Download • The Muscular System Muscle function and terminology • Five


















The Muscular System
Muscle function and terminology
Five Golden Rules of Skeletal Muscle Activity
Muscles and Body Movements
o Movement is attained due to a muscle moving an attached bone
Muscles are attached to at least two points
o Origin
o Attachment to a moveable bone
o Insertion
Attachment to an immovable bone
Muscles and Body Movements
Types of Ordinary Body Movements
Flexion
o Decreases the angle of the joint
o Brings two bones closer together
o Typical of hinge joints like knee and elbow
Extension
o Opposite of flexion
o Increases angle between two bones
o Types of Ordinary Body Movements
o Types of Ordinary Body Movements
o Types of Ordinary Body Movements
Rotation
o Movement of a bone around its longitudinal axis
o Common in ball-and-socket joints
o Example is when you move atlas around the dens of axis (shake your head “no”)
o Types of Ordinary Body Movements
o Types of Ordinary Body Movements
Abduction
o Movement of a limb away from the midline
Adduction
o Opposite of abduction
o Movement of a limb toward the midline
o Types of Ordinary Body Movements
o Types of Ordinary Body Movements
Circumduction
o Combination of flexion, extension, abduction, and adduction
o Common in ball-and-socket joints
o Types of Ordinary Body Movements
Special Movements
Dorsiflexion
o Lifting the foot so that the superior surface approaches the shin
Plantar flexion
 Depressing the foot (pointing the toes)
 Special Movements
 Special Movements
Inversion






o Turn sole of foot medially
Eversion
o Turn sole of foot laterally
o Special Movements
o Special Movements
Supination
o Forearm rotates laterally so palm faces anteriorly
Pronation
o Forearm rotates medially so palm faces posteriorly
o Special Movements
o Special Movements
Opposition
o Move thumb to touch the tips of other fingers on the same hand
o Special Movements
Types of Muscles
o Prime mover—muscle with the major responsibility for a certain movement
o Antagonist—muscle that opposes or reverses a prime mover
o Synergist—muscle that aids a prime mover in a movement and helps prevent rotation
o Fixator—stabilizes the origin of a prime mover
Naming Skeletal Muscles
o By location of the muscle
 Example: Temporalis (temporal bone)
 By number of origins
o Example: Triceps (three heads)
 Naming Skeletal Muscles
o By direction of muscle fibers
 Example: Rectus (straight)
o By relative size of the muscle
 Example: Maximus (largest)
o Naming Skeletal Muscles
 By location of the muscle’s origin and insertion




o Example: Sterno (on the sternum)
By shape of the muscle
o Example: Deltoid (triangular)
By action of the muscle
o Example: Flexor and extensor (flexes or extends a bone)
Arrangement of Fascicles
Summary
o Know the five rules of muscles
o Know the naming conventions of muscles
o Know the movements that muscles can allow