The skeleton is composed of bones that provide structure, protect organs, allow movement, and store minerals. Bones are classified by their shape as long, flat, irregular, short, or sesamoid. Long bones act as levers pulled by muscles and have a hollow shaft (diaphysis) of compact bone surrounded by spongy bone in the ends (epiphyses). Bones grow in childhood as the epiphyseal plate ossifies. The periosteum and endosteum lining bones are involved in growth, repair, and marrow production of red and white blood cells.

2. • The word skeleton
is derived from a
Greek word that
means “dried-up
body”.

4. oLegs, pelvis, vertebr
ae (spine) hold the
body UP
oSupport muscle and
other tissue types
• Jaw (mandible &
maxilla) serve to
support teeth

5. o Encloses and
protects vital organs
• Ex. Brain enclosed
by skull; rib cage
protects the heart,
lungs, and other
organ of the
thorax.

6. Bone act as lever
when attached
muscles contract,
causing
movement about
joints.

7. oMinerals (calcium,
phosphorous) – within
the matrix of bone tissue
oEnergy reserve
(adipose) – within the
yellow marrow of long
bones

8. or blood cell
formation
oRed bone marrow of
an adult produces
white and red blood
cells and platelets.

10. Bones are classified by their basic shape
Flat bones Sutural bones
Irregular bones
Long bones
Short bones
Sesamoid
bones

11. –LONG BONE
• A bone whose length
is greater than its
width.
• Act as levers that are
pulled by
contracting muscles.
• e.g., humerus, femur

12. –FLAT BONE
• Are actually thin or curved
more often then they are
flat.

13. –FLAT BONE
• main function is to
provide protection to the
bodies vital organs and
being a base for muscular
attachment
• e.g ribs, scapulae,
sternum, skull

14. –SUTURAL BONE

15. –IRREGULAR BONES
• They do not fit neatly into
any other category, due to
their non-uniform shape
• e.g. vertebrae, many facial
bones, hipbone

16. –SHORT BONES
• Are about equal in
length, width, and
thickness, but they are
shaped
irregularly
• e.g., carpals,
tarsals, patella

17. –SESAMOID BONES
• Are small bones embedded
within certain tendons.
• Helps the tendon overcome
compression
forces, increasing
the mechanical
efficiency of joints.

19.  The shaft of a long bone
 A hollow cylinder with walls
of compact bone tissue.

20. DIAPHYSIS
(compact bone)

21.  Ends of the long bone and
articulates or meets with a
second bone at a joint
 consist mainly of spongy bone
 surrounded by a thin layer of
compact bone

22. EPIPHYSIS
(spongy bone)
EPIPHYSIS

23. pad of hyaline cartilage on the
epiphyses where long bones
articulate or join.
"shock absorber“ -It forms a
smooth, shiny surface that
decreases friction within a joint.

24. ARTICULAR
CARTILAGE
ARTICULAR
CARTILAGE

25.  remnant of epiphyseal
disk/plate.
cartilage at the junction of
the diaphysis and epiphyses
(growth plate).

27.  is the wider portion of a long
bone adjacent to the epiphyseal
plate.
part of the bone that grows
during childhood; as it grows, it
ossifies near the diaphysis and
the epiphyses.

30. •In the adult- filled with
yellow bone marrow and
functions as a storage site for
fat.
 inside this cavity is lined with
connective tissue called the
endosteum.

31. MEDULLAR
CAVITY
ENDOSTEUM

32. inner lining of medullary
cavity.
contains layer of
osteoblasts & osteoclasts.

33. Double layered membrane
surrounding bone except at
articular cartilage.
Inner cellular layer contains
osteoprogenitor cells, osteoblasts,
osteoclasts; therefore
functions in bone growth &
repair.

34. Outer fibrous layer of dense
irregular CT for attachment of
tendons& ligaments; provides
route for blood vessels &
nerves; separates bone tissue
from surrounding tissues.

35. PERIOSTEUM

36. spongy bone
Proximal compact bone
epiphysis
Endosteum
diaphysis epiphyseal line
yellow marrow
Sharpey’s fibers
Distal
epiphysis periosteum
hyaline cartilage

37. THANK YOU!