Skeletal System
Functions of skeletal system
• Give our body shape so we’re not a puddle of
skin and guts lying on the floor!
• Protect the organs in our bodies, like our
brain, heart, and lungs.
• Produce blood cells-An average of 2.6 million
red blood cells are produced each second by
the bone marrow to replace those worn out
and destroyed by the liver every 3-4 months.
Our skeleton
• When you are born you have
nearly 300 bones in your body,
but as you grow some of those
bones fuse or combine
together to form the average
adult skeleton which has 206
bones!
• The longest of these bones is
the femur, which is commonly
referred to as your thigh bone.
• The smallest of these bones is
your stapes, or stirrup bone in
your ear. It gets its name
because it actually looks like a
stirrup!
Cartilage, Tendons, and Ligaments
• Cartilage: A very tough tissue
found at the ends of most bones
to protect them from rubbing
together. Cartilage absorbs
shock.
• Tendons: Tendons attach bone to
muscle. Our largest tendon is our
“Achilles tendon”. An injury to a
tendon is often referred to as a
strain.
• Ligaments: Ligaments attach
bone to bone. An injury to a
ligament is often referred to as a
sprain. The most commonly
injured ligaments are those in
your knee (ACL, MCL, LCL, PCL)
and ankle.
Kinds of fractures
• A common problem with
the skeletal system is bone
breaks. There are two kinds
of bone breaks, sometimes
called fractures.
• The first kind, simple
fracture, is when the bone
breaks but does not come
through the skin.
• The second kind, compound
fractures, are more severe
breaks which come through
the skin.
More compound fractures
Common causes of bone fractures
• The most common cause
of a bone fracture is a fall
or sports injury.
• Broken bones need to be
put into casts so the bone
can re-connect to it’s
original state before the
fracture. Often times,
when a bone is broken, it
heals stronger than it was
before it was broken.
Problems with the skeletal system
• Anemia: When a person does
not make enough healthy red
blood cells in the bone
marrow.
• Osteoporosis: A condition
where the bone becomes very
fragile and can easily break.
This is most common in postmenopausal women because
of a lower level of estrogen.
Also, a lack of calcium in the
body can lead to
osteoporosis…so drink your
milk.
Cranium (Skull)
Mandible (jaw bone)
Clavicle (Collar bone)
Scapula (Shoulder blade)
Sternum (Breast bone)
Humerus (Arm bone)
Ribs (Ribs?)
Vertebrae (Back bones)
Pelvis (Hip bone)
Radius (Forearm bone)
Ulna (Forearm bone)
Phalanges (Fingers)
Femur (Thigh bone)
Patella (Kneecap)
Tibia (Shin bone)
Fibula
Phalanges (Toes)