GA: Muscles Flashcards
What are the borders of the posterior triangle of the neck?
Anterior: Sternocleidomastoid M.
Posterior: Trapezius M.
Inferior: Clavicle
What are the 2 subtriangles of the posterior triangle?
- Occipital Triangle (sup. to omohyoid M.)
- Supraclavicular Triangle (inf. to omohyoid M.)
What is found in the posterior triangle?
Levator Scapulae M.
Anterior, Middle, + Posterior Scalene M.
Inferior belly of Omohyoid M.
Splenius Capitus M.
What is found in the occipital triangle?
External Jugular V.
Posterior branches of cervical plexus
Transverse cervical A.
What is found in the supraclavicular triangle?
3rd part of subclavian A. + suprascapular A.
What innervates the sternocleidomastoid muscle?
Spinal Accessory N. (also innervates trapezius)
What is the action of the sternocleidomastoid muscle?
Laterally flex neck + rotate face away
What is congenital torticollis?
A disorder where a fibrous tissue tumor forms in the sternocleidomastoid muscle which causes the head to turn and the face to look away from the affected side.
A hematoma can arise and impinge on the spinal accessort nerve, which denervates the SCM.
What is spasmatic torticollis?
Adult onset
Involves abnormal tonicity of the cervical muscles, usually the sternocleidomastoid and trapezius muscles.
What is the innervation + action of anterior scalene m.?
Elevate 1st rib + laterally flex neck + rotate face away
C4-6
What is the innervation + action of middle scalene m. ?
C3-8
Elevate 1st rib, laterally flex neck
What is the innervation + action of posterior scalene m. ?
C5-7
elevate 2nd rib + laterally flex neck
What are the borders of the anterior triangle of the neck?
Anterior: Median line of neck
Posterior: Anterior edge of SCM
Superior: Mandible
What are the muscular contents of the anterior triangle?
Mylohyoid M., Geniohyoid M., Diagastric M., Stylohyoid M., Sternohyoid M., Sternothyroid M., Thryohyoid M., superior belly of omohyoid M.
What are the two suprahyoid triangles of the anterior triangle?
- Submental triangle (ant.)
- Submandibular triangle (post.)
Separated by anterior belly of diagastric M.
What is found in the submental triangle?
Submental A.
Submental L.N.’s
small veins
What is found in the submandibular triangle?
Submandibular gland
Hypoglossal N.
Nerve to the mylohyoid M.
parts of the facial N.
What are the 2 infrahyoid triangles of the anterior triangle?
- Muscular triangle (ant.)
- Carotid triangle (post.)
Separated via superior belly of omohyoid M.
What are the contents of the carotid triangle?
Common carotid A.
Internal Jugular V.
Vagus N.
Hypoglossal N.
Spinal Accessory N.
Superior root of ansa cervicalis
thyroid gland
larynx
pharynx
braches of cervical plexus
What are the contents of the muscular triangle?
Thyroid gland
Parathyroid glands
I + A of mylohyoid M.
I: Mylohyoid N.
A: elevates hyoid bone + floor of mouth and tongue
I of gleniohyoid M.
I: C1 via hypoglossal N.
I of digastric M.
*is tendinous in middle*
Anterior belly –> mylohyoid N.
Posterior belly –> Facial N.
Stylohyoid M. innervation?
Facial N.
What are the 4 suprahyoid muscles?
(elevate hyoid)
- myohyoid
- geniohyoid
- diagastric
- stylohyoid
What are the 4 infrahyoid muscles?
(depress hyoid)
- Sternohyoid M.
- Sternothyroid M.
- Thryohyoid M.
- Omohyoid M.
What nerve innervates omohyoid, sternothyroid, and sternohyoid muscles?
Ansa cervicalis
Omohyoid + sternohyoid –> C1-3
sternothyroid –> C2,C3
What nerve innervates the thyrohyoid muscle?
C1 via hypoglossal N.
What innervates the platysma?
Cervical branch of facial N.
What 3 muscles constrict the pharyngeal wall?
- Superior Pharyngeal Constrictor
- Middle Pharyngeal Constrictor
- Inferior Pharyngeal Constrictor
What 3 muscles elevate the pharynx + larynx?
- Palatopharyngeus M.
- Salpingopharyngeus M.
- Stylopharyngeus M.
What nerve innervates the stylopharyngeus M.?
Glossopharyngeal N.
A + I of cricothyroid M.
A: Stretch + tense vocal fold, “vocal cord”
I: External Laryngeal N.
All the laryngeal muscles, except the cricothyroid muscle, are innervated by what?
Recurrent Laryngeal N.
What laryngeal muscles close the intercartilaginous portion of the rima glottidis?
Transverse Arytenoid M.
Oblique Arytenoid M.
Vocalis –> relaxes posterior cord + tenses anterior cord
What muscles make up the anterior vertebral column?
Longus Colli M. –> C2-6
Longus Capitis M. –> C1-3
Rectus Capitis Anterior + Laterallis –> C1-2
What is Zone 1 of penetrating neck trauma?
Root of neck
Structures @ risk = cervical pleurae, apices of lungs, thyroid + parathyroid glands, trachea, esophagus, common carotid A., Jugular V., Cervical vertebrae
What is zone 2 of penetrating neck trauma?
*most dangerous,more common, but easiest to fix*
From cricoid cartilage to the angle of mandible.
Structures at risk: Laryngeal cartilages, larynx, laryngopharynx, carotid A., Jugular V., esophagus, cervical vertebrae
What is zone 3 of penetrating neck trauma?
From angle of the mandible –> superiorly
Structures @ risk: Salivary glands, oral + nasal cavities, oro-nasopharynx
Injuries to zone 1 + 3 are less common and harder to access, thus harder to repair.
