W4 L4
Lecture 4 – Axial muscles of the head, neck and
the anterior and posterior trunk
Learning objectives
1. Identify the names of each skeletal muscles introduced this week.
2. Determine and describe the general location of the muscles within the head, neck and trunk.
3. Correlate the name of the muscle with the region and location on the skeleton. Muscles of facial expression, ant. & left lat. view
4. Begin to investigate and describe the layered muscular arrangement of the posterior muscles of
the axial skeleton.
5. Identify the posterior intrinsic (axial muscles), transversospinalis group, suboccipital muscles,
erector spinae and intermediate muscles of the back and the anterior and anterolateral
abdominal wall muscles.
6. Review the general attachment points of the posterior muscles of the axial skeleton.
7. Describe the fascia of the posterior abdominal wall, its layers, attachment points, enveloped
muscles and muscles that attach into the fascia.
__________________________________________________________________________________
Muscles of facial expression
• Occipitofrontalis (epicranial aponeurosis)
1. Frontal belly
2. Occipital belly
• Orbicularis oculi
• Levator labii superioris
• Depressor labii inferioris Temporalis and masseter
• Zygomaticus major Lateral and medial pterygoid muscles
• Zygomaticus minor
• Orbicularis oris
• Levator anguli oris
• Depressor anguli oris
• Risorius
• Buccinator
• Mentalis
• Platysma
Muscles of mastication
Temporalis and masseter
• The temporalis is a broad, convergent muscle on each side of the cranium that fills the temporal
fossa, superior to the zygomatic arch
• It covers much of the temporal bone and passes medially to the zygomatic arch as it projects
inferiorly while forming its tendon
• Proximal attachment: temporal fossa
• Distal attachment: coronoid process of mandible
• The masseter is a thick, somewhat quadrilateral muscle consisting of two heads
• Proximal attachment: inferior aspects of the zygomatic bone into the temporal process of
zygomatic bone, along the lateral and inferior borders of the zygomatic arch onto the zygomatic Location of the short nuchal muscles
process of the temporal bone
• Distal attachment: lateral surface of the ramus of the mandible as high as the coronoid process of
the mandible
Medial pterygoid
• Proximal attachment: pterygoid fossa and medial surface of the lateral plate of the pterygoid
process
• Distal attachment: medial surface of the angle of the mandible.
Lateral pterygoid
• Proximal attachment:
1. Superior head: greater wing of the sphenoid
2. Inferior head: lateral surface of the lateral pterygoid plate
• Distal attachment Short nuchal and craniovertebral joint muscles
1. Superior head: articular disk of the temporomandibular joint Origin and insertion of the short nuchal muscles
2. Inferior head: neck of the condylar process of the mandible
Superficial neck muscles
Sternocleidomastoid
• Proximal attachment: mastoid process of the temporal bone of the skull
• Distal attachment: via two heads to the manubrium of the sternum (sterno-) and the medial third
of the clavicle (cleido-)
Trapezius
• Has multiple attachment points and possesses three sets of fibres
CHI108 Page 1
Lecture 4 – Axial muscles of the head, neck and
the anterior and posterior trunk
Learning objectives
1. Identify the names of each skeletal muscles introduced this week.
2. Determine and describe the general location of the muscles within the head, neck and trunk.
3. Correlate the name of the muscle with the region and location on the skeleton. Muscles of facial expression, ant. & left lat. view
4. Begin to investigate and describe the layered muscular arrangement of the posterior muscles of
the axial skeleton.
5. Identify the posterior intrinsic (axial muscles), transversospinalis group, suboccipital muscles,
erector spinae and intermediate muscles of the back and the anterior and anterolateral
abdominal wall muscles.
6. Review the general attachment points of the posterior muscles of the axial skeleton.
7. Describe the fascia of the posterior abdominal wall, its layers, attachment points, enveloped
muscles and muscles that attach into the fascia.
__________________________________________________________________________________
Muscles of facial expression
• Occipitofrontalis (epicranial aponeurosis)
1. Frontal belly
2. Occipital belly
• Orbicularis oculi
• Levator labii superioris
• Depressor labii inferioris Temporalis and masseter
• Zygomaticus major Lateral and medial pterygoid muscles
• Zygomaticus minor
• Orbicularis oris
• Levator anguli oris
• Depressor anguli oris
• Risorius
• Buccinator
• Mentalis
• Platysma
Muscles of mastication
Temporalis and masseter
• The temporalis is a broad, convergent muscle on each side of the cranium that fills the temporal
fossa, superior to the zygomatic arch
• It covers much of the temporal bone and passes medially to the zygomatic arch as it projects
inferiorly while forming its tendon
• Proximal attachment: temporal fossa
• Distal attachment: coronoid process of mandible
• The masseter is a thick, somewhat quadrilateral muscle consisting of two heads
• Proximal attachment: inferior aspects of the zygomatic bone into the temporal process of
zygomatic bone, along the lateral and inferior borders of the zygomatic arch onto the zygomatic Location of the short nuchal muscles
process of the temporal bone
• Distal attachment: lateral surface of the ramus of the mandible as high as the coronoid process of
the mandible
Medial pterygoid
• Proximal attachment: pterygoid fossa and medial surface of the lateral plate of the pterygoid
process
• Distal attachment: medial surface of the angle of the mandible.
Lateral pterygoid
• Proximal attachment:
1. Superior head: greater wing of the sphenoid
2. Inferior head: lateral surface of the lateral pterygoid plate
• Distal attachment Short nuchal and craniovertebral joint muscles
1. Superior head: articular disk of the temporomandibular joint Origin and insertion of the short nuchal muscles
2. Inferior head: neck of the condylar process of the mandible
Superficial neck muscles
Sternocleidomastoid
• Proximal attachment: mastoid process of the temporal bone of the skull
• Distal attachment: via two heads to the manubrium of the sternum (sterno-) and the medial third
of the clavicle (cleido-)
Trapezius
• Has multiple attachment points and possesses three sets of fibres
CHI108 Page 1
