Skeletal and Muscular System
Tissue
• A tissue is considered a collection of cells that
are similar in structure and work together to
perform a certain function.
• There are different types of tissue:
– Muscle Tissue
– Nervous Tissue
– Epithelial Tissue
– Connective Tissue
Muscle Tissue
• Muscle tissue is composed of cells that can
contract. Contraction is their main function.
• There is three types of muscle tissue:
– Skeletal muscle: Moves your bones
– Smooth muscle: Movement of bodily functions we
don’t consciously control (Example: our bowels)
– Cardiac Muscle: Pumps the heart and has cells
that can send out an electrical impulse.
Nervous Tissue
• Nervous Tissue is made up of cells that can
send and receive chemical signals.
• Nervous Tissue is made up of neurons.
Epithelial Tissue
• Epithelial Tissue is designed as a covering. It’s
main function is to protect and give support.
• It lines your blood vessels, holds up your
organs and covers the outside of your body.
Connective Tissue
• These tissues are meant to connect and support
structures. They can be solids, liquid or in
between.
• These tissues include:
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Ligament
Tendons
Bone
Cartilage
Fat
Blood
Muscle Cells
• Each single muscle cell is elongated and is
called a fiber.
• Put the muscle fibers together and you have a
fascicles.
Muscle Movement
• Muscle movement is either voluntary or
involuntary.
• Contractions that can be consciously controlled
are called voluntary muscle movements.
• Contractions that can NOT be consciously
controlled are called involuntary muscle
movement.
How do the muscles contract
• With in each muscle fiber there are filaments.
• There is a set of Myosin filaments which have
little hooks and a set of Actin filaments that
look like strands of beads.
• Along the fiber there is a section where Actin
filaments attach. This region is called the
Sarcomere.
How Do muscles Contract
• When nerves in the muscle receive a signal to
contract it stimulates the muscle.
• The Myosin use their little hooks to pull the
Actin Filaments together.
Force
• When a single muscle fiber is stimulated is
contracts fully.
• If more force is needed more fibers are
activated. More Fibers more force.
Tendons
• Skeletal Muscles are generally attached
directly to the bone.
• The muscles itself can attach or a tough
fibrous cord called a Tendon attaches to the
muscle and the bone.
Ligaments/Cartilage
• Ligaments are also hard connective tissue, but
their main purpose is to hold together joints.
• Cartilage is another sturdy tissue, but in this
case it is made to either protect or replace
bone.
The skeleton
• The Skeleton has two main parts, the Axial
and the Appendicular.
• The Axial Skeleton is your skull, ribs, spine,
and sternum.
• Appendicular is the arms, legs and all the
bones that join them to the trunk of your
body.
Bones
• The Skeletal system provides protection and
support, but bones are not completely solid all
the way through.
• Bones have layers……….just like ogres.
Bone Structure
• The surface of a bone has a tough membrane
that is full of blood vessels and nerves.
• This outer layer is called the Periosteum.
Bone Structure
• Under the Periosteum is the hard thick layer
called the Compact Bone.
• This is the part of the bone that gives it its
rigidity and strength.
• It’s made of Proteins and Minerals (calcium)
Bone Structure
• In between the layers of protein are actual
bone cells called Osteocytes.
Bone Structure
• With in the compact bone are channels. Each
Channel carries a blood vein and an artery.
• These Channels are called Haversian Canals
Bone Structure
• Beneath the compact bone is the Spongy
Bone.
• You would think it was soft, but it’s not. It’s
hard and is another form of support and
strength.
Bone Structure
• With in the Spongy Bone is the Bone Marrow.
• Bone Marrow is a softer tissue that produces
red blood cells, platelets, and white blood
cells.
• This is where new blood cells are made.
Bone Development
• In the second month of fetal development the
skeleton is mostly cartilage.
• In the third month minerals start to grow in
between the cells of the cartilage turning the
cartilage to bone.
• This process is called Ossification.
Bone Growth
• After you are born (and through out your teenage
years) your bones continue to grow.
• The growth occurs at the end of your long bones
in an area called the Epiphyseal Plate (growth
plate)
• The plate produces cartilege cells that push
against the shaft of the bone there by elongating
it.
Bone Growth.
• The plate produces cartilage cells that push
against the shaft of the bone there by
elongating it.
• The older cartilage cells die off and are
replaced by bone.
Class work
• Write a paragraph describing the largest
muscle group on your animal as well as why
those muscles are the most developed.
• After you have written your paragraph go to a
lab table and begin the lab.