Lecture 12 - Muscles Of The Face, Head, & Neck

Question 1

What are the type of movements of the face, head, & neck?

Answer 1

• Fascial expressions: muscles surrounding eyebrows, mouth, cheeks etc
• Chewing: muscles surrounding mouth
• Speech: muscles surrounding mouth
• Vision (Blinking): muscles surrounding eyes
• Nose functions: muscles surrounding nose

Question 2

What are the 3 muscles of the mastication ?

Answer 2

• temporalis
• masseter
• platysma

Question 3

What is the origin/insertion/main action of the temporalis ?

Answer 3

• O: Temporal lines of the parietal bone
• I: Coronoid process of the mandible
• MA: Elevation & retraction of the mandible (i.e., clenching the jaw)

Question 4

What is the origin/insertion/main action of the masseter?

Answer 4

• O: Zygomatic arch & maxilla
• I: Ramus of mandible
• MA: Elevation & retraction of mandible, Antagonist to platysma

Question 5

What is the origin/insertion/main action of the platysma?

Answer 5

• O: Inferior to the clavicle
• I: Base of mandible, muscles around the mouth
• MA: Tenses the skin of the neck & Can move the lower lip & corners of the mouth down

Question 6

What is the zygomaticus major?

Answer 6

• Known as the smiling muscle
• Lifts the corner of the mouth
• Dimples = double or bifurcation in this muscle

Question 7

What is the frontalis muscle?

Answer 7

• A paired muscle located on the frontal bone
• Responsible for raising the eyebrows
• Can train this muscle to be able to raise one eyebrow at a time

Question 8

What is the sternocleidomastoid (SCM) muscle?

Answer 8

• Heavy cord-like muscle on lateral aspect of the neck
• Can be located by rotating your neck to the right, lifting your chin & then palpating the left side of your neck (& vice versa)

Question 9

What is the origin/insertion/Innervation/main action of the sternocleidomastoid?

Answer 9

• O: Medial, superior clavicle & manubrium
• I: Mastoid process of the temporal bone
• Inn: CN XI (accessory Nerve)
• MA: Bilateral: neck flexion, Unilateral: neck rotation & chin tilt upwards to the OPPOSITE side

Question 10

What are scalenes ?

Answer 10

• 3 paired muscles; anterior, middle, & posterior
• they form part of the floor of the posterior triangle of the neck
• act as accessory muscles of respiration and perform flexion at the neck

Question 11

What is the origin/insertion/main action of the anterior scalene?

Answer 11

• O: Transverse processes of C3-C6
• I: Rib 1
• MA: Neck flexion

Question 12

What is the origin/insertion/main action of the middle scalene?

Answer 12

• O: Transverse processes of C5-C7
• I: Rib 1
• MA: Neck lateral (side) flexion & Elevates rib 1 during forced inspiration

Question 13

What is the origin/insertion/main action of the posterior scalene?

Answer 13

• O: Transverse processes of C5-C7
• I: Rib 2
• MA: Neck lateral (side) flexion & Elevates rib 2 during forced inspiration