Do Now
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From class last week. Without the use of your notes
1. Write down the number of bones in the body.
2. Tendons connect what?
3. Name the three bones that make up the forearm?
Answers:
1. 206 (ish) some people have an extra or one less bone
in the their “tailbone.”
• 2. Tendons connect muscle to bone. Tendonitis
(anything itis means inflammation of (aka swelling)).
• Humerous, ulnar & radius
Homework
• Homework from last week was – Read pages 922-927
• 1. You must write a short summary (aka notes!) for
each section (Skeleton, Bones, Joints,….)
• 2. Identify & define each word in bold. For example:
Axial Skeleton.
• Pull that out now
• For tonight – complete the skeletal worksheet
New Material
• Axial Skeleton – maintains the central axis
(line) of the body.
• The Appendicular Skeleton – the bones of
the arms, legs & pelvis.
• The skeleton’s purpose is to give the body
structure, protect the body’s internal organs
(heart, lungs, brain), assist in movement,
stores minerals as well as blood formation
(primarily in the long bones such as
humerus and femur).
• Why / how do people need bone Marrow?
New Material
• Bone Marrow is the center of the bone where
white & red blood cells are made.
• The bones also serve as levers. Think of a
board placed under a rock with a fulcrum
(another rock) used to leverage the rock out.
For example.
• Here are examples of the body’s lever
system. Write each down. The W = weight,
the F = Fulcrum, P = Power
New Material
• Bones – the outer (rigid) layer of the bone is
known as the periosteum.
• The channels within the bones that allow
blood and nerves to run through are known
as Haversian Canals.
• Spongy bones are not as dense as found at
the end of long bones (like the femur).
• Also found in flat bones (clavicle – collar
bone), short bones like in the wrist or feet.
New Material
• Again, within the middle of the bone is bone
Marrow.
• There are two types of bone Marrow:
• 1. Yellow – the yellow contains fat cells which is
why it is yellowish.
• 2. Red – the red is stem cells that produce red
blood cells. This is what they want for bone
Marrow transfers.
• The idea is to allow the new red blood Marrow to
replace the cancer ridden Marrow. They
typically kill the bone Marrow with chemotherapy and then bone Marrow donation.
New Material
• Cartilage is the soft cushion between bones
• Cartilage does NOT contain blood vessels. It
relies on the surrounding tissue for the
blood supply. This is partly why when
people have a knee injury it can be difficult
because the doctor will remove the torn
cartilage which means there is less cartilage
for protection / cushion.
New Material
• Cartilage eventually will form (most but not
all) hard bone in a process called
ossification.
• Osteoblasts – cells that start off as cartilage
and will eventually form bone known as
osteocytes.
• These osteocytes keep the minerals
flowing and continue to strengthen the
bone.
New Material
• Bone grow from the middle out. The end of
the bones contain the softer cartilage to
protect the bones (acting as cushions) and
allowing for greater movement.
• The growth plate is the end of the bones.
Around 18 these epiphyseal plates will
eventually harden. This is why when punch
walls and break bones, doctors are
concerned if the fracture will interrupt the
growth plate.
• If interrupted then growth stops. Not good if
a young child.
New Material
• When a person breaks a bone, the bone
repairs itself because the bone never stops
regenerating.
• People with osteoporosis which is a
weakening of the bone. More common in
women. Often the bone becomes brittle
enough that they fall and cause a break.