Download T6 Naming muscles

Bell Ringer
Describe:
Flexion
• Decreases the angle of the joint
• Brings two bones closer together
• Typical of hinge joints like knee and elbow
Extension
• Opposite of flexion
• Increases angle between two bones
Essentials of Human Anatomy & Physiology
Elaine N. Marieb
Seventh Edition
Chapter 6
The Muscular System
Naming of Skeletal Muscles
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Naming of Skeletal Muscles
 Muscles come in many shapes and sizes.
 Muscles are named on the basis of several
criteria (structure or function)
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Naming of Skeletal Muscles
 Direction of muscle fibers (In reference
to some imaginary line, usually midline of
the body)
 Rectus (straight) and oblique,
Examples: rectus femoris
 Relative size of the muscle
 maximus (largest), minimus (smallest), longus
(long)
 Example: gluteus maximus
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Naming of Skeletal Muscles
 Location of the muscle (For the bone
with which they are associated)
 Example: temporalis and frontalis (overlie
the temporal and frontal bones of the skull)
 Number of origins
Example: biceps, triceps, quadriceps
(Two, three and four heads)
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Naming of Skeletal Muscles
 Location of the muscles origin and
insertion (atachments sites)
 Example: sternocleidomastoid (origin on
the sternum and clavicle and inserts on the
mastoid process of the temporal bone)
 Shape of the muscle
 Example: deltoid (triangular)
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Naming of Skeletal Muscles
Action of the muscle (Name for their
actions)
 Examples:
Flexor and Extensor (flexes or extends a
bone)
The extensor muscles of the wrist all
extend the wrist.
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Arrangement of Fascicles in Muscles
• All skeletal muscles consist of
(bundles of muscle fibers)
• How the fascicles are arranged
resulting in different shapes and
capabilities
• Common patterns – parallel,
convergent, and circular
fascicles
can vary
functional
pennate,
Arrangement of Fascicles in Muscles
• Circular
– Fascicles are arranged
into concentric rings.
– Surround external body
openings.
• Close by contraction
– Aka:
sphincters
(“squeezers”)
– Ex: Orbicularis oris
Arrangement of Fascicles in Muscles
• Convergent
– Has a broad origin and
the fascicles converge
towards a single tendon
of insertion.
– Muscle is triangular or
fan shaped
– Ex: pectoralis major
Arrangement of Fascicles in Muscles
• Parallel
– The long axes of the
fascicles run parallel to
the long axis of the
muscle
– Straplike
or spindle
shaped (expanded belly
of muscle)
• Fusiform
– Spindle
sometimes
separately
shaped
classified