Muscle Gross Anatomy

Muscles of the Face, Neck, Abdomen, Thorax

What are the four functional classifications of muscles?

Primer Mover (Agonist)
Synergist
Antagonist
Fixator

What is a Primer Mover (Agonist)

The muscle most responsible for a movement or action

What is a Synergist?

Aids a prime mover (agonist)

What is an Antagonist?

Opposes action of prime mover

What is a Fixator?

Stabilizes origin of prime mover; holds it steady

Muscles of the Face

Frontalis
Occipitals
Orbicularis Oculi
Orbicularis Oris
Buccinator
Zygomaticus Minor
Zygomaticus Major
Platysma
Masseter
Temporalis

Frontalis

Occipitalis

Orbicularis Oculi

Buccinator

Zygomaticus Minor

Zygomaticus Major

Platysma

Masseter

Temporalis

Orbicularis Oris

Buccinator

Muscles of the Neck

Platysma
Digastric
Mylohyoid
Sternohyoid
Sternocleidomastoid
Scalenes

Digastric

Mylohyoid

Sternohyoid

Sternocleidomastoid

Scalenes

Splenius Capitis

Muscles of the Abdomen

External Oblique
Internal Oblique
Transversus Abdominis
Rectus Abdominis

Which layer does the External Oblique form?

Superficial Layer

External Oblique

Internal Oblique

Transversus Abdominis

Rectus Abdominis

Which layer does the Internal Oblique form?

Intermediate Layer

Which layer does the Transverse Abdominus form?

Deep Layer

Muscles of the Thorax

Pectoralis Major
Pectoralis Minor
Serratus Anterior
Diaphragm
External Intercostals
Internal Intercostals

Pectoralis Major

Pectoralis Minor

Serratus Anterior

Deltoid

Diaphragm

External Intercostals

Internal Intercostals

Frontalis Muscle Function

Raises eyebrows

Occipitalis Muscle Function

Pulls scalp posteriorly

Orbicularis Oculi Muscle Function

Closes eye

Orbicularis Oris Muscle Function

Closes and protrudes lips

Buccinator Muscle Function

Manipulate food during chewing
Expels air through pursed lips

Zygomaticus Major Muscle Function

Pulls angle of mouth superiorly and laterally
(Smiling)

Zygomaticus Minor Muscle Function

Raises lateral portion of upper lip
(Smiling)

Platysma Muscle Function

Depresses lower lip
Depresses mandible
Tenses skin of neck

Masseter Muscle Function

Elevates mandible

Temporalis Muscle Function

Elevates and retracts mandible

Digastric Muscle Function

Depresses mandible
Fixator of the hyoid bone during swalloing

Mylohyoid Mucle Muscle Function

Elevates hyoid and floor of mouth
Assists tongue to push food toward the pharynx

Sternohyoid Muscle Function

Depresses hyoid and larynx

Sternocleidomastoid Muscle Function

Bilateral action: Flexes head
Unilateral Action: Lateral flex the head toward the same side, rotate to the opposite side

Scalenes Muscle Function

Bilateral Action: Flexes head; elevates rib cage with vertebral column during forced inspiration
Unilateral Action: Rotate head laterally

Pectoralis Major Muscle Function

Flexes and adducts the arm
Rotates arm medially

Pectoralis Minor Muscle Function

Protracts and depresses scapula

Serratus Anterior Muscle Function

Protracts scapula
Assists in upward rotation of scapula

Diaphragm Muscle Function

Flattens to lower floor of thoracic cavity, increasing volume

External Intercostals Muscle Function

Elevates rib cage

Internal Intercostals Muscle Function

Depresses rib cage

External Oblique + Internal Oblique + Transversus Abdominus Muscle Function

Bilateral Action: Flexes the trunk
Unilateral Action: Laterally bends the trunk

Rectus Abdominus Muscle Function

Flexes the trunk

Which muscles are responsible for Facial Expression?

Frontalis
Occipitalis
Orbicularis Oculi
Orbicularis Oris
Buccinator
Zygomaticus Major
Zygomaticus Minor
Platysma

Which muscles are responsible for Mastication?

Masseter
Temporalis

Muscles of the Shoulder and Back

Trapezius
Deltoid
Latissimus Dorsi
Supraspinatus
Infraspinatus
Subscapularis
Rhomboid Major
Rhomboid Minor
Teres Major
Teres Minor
Splenius Capitis
Levator Scapulae

Superficial Muscles of the Shoulder and Back

Trapezius
Deltoid
Latissimus Dorsi

Deep Muscles of the Shoulder and Back

Supraspinatus
Infraspinatus
Subscapularis
Rhomboid Major
Rhomboid Minor
Teres Major
Teres Minor
Splenius Capitis
Levator Scapulae

Trapezius

Deltoid

Latissimus Dorsi

Levator Scapulae

Rhomboid Minor

Rhomboid Major

Supraspinatus

Infraspinatus

Teres Minor

Teres Major

Splenius Capitis

Trapezius

Deltoid

Latissimus Dorsi

Levator Scapulae

Splenius Capitis

Supraspinatus

Infraspinatus

Teres Minor

Teres Major

Rhomboid Minor
Rhomboid Major

Trapezius Muscle Function

Extends the head
Retracts Scapula
Depresses Scapula
Rotates Scapula upward

Deltoid Muscle Function

Abducts the arm
Secondarily flexes and extends the arm

Latissiumus Dorsi Muscle Function

Adducts the arm
Extends the arm
Rotates arm medially

Supraspinatus Muscle Function

Assists abduction of the arm
Holds the humerus
Stabilizes the shoulder joint

Infraspinatus Muscle Function

Rotates the arm laterally
Stabilizes shoulder joint

Subscapularis Muscle Function

Adducts and rotates the arm medially
Stabilizes the shoulder joint

Teres Minor Muscle Function

Rotates the arm laterally
Stabilizes shoulder joint

Levator Scapulae Muscle Function

Elevates Scapula