Neck Myology

Question 1

What are the borders of the posterior triangle of the neck?

Answer 1

anterior = sternocleidomastoid m

posterior = trapezius m

inferior = clavicle

Question 2

What other two triangles are located within the posterior triangle of the neck?

Answer 2

occipital triangle

omoclavicular triangle

Question 3

What separates the occipital triangle and the supraclavicular triangle?

Answer 3

the inferior belly of the omohyoid M

Question 4

What is the innervation of the sternocleidomastoid M?

Answer 4

spinal accessory N (CN 11)

Question 5

What are the two types of torticollis?

Answer 5

congenital toritcollis = unilateral shortening of SCM m –> head rotatd away and sidebent toward fibrous “tumor”

spasmodic torticollis = adult onset, abnormal tonicity of cervical ms, usually SCM and trapezius

Question 6

Where do the scalenes insert?

Answer 6

anterior and middle = 1st rib

posterior = 2nd rib

Question 7

What are the innervations of the scalene Ms?

Answer 7

anterior: C4-6

Middle: C3-8

Posterior: C5-7

Question 8

What are the borders of the anterior triangle of the neck?

Answer 8

medial: median line of neck
lateral: SCM
superior: mandible

Question 9

What are the 4 triangles within the anterior triangle of the neck?

Answer 9

submental triangle

submandibular triangle

carotid triangle

muscular triangle

Question 10

What separates the two suprahyoid triangles and what are those triangles?

Answer 10

anterior belly of the digastric M separates

submandibular triangle

submental triangle

Question 11

What are the contents of the submental triangle?

Answer 11

submental A, LNs, and small veins

Question 12

What are the contents of the submandibular triangle?

Answer 12

submandibular gland, hypoglossal N, N to mylohyoid M, parts of facial A

Question 13

What separates the two infrahyoid triangles and what are they?

Answer 13

superior belly of omohyoid M separates

muscular triangle (more anterior)

carotid triangle (more posterior)

Question 14

What are the contents of the muscular triangle?

Answer 14

thyroid gland and parathyroid glands

Question 15

What are the contents of the carotid triangle?

Answer 15

common carotid A

internal jugular V

Vagus N

hypoglossal N

spinal accessory N

superior root of ansa cervalis

thyroid gland, larynx, pharynx, branches of cervical plexus

Question 16

What are the action and innervation of the geniohyoid m?

Answer 16

A: pulls hyoid b anteriorsuperiorly, shortens floor of mouth, widens pharynx

I: C1 via hypoglossal N

Question 17

What are the action and innervation of mylohyoid m?

Answer 17

A: elevates hyoid bone, floor of mouth, and tongue

I: mylohyoid N

Question 18

What are the action and innervation of the digastric M?

Answer 18

A: depresses mandible, elevates and steadies hyoid bone

I: anterior belly - mylohyoid n

posterior belly - facial n

Question 19

What are the action and innervation of stylohyoid m?

Answer 19

A: elevate and retract hyoid b, elongate floor of mouth

I: facial N

Question 20

What are the 4 infrahyoid ms?

Answer 20

thyrohyoid

sternothyroid

sternohyoid

omohyoid (sup and inf bellies)

Question 21

What are the innervations for the infrahyoid Ms?

Answer 21

All ansa cervicalis (C1-C3)

except: thyrohyoid = C1 via hypoglossal N

Question 22

what is the innervation of platysma M

Answer 22

cervical branch of facial N

Question 23

Where do all of the pharyngeal constrictor Ms insert?

Where do they originate respectively?

Answer 23

median raphe of pharynx

Superior: (also I on pharyngeal tubercle of occipital b) part of the mandible, pterygoid hamulus, side of tongue

middle: stylohyoid L, greater and lesser hornds of hyoid b
inferior: thyroid and cricoid cartilage

Question 24

What are the innervations of the pharyngeal constrictor Ms?

Answer 24

Superior: Pharyngeal branch of Vagus N and pharyngeal plexus

Middle and Inferior: pharyngeal branch of vagus N and pharngeal plexus, branches of recurrent laryngeal N

Question 25

What n innervates levator scapulae m?

Answer 25

dorsal scapular n

Question 26

What n innervates splenius capitis ms?

Answer 26

posterior rami C3-C5

Question 27

What n innervates both the posterior belly of digastric m and stylohyoid m?

Answer 27

facial n

Question 28

What n innervates palatopharyngeus and salpingopharyngeus ms?

Answer 28

pharyngeal branch of vagus n

Question 29

What n innervates stylopharyngeus m

Answer 29

glossopharyngeal n

Question 30

what are the laryngeal muscles (6) and what innervates them?

Answer 30

cricothyroid m posterior cricoarytenoid m lateral cricoarytenoid m transverse and oblique arytenoid m thyroarytenoid m vocalis m \*all innervated by **recurrent laryngeal** n except **cricothyroid = external laryngeal** n\*

Question 31

What is the action of cricothyroid m?

Answer 31

stretches and tenses vocal L

Question 32

What does the posterior crucoarytenoid m do?

Answer 32

abducts focal fold

Question 33

What does the lateral cricoarytenoid m do?

Answer 33

adducts vocal fold

Question 34

What do the transverse and oblique arytenoid ms do?

Answer 34

adduct arytenoid cartilage closes intercartilaginous part of rima glottidis

Question 35

what does the thyroiarytenoid m do?

Answer 35

relaxes vocal l

Question 36

What does the vocalis m do?

Answer 36

relaxes posterior part of vocal L tenses anterior part of vocal L

Question 37

What is zone one of injury in the neck?

Answer 37

clavicle to cricoid c great vessels, trachea, esophagus, lung apices, cervical spine and nerves are at risk

Question 38

What is zone 2 of injury in the neck?

Answer 38

cricoid cartilage to angle of mandible carotid and vertebral As jugular Vs pharynx, larynx, trachea esophagus, cervical spine, spinal cord

Question 39

What is zone 3 of injury in the neck?

Answer 39

angle of mandible to base of skull salivary and parotid glands esophagus, trachea, vertebral bodies carotid As, jugular Vs spinal cord and other major nerves