Download Notes - The Muscular System

The Muscular System
Skeletal & Muscular Systems - video
Your Muscular Body
• Your skeletal system provides
shape, support, protection
and allows movement but
CANNOT actually move
without the muscular system.
– Your muscles are responsible for
every move you make.
• Blinking, breathing, running and
lifting.
• Muscle make up about 40% of
your body mass.
• More than 600 muscles that
make up the muscular
system.
Muscle Categories & Types
• Two Categories of Muscles:
1. Involuntary muscles
• Not under our conscious control
– breathing, heart beating, digestion
2. Voluntary muscles
• Under our conscious control
– smiling, bending or standing
•
Muscle is make up of muscle tissue.
–
Three kinds:
1.
2.
3.
Skeletal
Smooth
Cardiac
Muscle Types
1. Skeletal Muscle (Striated)
A. Attached to the bones of your skeleton by
tendons used for movement.
i. Pulls on bones to make the body move.
ii. Voluntary – you control them.
B. Made up of long, thin cells that each contain
more than one nucleus.
i.
Biceps, triceps, and quadriceps.
Skeletal Muscle
Muscle Fibers
Nucleus
Striations
Muscle Types
2. Smooth Muscle
A. Located in the internal organs of the body:
i.
Stomach, intestines, kidney, and liver.
a.
b.
Movement of food through the digestive system
Movement of blood through blood vessels
ii. Involuntary – you don’t control them.
B. Made up of spindle-shaped cells that contain
only one nucleus.
Smooth Muscle
Smooth Muscle
Fiber
Nucleus
Muscle Types
3. Cardiac Muscle
A. Found ONLY in the heart!
B. Has characteristics in common with both smooth
and skeletal muscle:
i. Like smooth, it’s involuntary – no control
ii. Like skeletal, it’s striated
Cardiac Muscle
Nucleus
Cardiac
Muscle Fibers
Striations
Muscles and Movement
• Skeletal muscles are held to bone by tendons.
– Tendons allow the muscles to pull on the bones
and move the body.
• The pull of a muscle on a bone is called a
contraction.
– This causes the muscle to get thicker and shorter.
• Because muscles can ONLY contract they must
work in pairs to complete an opposite
movement, relax.
Simulation – bicep/tricep
Biceps/Triceps Muscles
Hinge Joint