Muscles of facial expression

Question 1

Where do the muscles of facial expression arise from embryologically? What nerve innervates them?

Answer 1

• The muscles of facial expression derive from the second pharyngeal arch
• They are innervated by branches of the facial nerve

Question 2

What are the muscles of the eye? What are their functions?

Answer 2

The muscle of the eye is the orbicularis oculi and it can be split into two parts:

• palpebral part - use of this muscle closes the eye gently
• orbital part - use of this muscle closes the eyes forcefully
• corrugator supercilii - this moves the eyebrows to the middle and downwards

Question 3

Where do the muscles of the eye originate?

Answer 3

• The palpebral part of OO originates from the medial palpebral ligament
• The orbital part of the orbicularis oculi originates from the nasal part of the frontal bone, the frontal process of the maxilla and the medial palpebral ligamment
• The corrugator supercilii orginates from the medial end of the superciliary arch

Question 4

Where do the muscles of the eye insert?

Answer 4

The muscles of the eye include the palpebral and orbital parts of the orbicularis oculi and the corrugator supercilii.

Palpebral part inserts into the lateral palpebral raphe
Orbital part inserts into the orbit
Corrugator supercilii inserts into the skin of the medial half of the eyebrown

Question 5

What are the muscles of the nose?

Answer 5

The nasalis (nose muscle) can be divided into 3 parts:

• procerus
• transverse part
• alar part
• depressor septi

Question 6

Where do the nasalis muscles originate from?

Answer 6

• The transverse part of the nasalis orginates from the maxilla (just lateral to the nose)
• The alar part of the nasalis originates from the maxilla, over the lateral incisor
• The procerus originates from the nasal bone and upper part of the nasal cartilage
  The depressor septi originates from the maxilla above the medial incisor

Question 7

What are the functions of the nasalis muscles?

Answer 7

• Depressor septi moves the nose inferiorly
• Transverse part compresses the nostrils
• Alar part opens the nostril by drawing the cartilage downwards and laterally
• • Procerus draws down medial angle of eyebrows, producing transverse wrinkles over bridge of nose

Question 8

What are the muscles of the mouth?

Answer 8

• Depressor anguli oris
• Depressor labii inferioris
• Mentalis
• RIsorius
• Zygomatic major
• Zygomatic minor
• Levator labii superioris
• Levator labii superioris alaeque nasi
• Levator anguli oris
• Orbicularis oculi
• Buccinator