Transcript The Skeleton System - Mrs. Brenner`s Biology

The Skeletal and Muscular
Systems
Chapter 13 Sections 2 and 3
The Skeletal System
Five functions:
1. Provides shape and support
2. Enables you to move
3. Protects your organs
4. Produces blood cells
5. Stores mineral and other
materials
Backbone
a.k.a Vertebral Column
Made of 26 bones (vertebrae)
Joint: where two bones come
together
Joints allow bones to move in
different ways
Backbone
Ligaments
Connective tissue that
holds bones
together
Cartilage
Connective tissue that
is more flexible
than bone
Covers the ends of
the bones
Prevents friction
Bones are Living!
Bones grow and develop over time
Bones have an outer membrane
Blood and nerves enter the bone through this
membrane
Layers of bone
Compact bone: Dense, but not solid
Spongy bone: Has many small spaces
Marrow: fills large spaces in the bone
Red marrow produces blood cells
Yellow marrow stores fat (energy reserve)
Layers of bone
Bone characteristics
Bones are…
Strong
Lightweight
Hard (contain phosphorus and calcium)
Continually forming new bone tissue
throughout your life
Keeping your bones healthy
Eat a balanced diet (get enough calcium!)
Exercise regularly
As you age, you
lose minerals
This can lead to
osteoporosis
The Muscular System
.• You have more than
600 active muscles in
your body.
• Voluntary: you control
their movements
• Involuntary: move
without your
conscious control
• 3 types of muscle
[smooth, skeletal, and
cardiac.]
Skeletal Muscle
• Skeletal muscles are
attached to your bones
• Tendon: connective
tissue that attaches
muscle to bone
• Skeletal muscles are
also called striated
muscle because they
look striped!
Skeletal (Striated) Muscle
Smooth Muscle
• Smooth muscle is
involuntary
• Smooth muscle lines
many internal organs
• Smooth muscle allows
your esophagus and
stomach to move and
digest your food
• Smooth muscle tires less easily than skeletal
muscle.http://dante.med.utoronto.ca/skeletalmuscle/publicationpictures4.htm
Cardiac Muscle
• Cardiac muscle is
found only in the heart
• Cardiac muscle does
not get tired!
http://www.bio.psu.edu/faculty/strauss/anatomy/skel/atlas.htm
Muscles Contract!
• Muscles work by
contracting (getting
shorter)
• They cannot stretch
out again, so they have
to work in pairs.
• After a muscle
contracts, it’s partner
contracts to stretch the
first one out.
Exercise!
• Exercise makes muscle
cells grow wider,
thicker, and stronger.
• It helps your flexibility
and strength.
• If you get a strain or a
cramp, rest the injured
muscle to allow it to
heal.