L19 Head & Neck I (1) PDF

L19 Head & Neck Overview I: Musculoskeletal structures Dr. Erin Stephenson [email protected] Lecture Overview Skull overview Vertebral column overview Muscle groups in the head Muscle groups in the neck Lecture Objectives Identify the bones of the head & discuss th...

L19 Head & Neck Overview I: Musculoskeletal structures Dr. Erin Stephenson [email protected] Lecture Overview Skull overview Vertebral column overview Muscle groups in the head Muscle groups in the neck Lecture Objectives Identify the bones of the head & discuss the structure of the skull & its various components Identify & describe the bones & joints of the neck Describe the curvatures of the vertebral column Describe the different muscles groups found in the head & any associated functions Describe the different muscle groups found in the neck & any associated functions Describe the general musculoskeletal organization of the adult head & neck Lecture Overview Skull overview Vertebral column overview Muscle groups in the head Muscle groups in the neck Key objective(s): Identify the bones of the head & discuss the structure of the skull & its various components Skull Overview Neurocranium Brain case Viscerocranium Facial skeleton  Facial skeleton (viscerocranium) Anterior skull  Facial skeleton  Orbits  Zygomatic arches  Nasal cavity & septum  Maxilla & hard palate  Mandible  15 bones Bone  Maxilla x2  Zygomatic x2  Nasal x2  Lacrimal x2  Inferior nasal concha x2  Palatine x2  Mandible  Vomer  Ethmoid  Brain case (neurocranium) Houses the brain & Calvaria associated structures Eight bones  2 paired  4 unpaired Cranial Base Bone  Frontal  Parietal x2  Temporal x2  Occipital  Sphenoid  Ethmoid  Calvaria Frontal bone Protects superior aspect of the brain Union of frontal, parietal, & occipital bones Parietal bone Occipital bone  Cranial base Frontal bone Ethmoid bone Sphenoid bone Tiered platform for brain to sit upon  Three fossae Contains openings that transmit Temporal bone neurovascular structures Parietal bone Anterior Occipital bone Middle Posterior  Sphenoid bone Frontal bone Maxilla Openings Mandible Supraorbital foramen Optic canal Supraorbital fissure Transmission of structures between the braincase & the Infraorbital facial skeleton & neck foramen Mental foramen  Sphenoid bone Temporal bone Occipital bone Openings Maxilla Palatine bone Incisive foramen Inferior orbital fissure Foramen ovale Greater & lesser palatine Foramen spinosum foramina Transmission of structures between the braincase & the Carotid canal External facial skeleton & neck acoustic meatus Stylomastoid foramen Foramen Jugular foramen magnum Lecture Overview Skull overview Vertebral column overview Muscle groups in the head Muscle groups in the neck Key objective(s): Identify & describe the bones & joints of the neck Describe the curvatures of the vertebral column  Vertebrae T6 Body Vertebral foramen Pedicle Superior articular facet Irregular bones Transverse process Lamina All unique but share common features Spinous process  Body  Transverse processes  Spinous process  Vertebral arch  Lamina  Pedicle  Vertebral foramen  Articular facets  Superior  Inferior  Cervical vertebrae Anterior tubercle C4 Transverse foramen Posterior tubercle 7 cervical vertebrae Transverse foramina Bifid spinous process Bifid spinous process Anterior arch C1 - Atlas  No body Anterior tubercle Dens C2 - Axis Lateral mass  Dens Facet C7 for dens C2  Long spinous process Superior C1 articular surface Posterior tubercle Posterior arch  Thoracic vertebrae Superior costal facet Transverse costal Inferior facet Superior costal T6 12 thoracic vertebrae costal facet facet Costal facets  Articular sites for ribs Transverse costal facet Rib  Lumbar vertebrae L1 L2 L2 5 lumbar vertebrae Mammillary processes L3  Deep back muscle attachment sites L4 Mammillary process L5  Sacrum & coccyx Ala Anterior foramen Posterior foramen 5 fused sacral vertebrae Auricular  Lateral, intermediate, & medial crests surface  Anterior & posterior sacral foramina  Sacral hiatus Crests  Sacral horn  Ala Sacral hiatus  Auricular surface Typically, 4 fused coccygeal vertebrae Sacrum Sacral horn  Coccygeal horn Coccyx Coccygeal horn  7 cervical Vertebral column 12 thoracic 33 stacked vertebrae Functions to support body weight Bony protection for spinal cord 5 lumbar 5 Sacral 4 coccygeal Lateral Anterior Posterior  Curvatures Weight distribution, shock absorption, stability Kyphoses  Primary curvatures  Thoracic & sacral regions  Anteriorly concave Lordoses  Secondary curvatures  Cervical & lumbar regions  Posteriorly concave  Intervertebral joints Unite adjacent vertebrae  Intervertebral symphyses  Between vertebral bodies  Zygapophyseal joints  Between superior & inferior articular facets  Atlantoaxial joints  Between C1 & C2 The vertebral column also articulates with the skull  Atlanto-occipital joints  Between C1 & the occipital bone Lateral Anterior Posterior  Intervertebral symphyses Joint between bodies of adjacent vertebrae Intervertebral discs Anulus fibrosus  Anulus fibrosus Nucleus  Outer fibrocartilage ring pulposus  Nucleus pulposus  Gelatinous central mass  Size/shape varies by region  Provide resilient deformability  Zygapophyseal joints Zygapophyseal joint capsule Facet joints Between superior & inferior facets of adjacent vertebrae Permit gliding movements but limit Inferior articular flexion & extension process Superior articular process  Anterior tubercle Atlantoaxial joints Dens Ligaments of median atlantoaxial joint Superior view Trio of joints between atlas & axis Median atlantoaxial joint  Between anterior arch of atlas & dens  Permit rotation Paired lateral atlantoaxial joints  Between inferior articular facets of atlas & superior articular facets of axis  Alignment of facets allows rotation but limits flexion & extension Lateral atlantoaxial joint capsule Posterior view  Atlanto-occipital joints Bilateral articulations between vertebral column & skull  Occipital condyles  Superior facets of Atlas (C1) Permit flexion & extension Occipital condyle  Nodding (“yes”) motion Superior facet Atlanto-occipital joint capsule Lecture Overview Skull overview Vertebral column overview Muscle groups in the head Muscle groups in the neck Key objective(s): Describe the different muscles groups found in the head & any associated functions Describe the general musculoskeletal organization of the adult head & neck  Muscles groups in the head Muscles of facial expression Muscles of the eye & orbit Muscles of mastication Extrinsic muscles of the tongue  Muscles of facial expression Muscles that move the face  Non-verbal communication  Many different muscles All innervated by the facial nerve (CN VII)  Superior rectus Muscles of the eye & orbit Superior oblique Levator palpebrae Medial rectus superioris Inferior rectus 6 muscles that move eyeball 1 muscle that moves the upper eyelid Innervated by 3 different cranial nerves  Oculomotor (CN III) Lateral rectus  Levator palpebrae superioris Inferior oblique  Superior rectus  Inferior rectus  Medial rectus  Inferior oblique  Trochlear (CN IV)  Superior oblique Lateral rectus  Abducens (CN VI)  Lateral rectus Superior oblique Superior rectus  Temporalis (cut) Muscles of mastication Temporalis Muscles that act on the temporomandibular joint  Mandibular movements  Chewing All innervated by the mandibular division of the trigeminal nerve Lateral (CN V3) Masseter pterygoid Medial pterygoid Masseter (cut)  Extrinsic muscles of the tongue Palatoglossus Muscles that control the tongues position & movement Four muscles  Genioglossus  Styloglossus  Hyoglossus Styloglossus  Palatoglossus  Also a muscle of the soft palate Hyoglossus All innervated by the hypoglossal nerve (CN XII) except palatoglossus which is innervated by the vagus nerve (CN X) Genioglossus Lecture Overview Skull overview Vertebral column overview Muscle groups in the head Muscle groups in the neck Key objective(s): Describe the different muscle groups found in the neck & any associated functions Describe the general musculoskeletal organization of the adult head & neck  Muscles in the anterior neck Four groups:  Superficial muscles  Suprahyoid muscles  Infrahyoid muscles  Prevertebral muscles  Superficial muscles Sternocleidomastoid Platysma Platysma  Muscle of facial expression Sternocleidomastoid  Primary neck flexor  Suprahyoid muscles Digastric (anterior belly) Mylohyoid Attach to hyoid bone from above Stylohyoid Elevate the hyoid, depress the mandible, Hyoid bone &/or act on the floor of the oral cavity Digastric (posterior belly) Four muscles  Digastric  Anterior & posterior bellies  Stylohyoid  Mylohyoid  Geniohyoid  Infrahyoid muscles Attach to hyoid bone from below Depress the hyoid &/or act on the larynx Four muscles  Omohyoid Thyrohyoid  Superior & inferior bellies  Sternohyoid Sternohyoid  Sternothyroid Omohyoid  Thyrohyoid (superior belly) Sternothyroid Omohyoid (inferior belly)  Rectus capitis Rectus capitis anterior Prevertebral muscles lateralis Longus capitis Deep muscles located immediately Longus colli anterior to vertebral bodies Four muscles  Longus capitis  Longus colli  Rectus capitis anterior  Rectus capitis lateralis  Muscles of the lateral neck Three scalene muscles  Anterior scalene  Middle scalene  Posterior scalene Middle Produce lateral flexion scalene  Ipsilateral action Stabilization of frontal plane Anterior Posterior  Bilateral action scalene scalene  Muscles in the posterior neck Semispinalis capitis Neck extension Splenius capitis  Also, lateral flexion & rotation Trapezius Splenius cervicis From superficial to deep: Levator scapulae  Trapezius  Levator scapulae  Splenius capitis/cervicis  Semispinalis capitis/cervicis  Longissimus capitis/cervicis  Suboccipital muscles Rectus capitis Deepest posterior neck muscles posterior minor Obliquus capitis Four muscles: Rectus capitis superior  Rectus capitis posterior major posterior major  Rectus capitis posterior minor  Obliquus capitis superior  Obliquus capitis inferior Obliquus capitis inferior  Summary of muscle actions in the neck Median plane Transverse plane Frontal plane Flexion Extension Ipsilateral rotation Contralateral rotation Lateral flexion Superficial group (SCM) Posterior group Posterior group (splenius) Superficial group (SCM) Superficial group (SCM) Prevertebral group Suboccipital group Posterior group (trapezius) Posterior group group(s) Muscle Anterior scalene Scalenes Supra- & infrahyoid muscles move the hyoid bone and/or mandible or larynx Lecture Objectives  Identify the bones of the head & discuss the structure of the skull & its various components  Identify & describe the bones & joints of the neck  Describe the curvatures of the vertebral column  Describe the different muscles groups found in the head & any associated functions  Describe the different muscle groups found in the neck & any associated functions  Describe the general musculoskeletal organization of the adult head & neck