Neck Triangels

Question 1

Boundaries of the posterior triangle

Answer 1

Roof= investing fascia 
anterior= SCM
Posterior= anterior trap 
inferior: clavicle 
Floor= prevertebral fascia covering the scalenes, and neck muscles

Question 2

subtrapezial plexus

Answer 2

ventral rai of spinal nn C3 and C4 (which provide proprioceptive GSE

Question 3

Dorsal scapular n.

Answer 3

C5

passes thru the middle scalene, along the ventral surface of the levator scap and medial scapula to the rhomboids

Question 4

Accessory phrenic

Answer 4

branch of C5, parallels the phrenic n on the anterior scalene

Question 5

n to subclavius

Answer 5

C5-C6

descends anterior to brachial plexus and subclavian vessels and posterior to the subclavius muscle

Question 6

Suprascapular n

Answer 6

C5 C6

arises from the upper trunk and parallels the course of the suprascapular vessels to the area of the scapular notch to innervate the supra and infraspinatus muscles

Question 7

long thoracic n.

Answer 7

C 567, dorsal to brachial plexus

runs on lateral surface of the serratus anterior which it innervates

Question 8

subclavian aa.

Answer 8

lateral to the anterior scalene in the anterior/inferior extent of the posterior triangle
Invested in axillary sheath ( of prevertebral fascia origin)
Give off transverse cervical, suprascapular, and dorsal a. (parallels the dorsal scapular n.)

Question 9

Accessory nodes

Answer 9

located along the path of the spinal accessory n.

receive drainage from the occipital nodes and retroauricular nodes

Question 10

transverse cervical nodes

Answer 10

receive lymph from accessory chain, posterior thorax, latearl neck, anterior thoracic wall (mammary gland) and apical nodes from axilla

drain into inferior deep cervical nodes

**parallels the transverse cervical a.

Question 11

Digastric

Answer 11

two-bellied muscle with intermediate tendon that passes thru the SH
Both bellies insert on the hyoid
A: elevate the hyoid and base of the tongue. assists in opening the mouth when the hyoid if fixed
N: anterior belly= mylohyoid n. (CN V3)
Posterior= digastric branch of facial n. (CN VII)

Question 12

Stylohyoid

Answer 12

inserts on the hyoid bone near the lesser horn, splits around the digastric m.

elevates and retracts the hyoid and base of tongue
n: digastric branch of facial n. (CN VII)

Question 13

Mylohyoid

Answer 13

O: mylohyoid line of both sides of mandible
I: midline raphe from symph menti to body of the hyoid bone
A: elevates the hyoid and floor of mouth. Depresses the mandible when hyoid is fixed

Question 14

Sternohyoid

Answer 14

runs from the posterior part of the sternum , clavicle and SC ligament to the inferior margin of the hyoid

A: depresses hyoid and larynx
N: ansa cervicalis of the cervical plexus

Question 15

Sternothyroid

Answer 15

runs from the posterior surface of the manubrium inferior to SH
inserts ont eh oblique line of the thyroid cartilage
A: depresses larynx
N: ansa cervicalis

Question 16

Thyrohyoid

Answer 16

runs from oblique line of the thyroid cartilage to the inferior margin of the body and greater horn of the thyroid

A: depresses hyoid and tongue when larynx is fixed from below (by ST and SH), elevates the larynx when the hyoid is fixed from above.
N: C1 via hypoglossal n.

Question 17

Omohyoid

Answer 17

intermediate tendon tethers it to the posterior surface of the clavicle and first rib

Superior belly originates on the hyoid
Inferior belly originates on the scapula near notch

both insert on the clavicle and first rib
A: stabilize, retract, depress the hyoid and larynx
N: ansa cervicalis of the cervical plexus

Question 18

Isthmus of the thyroid gland

Answer 18

connects the two lobes medially, crosses over the 2nd, 3rd and 4th tracheal rings

pyramidal lobe may also be seen extending superiorly toward the hyoid

Question 19

superior thyroid artery

Answer 19

first branch off of the external carotid artery

has superior laryngeal a., anterior branch, and posterior branches

Question 20

superior laryngeal a.

Answer 20

pierces the thyrohyoid membrane with the internal laryngeal n. to provid branches to the interior of the larynx

Question 21

anterior branch

Answer 21

runs to the anterior portion of the thyroid gland where it anastomoses with the opposite counterpart

Question 22

posterior branch

Answer 22

runs to the posterior portion of the gland, anastomoses with branches of the inferior thyroid a.

Question 23

Inferior thyroid a.

Answer 23

branch of the thyrocervical trunk, ascends along the medial border of the ant. scalene

runs BEHIND teh carotid sheath and symp. trunk

anastamoses with posterior branches of the thyroid and supplies the posterior and inferior portions of teh thyroid

Question 24

thyroid ima a.

Answer 24

variable, unpaired branch of the brachiocephalic trunk or from the aortic arch

ascends the ventral surface of the trachea to the isthmus

anastomoses with the branches of the inferior thyroid a.

Question 25

Venous drainage of the thyroid

Answer 25

1) Superior thyroid v (runs with superior a.)
2) Middle thyroid v.: drains the lateral gland—>internal jugular
3) inferior thyroid v.: drains inferior thyroid, esophagus and trachea, runs down midline, may fuse into thyroid ima v.

Question 26

lymphatic drainage to the thyroid

Answer 26

**surrounded by juxtavisceral, which eventually drain into the deep cervical plexus

Question 27

innervation of thyroid

Answer 27

pre SNS: T1-T4 run in the chain, synapse on the superior, middle and cervicothroacic ganglia, via cardiac n. and sup/inf laryngeal nn.

some vasomotor fibers,

Question 28

innervation and blood supply to the trachea

Answer 28

inferior thyroid a. and v.

innervation: SNS from trunk
PSNS from vagus and recurrent laryngeal