Anterior Triangle

Front 1

Carotid Sheath
-3 layers
-contents

Back 1

-investing fascia (outer layer)
-pretracheal fascia
-prevertebral fascia
-contents: common carotid a., internal jugular v., vagus n.
*common carotid branches into internal and external at ~C4

Front 2

Boundaries of Anterior Triangle

Back 2

-superiorly: inf. border of mandible
-posteriorly: SCM
-anteriorly: midline of neck (imaginary line)

Front 3

Anterior Belly of Digastric M.

Back 3

I: mylohyoid n. (V3)
A: depresses mandible; raises hyoid bone and steadies it during speaking/swallowing
O: digastric fossa of mandible
I: intermediate tendon of body and greater horn of hyoid bone

Front 4

Posterior Belly of Digastric M.

Back 4

I: facial n.
A: depresses mandible; raises hyoid bone and steadies it during speaking/swallowing
O: mastoid notch of temporal bone
I: intermediate tendon of body and greater horn of hyoid bone

Front 5

Platysma

Back 5

I: facial n. (cervical branch)
A: draws corners of mouth inferiorly and widens (sadness/fright); draws skin of neck superiorly when teeth are clenched
O: fascia covering clavicle; superior parts of pec major and deltoid
I: inf. border of mandible; skin and subcutaneous tissues of lower face

Front 6

Submental Triangle: Borders

Back 6

-inferiorly: body of hyoid bone
-laterally: ant. belly of digastrics m.
-floor: mylohyoid m.

Front 7

Submental Triangle: Contents

Back 7

-submental lymph nodes
-mylohyoid m. (forms floor)
-mylohyoid n.
-veins that unite ant. jugular vs.

Front 8

Submandibular Triangle: Boundaries

Back 8

-superiorly: inf. border of mandible
-medially: ant. belly of digastrics m.
-laterally: post. belly of digastrics m.

Front 9

Submandibular Triangle: Floor

Back 9

-mylohyoid m.
-hyoglossus m.
-middle pharyngeal constrictor m.

Front 10

Mylohyoid M.

Back 10

I: mylohyoid n. (V3)
A: elevates hyoid bone/floor of mouth/tongue during speaking/swallowing
O: mylohyoid line of mandible
I: raphe and body of hyoid bone

Front 11

Hypoglossus M.

Back 11

I: hypoglossal n. (CN XII)
A: depresses and retracts tongue
O: body and greater horn of hyoid bone
I: lateral side and inf. aspect of tongue

Front 12

Middle Pharyngeal Constrictor M.

Back 12

I: spinal accessory n. (CN XI via CN X)
A: constrict wall of pharynx during swallowing
O: stylohyoid ligament and greater/lesser horns of hyoid bone
I: median raphe of pharynx

Front 13

Submandibular Triangle:
Contents

Back 13

-submandibular gland
-submandibular lymph nodes
-facial a.
-facial v. (empties into internal jugular v.)
-CN XII
-mylohyoid n (V3)

Front 14

Muscular Triangle:
Boundaries

Back 14

-superior-laterally: superior belly of omohyoid m.
-inferior-laterally: ant. border of SCM
-medially: midline of neck

Front 15

Muscular Triangle:
Contents:
Infrahyoid Ms. AKA Strap Ms.

Back 15

-sternohyoid (superficial)
-omohyoid (superficial)
-sternothyroid (deep)
-thyrohyoid (deep)

Front 16

Muscular Triangle:
Contents:
Non-muscular Structures:

Back 16

-thyroid gland
-parathyroid glands
-L/R recurrent laryngeal ns.
-ant. jugular v.
-larynx
-trachea

Front 17

Omohyoid M.

Back 17

I: ansa cervicalis
A: depresses, retracts and steadies hyoid bone
O: superior border of scapula near suprascapular notch
I: inf. border of hyoid bone

Front 18

Sternohyoid M.

Back 18

I: ansa cervicalis
A: depresses hyoid after elevation from swallowing
O: manubrium of sternum; medial end of clavicle
I: body of hyoid bone

Front 19

Thyrohyoid M.

Back 19

I: C1 via CN XII
A: depresses hyoid and elevates larynx
O: oblique line of thyroid cartilage
I: inf. border of body and greater horn of hyoid

Front 20

Sternothyroid

Back 20

I: ansa cervicalis
A: depresses hyoid bone and larynx
O: 1st costal cartilage; post surface of manubrium
I: oblique line of thyroid cartilage

Front 21

Thyroid Gland:
-Structures?
-Function?

Back 21

-left and right lobe connected by the isthmus
-50% have a pyramidal lobe
-produces: triiodothyronine (T3) and thyroxine (T4), which regulate metabolism; calcitonin

Front 22

Thyroid Gland:
Arterial Supply

Back 22

-superior thyroid a. off external carotid
-inf. thyroid a. off thyrocervical trunk
-10% have thyroid ima a.

Front 23

Thyroid Gland:
Venous Drainage

Back 23

-superior thyroid v. draining into internal jugular
-middle thyroid v. draining into internal jugular
-inf. thyroid v. draining into L/R brachiocephalic v

Front 24

Parathyroid Gland:
-Function?

Back 24

produces PTH, which increases Ca (antagonistic to calcitonin)

Front 25

Carotid Triangle:
Boundaries:

Back 25

-medially: omohyoid m.
-laterally: SCM
-superiorly: post. belly of digastric

Front 26

Carotid Triangle:
Contents:

Back 26

-carotid sheath structures
-external carotid a. and some branches
-superior laryngeal n. and its external and internal branches
-spinal accessory n. (CN XI)
-hypoglossal n. (CN XII)
-ansa cervicalis

Front 27

External Carotid Branches
-Non-terminal?
-Terminal?

Back 27

(inferior to superior) SALFOP
-superior thyroid
-ascending pharyngeal
-lingual
-facial
-occipital
-posterior auricular
Terminal Branches:
-superficial temporal a.
-maxillary a.

Front 28

Carotid Body:
-Location?
-Function?
-Innervated by?

Back 28

-location: bifurcation of common carotid
-function: chemoreceptor that monitors the level of oxygen in blood
-innervated by VA fibers of CN IX

Front 29

Carotid Sinus
-Function?
-Innervated by?

Back 29

-function: reacts to changes in arterial blood pressure
-innervated by VA fibers of CN IX

Front 30

Superior Laryngeal Nerve:
-Arises from?
-Branches?
-What do the branches innervate?

Back 30

-arises from inf. vagal ganglion
-branches:
1. internal laryngeal n. innervates laryngeal mucous mb
2. external laryngeal n. innervates cricothyroid m.

Front 31

Ansa Cervicalis
-Branches formed by?
-Innervates?

Back 31

-branches:
1. superior root (C1)
2. inferior root (C2, C3)
-innervates all infrahyoid ms. except thyrohyoid