Muscles of Head and Neck Part 1

Question 1

Sternocleidomastoid (O, I, A, N)

Answer 1

O: two heads (1) sternum- manubrium (2) clavicle- medial 1/3 of clavicle
I: Mastoid Process of Temporal Bone
A: bilaterally- flex neck, unilaterally- rotate head so face is directed to opposite side
N: Accessory (CN XI)

Question 2

Scalenus Anterior and Medius (O, I, A, N)

Answer 2

O: vertebra- transverse processes of upper cervical
I: Rib 1
A: flex neck and elevate rib 1
N: branches of ventral rami of cervical spinal nerves

Question 3

Omohyoid (O, I, A, N)

Answer 3

O: Inferior Belly- scapula, medial to suprascapular notch
(Intermediate tendon- clavicle and rib 1)
Superior Belly- continues to insertion
I: Hyoid bone
A: Depress hyoid bone
N: Ansa cervicalis

Question 4

Sternohyoid (O, I, A, N)

Answer 4

O: Sternum (manubrium) and clavicle
I: Hyoid Bone
A: Depresses hyoid bone
N: Ansa cervicalis

Question 5

Sternothyroid (O, I, A, N)

Answer 5

O: Sternum- manubrium
I: Thyroid Cartilage
A: depresses thyroid cartilage, indirectly depresses hyoid bone and larynx
N: Ansa cervicalis

Question 6

Thyrohyoid (O, I, A, N)

Answer 6

O: Thyroid cartilage
I: Hyoid bone
A: depresses hyoid bone, elevates larynx
N: C1 via branch hitch-hiking with CN XII

Question 7

Infrahyoid Muscles

Answer 7

All depress hyoid

Omohyoid, Sternohyoid, Sternothyroid, and Thyrohyoid

Question 8

Suprahyoid Muscles

Answer 8

All elevate hyoid

Digastric, Stylohyoid, Mylohyoid, and Geniohyoid

Question 9

Digastric (O, I, A, N)

Answer 9

O: Posterior Belly- mastoid notch of temporal bone
Anterior Belly- inner side of mandible
I: Hyoid bone- via intermediate tendon
A: elevates hyoid bone, depresses mandbile
N: Posterior Belly- CN VII (Facial)
Anterior Belly- CN V-Trigeminal

Question 10

Stylohyoid (O, I, A, N)

Answer 10

O: Styloid process of temporal bone
I: Hyoid Bone
A: Elevates Hyoid bone
N: CN VII (facial nerve)

Question 11

Mylohyoid (O, I, A, N)

Answer 11

O: Mylohyoid line of mandible
I: hyoid bone
A: elevates hyoid bone, raises floor of mouth during swallowing
N: CN V (trigeminal nerve)

Question 12

Geniohyoid (O, I, A, N)

Answer 12

O: Inner side of mandible
I: hyoid bone
A: elevates hyoid bone, draws hyoid forward
N: C1 via branch hitch-hiking with CN XII (hypoglossal

Question 13

Muscles of Mastication

Answer 13

Masseter, Temporalis, Medial Pterygoid, and Lateral Pterygoid

Question 14

Masseter (O, I, A, N)

Answer 14

O: Zygomatic Arch
I: Mandible- lateral side of rams
A: elevate mandible
N: V3

Question 15

Temporalis (O, I, A, N)

Answer 15

O: Temporal bone
I: Mandible- coronoid process
A: elevate and retrude mandible
N: V3

Question 16

Medial Pterygoid (O, I, A, N)

Answer 16

O: Lateral pteryoid plate- medial side
I: Mandible- medal side of ramus
A: Elevate mandible
N: V3

Question 17

Lateral Pterygoid (O, I, A, N)

Answer 17

O: (1) Sphenoid bone- greater wing (2) Lateral pterygoid plate- lateral side
I: (1) mandible- neck (2) articular disc of TMJ
A: Depress, protrude mandible
N: V3