Anterior Triangle Muscles

Front 1

Boundaries of Anterior Triangle

Back 1

Superior: Inferior border of mandible.

Posterior: SCM muscle

Inferior: Anterior midline of neck

Front 2

Subdivisions of Anterior Triangle

Back 2

1) Submental triangle
2) Submandibular triangle
3) Muscular triangle
4) Carotid Triangle

Front 3

Structures that divide the Anterior triangle into further sub-triangles

Back 3

1) Anterior Belly of Digastric M.
2) Posterior Belly of Digastric M.
3) Hyoid Bone
4) Omohyoid Muscle

Front 4

Anterior Belly of Digastric Muscle
[origin, insertion, innervation, function]

Back 4

Origin: Digastric fossa of mandible

Insert: Intermediate tendon of body
Greater horn of hyoid bone.

Nerve: Mylohyoid nerve (V3-mand.)

Function: Depresses jaw
Raise hyoid bone + stab.
it when swallowing and
speaking

Front 5

Posterior Belly of Digastric Muscle
[origin, insertion, innervation, function]

Back 5

Origin: Mastoid notch (temp. bone)

Insert: Intermediate tendon of body
Greater horn of hyoid bone.

Nerve: Facial Nerve (CN VII)

Function: Depresses jaw
Raise hyoid bone + stab.
it when swallowing and
speaking

Front 6

(Skin)
(Superficial Cervical Fascia)
Platysma
[origin, insertion, innervation, function]

Back 6

Origin: fascia (clavicle+superior
parts of pec. major/deltoid)

Insert: inferior border of mandible
skin, subcutaneous tissue of
lower face

Nerve: Facial n. (cervical branch)

Function: draws corner of mouth
inferior+lateral (sad face)
-tenses skin of neck.

Front 7

Components of Deep Cervical Fascia

and function

Back 7

1) Investing Fascia
2) Pretracheal Fascia
3) Prevertebral Fascia

Function: support viscera, muscles, vessels, deep lymph nodes

Front 8

Submental Triangle
[boundaries]

Back 8

Inferior: body of hyoid bone

Lateral: Ant. Bellies of digastric m.

Floor: Mylohyoid Muscle

Front 9

Submental Triangle
[contents]

Back 9

1) Mylohyoid muscle
2) Mylohyoid nerve
3) Hyoid bone
4) veins that unite anterior jugular veins

Front 10

Submandibular Triangle
[boundaries]

Back 10

Hypotenuse: Lower border of mandible

Two Legs: Digastric M.
(Anterior/Posterior)

Front 11

Submandibular Triangle
[Floor]

Back 11

1) mylohyoid muscle
2) hyoglossus muscle
3) Middle pharyngeal constrictor m.

Front 12

Mylohyoid Muscle
[origin, insert,innervation, function]

Back 12

Origin: Mylohyoid midline of mandible

Insert: Raphe + body of hyoid bone.

Nerve: Mylohyoid N. (V3)

Function: Elevates hyoid bone, floor
of mouth, and tongue
during speakin/swallowin

Front 13

Hyoglossus M.
[origin, insert,innervation, function]

Back 13

Origin: Body + greater horn of hyoid

Insert: inferior + lateral tongue

Nerve: hypoglossal n. (CN XII)

Function:depresses+retracts tongue

Front 14

Middle Pharyngeal Constrictor Muscle.
[origin, insert,innervation, function]

Back 14

Origin: Stylohyoid ligament
greater/lesser horns of hyoid

Insert: median Raphe of Pharynx

Nerve: spinal accessory n. via vagus
(CN XI via X)

Function: Constricts pharynx wall
during swallowing.

Front 15

Submandibular Triangle
[Contents]

Back 15

Mylohyoid n.
Hypoglossal n.
Submandibular gland
Facial Veins + Arteries

Front 16

Muscular Triangle
[Boundaries]

Back 16

Superior Belly of Omohyoid
SCM
Midline of Neck

Front 17

Muscular Triangle
[Contents]

Back 17

Infrahyoid muscles (sternohyoid, omohyoid, sternothyroid, thyrohyoid)

Parathyroid
Thyroid
Larynx
Trachea
Left/Right Recurrent Laryngeal N.
Anterior Jugular Vein

Front 18

Sternohyoid

Back 18

Origin: Manubrium + Medial end of Clavicle

Insert: body of hyoid bone

Nerve: Ansa Cervicalis

Fcn: Depresses hyoid bone

Front 19

Omohyoid

Back 19

Origin: Sup. border of Scapula (near suprascapular notch)

Insert: Inf. border of hyoid bone

Nerve: Ansa Cervicalis

Fcn: Depresses, retracts, steadies hyoid bone

Front 20

Sternothyroid

Back 20

Origin: posterior manubrium + 1st costal cartilage

Insert: Oblique line of thyroid cartilage

Nerve: Ansa cervicalis

Fcn: Depresses hyoid + elevates larynx

Front 21

Thyrohyoid

Back 21

Origin: Oblique line of thyroid cartilage

Insert: inferior body + greater horn of hyoid bone

Nerve: C1 via Hypoglossal N (CN XII)

Fcn: depresses hyoid bone + elevates larnyx.

Front 22

Carotid Triangle
[boundaries]

Back 22

Superior omohyoid m.
SCM
Posterior belly of digastric m.

Front 23

Carotid Triangle
[contents]

Back 23

Carotid Sheath (internal jugular vein, common carotid, vagus n)

External Carotid (and branches)

Superior Laryngeal N (Internal/External)
Hypoglossal N
Ansa Cervicalis
Spinal Accessory . (CN XI)

4 nerves + carotid.