Head and Neck Musculature and Fascia (1) PDF

Head and Neck Fascia and Musculature Fascia of the scalp ➔ Scalp layers (5) ◆ Adding the 1st letter of each layer reads out SCALP ◆ First 3 layers are intimately connected and move as a unit Skin → thin layer containing hair follicles, and sweat and sebaceous...

Head and Neck Fascia and Musculature Fascia of the scalp ➔ Scalp layers (5) ◆ Adding the 1st letter of each layer reads out SCALP ◆ First 3 layers are intimately connected and move as a unit Skin → thin layer containing hair follicles, and sweat and sebaceous glands necessary in healing Connective tissue → thick, dense, and richly vascular subcutaneous layer sconnects front to back of head with cutaneous nerves Aponeurosis → broad, strong tendon that serves as muscle attachment Loose areolar tissue → sponge-like, allows free movement of above 3 layers ○ May swell due to infection or injury Pericranium → dense layer of connective tissue forming the outer membrane of cranium (periosteum) adirectly on bone É Fascia of the neck ➔ Neck layers SPSD ◆ Fascial planes determine the potential direction in which infection may spread ◆ Skin ◆ Platysma → broad, thin sheet of muscle Covers anterolateral part of neck double chin External jugular vein and main cutaneous nerves of the neck are deep to the platysma ◆ Superficial fascia → layer of fatty subcutaneous tissue surrounding the whole neck Located between the skin and investing layer of deep cervical fascia ◆ Deep fascia → several layers that compartmentalize structures in the neck Investing encircles I Pretracheal Prevertebral anterior TQ Carotid sheath posterior lateral O neck layers skin Platysma Superficial fascia deep fascia ◆ Deep fascia → allow separation of tissue during surgery, and limit the spread of infection; permit sliding of structures pass over one another without difficulty d'éép Investing: encircles the entire neck deep to superficial fascia fascia ○ Superior attachment closer to head ◆ Superior nuchal line of the OB layers ◆ Mastoid process of the TB ◆ Zygomatic arches ◆ Inferior border of the mandible Investing ◆ Hyoid bone ◆ Spinous process of cervical vertebrae protracheal ○ Inferior attachment ◆ Manubrium closer to clavicle ◆ Clavicles Prevertebral ◆ Acromions and spines of scapulas Pretracheal: surrounds structures in the anterior part of the neck Carotid sheath ○ Attachments ◆ Extends from hyoid bone to thorax, where it blends with pericardium invest pennies ○ Muscular part: encloses infrahyoid muscles ○ Visceral part: encloses thyroid gland, trachea, esophagus, and pretty catchy pharynx o ○ Buccopharyngeal fascia: thin lamina of the prevertebral fascia that surrounds the pharyngeal constrictor muscles  Prevertebral: surrounds vertebral column and associated muscles ○ Attachments ◆ Extends from the cranial base superiorly and blends inferiorly with the endothoracic fascia, communicating with the mediastinum Carotid sheath: surrounds common and internal carotid arteries, internal jugular vein, and vagus nerve (CN X) ○ Attachments neurovascular bundle ◆ Extends from the cranial base to the root of the neck, where it communicates with the mediastinum ◆ Investing, pretracheal, and prevertebral layers contribute to the formation of the carotid sheath ◆ Alar fascia → thin laer of fascia Attachments bothsides of carotid ○ Extends from the cranial base to the root of the neck ○ Attached at the midline to buccopharyngeal fascia and laterally to the carotid sheath ◆ Retopharygneal space → interfascial space between pretracheal (anteriorly), prevertebral (posteriorly), and carotid sheaths (laterally) Musculature of the head ➔ General characteristics of muscles of facial expression ◆ Located in the subcutaneous tissue of scalp, face, and neck ◆ Move skin and change the facial expression to convey mood ◆ Attachment originates from deep fascia and bone and inset on skin ◆ Innervation by the facial nerve (CN VII) ◆ Muscles Scalp and forehead Mouth, lips, and cheeks Eyes, ears, TQ all muscles and nose of facial expression are innervated by facial nerve CNVil  sideeffect of could shot if you had FOREHEAD SCALP botox done Bells palsy ➔ Muscles of forehead and scalp ◆ Frontalis sits on frontal bone Attachment → skin of eyebrows and root of nose Function → elevates eyebrows and wrinkles forehead on occipital bone ◆ Occipitalis Attachment → the lateral ⅔ rds of the superior nuchal line Function → draws scalp back and wrinkles back of head temporalis m orbicularis oculiM I Som orbicularis orism MOUTH LIPS CHEEKS Zygomatic ➔ Muscles of mouth, lips, and cheeks (8) mlmin M ◆ Levator labii superioris maxillary bone Attachment → from infraorbital margin to skin of upper lip Function → elevates upper lip ◆ Zygomaticus major Attachment → zygomatic bone to angle of mouth Function → elevates corner of mouth smiling ◆ Depressor anguli oris Attachment → anterolateral base of mandible to angle of mouth Function → depresses corner of mouth ◆ Depressor labii inferioris Attachment → from mandible to skin of lower lip Function → depresses lower lip  ◆ Platysma Attachment → from fascia and skin over clavular region to base of mandible, angle of mouth, lower part of face Function → depresses mandible, tenses skin of inferior face and neck superficial deeper d L ◆ Levator anguli oris Deep to levator labii superioris muscle, and accessory muscle to zygomaticus major Attachment → from maxilla (just below infraorbital foramen) to angle of mouth Function → elevates corner of the mouth ◆ Buccinator smiling Deep to the masseter aids in mastication but Forms principal substance of cheeks NOT directly involved Attachment → anteriorly angle of mouth and posteriorly to mandible, maxilla, and pterygomandibular raphe tendon, a tendinous extension of buccopharyngeal fascia Function → mastication (keeps cheeks taut), smiling ◆ Orbicularis oris aids in closing opening mouth Attachment → encircles mouth and attaches into upper and lower lips, oral sphincter forms it Function → articulation and mastication ➔ Muscles of eyes, ear, and nose (7) ◆ Eyes EYES EAR NOSE Orbicularis oculi ○ Attachment → circular muscle around orbital margin into eyelids, sphincter of eyes ○ Function → closes orbital opening, encourages flow of tear by helping empty lacrimal sack ◆ Ear have to squeeze to cry Aurciularis anterior Aricularis posterior Auricularis superior ○ Attachment → skin of the auricle of ear ◆ Nose Procerus being serious ○ Attachment → from forehead to skin over bridge of nose ○ Function → depresses medial angle of eyebrows (when very serious) Nasalis flared nostrils ○ Attachment → from maxilla to bridge and alar cartilage of nose ○ Function → widen nasal aperture ◆ Depressor septi right underneath nose motion to bring it Attachment → from incisive fossa of maxilla to nasal septum Function → depresses and widen nasal aperture down  MASTICATION ➔ Muscles of mastication (4) ◆ Temporalis its job is to Occupies temporal fossa Attachment → from temporal fossa to coronoid process of mandible lift retract Function → elevation, retraction, lateral excursion of mandible ◆ Masseter Very strong, thick muscle Attachment → zygomatic arch to lateral surface of ramus and angle of mandible Function → elevation, and protraction of mandible, clenches teeth All muscles of mastication are innervated by the mandibular branch of the trigeminal n ION V medial ◆ Medial pterygoid helps temporalis Located in the infratemporal fossa elevation Attachment → from lateral pterygoid plate and maxillary tuberosity to medial (or internal) surface of ramus and angle of mandible mountains Function → elevation, protraction, and lateral excursion of mandible ○ Synergistic with masseter muscle re elevated◆ Lateral pterygoid Deep in the temporal fossa Short, strong, and runs horizontally Attachment → lateral pterygoid plate and greater wing of sphenoid to neck of mandible and penetrating the TMJ capsule inserts on the articular disc lateral depression lucy is depressed  Function → depression, protraction, and lateral excursion of mandible temporalis m four muscles 0 of mastication 0 masseter Musculature of the neck ➔ Muscles of the neck bisects the neck becomes a landmark for whats ◆ Sternocleidomastoid ◆ Muscles in anterior cervical region Suprahyoid muscles Infrahyoid muscles pos vs ant ◆ Prevertebral muscles  ◆ Muscles in posterior cervical region Superficial and deep muscles Suboccipital region muscles and triangle ◆ Muscles associated to styloid process ◆ Extrinsic tongue muscles ◆ Neck triangles ➔ Muscles of neck ◆ Sternocleidomastoid (SCM) Bisects the neck diagonally Attachment → from mastoid process and lateral ½ of superior nuchal line to manubrium, of sternum and medial ⅓ rd of clavicle Function → unilaterally – rotating head left and right, bilaterally – flexes neck Innervation → accessory nerve (CN XI) Clinical relevance → unilateral contraction used to test integrity of SCM and accessory nerve (CN XI) ABOVEHYOIDBONE tolerate hyoid SUPRAHYOID M digastic 2 nerves Pos facial Muso I ◆ Digastric Attachment → mandible and mastoid process of TB ant trigeminal ○ Both bellies attach to intermediate tendon, which is tied down to Digastric the hyoid bone by a sling of fascia Function → depress mandible, open mouth, and elevate hyoid bone Mylohyoid Innervation → posterior belly – facial nerve (CN VI), anterior belly – trigeminal nerve (CN V) 3 Geniohyoid ◆ Mylohyoid Attachment → medial surface of mandible to hyoid bone M medial surface of mandible  Function → elevates hyoid bone, floor of mouth, and tongue during swallowing and speaking ○ Forms the floor of the oral cavity Innervation → trigeminal nerve (CN V) ◆ Geniohyoid Attachment → from genio )or bend) of mandible to hyoid bone Function → elevate hyoid, shortens floor of mouth Innervation → C1 via hypoglossal nerve (CN XII) genie is hyper I genionyoid hypoglossal  BELOW HYOID BONE Idepress hyoid ➔ Muscles of the neck INFRA HYOID M ◆ Infrahyoid muscles Muscles t Omohyoid bellies ○ Attachment → superior border of scapula andhyoid bone ◆ Both bellies attached to intermediate tendon, which is tied omonyoid down to clavicle by sling of fascia ○ Function → depress, retracts, and seadies hyoid 2 Sternonyoid ○ Innervation → Ansa cervicalis Sternohyoid ○ Attachment → from manubrium of sternum and medial end of 3 Sternothyroid clavicle to hyoid ○ Function → depress hyoid bone after elevation during swallowing 4 Thyronyoid ○ Innervation → Ansa cervicalis Sternothyroid ○ Attachment → from manubrium of sternum to thyroid cartilage of larynx ○ Function → depress hyoid and larynx ○ Innervation → Ansa cervicalis Thyrohyoid ○ Attachment → from thyroid cartilage of larynx to hyoid bone ○ Function → depress hyoid bone and elevate larynx ○ Innervation → C1 via hyoglossal nerve (CN XII) digastric g armylongsuprahyoidM HYOID B  PREVERTEBRAL M ➔ Muscles of the neck (con’t) ◆ Prevertebral muscles (5) Location: deep to prevertebral fascia and posterior to retropharyngeal space Anterior scalene ○ Attachment → from transverse process of c3-C6 to 1st rib ○ Function → flex neck and elevates 1st rib ○ Innervation → cervical spinal nerves C4-C6 Middle scalene ○ Attachment → from posterior tubercle of transverse process of C5-C7 to 1st rib switch to ○ Function → flex neck laterally and elevates 1st rib ○ Innervation → anterior rami of cervical spinal nerves anterior Posterior scalene ○ Attachment → from posterior tubercle of transverse process of rami inn C5-C7 to 2nd rib ○ Function → flex neck laterally and elevates 2nd rib ○ Innervation → anterior rami of spinal nerves C7-C8 Longus capitis goes to the ○ Attachment → from basillar part of OB to anterior tubercles of C3-C6 transverse processes head ○ Function → flexion of head ○ Innervation → anterior rami of spinal nerves C1-C3 to the OB Longus colli ○ Attachment → from anterior tubercle of C1, bodies of C1-C3, and neck trasnverse processes of C3-C6 to bodies of C5-T3, and transverse processes of C3-C5 cervical area ○ Function –. Flexion of the neck (hilateral) and slight rotation of neck to contralateral side (unilateral) ○ Innervation → anterior rami of spinal nerves C2-C6  POSTERIOR CERVICAL M ◆ Posterior cervical muscles Superficial and deep muscles ○ Splenius cervicis ◆ Attachment → from nuchal ligament and spinous processes of C7-T6 to transverse processes of C1-C4 ◆ Function → extend head and neck (bilaterally), rotate and flex the head to same side ◆ Innervation → posterior rami of cervical spinal nerves ○ Semispinalis capitis ◆ Attachment → from transverse process of C4-T12 to OB and spinous processes of cervical and thoracic vertebrae ◆ Function → extend head and neck, and rotate them contralaterally ◆ Innervation → posterior rami of spinal nerves Suboccipital muscles and triangle ○ Rectus capitis posterior major ◆ Attachment → from spinous process of C2 to inferior nuchal line ○ Rectus capitis posterior minor ◆ Attachment → from tubercle on posterior arch of Atlas to inferior nuchal line  Obliquus capitis superior OA from lateral mass of Atlas to ○ Obliquus capitis inferior int nuchal line ◆ Attachment → from lateral mass of Atlas to inferior nuchal line know all the ○ Suboccipital triangle ◆ Boundaries → obliquus capitis inferior, obliquus capitis muse that superior and rectus capitisposterior major ◆ Contains → vertebral artery and suboccipital nerve make up the f ◆ Clinical relevance → the vertebral artery is accessed here in order to conduct angiography of the circle of Willis aneurysm boundaries of All muscles in the suboccipital triangle are innervated by the suboccipital nerve (posterior ramus of C1) stroke the suboccipital hemorrhage triangeocontents nerve inn O is Muscles ➔ Muscles associated to styloid process STYLOID PROCESS M ◆ Stylohyoid Attachment → from styloid process to hyoid bone Function → elevates and retracts hyoid bone Innervation → facial nerve (CN VII) ◆ Styloglossus Extrinsic tongue muscle Attachment → from styloid process to tongue Function → retract and curls (elevates sides) tongue Innervation → hypoglossal nerve (CN XII) tongue rolling  ◆ Stylopharyngeus Attachment → from styloid process to thyroid cartilage of pharynx and pharyngeal wall Function → elevates pharynx Innervation → glossopharyngeal nerve (CN IX) process gstyloid 8 Muscles ➔ Extrinsic tongue muscles TONGUE M hypoglossal n ◆ Genioglossus Attachment → from mental spine to dorsum of tongue Function → protrudes and depresses tongue Innervation → hypoglossal nerve (CN XII) ◆ Hyoglossus Attachment → from hyoid bone to inferolateral aspect of tongue Function → retrudes and depresses tongue Innervation → hypoglossal nerve (CN XII) know boundaries a contents NECK TRIANGLES ➔ Neck regions and triangles triangles ◆ Anterior cervical region (anterior triangle) Submental triangle before SCM ○ Area inferior to the chin ○ Boundaries → between right and left anterior belly of digastric muscle and body of hyoid ○ Content → submental lymph nodes, small veins joining to form anterior jugular vein Submandiublar triangle ○ Glandular area ○ Boundaries → between anterior and posterior bellies of digastric and inferior border of mandible ○ Content → submandibular gland, submandibular lymph nodes, hypoglossal nerve (CN XII), mylohyoidnerve, parts of facial artery and vein Carotid triangle ○ Vascular area ○ Boundaries → between anterior border of SCM, superior belly of omohyoid, and posterior belly of digastric ○ Content → common carotid artery, internal jugular vein, vagus nerve (CN X), external carotid artery, hypoglossal nerve (CN XII), motor branches of cervical plexus, thyroid gland, larynx, and pharynx Muscular triangle think of Platysma area ○ Boundaries → anterior border of SCM, superior belly of omohyoid, and median plane of neck ○ Content → infrahyoid muscldes, thyroid, and parathyroid glands triangles ◆ Posterior cervical region (posterior triangle) Occipital triangle after Sam ○ Content → part of external jugular vein, sensory branches of cervical plexus, accessory nerve (CN XI), brachial plexus, cervical lymph node Omoclavicular (subclavian) triangle ○ Content → subclavian artery, subclavian vein, and suprascapular artery think scapula add