Muscles Of The Neck Flashcards
(17 cards)
What are the suprahyoid muscles
Mylohyoid, geniohyoid, digastric, stylohyoid
What are the infrahyoid muscles
Omohyoid, sternohyoid, thyrohyoid, sternothryoid
Stylohyoid
Anterior triangle of neck
Origin: base of styloid process
Insertion: lateral area of body of hyoid bone
Innervation: facial nerve CNVII
Function: pulls hyoid bone upward in posterosuperior direction
Digastric
Anterior triangle of neck
Anterior belly:
Origin: digastric fossa on Lower inside mandible
Insertion: attachment of tendon between 2 bellies to body of hyoid bone
Innervation: mylohyoid nerve from inferior alveolar branch of mandibular nerve V3
Function: opens mouth by lowering mandible raises hyoid bone
Posterior belly:
Origin: mastoid notch on medial side of mastoid process of temporal bone
Insertion: same as anterior belly
Innervation: facial nerve CNVII
Function: pulls hyoid bone upward and back
Mylohyoid
Anterior triangle of neck
Origin: mylohyoid line on mandible
Insertion: body of hyoid bone and fibres from muscle on opposite side
Innervation: mylohyoid nerve from inferior alveolar branch of mandibular nerve V3
Function: support and elevation of floor of oral cavity; elevation of hyoid bone
Geniohyoid
Anterior triangle of neck
Origin: inferior mental spine on inner surface of mandible
Insertion: anterior surface of body of hyoid bone
Innervation: branch from anterior ramus of C1 (carried along Hypoglossal nerve CNXII)
Function: fixed mandible elevates and pulls hyoid bone forward; fixed hyoid bone pulls mandible downward and inward
Sternohyoid
Anterior triangle of neck
Origin: posterior aspect of sternoclavicular joint and adjacent manubrium of sternum
Insertion: body of hyoid bone medial to attachment of omohyoid muscle
Innervation: anterior rami of C1 to C3 through the ansa cervicalis
Function: depresses hyoid bone after swallowing
Omohyoid
Anterior triangle of neck and posterior triangle
Origin: superior border of scapula medial to suprascapular notch
Insertion: lower border of body of hyoid bone just lateral to attachment of sternohyoid
Innervation: anterior rami of C1 to C3 through the ansa cervicalis
Function: depresses and fixes the hyoid bone
Thryohyoid
Anterior triangle of neck
Origin: oblique line on lamina of thyroid cartilage
Insertion: greater horn and adjacent aspect of body of hyoid bone
Innervation: fibres from anterior ramus of C1 carried along Hypoglossal nerve CNXII
Function: depresses hyoid bone but when hyoid bone is fixed raises larynx
Sternothyroid
Anterior triangle of neck
Origin: posterior surface of manubrium of sternum
Insertion: oblique line on lamina of thyroid cartilage
Innervation: anterior rami of C1 to C3 through the ansa cervicalis
Function: draws larynx (thyroid cartilage) downward
Sternocleidomastoid
Posterior triangle of neck
Origin:
Sternal head- upper part of anterior surface of manubrium of sternum
Clavicular head- superior surface of medial one third of clavicle
Insertion:
Sternal head- lateral one half of superior nuchal line
Clavicular head- lateral surface of mastoid process
Innervation: accessory nerve CNXI and branches from anterior rami of C2 to C3 (C4)
Function: individually it tilts the head toward shoulder on same side rotating head to turn face to opposite side; together it draws head forward, flexion
Trapezius
Posterior triangle of neck
Origin: superior nuchal line; external occipital protuberance; ligamentum nuchae; spinous processes of C7 to T12
Insertion: lateral 1/3 clavicle, acromion, spine of scapula
Innervation: motor- accessory nerve CNXI, proprioception- C3 and C4
Function: assists in rotation scapula during abduction of humerus above horizontal; upper fibres elevate, middle fibres adduct, lower fibres depress scapula
Splenius capitis
Posterior triangle of neck
Origin: lower half of ligamentum nuchae, spinous processes of vertebrae C7 to T4
Insertion: mastoid process, skull below lateral 1/3 of superior nuchal line
Innervation: posterior rami of middle cervical nerves
Function: together draws head backward, individually draw and rotate head to one side
Levator scapulae
Posterior triangle of neck
Origin: transverse processes of C1 to C4
Insertion: upper part of medial border of scapula
Innervation: C3, C4 and dorsal scapular nerve C4 C5
Function: elevates scapula
Posterior scalene
Posterior triangle of neck
Origin: posterior tubercles of transverse processes of C4 to C6
Insertion: upper surface of rib 2
Innervation: anterior rami of C5 to C7
Function : elevation rib 2
Middle scalene
Posterior triangle of neck
Origin: transverse processes of C2 to C7
Insertion: upper surface rib 1 posterior to groove for subclavian artery
Innervation: anterior rami of C3 to C7
Function: elevation rib 1
Anterior scalene
Posterior triangle of neck
Origin: anterior tubercles of the transverse processes of C3 to C6
Insertion: scalene tubercle and upper surface rib 1
Innervation: anterior rami of C4 to C7
Function: elevates rib 1
