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Quick Quiz Complete each of these statements with
always, sometimes, or never.
I ____ warm up before exercising.
When I ride a bicycle or play contact sports, I
____ wear a helmet and other protective gear.
When I ride in a vehicle, I ____ fasten my seat
belt.
My backpack for school is ____ less that 15 of
my body weight.
I ____ make an effort to eat balance meals and
exercise regularly.
Why do you think that teens might not always
practice these healthful behaviors?
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Section 11.1
Your Skeletal System
Goals/Objectives
Identify the five main roles of the
skeletal system.
Describe the functions of bones and joints.
Explain how you can keep your skeletal system
healthy.
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Key Terms
Skeletal system
The body system that serves as a support
framework, protects vital organs, works with
muscles to produce movement, and produces blood
cells.
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Functions of the Skeletal System
Your skeletal system has five main roles.

• provides support

• protects internal organs

• allows your body to move

• stores and produces materials that your body
  needs (blood cells)

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Support and Protection

• Your skeleton is made up of all the bones inyour
  body.

• Your skeleton gives your body its basic shape and
  provides the support that you need.

• Many bones of the skeletal system protect
  internal organs.

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Movement
In coordination with your muscular and nervous
systems, your skeletal system allows you to move.
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Storage and Production of Materials

• Your bones store essential substances which are
  released when other parts of the body need them.

• Some bones also produce blood cells.

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Skull
The Skeletal System
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1) Sternum (breastbone)
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2) Vertebral column (backbone)
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3) Carpals
12) Ribs
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4) Metacarpals
13) Radius
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5) Phalanges
14) Ulna
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6) Tarsals
15) Pelvic girdle
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16) Femur
7) Metatarsals
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17) Patella
8) Phalanges
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18) Fibula
9) Clavicle (collarbone)
10) Scapula (shoulder blade)
19) Tibia
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11) Humerus
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Skull
The Skeletal System
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1) __________________
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2) _____________________
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3) ____________
12) ______
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4) ____________
13) ________
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5) ____________
14) ______
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6) ____________
15) __________
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16) ________
7) ____________
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17) ________
8) ____________
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18) ________
9) ____________
10) __________________
19) _______
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11) ____________
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Radius
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Carpals
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Fibula
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Phalanges
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Bones and Joints

• Your skeletal system is made up of just over 200
  bones.

• A place in your body where two or more of your
  bones come together is called a joint.

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Development of Bones

• Your bones are living structures that undergo
  change throughout your life.

• Cartilage is a tough supportive tissue that is
  softer and more flexible than bone.

• By young adulthood, most of this cartilage is
  replaced by bone in a process called
  ossification.

• In a process called ossification minerals, such
  as calcium and phosphorus, are deposited within
  the cartilage, making it hard.

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Structure of Bones

• Bone consists of two different types of
  tissuecompact bone and spongy bone.

• Another type of tissue called marrow fills the
  spaces in bones.

• There are two types of marrowred and yellow.

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Compact Bone Compact bone makes up theouter
layer of all bones. Althoughit looks dense and
solid, It is fullof holes for nerves and blood
vessels.
Spongy Bone Spongy bone contains flatand
needlelike structuresthat resist stress. Red
bonemarrow may fill the openspaces in some
bones.
Outer Membrane An outer membranecovers most of a
long bone.The inner portion of a membrane
contains cells that build up and breakdown bone.
Central Cavity Central cavities in long bones
usually contain yellow bone marrow (fat).
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Joints

• Joints allow for movement and protect bones from
  friction and force.

• Bones are held together at joints by strong,
  fibrous bands called ligaments.

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Pivot Joint A pivot joint connects your head to
the first vertebra in your backbone. It allows
you to turn your head from side to side.
Ball-and-Socket Joint A ball-and-socket joint
allows movement in all directions. Your shoulders
and hips are ball-and-socket joints.
Gliding Joint Gliding joints allowmovement in
many directions as the bones slide along each
other. Your wrists and ankles contain gliding
joints.
Hinge Joint Hinge joints allow bending and
straightening movements.Your knees and elbows
are hinge joints.
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1)_______ Joint connects your head to the first
vertebra in your backbone. It allows you to
turn your head from side to side.
3)_____________ Joint allows movement in all
directions. Your shoulders and hips are these
joints.
2)_______ Joint allow movement in many
directions as the bones slide along each other.
Your wrists and ankles contain these joints.
4)_______ Joint allow bending and straightening
movements. Your knees and elbows are these
joints.
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FYI Cracking Knuckles

• Cracking knuckles has not been clearly linked to
  causing arthritic problems.
• The popping or cracking sound is normal.
• When a joint is pulled, lower pressure is created
  in the joint area, causing tiny air bubbles to
  break.
• Which is the noise people hear.

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Keeping Healthy

• A combination of eating well, exercising, and
  avoiding injuries contributes to lifelong bone
  andjoint health.

• Regular medical checkups can help detect skeletal
  system problems.

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Eating Well

• Adequate intake of calcium and phosphorus will
  help your bones grow to their maximum size and
  strength.

• Osteoporosis is a condition in which the bones
  become weak and break easily.

• Other nutrients that are important for bone
  health include potassium, magnesium, and vitamins
  A, C, and D.

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Exercising

• Another way to build strong bones and prevent
  osteoporosis is to get plenty of weight-bearing
  exercise.

• Activities in which the bones support the entire
  weight of your body help your bones grow strong
  and dense.

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Avoiding Bone Injuries

• A fracture is a break in a bone.

• You can protect your bones from fractures.

• When participating in a physical activity, wear
  appropriate safety equipment, such as helmets and
  pads.

• Always wear a seat belt when traveling in a
  vehicle.

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Avoiding Joint Injuries
Proper warm-up and stretching exercises are
important to help prevent joint injuries.

• Sprains - A sprain is an overstretched or torn
  ligament.

• Dislocations - In a dislocation, the ends of the
  bones in a joint are forced out of their normal
  positions.

• Torn Cartilage - Serious damage to the cartilage
  between the bones in a joint is known as torn
  cartilage.

• Overuse Injuries - When an activity is performed
  too often or too strenuously, joints may become
  irritated and inflamed.

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Medical Checkups

• A doctor can advise you on how to prevent serious
  injury or recommend other professionals who can
  help you.

• A nurse or doctor may check your spine for
  scoliosis, an abnormal curvature of the spine.

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Questions

1. List the 4 main functions of the skeletal system.
2. Explain the function of bones.
3. Describe the two types of bone marrow.
4. What is a joint? Describe the function of movable
   joints in the body.
5. Identify 4 ways you can help your skeletal system
   stay healthy.
6. What type of joint allows you to kneel down?
7. What type of joint allows you to move your arm in
   a circle?
8. If you run your fingers down the center of your
   back, which bones can you feel?
9. What joint allows you to wave hello to a friend?
   What type of joint is it?
10. What connects bones?