Voluntary Muscles (skeletal)
Names of Muscles
Deltoid
Biceps
Abdominals
Quadriceps
Pectoral
Latissimus Dorsi
Trapezius
Triceps
Gluteals
Hamstrings
Gastrocnemius
Three types of muscles.
• Cardiac
• This muscle is only found in the walls of the
heart.
• They contract and relax the heart
continuously to pump blood through it,
without conscious effort from you.
• Involuntary Muscles - smooth
• These are the muscles around organs
such as the intestines and blood vessels.
Like the cardiac muscles, they work
without conscious effort from you.
• Voluntary Muscles - skeletal
• These muscles are attached to the skeleton
and are under your control.
Different types of joints
Antagonist & Agonist
• Muscles can only pull. To make a joint
move in two directions, you need two
muscles that can pull in opposite
directions.
– Antagonistic muscles are pairs of
muscles that work against each other.
• One muscle contracts (agonist, or
prime mover) while the other one
relaxes (antagonist) and vice versa.
_______________
tendon
_______________
tendon
_______________
tendon
_______________
tendon
forearm is lowered
Origin & Insertion
• Muscles are attached to two different bones by
tendons. When the muscle contracts only one bone
moves.
• The place where the muscle is attached to the
stationary bone is called the Origin.
• The place where the muscle is attached to the
moving bone is called the Insertion.
Origin
FLEXION
Insertion
___origin _____
tendon
___insertion___
tendon
___origin______
tendon
___insertion____
tendon
forearm is lowered
Synergists
• Any other muscle which helps the prime
mover to cause a movement is a
Synergist.
• An example of this is when bending the
arm at the elbow, the synergist would be
the brachialis muscle in the forearm.
Agonist and Antagonist Muscles
Agonist Muscle
Preparing to
kick a ball
Kicking a
football
Abduction of the
arm from the side
of your body
Bicep curl
Antagonist
Muscle
Questions
For the following movements give the agonist
and antagonist
Bicep Curl
a) Preparing to kick a ball
b) Kicking a football
c) Abduction of the arm from the side of your
body
d) Bicep curl