anterior triangle

Question 1

boundaries

Answer 1

Anteriorly: midline of neck
Posteriorly: anterior border of sternocleidomastoid
Superiorly: inferior border of body of mandible

Question 2

muscle groups

Answer 2

• infrahyoid muscles
• suprahyoid muscles
• anterior vertebral muscles

Question 3

infrahyoid muscles

Answer 3

• below the hyoid bone
• thin, strap like muscles
• sternohyoid
• sternothyroid
• thyrohyoid
• omohyoid(superior belly)

Question 4

Sternohyoid

Answer 4

-located superficially, medial to superior belly of omohyoid
Origin: posterior surfaces of manubrium of sternum and sternal end of clavical
Insertion: body of hyoid
Nerve supply: ansa cervicalis(C1-C3)
Action: depress hyoid bone

Question 5

Sternothyroid

Answer 5

-located deep to sternohyoid
Origin: posterior surface of manubrium of sternum
Insertion: oblique line of thyroid cartilage
Nerve Supply: ansa cervicalis(C1-C3)
Action:depress larynx

Question 6

thyrohyoid

Answer 6

-upward continuation of sternothyroid
Origin: oblique line of thyroid cartilage
Insertion: runs superiorly over thyrohyoid membrane, inserts into greater horn and body of hyoid
Nerve Supply: C1 fibers via hypoglossal nerve
Action: depress hyoid bone or elevate larynx

Question 7

ansa cervicalis

Answer 7

-nerve loop that contains fibers from ventral rami of C1 to C3 spinal nerves

Question 8

lower root of ansa cervicalis

Answer 8

• direct branch of cervical plexus
• contains fibers from ventral rami of C2 and C3
• passes superficial(or deep) to internal jugular vein

Question 9

Upper root of ansa cervicalis

Answer 9

• appears to originate from hypoglossal nerve, but contains no hypoglossal fibers
• consists of C1 fibers that join hypoglossal nerve and travel with it

Question 10

what does the ansa cervicalis supply?

Answer 10

-branches supply sternohyoid, sternothyroid, and both bellies of the omohyoid

Question 11

do all C1 fibers branch off hypoglossal to form ansa cervicalis?

Answer 11

• nope

- some continue with it and supply thyrohyoid and geniohyoid muscles

Question 12

suprahyoid muscles

Answer 12

• above the hyoid bone
• digastric
• stylohyoid
• mylohyoid
• geniohyoid

Question 13

Digastic

Answer 13

-consists of posterior and anterior bellies connected by an intermediate tendon

Question 14

Digastric posterior belly

Answer 14

• attaches to digastric notch

- runs anteriorly and inferiorly

Question 15

digastric intermediate tendon

Answer 15

-pierces stylohyoid and runs in fibrous sling connected to body and greater horn of hyoid

Question 16

Digastric inferior belly

Answer 16

• runs anteriorly and superiorly

- attaches to digastric fossa of mandible

Question 17

nerve supply of digastric

Answer 17

Posterior belly: facial nerve

Anterior: nerve to myohyoid

Question 18

Action of digastric

Answer 18

-depress mandible and elevate hyoid bone

Question 19

stylohypid

Answer 19

Origin: styloid process
Insertion: passes anterior and inferior, inserts into hyoid bone at junction of body and greater horn
Nerve Supply: facial nerve
Action: elevates hyoid bone and draws it backwards

Question 20

stylohyoid piercing???

Answer 20

-pierced near its insertion by intermediate tendon of digastric

Question 21

mylohyoid

Answer 21

• lies superior to anterior belly of digastric

- two mylohyoid muscles form muscular floor of oral cavity

Question 22

mylohyoid origin and insertion

Answer 22

Origin: mylohyoid line of mandible
Insertion: attach to body of hyoid bone OR in midline raphe extending from mandible to hyoid

Question 23

Mylohyoid nerve supply

Answer 23

nerve to mylohyoid

Question 24

Mylohyoid action

Answer 24

elevates floor of mouth during swallowing

• elevates hyoid bone
• depresses mandible

Question 25

geniohyoid

Answer 25

-narrow muscle that lies above mylohyoid Origin: mental spine Insertion: anterior surface of body of hyoid Nerve supply: C1 fibers via hypoglossal nerve Action: elevates hyoid bone and draws it forward, depresses mandible

Question 26

anterior vertebral muscles

Answer 26

- longus capitis - longus coli - rectus capitis anterior - rectus capitis lateralis

Question 27

Longus capitis

Answer 27

Origin: transvers process of C3-C6 vertebrae Insertion: inferior surface of basilar part of occipital bone Nerve supply: ventral rami of C1-C3 Action: flexion of head and neck

Question 28

what are the subunits of longus colli?

Answer 28

inferior oblique superior oblique vertical part

Question 29

inferior oblique part

Answer 29

-extends from bodies of thoracic vertebrae to transverse processes of C5 and C6

Question 30

Superior oblique part

Answer 30

-extends from transverse process of C3 to C5 to anterior tubercle of atlas

Question 31

Vertical part

Answer 31

-extends from bodies of upper 3 thoracic and lower 3 cervical vertebrae to bodies of C2-C4 vertebrae

Question 32

Nerve supply of longus colli

Answer 32

-branches from ventral rami of C2 to C6 spinal nerves

Question 33

Action of longus colli

Answer 33

flexion of neck

Question 34

Rectus capitis anterior

Answer 34

-located posterior to upper part of longus capitis Origin: anterior surface of lateral mass of atlas and root of its transverse process Insertion: inferior surface of basilar part of occipital bone

Question 35

rectus capitis anterior nerve supply

Answer 35

branches from loop between ventral rami of C1 and C2 spinal nerves

Question 36

Action of rectus capitis anterior

Answer 36

flexion of the head

Question 37

Rectus capitis lateralis

Answer 37

Origin: upper surface of transverse process of atlas Insertion: inferior surface of jugular process of occipital bone

Question 38

Rectus capitis lateralis nerve supply

Answer 38

branches from loop between ventral rami of C1 and C2 spinal nerves

Question 39

Action of rectus capitis lateralis

Answer 39

lateral flexion of head to same said of contracting muscle

Question 40

subdivisions of the anterior triangle

Answer 40

- submandibular triangle - carotid triangle - muscular triangle - submental triangle

Question 41

submandibular triangle borders

Answer 41

Anteriorly: anterior belly of digastric Posteriorly: posterior belly of digastric and stylohyoid Superiorly: inferior border of body og mandible Floor: mylohyoid and hypoglossus muscles

Question 42

Contents of submandibular triangle

Answer 42

- submandibular gland - facial vessels - submandibular lymph nodes - hypoglossal nerve - mylohyoid nerve and vessels

Question 43

Carotid triangle borders

Answer 43

Anteriorly and superiorly: posterior belly of digastric Anterioinferiorly: superior belly of omohyoid Posteriorly: anterior border of sternocleidomastoid

Question 44

Contents of carotid triangle

Answer 44

-Arteries:common carotid, initial segments of external and internal carotid -Veins: internal jugular and some of its tributaries Nerves: vagus, accessory, hypoglossal, ansa cervicalis, internal and external laryngeal Nodes: deep cervical lymph nodes

Question 45

Muscular triangle borders

Answer 45

Anteriorly: anterior midline of neck Posteriosuperiorly: superior belly og omohyoid Posterioinferiorly: anterior border of sternocleidomastoid

Question 46

Contents of muscular triangle

Answer 46

- sternohyoid and sternothyroid muscles | - viscera of the neck

Question 47

Viscera of the neck

Answer 47

- thyroid and parathyroid glands - larynx - trachea

Question 48

Submental triangle boundaries

Answer 48

Laterally: anterior bellies of digastric Inferiorly: body of hyoid Floor: mylohyoid muscles(deep)

Question 49

Contents of submental triangle

Answer 49

- submental lymph nodes - small veins that join to make the internal jugular veins - mostly connective tissue