Muscular System
PART II
Muscular System PART II
OBJECTIVES
Muscle Movements, Types and Names (pp. 198 – 206)
• Define prime mover, antagonist, synergist, and fixator as they relate to muscles.
• Identify these types of body movements (from images): flexion/extension,
supination/pronation, adduction/abduction, and inversion/eversion
• List some criteria used in naming muscles.
Gross Anatomy of Skeletal Muscle (pp. 206 – 219)
• Name and locate the major muscles of the human body.
Developmental Aspects (p. 221)
• Explain the importance of a nerve supply and exercise in keeping muscles
healthy.
• Describe the changes that occur in aging muscles.
Systems in Sync (p. 222)
• Describe the homeostatic relationship between the muscular system and any
one other system.
Anterior and
Posterior Diagrams
*See Text
p. 216 and 218
What’s in a name?
MUSCLES ARE NAMED ACCORDING TO:
1. Muscle size - Examples: Gluteus maximus vs. Gluteus medius
(Incidentally, there is also a Gluteus minimus…)
2. Muscle shape – Examples: Trapezius and Rhomboideus
3. Associated bones – Examples: Zygomaticus
4. Action of the muscle – Example: Masseter and Flexor carpi
ulnaris
More about names……
• Orbicularis - orbit, circular muscle
Major/Minor - large/small or sometimes upper and lower
Vastus - large
Dorsi or Dorsal - backside
Infra / Supra - lower and upper
Longis / Brevis - long/ short (brief)
Medialis / Lateralus - medial (toward the inside), lateral
(toward the outside)
Major Muscles of the Face and Neck
A. Frontalis
F. Temporalis
G.
Obicularis
oculi
B. Occipitalis
C. Masseter
D. Sternocleidomastoid
H. Zygomaticus
I. Obicularis oris
J. Buccinator
K. Platysma
A Human Body Dissected
Major Muscles of the Anterior Trunk
A. Sternocleidomastoid
H. Zygomaticus
B. Pectoralis minor
I. Deltoid
J. Pectoralis major
C. Intercostals
D. Serratus anterior
E. Rectus abdominus
F. Internal oblique
G. Transversus abdominus
K. External oblique
Major Muscles of the Posterior Trunk
D. Levator scapulae
A. Trapezius
B. Deltoid
C. Latissimus dorsi
F. Infraspinatus
H. Teres major
I. Rhomboideus
Two areas used for intramuscular injections
• Deltoid
• Gluteus medius
Major Muscles of the Lower Arm
(Pronated – radius rotated over ulna)
A. Triceps brachii
D. Extensor carpi radialis
B. Flexor carpi ulnaris
(C. and E.) Extensors
Major Muscles of the Lower Arm
(Supinated – radius and ulna are parallel)
A. Biceps brachii
D. Brachioradialis
E. Flexor carpi radialis
F.-G. various flexors
*Define prime mover, antagonist, synergist, and fixator as they relate to muscles.
A prime mover is the muscle that has the major responsibility for causing a movement.
Synergists – reinforce the same movement
as the prime mover. If it stabilizes the
Antagonists – oppose or reverse a movement.
movement it may be called a fixator.
Major Muscles of the Anterior Upper Leg
B. Sartorius
E. Adductors
C. Rectus femoris
D. Vastus lateralis
F. Gracilis
G. Vastus medialis
Major Muscles of the Posterior Upper Leg
A. Gluteus medius
D. Gracilis
E-F. Semitendinosus*
G. Gastrocnemius
B. Gluteus maximus
C. Iliotibial tract
H. Biceps femoris*
*E. F. and H. are commonly
known as the Hamstrings.
Major Muscles of the Lateral Upper Leg
A. Gluteus medius
B. Gluteus maximus
C. Biceps femoris
E. Sartorius
F. Rectus femoris
G. Vastus lateralis
Major Muscles of the Lateral Lower Leg
A. Biceps femoris
B. Vastus lateralis
C. Gastrocnemius
D. Soleus
E. Tibialis
Muscle Movements
Developmental Aspects
1. Embryonic Development
• laid down in segments and then nervous tissue develops
Maturation of Muscle Control
• cephalic to caudal direction (head to tail)
• Babies raise their head, then sit up, and then stand
• proximal to distal direction- gross motor skills first, fine motor skills last
Aging Effects
• atrophy- decrease in muscle tissue, increase in
connective tissue over time
• muscles become stringier, more sinewy
• decreased muscle strength
• aging can be delayed (and to a degree reversed)
with regular exercise