Introduction to
myology. Functional
anatomy of muscle.
Function of Skeletal Muscles
1.
Skeletal movement
2.
Posture and body position
3.
Support of soft tissues
4.
Guarding of entrances & exits
5.
Maintenance of body temperature
Gross Anatomy
Each skeletal muscle is wrapped by 3 concentric layers of
connective tissue.
Epi-, Peri-, and Endomysium
Are interwoven - Go over into tendon
Distinguish between:
Tendon
Aponeurosis
Ligament
Function:
Protection
Blood supply
Innervation
Fig 9-1
Nerve and Blood Vessel Supply
Skeletal muscles are rich in nerves
and blood vessels
Chemical communication at Synapsis
(neuromuscular junction)
Synaptic terminal of axon meets motor end
plate of muscle cell
Coiled capillaries are able to adapt to
changes in length of muscle fiber
Sarcomeres
Thick and Thin Filaments are organized in
repeating functional units
Each myofibril has linear arrangement of
~ 10,000 sarcomers
Banded appearance (striation) due to arrangement
of thick and thin filaments
Interaction of thick and thin filaments
responsible for skeletal muscle fiber contraction
Development of Myofibers from
Myoblasts
Some Myoblasts do not fuse
satelite cells in endomysium
regeneration of muscle
Organization of Skeletal Muscle Fibers
Effect of individual muscle contraction
determined by:
1. arrangement of muscle fibers
2. way of attachment to skeletal system
Bundles of muscle fibers = muscle
Muscle fibers within 1 fascicle are parallel
4 types of fascicle organization
Parallel Muscels
Majority
Spindle shaped with
cord-like tendons
Some flat bands with
broad tendons on
each end
Convergent muscels
Broad origin,
pointed
insertion
Direction of pull
can be varied:
versatility!!
Example = deltoid
Pennate Muscles: Unipennate
One or more tendons
run though muscle
body
Fascicles in oblique angle
to tendon
Can generate more
tension
Example = biceps brachii
Pennate Muscles:
Bipennate &
Multipennate
Circular Muscles
= Sphincters
Concentric fibers
adjust opening
Examples: orbicularis
occuli and oris
Muscle Terminology
Flexor
Origin
Agonist
Synergist
Extensor
Insertion
Antagonist
Possible: multiple origins
Note: Agonist = Prime
Mover
Types of Actions
 flexion, extension
 adduction, abduction
 elevation, depression
 rotation,
circumduction
 pronation, supination
etc. . . .
Grouping of Muscles according to
Primary Action
Agonist = Prime Mover
Antagonist (action opposes agonist)
Synergists = Assistants of prime mover
Naming of skeletal Muscles
1.
Orientation of fibers: rectus, transverse, oblique
2.
Size & shape: maximus, longus, brevis
rhomboideus, trapezius, triceps, biceps
3.
Location: pectoralis, intercostal, brachia
4.
Action: adductior, flexor, extensor, pronator
5.
Origin & / or insertion: temporalis,
sternocleidomastoid
6.
Relative position: lateral, external
MUSCLES OF THE BODY
Part 1: The Axial Musculature
 Consists of the
 Head and Neck
 Spine
 Ribs
The Head (and face)
1. MIMIC MUSCLES
A. Muscle Calvarial:
 m. occipitofrontalis
 m. temporoparietalis
 m. procerus
B. The muscles surrounding the eye slit:
 m. orbicularis oculi
 m. corrugator supercilii
C. The muscles of the ear:
 m. auricularis anterior
 m. auricularis superior
 m. auricularis posterior
D. The muscles surrounding the nostrils:
 m. nasalis
 m. depressor septi nasi
E. The muscles surrounding the mouth slit:
 m. orbicularis oris
 m. levator labii superioris
 m. levator anguli oris
 m. depressor labii inferioris
 m. depressor anguli oris
 m. zygomaticus major
 m. zygomaticus minor
 m. buccinators
 m. risorius
 m. mentalis
2. Muscles of Mastication
(chewing)

m. masseter
 m. temporalis
 m. pterygoideus medialis
 m. pterygoideus lateralis
The Neck
1. Superficial muscles:
- m. platisma
- m. sternocleidomastoideus
- the muscles that attach to the hyoid bone:
A. mm. suprahyoidei:
B. mm. infrahyoidei:
1. m. digastricus
1. m. sternohyoideus
2. m. stylohyoideus
2. m. sternothyroideus
3. m. mylohyoideus
3. m. thyrohyoideus
4. m. geniohyoideus
4. m. omohyoideus
2. Deep muscles:
A. Lateral group:
- m. scalenus anterior
- m. scalenus medius
- m. scalenus posterior
B. Medial group:
- m. longus capitis
- m. longus colli
- m. rectus capitis
anterior
- m. rectus capitis
lateralis
The Spine
1. Superficial muscles:
2. Deep muscles:
- m. trapezius
- m. latissimus dorsi
- m. rhomboideus major
- m. rhomboideus minor
- m. levator scapulae
- m. serratus posterior superior
- m. serratus posterior inferior
- m. splenius capitis
- m. splenius cervicis
- m. erector spinae
- m. transversospinalis
- mm. interspinales
- mm. intertransversarii
- suboccipital muscle group:
1. m. rectus capitis posterior major
2. m. rectus capitis posterior minor
3. m. obliquus capitis inferior
4. m. obliquus capitis superior
The Abdominal Group
1. Muscle sidewalls 2. Anterior muscles
of the abdominal
abdomen:
- m. oblique externus
abdominis
- m. oblique internus
abdominis
- m. transversus
abdominis
wall:
- m. rectus abdominis
- m. pyramidalis
3. Posterior muscles
of the abdominal
wall:
- m. quadratus lumborum
Chest muscle
1. Superficial:
2. Own:
- m. pectoralis major
- m. pectoralis minor
- m. subclavius
- m. serratus anterior
- mm. intercostales externi
- mm. intercostales interni
- mm. subcostales
- m. transversus thoracic
- mm. levatores costarum
Part 2: The Appendicular
Musculature
The muscles of the upper limb:
A. The muscles of the shoulder girdle:
- m. deltoideus
- m. supraspinatus
- m. infraspinatus
- m. subscapularis
- m. teres major
- m. teres minor
B. Shoulder muscles:
 Anterior group of
 Posterior group of
muscles:
- m. coracobrachialis
- m. brachialis
- m. biceps brachii:
1. caput breve
2. caput longus
muscles:
- m. anconeus
- m. triceps brachii:
1. caput laterale
2. caput mediale
3. caput longus
C. Forearm muscles:
 Anterior group:
- m. brachioradialis
- m. pronator teres
- m. flexor carpi radialis
- m. flexor carpi ulnaris
- m. palmaris longus
- m. flexor digitorum
superficialis
- m. flexor digitorum
profundus
- m. flexor pollicis longus
- m. pronator quadratus
 Posterior group:
- m. extensor carpi radialis
longus
- m. extensor carpi radialis
brevis
- m. extensor digitorum
- m. extensor digiti minimi
- m. extensor carpi ulnaris
- m. supinator
- m. abductor pollicis longus
- m. extensor pollicis brevis
- m. extensor pollicis longus
- m. extensor indicis
D. Hand muscles
 The Thenar Muscles:
- m. abductor pollicis
brevis
- m. opponens pollicis
- m. flexor pollicis brevis
- m. adductor pollicis
 The Hypothenar Muscles:
- m. palmaris brevis
- m. abductor digiti minimi
- m. opponens digiti minimi
- m. flexor digiti minimi brevis
 Muscles of the Hollow of the Hand:
- mm. lumbricales
- mm. interossei palmares
- mm. interossei dorsales
The muscles of the lower limb:
A. Pelvic muscles:
 Internal group:
 External group:
- m. iliopsoas
- m. iliacus
- m. psoas major
- m. psoas minor
- m. obturatorius internus
- m. gemellus superior
- m. gemellus inferior
- m. piriformis
- m. gluteus maximus
- m. gluteus medius
- m. gluteus minimus
- m. tensor fasciae latae
- m. quadratus femoris
- m. obturatorius externus
B. The Thigh Muscles
 Anterior group:
- m. sartorius
- m. quadriceps femoris:
1. m. rectus femoris
2. m. vastus lateralis
3. m. vastus medialis
4. m. vastus intermedius
 Medial group:
- m. gracilis
- m. pectineus
- m. adductor longus
- m. adductor brevis
- m. adductor magnus
 Posterior group:
- m. biceps femoris
- m. semitendinosus
- m. semimembranosus
C. Muscles of the Leg:
 Anterior group:
- m. tibialis anterior
- m. extensor digitorum
longus
- m. extensor hallucis longus
 Lateral group:
- m. peroneus longus
- m. peroneus brevis
 Posterior group:
- m. triceps surae:
1. m. gastrocnemius
2. m. soleus
- m. plantaris
- m. flexor digitorum longus
- m. flexor hallucis longus
- m. tibialis posterior
- m. popliteus
D. Muscles of the Foot:
 The Dorsal Muscles:
- m. extensor digitorum brevis
- m. extensor hallucis brevis
 The Plantar Muscles:
 Middle group:
- m. flexor digitorum brevis
- m. quadratus plante
- mm. lumbricales
- mm. interossei plantaris
- mm. interossei dorsalis
 Medial group:
- m. abductor hallucis
- m. flexor hallucis brevi
- m. adductor hallucis
 Lateral group:
- m. abductor digiti minimi
- m. flexor digiti minimi brevis
- m. opponens digiti minimi