Face, Parotid and Scalp

Face, Parotid and Scalp


Muscles of Facial Expression

There are 21 muscles of facial expression in the face and neck, with the 12 major muscles spanning the orbital, nasal, and oral regions. All these muscles receive motor innervation from CN VII (Facial Nerve).

Major Muscles of Facial Expression

Major Facial Muscles

  • Platysma Platysma Muscle
  • Occipitofrontalis
    • Frontalis (frontal belly) Frontalis Muscle
    • Occipitalis (occipital belly) Occipitalis Muscle
  • Orbicularis Oculi
    • Orbital
    • Palpebral Palpebral Part of Orbicularis Oculi
  • Orbicularis Oris Orbicularis Oris Muscle
  • Mentalis Mentalis Muscle
  • Zygomaticus Major Zygomaticus Major Muscle
  • Zygomaticus Minor Zygomaticus Minor Muscle
  • Levator Labii Superioris Levator Labii Superioris Muscle
  • Levator Labii Superioris Alaeque Nasi Levator Labii Superioris Alaeque Nasi Muscle
  • Levator Anguli Oris Levator Anguli Oris Muscle
  • Risorius Risorius Muscle
  • Depressor Anguli Oris Depressor Anguli Oris Muscle
  • Depressor Labii Inferioris Depressor Labii Inferioris Muscle
  • Buccinator Buccinator Muscle

Parotid Gland

The parotid gland is located near the mandible and is associated with the parotid duct. Notably, it receives parasympathetic innervation from CN IX, with CN VII passing through it without innervating it.

Parotid Gland Location

Facial Nerve (CN VII)

The motor branches of CN VII include:

  • Temporal branches
  • Zygomatic branches
  • Temporofacial branch
  • Posterior auricular nerve
  • Buccal branches
  • Cervicofacial branch
  • Marginal mandibular branches
  • Cervical branches
  • Digastric branch
Facial Nerve Branches

Cutaneous Distribution of CN V

CN V (Trigeminal Nerve) has three main branches, each responsible for sensory innervation to different regions of the face:

  • V1: Ophthalmic nerve Ophthalmic Nerve Distribution
  • V2: Maxillary nerve Maxillary Nerve Distribution
  • V3: Mandibular nerve Mandibular Nerve Distribution

Notable Nerves

  • Supra-orbital nerve Supra-Orbital Nerve
  • Supratrochlear nerve Supratrochlear Nerve
  • Infratrochlear nerve Infratrochlear Nerve
  • External nasal nerve External Nasal Nerve
  • Infra-orbital nerve Infra-Orbital Nerve
  • Auriculotemporal nerve Auriculotemporal Nerve
  • Buccal nerve Buccal Nerve
  • Mental nerve Mental Nerve
  • Zygomaticotemporal nerve Zygomaticotemporal Nerve
  • Zygomaticofacial nerve Zygomaticofacial Nerve

Pattern of Arterial Supply to the Face and Scalp

The external carotid artery and its branches supply blood to the face and scalp. Some of the major branches include:

  • Facial artery Facial Artery
  • Maxillary artery Maxillary Artery
  • Superficial temporal artery Superficial Temporal Artery
  • Transverse facial artery Transverse Facial Artery
  • Infra-orbital artery Infra-Orbital Artery
  • Buccal artery Buccal Artery
  • Lingual artery Lingual Artery
  • Mental artery Mental Artery

Some arteries like the supratrochlear and supraorbital arise from the internal carotid system.

Arterial Supply of Face and Scalp

Venous Drainage of the Face

The veins of the face include the facial, angular, and ophthalmic veins, which are valveless. The facial vein drains into the internal jugular vein (IJV) while the ophthalmic veins and pterygoid plexus drain into the cavernous sinus. Anastomoses present potential danger due to possible spread of infection.

Venous Drainage of Face

Lymphatic Drainage of the Face

The lymphatic vessels of the face primarily drain into the following nodes:

  • Submental nodes Submental Lymph Nodes
  • Submandibular nodes Submandibular Lymph Nodes
  • Pre-auricular and parotid nodes Pre-auricular and Parotid Lymph Nodes

Layers of the Scalp

The scalp consists of five layers:

  • Skin Skin Layer of Scalp
  • Connective tissue Connective Tissue Layer of Scalp
  • Aponeurosis Aponeurosis Layer of Scalp
  • Loose connective tissue Loose Connective Tissue Layer of Scalp
  • Periosteum/Pericranium Periosteum Layer of Scalp

Clinical Correlations

  • Lump on the forehead Lump on Forehead
  • Raccoon's eyes (periorbital ecchymosis) Raccoon's Eyes
  • Profuse scalp bleed which is exacerbated by:
    • The occipitofrontalis muscle pulling the sides of the wound apart
    • Dense connective tissue holding cut vessels open