Skeletal
System
What is the skeletal system?
 Skeletal
system consists of bones, teeth, joints,
& structures that connect bones to other bones or
muscles (ligaments, tendons, & cartilage).
Brainstorm … What are
the functions of the
skeletal system?
(why is it important)
1. Support
 Many
bones provide support, but long bones
especially important
 Acts as the frame for the rest of the body


long bones in legs help support the trunk
other than long bones
 the
first vertebra supports
the skull
2. Protection
 Protect


vital internal organs
skull ->the brain
rib cage ->heart, lungs, & abdominal organs
3. Movement
 Combination
w/muscular system, the
skeletal system aids in movement

Skeletal muscles are attached to bones
by tendons that act as a lever to move
bones.
4. Mineral Storage
 Outer
layers of bony tissues are used for the
storage of minerals (primarily calcium and
phosphorus)
5. Blood Cell Formation &
Energy Storage
 Inner

core of bone ->bone marrow
Red marrow is a major site of blood cell & platelet
formation.
 Yellow
bones

marrow ->long bones & other mature
Yellow marrow consists mostly of fat & serves as
an energy reserve.
What is the purpose?
Why is it important?
Provides
frame and
support
Aids movement
Protects vital organs
Mineral storage
Blood cell formation
TURN AND TALK
Which
of the 5
functions is the most
important and why?
3 cell types found in bones



1. Osteoblasts form a bone structure by secreting
collagen, become enclosed in the matrix, & develop
into osteocytes. (BUILD NEW BONE)
2. Osteocytes - exchange of nutrients & wastes
with blood (SITE OF CYTE EXCHANGE)
3. Osteoclasts secrete enzymes that digest bone.
 Bone
is a living tissue that is continually remodeled in
response to the body’s need for calcium
 Osteoclasts are important in the development, growth,
maintenance, & repair of bone (CLASH to break DOWN
OLD BONE)
TYPES OF BONE
 Short
bone – cube shaped, (think complex joins
like the hock or knee) i.e. carpus and tarsus
 Flat bone – plate of bone, (think thin and curved
to protect organs) i.e. scapula, rib, skull
 Irregular bone – complex shaped attached to
muscles, i.e. vertebrae
 Long bone – bone is longer that it is wide, i.e.
femur, tibia, humerus, etc. (think legs/support)
 NOT
AS COMMON IN ANIMALS EXCEPT IN
PAWS/HANDS

Sesamoid – small, seed-shaped bone, i.e. proximal and
distal sesamoids, patella
How are bones classified?
 Long
bones – femur
 Short bones – knee
 Flat bones – ribs, scapula
 Irregular bones – vertebrae
 Sesamoid bones –knee cap
Test Your Knowledge
Can
you ID what “type” of
bone each of these
examples are?