Neck Triangles, Fascial System and Muscles

Question 1

list the borders of the neck, anterior and posterior

Answer 1

anterior: from lower border of the mandible to the upper surface of the manubrium
posterior: from the superior nuchal line on the occipital bone to the discs between C7 and T1 vertebrae

Question 2

list the boundaries of the anterior triangle of the neck

Answer 2

anterior border of the sternocleidomastoid muscle, the inferior border of the mandible, the midline of the neck

Question 3

list the boundaries of the posterior triangle of the neck

Answer 3

posterior border of the sternocleidomastoid muscle, the anterior border of the trapezius muscle and the middle 1/3 of the clavicle.

Question 4

what are the 4 components of the neck

Answer 4

the visceral, vertebral and 2 vascular compartments

Question 5

what does the visceral component of the neck include?

Answer 5

it is anterior, and contains part of the digestive, respiratory and endocrine systems

Question 6

what does the vertebral component of the neck include?

Answer 6

it is posterior, it contains the cervical vertebrae, spinal chord, cervical nerves, and muscles of the vertebral column

Question 7

the 2 vascular compartments of the neck include?

Answer 7

they are laterally positioned. they contain major blood vessels (common carotid and internal jugular) and the vagus nerve

Question 8

list the neck fascias

Answer 8

superficial fascia, deep cervical fasica (has 4 parts)

Question 9

explain the purpose of the superficial fascia?

Answer 9

it contains the platysma muscle, which attaches to the mandible.

Question 10

what innervates the platysma

Answer 10

cervical branch of the facial nerve

Question 11

explain the deep cervical fasica and its parts

Answer 11

• investing layer: surrounds all structures of the neck
• pre-vertebral layer: surround vertebral column and the deep muscles of the back
• pre-tracheal layer: enclosed viscera of the neck
• carotid sheaths: has parts of all the other fascias and surrounds the major neurovascular bundles on either side of the neck

Question 12

where does the investing layer of fascia lie?

Answer 12

it attaches posteriorly to the ligamentum nuchae and the spinous process of the C7 vertebrae. This layer splits to enclose the trapezius muscle, and reunites to a single layer forming the roof of the posterior triangle, splits again to surround the sternocleidomastoid and becomes one and merges with the other side.
anteriorly it surrounds the infrahyoid muscles

Question 13

explain the prevertebral layer of fascia

Answer 13

• surrounds vertebral column and its muscles: ant. mid. post. scalene, and deep muscles of the back
• it splits into layers creating a longitudinal fascial space with loose CT that extends from the base of the skull through the thorax

Question 14

explain the pretracheal layer of fascia

Answer 14

• surrounds the trachea, esophagus, thyroid gland
• anteriorly it crosses the neck behind the infrahyoid muscles and covers the trachea and thyroid.
• it begins a hyoid bone and ends in upper thoracic cavity.
• laterally is covers the thyroid and esophagous
• posteriorly it is aka buccopharyngeal fascia and it separates the esophagous and pharynx from the prevertebral layer.

Question 15

where is the buccopharyngeal fascia

Answer 15

begins superiorly a the base of the skull and ends inferiorly in the thoracic cavity

Question 16

where is carotid sheath fascia

Answer 16

it surrounds the common carotid artery (medially), the internal carotid artery, the internal jugular vein(laterally), and the vagus nerve (posteriorly). In the upper part it also contains IX, XI, XII. The ansa cervicalis is embedded in the anterior wall of the sheath

Question 17

anterior triangular of the neck is divided into? (4)

Answer 17

• submandibular triangle: is outlined by the inf border of the mandible
• submental triangle: outlined by the hyoid bone inferiorly, the anterior belly of the digastric muscle
• the muscular triangle: outlined by the hyoid bone superiorly, the superior belly of the omohyoid muscle, and the anterior border of the sternocleidomastoid muscle
• the carotid triangle: is outlined by the superior belly of the omohyoid muscle anterioinferiorly, the stylohyoid muscle and the posterior belly of the digastric superiorly, and the anterior border of the sternocleidomasoid muscle posteriorly

Question 18

list the suprahyoid muscles (DIG MY STYLe, its GENIus)

Answer 18

stylohyoid, digastric, mylohyoid, and geniohyoid

Question 19

list the infrahyoid muscles (TOSS)

Answer 19

omohyoid, sternohyoid, thyrohyoid, sternothyroid (the thyrohyoid is innervated by the XII nerve while the others are innervated by the ansa cevicalis)

Question 20

function, origin, insertion, innervation of the stylohyoid

Answer 20

pull hyoid bone upward in posterior direction, base of styloid process, lateral body of hyoid, VII

Question 21

function, origin, insertion, innervation of the anterior digastric

Answer 21

open mouth by lowering mandible and raising hyoid bone, digastric fossa on lower inside of mandible, attachement of tendon between 2 bellies to the body of the hyoid, myelohyoid nerve from inf. alveolar brnch of V3

Question 22

function, origin, insertion, innervation of the posterior digastric

Answer 22

pulls hyoid bone upwards and back, mastoid notch on medial side of mastoid process of temporal bone, same as 21, VII

Question 23

function, origin, insertion, innervation of the mylohyoid

Answer 23

support and elevation of the floor of mouth and elevation of hyoid, mylohyoid line on mandible, body of hyoid bone,myelohyoid nerve from inf. alveolar branch of V3

Question 24

function, origin, insertion, innervation of the geniohyoid

Answer 24

mandible elevates and pulls hyoid forward, while hyoid pulls mandible down and inwards, inferior mental spine on inner surface of mandible, anterior surface of hyoid body, branch from anterior ramus of C1

Question 25

function, origin, insertion, innervation of the sternohyoid

Answer 25

depress hyoid bone after swallowing, posterior aspect of sternoclavicular joint and adjacent manubrium of sternum, body of hyoid medial to attachment of omohyoid, anterior rami of C1 to C3 through ansa cervicalis

Question 26

function, origin, insertion, innervation of the omohyoid

Answer 26

depresses and fixes the hyoid bone, superior border of scapula medial to suprascapular notch, lower border hyoid lateral to sternohyoid attachment, anterior rami of C1 to C3 through ansa cervicalis

Question 27

function, origin, insertion, innervation of the thyrohyoid

Answer 27

depress hyoid but if hyoid is fixed it raises larynx, oblique line on lamina of thyroid cartilage, greater horn and adjacent aspect of body of hyoid, fibers from anterior ramus of C1 carried along XII

Question 28

function, origin, insertion, innervation of the sternothyroid

Answer 28

pulls larynx (thyroid cartilage) downwards; posterior surface of manubrium, oblique line on thyroid cartilage, anterior rami of C1 to C3 through ansa cervicalis

Question 29

function, origin, insertion, innervation of the sternocleidomastoid sternal head

Answer 29

tilt head to shoulder on same side or rotating head to side, upper manubrium, lateral 1/2 of superior nuchal line, XI from ant rami of C2-C3

Question 30

function, origin, insertion, innervation of the sternocleidomastoid clavicular head

Answer 30

tilt head to shoulder on same side or rotating head to side, superior surface of medial 1/3 clavical, lateral suface of mastoid process.

Question 31

what motion do both sternocleidomasoids perfom together

Answer 31

draw head forward

Question 32

function, origin, insertion, innervation of the trapezius

Answer 32

rotating scapula during abduction of humerus (upper fibers elevate, middle fibers adduct, lower fibres depress scapula), superior nuchal line, external occipital protuberance, ligamentum nuchae, spinous processes of vertebrae CVII to TXII, lateral 1/3 clavical acromium spine of scapula, motor XI proprioception C3,C4

Question 33

function, origin, insertion, innervation of the splenius capitis

Answer 33

together draw head back, alone draw and rotate head to one side, lower half of ligamentum nuchae and spinous processes of CVII to TIV, mastoid process and skull below lateral 1//3 of superior nuchal line, posterior rami of middle cervical nerves

Question 34

function, origin, insertion, innervation of the levator scapular muscle

Answer 34

elevates scapula, transverse processes of CI to CIV, upper part of medial border of scapula, C3,C4 and dorsal scapular nerve

Question 35

where is the retropharyngeal space?

Answer 35

between the prevertebral fascia posteriorly and the pretracheal fascia anteriorly (back part of pretracheal fascia is the buccopharyngeal fascia)

Question 36

all the muscles of the tongue are innervated by

Answer 36

cn XII (hypoglossal) except the palatoglossus which is by CN X