LESSON 11 IMPORTANT SKELETAL MUSCLES Head, neck, thorax, abdomen, back and pelvic floor

Objectives At the end of this lesson, you should be able to: 1. Describe organization of muscle organ 2. List muscles of facial expression 3. Describe the functions of muscles of facial expression 4. Classify and describe muscles of the head 5. Classify and describe muscles of the neck 6. Classify and describe muscles of the trunk – back, thorax, abdomen & pelvic floor

Organization of muscle organ Skeletal Muscle Cell Facial Muscles – Terminology

• “Levator. . .” - Raises • “Depressor. . .” - lowers • “Major” – the larger • “Minor” – the smaller • “Superioris” – superior • “Inferiorioris” – inferior • “Orbicularis” - encircles Facial Muscles – Surprise Occipitofrontalis /Epicranial M

• Epicranial: Raises forehead, pulls scalp backward Facial Muscles – Surprise

• Epicranial: Raises forehead, pulls scalp backward Facial Muscles – Closing Eyelid

• Orbicularis oculi: Closes eyelid

Facial Muscles – Closing Eyelid

• Orbicularis oculi: Closes eyelid

Facial Muscles – Frowning

• Corrugator supercilii: Draws eyebrow medially Facial Muscles – Frowning

• Corrugator supercilii: Draws eyebrow medially Facial Muscles – Closing Lips

• Orbicularis oris: Closes or purses lips Facial Muscles – Closing Lips

• Orbicularis oris: Closes or purses lips Facial Muscles – Assist Chewing

• Buccinator: Moves “bolus” of food Facial Muscles – Opening

• Risorius: Smile widely

Fig 4-12 Facial Muscles – Opening

• Risorius: Smile widely Facial Muscles – Raising Upper Lip

• Levator labii superioris: Raises upper lip Facial Muscles – Raising Upper Lip

• Levator labii superioris: Raises upper lip Facial Muscles – Raising Upper Lip

• Levator labii superioris alaeque nasi: Raises upper lip and widens nostril Facial Muscles – Raising Upper Lip

• Levator labii superioris alaeque nasi: Raises upper lip and widens nostril Facial Muscles – Smiling • Zygomaticus major: Draws cheek back and corner of mouth open • Zygomaticus minor: Raises upper lip • Levator anguli oris: Raises angle of mouth

Facial Muscles – Smiling

• Zygomaticus major: Draws cheek back and corner of mouth open • Zygomaticus minor: Raises upper lip • Levator anguli oris: Raises angle of mouth

Facial Muscles – Frowning & Lowering Lower Lip

• Depressor anguli oris: Lowers angle of mouth • Depressor labii inferioris: Lowers lower lip

Facial Muscles – Frowning

• Depressor anguli oris: Lowers angle of mouth • Depressor labii inferioris: Lowers lower lip

Facial Muscles – Raising Chin

• Mentalis: Raises chin, protrudes lower lip, and Decreases depth of lower vestibule. Facial Muscles – Raising Chin

• Mentalis: Raises chin, protrudes lower lip, and decreases depth of lower vestibule. Facial Muscles – Grimacing

• Platysma: Raises skin of neck and lowers corner of mouth. Facial Muscles – Grimacing

• Platysma: Raises skin of neck and lowers corner of mouth MUSCLES OF FACIAL EXPRESSION 1. Orbicularis oculi 2. Nasalis 3. Orbicularis oris 4. Levator labii superioris 5. Levator anguli oris 6. Zygomaticus major 7. Zygomaticus minor 8. Risorius 9. Depressor anguli oris 10.Depressor labii inferioris 11.Mentalis

Muscles of Mastication 1. MASSETER 2. TEMPORALIS 3. LATERAL PTERYGOID 4. MEDIAL PTERYGOID

MUSCLES OF THE TONGUE & PHARYNX MUSCLES OF THE TONGUE • Platoglossus • Styloglossus • Inferior longitudinal muscle of the tongue • Genioglossus • Hyoglossus MUSCLES OF THE PHARYNX • Superior constrictor • Middle Pharyngeal constrictor • Inferior pharyngeal constrictor OTHER ASSOCIATED MUSCLES • Genioglossus, Mylohyoid, Stylohyoid • Digastric

MUSCLES THAT MOVE THE HEAD

• Sternocleidomastoid (flexor (“prayer muscle”), rotation to opposite side of contracting muscle) • Semispinalis capitis (extensor, tilting laterally, rotation) • Splenius capitis (extensor, tilting laterally, rotation) • Longissimus capitis (extensor, tilt and rotate towards side of contracting muscle)

MUSCLES THAT MOVE THE HEAD Muscles of the thorax MUSCLES OF THE ABDOMEN

1. External oblique abdominis 2. Internal oblique abdominis 3. Transversus abdominis 4. Rectus Abdominis Muscles of the abdomen

MUSCLES OF THE BACK

SUPERFICIAL MUSCLES OF THE BACK • Trapezius • Latissimus dorsi • Extenal abdominis • Thoracolumbar fascia • Gluteus Maximus

INTERMIDIATE MUSCLES OF THE BACK • Rhomboideus minor and major • Supraspinatus • Infraspinatus • Teres minor • Teres major • Seratus anterior and posterior • Erector spinae • Internal abdominis • Gluteus Medius • Piriformis • Superior gemellus • Inferior gemellus DEEP MUSCLES OF THE BACK

• Multifidus cervicis, thoracis, lumborum • Interspinales • Semispinalis cervicis, thoracis, lumborum • Diaphragm • Quadratus lumborum • Intertransversarii

Muscles of the pelvic floor Conclusion

 organization of muscle organ  List of muscles of facial expression  functions of muscles of facial expression  muscles of the head – mastication, tongue & pharynx  Muscles that move the head  muscles of the neck  muscles of the trunk – back, thorax, abdomen & pelvic floor