4: Muscles Of The Neck Flashcards
Difference between temporal fossa and infratemporal fossa
Temporal: superior to zygomatic arch
Infratemporal: inferior to zygomatic arch
Four muscles of mastication
Temporalis, masseter, lateral pterygoid, medial pterygoid
general innervation to Muscles of mastication
CN V3
General innervation to TMJ
CN V3
Temporalis O and I
O: temporal fascia and fossa
I: coronoid process of mandible
Temporalis N
Deep temporal N
Temporalis A (3 parts)
Vertical fibers: elevates mandible
Horizontal fibers: retract mandible
Unilaterally: lateral movement of mandible
Masseter O and I
O: zygomatic arch
I: mandibular ramus and angle, deep head also on coronoid process
Masseter N
Masseteric N
Masseter A
Elevates mandible, protraction, retraction, side-to-side motion
Lateral pterygoid O and I
O: greater wing of sphenoid, lateral pterygoid plate
I: neck of mandible, TMJ
Lateral pterygoid N
Lateral pterygoid N
lateral pterygoid A: bilaterally and unilateral
Bilaterally: protrudes mandible, opens mouth
Unilateral: side-to-side movement
Medial pterygoid N
Medial pterygoid N
Medial pterygoid O and I
O: maxilla, palatine bone, pterygoid plate, pterygoid fossa
I: pterygoid rugosity, medial mandible
Medial pterygoid A (bilateral and unilaterally)
Bilateral: elevates mandible, protrusion
Unilateral: protrusion, medial movement towards opposite side, side-to-side chewing movement
Three muscles for mandible elevation
- Temporalis
- Masseter
- Medial pterygoids
Three muscles for mandible depression
- Lateral pterygoid
- Suprahyoids
- Infrahyoids
Three muscles for mandible protrusion
- Lateral pterygoids
- Medial pterygoids
- Masseter
Two muscles for mandible retrusion
- Temporalis
2. Masseter
Three muscles for lateral movement of mandible
- Ipsilateral temporalis + masseter
2. Contralateral pterygoids
Seven prevertebral muscles
- Posterior scalene
- Anterior scalene
- Middle scalene
- Longus capitis
- Longus colliculi
- Rectus capitis lateralis
- Rectus capitis anterior
Where are prevertebral muscles?
Posterior to retropharyngeal space
Innervation to all prevertebral muscles
Cervical and/or brachial plexus
Posterior scalene O and I
O: posterior tubercles C5-7
I: 2nd rib
Action of all three scalene muscles
Flexes neck laterally, elevates rib during deep inspiration
Middle scalene O and I
O: posterior tubercles C2-7
I: superior 1st rib
Anterior scalene O and I
O: anterior C3-6 TPs
I: 1st rib
Where are Longus capitis and coli?
Span between vertebral bodies, TPs of cervical vertebrae
Where does longus capitis insert?
Occipital bone
SCM O and I
O: manubrium, medial 1/3 of clavicle
I: mastoid process
SCM bilateral action
Flexes neck
SCM action when working with neck extensors
Protrudes head
SCM unilateral action
Laterally flexes head, rotates ear so it approaches shoulder on same side, turns chil to opposite side, tilting head
SCM N
- CN 11
2. C2-4: propriosensory info
CN 11 pathway to SCM and trapezius
Exits jugular foramen -> posterior to SCM -> emerges about 1/3 down along posterior margin of SCM to cross posterior triangle -> trapezius
Torticollis
Causes head to turn to side + face turns away from affected side
Congenital vs muscular torticollis
Congenital: fibrous tumor within SCM in utero
Muscular: SCM injured during difficult birth, tearing fibers -> fibrotic mass that affects CN 11
