples of traction epiphyses are
tubercles of the humerus (greater
tubercle and lesser tubercle), and
trochanters of the femur (greater and
lesser).
45. 3Atavistic epiphysis:
These types of fused
bones are called
atavistic;
e.g. the coracoid
process of the
scapula which has
been fused in
humans but is
separate in four-
legged animals.
47. METAPHYSIS
Epiphysis end of
diaphysis is called
metaphysis.
Hair pin bend
formed by end
arteries.
Common site for
osteomyelitis in
childrean
Adult no more end
arteries
51. Epiphysial plate of cartilage
It separates epiphysis
from metaphysis.
Proliferation of cell in
cartilage growth
plate is responsible
for growth of bones.
56. Osteoporosis- bone reabsorption
outpaces bone deposit; bones become
lighter and fracture easier
Factors:
• age, gender (more in women)
• estrogen and testosterone decrease
• insufficient exercise (or too much)
• diet poor in Ca++ and protein
• abnormal vitamin D receptors
• smoking
59. Bone grafts and artificial bone
Widely used cutting-edge technologies
Bone cells highly regenerative and move into any
suitable matrix
Use bone pieces from same body—fibula
Use crushed bone from cadavers
Use bone substitutes—coral, synthetics—
”nanotechnology”
Applications are numerous
Jaw bone filler for dental work
Birth defects
Osteoporosis
Bone repair
