Module 5.2 Head (Part 1) PDF

OT 505 Module 5.2: Head  SKULL 22 Bones  8 Cranial bones  14 Facial bones Houses and protects the brain Fibrous joints  Woven tightly together to form tight fitting sutures  Cranial Bones 1 Frontal 1 Occipital 1 Sphenoid 1 Ethmoid...

OT 505 Module 5.2: Head  SKULL 22 Bones  8 Cranial bones  14 Facial bones Houses and protects the brain Fibrous joints  Woven tightly together to form tight fitting sutures  Cranial Bones 1 Frontal 1 Occipital 1 Sphenoid 1 Ethmoid 2 Temporal 2 Parietal  Facial Bones- 14 -Maxilla (2) -Zygomatic (2) -Lacrimal (2) -Nasal (2) -Inferior Nasal Conchae 2 -Palatine (2)* -Vomer (1)* -Mandible (1) * Not visible externally  Bones and Landmarks (cont’d) A. Occipital B. Parietal C. Frontal Frontal D. Nasal Parietal Nasal E. Zygomatic F. Maxilla sphenoid Temporal zygomatic G. Mandible maxilla H. Temporal Occipital I. Sphenoid mandible Copyright 2001, F. A. Davis Company Skull- Frontal View  Occipital Bone Forms the posterior and base of the skull Foramen magnum - large hole where spinal cord passes Occipital Condyles - articulate with first vertebra  MANDIBLE THE “JAW” Largest strongest facial bone Horseshoe shape Articulates with the temporal bone on each side of the face forming 2 identical joints  Joint Structure & Motions (cont’d) Motions Mandibular movements A. Elevation (return from depression) B. Depression C. Protraction = protrusion D. Retraction = retrusion E. Lateral deviation Copyright 2001, F. A. Davis Company  Joint Structure & Motions (cont’d) Mandible at Rest Condyle of the mandible is seated in the mandibular fossa of the temporal bone Resting position – Lips closed – Teeth several millimeters apart – Maintained by low levels of activity of the temporalis muscles Copyright 2001, F. A. Davis Company  TEMPEROMANDIBULAR JOINT TMJ Joint capsule Articular disk 4 ligaments 4 muscles 5 motions Located anterior to ear Articular fossa temporal bone Condyle of mandible inferior  Four Ligaments of TMJ The Lateral Ligament (aka temporomandibular ligament) limits downward,posterior,lateral Sphenomandibular Ligament-limit anterior Stylomandibular Ligament- limit anterior Stylohyoid Ligament-hold hyoid bone in place  TMJ Motions Depression ( OPEN MOUTH) Elevation (CLOSE MOUTH) Protraction( JAW MOVES FORWARD) Retraction( JAW MOVES BACK) Lateral deviation( LATERAL MOVEMENT)  TMJ Normal motion of TMJ should allow 2-3 fingers between the upper & lower teeth  Muscles of Mastication The four PRIME MOVERS of the TMJ are Temporalis Masseter Medial Pterygoid Lateral Pterygoid The action IS BILATERAL and occurs at each joint (right and left) simultaneously All are innervated by the Trigeminal Nerve (CN 5)  Temporalis O: Temporal fossa I: Coronoid process of mandible A: Elevate and retracts mandible (unilaterally: ipsilateral lateral deviation  Masseter O: Zygomatic arch I: Angle of the ramus & coronoid process of mandible A: elevates mandible (ipsilateral lateral deviation)  Medial Pterygoid =B O: Sphenoid bone I: Ramus & angle of mandible A: Elevates & protracts mandible (contralateral lateral deviation)  Lateral Pterygoid = A O: Sphenoid bone I: Mandibular condyle A: Depresses & protracts mandible (contralateral lateral deviation)  Muscles of facial expression 4 groups mouth, eyes,nose,scalp Vast array of expressions created by 30 facial muscles Integumentary muscles  Embedded into superficial fascia and skin MIMETIC muscles  Express emotion  Facial Muscles Muscles of Facial Expression  Orbicularis oculi-eye  Corrugator supercilii-eye  Occipitofrontalis-forehead Innervated by facial nerve (VII) Smiling uses 8 muscles Frowning 20. Muscles of Facial Expression  Orbicularis occuli O: Bones of the medial orbit I: Tissues of eyelid A: Closes eye Muscles of the Eyes Orbicularis Oculi  Corrugator Supercilii O: Fascia above eyebrow I: Root of nose A: Draws eyebrow toward midline (frown) Muscles of the Eyes Corrugator Supercilii  Occipitofrontalis O: Galea aponeurotica I: Skin of eyebrow A: Wrinkles forehead, raises eyebrows Unique muscle with 4 muscle bellies 2 frontalis 2 occipitalis joined by galea Muscles of the Scalp Occipitofrontalis  Facial Muscles 11 muscles form expressions of mouth/emotions exist bilaterally except orbicularis total 23 to create expressions of mouth Muscles of the mouth  Buccinator  Orbicularis oris  Platysma Innervated by facial nerve (VII)  Buccinator O. Maxilla and mandible I. Modiolus A. Compresses cheeks for blowing air Muscles of the Mouth Buccinator  Orbicularis oris O. No bony attachment I. Modiolus A. Closes lips  Platysma O. Fascia of neck and chest I. Inferior border of mandible A. Depresses lower lip and mandible  Hyoid Bone Horseshoe shaped bone Superior to the thyroid at level of C3 No bony articulation Suspended from styloid processes of the temporal bones Provides attachment for tongue muscles and muscles that help depress mandible Hyoid Muscles Name the Muscle Name the Muscle Bones & Bony Landmarks of the Head, Neck and Face  REVIEW The TMJ is located ______ to the ear The TMJ is an articulation between the articular fossa of the ________________ bone of the cranium & the condyle of the mandible