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Muscles of the face and scalp

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Notes

Figure 1: Layers of the scalp.
Figure 2: Muscles of the face. A. Superficial and B. Deep
Figure 3: Branches of the facial nerve.
MUSCLE TABLE
Muscle
Origin
Insertion
Innervation
Action
Occipitofrontalis muscle
Frontal belly:
  • Epicranial aponeurosis
Occipital belly:
  • Superior nuchal line
Frontal belly:
  • Skin & subcutaneous tissue superior to eyes
Occipital belly:
  • Epicranial aponeurosis
Frontal belly:
  • Temporal branch of CN VII
Occipital belly:
  • Posterior auricular branch of CN VII
  • Elevate eyebrows
  • Wrinkle forehead
Orbicularis oculi
  • Medial orbital margin & medial palpebral ligament
  • Lacrimal bone
  • Skin around orbit
  • Superior and inferior tarsal plates
Superior part:
  • Temporal branch of CN VII
Inferior part:
  • Zygomatic branch of CN VII
Palpebral part:
  • Closes eyelid gently
Orbital part:
  • Closes eyelid tightly
Corrugator supercilii
  • Medial part of superciliary arch
  • Skin of medial half of eyebrow
  • Temporal branch of CN VII
  • Makes vertical wrinkles at root of nose
Procerus
  • Aponeurosis covering nasal bone
  • Lower part of forehead between eyebrows
  • Zygomatic branch of CN VII with contributions from Buccal branch of CN VII
  • Depresses medial ends of eyebrows
Nasalis
  • Maxilla
Transverse part:
  • Midline aponeurosis
Alar part:
  • Alar cartilage
Transverse part:
  • Narrows nostrils
Alar part:
  • Flares nostrils
Levator labii superioris alaeque nasi
  • Frontal process of maxilla
  • Upper lip & alar cartilage of nose
  • Flares nostrils
  • Raises upper lip
Orbicularis oris
  • Maxilla, mandible, & angle of the mouth
  • Mucous membranes of lips
  • Buccal branch of CN VII
  • Close mouth
  • Protrude lips
Risorius
  • Parotid fascia & buccal skin
  • Angle of the mouth
  • Zygomatic branch of CN VII
  • Buccal branch of CN VII
  • Retracts corner of mouth (frowning)
Levator anguli oris
  • Infraorbital maxilla
  • Raises corner of mouth (grinning)
Zygomaticus major
  • Lateral aspect of zygomatic bone
  • Elevates corner of the mouth
Zygomaticus minor
  • Anterior aspect of zygomatic bone
  • Skin of upper lip
  • Raises upper lip
Levator labii superioris
  • Infraorbital margin of maxilla
Depressor anguli oris
  • Base of mandible & platysma muscle
  • Angle of the mouth
  • Marginal mandibular branch of CN VII
  • Pulls corner of the mouth downwards (frowning)
Depressor labii inferioris
  • Anterolateral body of mandible & platysma muscle
  • Skin of lower lip
  • Pulls lower lip downward (pouting)
Mentalis
  • Body of mandible
  • Skin of chin
  • Elevates & protrudes lower lip
Buccinator
  • Alveolar processes of maxilla and mandible & pterygo-mandibular raphe
  • Angle of the mouth
  • Buccal branch of CN VII
  • Presses cheek against teeth
  • Prevents biting cheeks during chewing
Platysma
  • Suprascapular & infraclavicular subcutaneous tissue
  • Base of mandible
  • Skin of the cheek and lower lip
  • Angle of the mouth
  • Cervical branch of CN VII
  • Depresses mandible & draws corners of mouth down
  • Tenses skin of lower face & neck
UNLABELLED DIAGRAMS

Transcript

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Content Reviewers

Viviana Popa, MD

Humans make many different facial expressions and they are an extremely important way that we communicate. They let people know when you are happy, like after getting a good mark on an anatomy test, or curious like when you learn something new about the human body. Let’s learn about the muscles responsible for our facial expressions!

First, let’s start with the scalp which is a layer of skin and subcutaneous tissue that covers the cranium. It extends from the supraorbital margins on the frontal bone to the superior nuchal line on the occipital bone.

Laterally, it covers the temporal fascia and extends to the zygomatic arches on each side. The scalp is made of five layers, which can be remembered easily as the first letter of each spells out the word SCALP.

Going in the order from superficial to deep: S stands for skin, C stands for connective tissue, A stands for aponeurosis or epicranial aponeurosis, L stands for loose connective tissue, and P stands for pericranium, which is the periosteum on the external surface of the cranium.

The first three layers - skin, connective tissue, and the aponeurosis - are connected tightly together, forming a single unit called the scalp proper.

Muscles of facial expression, simply known as the facial muscles are found deep to the skin of the scalp, face, and neck.

Most facial muscles are attached to bones or fascia on one end, and skin on the other, so that when they contract they create facial expressions.

All facial muscles originate from the mesoderm of the second pharyngeal arch, along with the facial nerve. During embryological development, a muscular sheet forms and begins to spread over the scalp, face and neck which later forms the facial muscles.

This spreading carries the branches of the nerve of the second arch with it, which is the facial nerve, or cranial nerve seven.

So, all facial muscles are innervated by the branches of the facial nerve which are the posterior auricular, temporal, zygomatic, buccal, marginal mandibular, and cervical nerves.

A way to remember these last five branches that emerge from the parotid gland is by using the mnemonic “To Zanzibar By Motor Car!”