Facial Anatomy and Physiology

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Questions and Answers

What is a characteristic of facial skin?

It is very elastic and thick due to facial muscle attachment. (correct)

It lacks sebaceous glands.

It is always taut and rigid.

It is avascular with low elasticity.

Which cranial nerve is responsible for the sensory supply of the face?

Trigeminal nerve (5th cranial) (correct)

Optic nerve (2nd cranial)

Vagus nerve (10th cranial)

Accessory nerve (11th cranial)

Where is fat absent in the facial region?

Forehead

Eyelids (correct)

Cheeks

Nostrils

What structure is formed by deep fascia over the parotid gland?

Parotid fascia Signup and view all the answers

How do facial muscles primarily function?

To regulate openings such as palpebral fissures. Signup and view all the answers

Which muscle is responsible for puffing the mouth and then blowing forcibly, as in whistling?

Buccinator Signup and view all the answers

What structure extends from the superciliary arches anteriorly to the external occipital protuberance posteriorly?

Scalp Signup and view all the answers

Which layer of the scalp is firmly attached to the epicranial aponeurosis through dense fascia?

Skin Signup and view all the answers

What characteristic of the connective tissue layer of the scalp contributes to profuse bleeding during wounds?

Contains blood vessels and nerves Signup and view all the answers

Which of the following lymph glands is NOT associated with the mandible area?

Preauricular Signup and view all the answers

Which sensory area is NOT supplied by the maxillary division of the trigeminal nerve?

Anterior 2/3 of the tongue Signup and view all the answers

What symptom is primarily associated with trigeminal neuralgia?

Sudden, severe facial pain Signup and view all the answers

Which of the following is a motor nerve supply provided by the zygomatic branch?

Orbicularis oculi (lower eyelid part) Signup and view all the answers

Which clinical feature indicates an infranuclear lesion of the facial nerve?

Asymmetrical facial appearance Signup and view all the answers

What is the consequence of a supranuclear lesion of the facial nerve?

Only the lower quarter of the opposite side is paralyzed Signup and view all the answers

Which part of the face is primarily affected by trigeminal neuralgia?

Lower part of the face Signup and view all the answers

Which of the following conditions can lead to headaches as related to the trigeminal nerve?

Sinusitis Signup and view all the answers

Which division of the trigeminal nerve supplies the floor of the oral cavity?

Mandibular division Signup and view all the answers

Which muscle is primarily responsible for closing the eyelids?

Orbicularis oculi Signup and view all the answers

What action is primarily facilitated by the Nasalis muscle?

Flaring of the nostrils Signup and view all the answers

Which muscle is commonly referred to as the 'happy muscle' due to its role in smiling?

Zygomaticus major Signup and view all the answers

Which part of the Occipitofrontalis muscle is responsible for lifting the eyebrow and producing horizontal wrinkles?

Frontal part Signup and view all the answers

What is the main function of the Buccinator muscle?

Compressing the cheeks Signup and view all the answers

The Orbicularis oris muscle primarily functions to:

Compress and bring lips together Signup and view all the answers

Which muscle pulls the skin of the eyebrow downward and medially?

Corrugator supercilii Signup and view all the answers

What is the primary function of the Risorius muscle?

Pulling the lips horizontally Signup and view all the answers

What causes subcutaneous hemorrhages to be relatively limited in extent?

Dense fascia Signup and view all the answers

Which layer of the scalp is considered dangerous due to the presence of emissary veins?

Loose areolar tissue Signup and view all the answers

What supplies the scalp anteriorly from the external carotid artery?

Superficial temporal artery Signup and view all the answers

What results from a collection of blood in the loose connective tissue of the scalp?

Generalized swelling Signup and view all the answers

Which muscle's action is associated with the frontal belly of the occipitofrontalis?

Raising the eyebrows Signup and view all the answers

What anatomical feature causes the black eye effect due to bleeding?

Origin of the frontalis muscle Signup and view all the answers

Where do lymph vessels in the anterior part of the scalp drain?

Submandibular lymph nodes Signup and view all the answers

What happens if the aponeurosis of the scalp is cut transversely?

It results in a gap that requires stitching Signup and view all the answers

Study Notes

Boundaries of the Face

Extends superiorly from the adolescent position of the hairline
Inferiorly to the chin and the base of the mandible
On each side to the auricle.

Facial Skin

Highly vascular
Rich in sebaceous glands
Rich in sweat glands
Laxity of skin facilitates rapid spread of edema
Boils in the nose and ear are acutely painful due to the fixity of the skin to the underlying cartilages
Facial skin is very elastic and thick because the facial muscles are inserted into it.

Superficial Fascia

Contains facial muscles
Contains vessels and nerves to muscles and skin
Variable amount of fat: absent from the eyelids but well-developed in the cheeks

Deep Fascia

Absent from the face, except over the parotid gland where it forms the parotid fascia, and over the buccinator where it forms the buccopharyngeal fascia.

Facial Muscles

Subcutaneous muscles
Inserted into skin, and bring out various facial expressions
Have small motor units
Embryologically, they develop from the mesoderm of the second branchial arch, and are, therefore, supplied by the facial nerve.

Functional Groups of Facial Muscles

Regulators of 3 openings situated on the face
- Palpebral fissures
- Nostrils
- Oral fissure.

Sensory Supply of Face

Trigeminal 5th cranial nerve

Motor Supply to Muscles of Facial Expression

Facial nerve 7th cranial

Ophthalmic Nerve (V1)

Sensory supply: Forehead & scalp, frontal & ethmoidal sinus, upper eyelid & its conjunctiva, cornea & dorsum of nose

Maxillary Nerve (V2)

Sensory supply: skin and mucous membrane of lower eyelid & its conjunctiva, cheeks & maxillary sinus, nasal cavity & lateral nose, upper lip, upper molar, incisor & canine teeth & associated gingiva & superior palate.

Mandibular Nerve (V3)

Sensory Supply: floor of oral cavity, external ear, lower lip, chin, anterior 2/3 of the tongue & lower molar, incisor & canine teeth & the associated gingiva

Clinical Anatomy Sensory Innervation of Face

Sensory distribution of 5th cranial nerve is cause of headache in conditions involving:
- Nose (common cold, boils)
- Paranasal air sinuses (sinusitis)
- Infections and inflammations of teeth and gums
- Refractive errors of the eyes

Trigeminal Neuralgia

Sudden, severe facial pain.
Sharp shooting pain or like having an electric shock in the jaw, teeth, or gums.
Maxillary and mandibular division of the trigeminal nerve are involved
In most cases, affects just one side of the face, with the pain usually felt in the lower part of the face.

Motor Nerve Supply to Facial Muscles

Temporal branch of the facial nerve: frontalis, auricular muscles, orbicularis oculi
Zygomatic branch of the facial nerve: orbicularis oculi (lower eyelid part)
Buccal branch of the facial nerve: muscles of the cheek and upper lip.
Mandibular branch of the facial nerve: muscles of the lower lip.
Cervical branch of the facial nerve: platysma.

Infranuclear Lesion of Facial Nerve

Occurs at stylomastoid foramen
Paralysis of upper and lower quarters of face on the same side
Face is asymmetrical and drawn up to the normal side.
No motion on affected side
Wrinkles disappear from the forehead
Eye cannot be closed leading to keratitis
When smiling, the mouth draws to the normal side.
During mastication, food accumulates between the teeth and the cheek.
Drooling of saliva

Supranuclear Lesion of Facial Nerve

Only the lower quarter of the opposite side of the face is paralyzed.

Muscles of Facial Expression

Muscles of the Eyelids/Orbital Openings
- Orbicularis oculi
- Corrugator supercilii
- Levator palpebrae superioris
Muscles of the Nose
- Procerus
- Compressor naris
- Dilator naris
- Depressor septi

Muscles around the Mouth

Orbicularis oris
Buccinator
Levator labii superioris alaeque nasi
Zygomaticus major & minor
Levator labii superioris
Levator anguli oris
Depressor anguli oris
Depressor labii inferioris
Mentalis
Risorius

Functions of Facial Muscles

Dilators of mouth: Showing teeth
Orbicularis oculi: Tight closure of the eyes
Buccinator: Puffing the mouth and then blowing forcibly as in whistling

Occipitofrontalis

One of the muscles of the scalp
Arises from two distinct parts:
- Occipital part (belly)
- Frontal part (belly)
The frontal part lifts the eyebrow and the upper eyelid producing horizontal wrinkles on the forehead.

The Orbicularis Oculi

Constructed of three parts, the palpebral, orbital and lacrimal.
The palpebral area lies at the centre of this sphincter muscle and forms the eyelids
Allows us to open and close the eyelids
Closes eye in blinking and sleep
Dilates lacrimal sac for the sucking of lacrimal fluid into the lacrimal sac

Corrugator Supercilii

Small, narrow, pyramidal muscle
Located at the medial end of the eyebrow, beneath frontalis and just above orbicularis oculi muscle.
When contracted it pulls the skin of the eyebrow downward and medially.
Produces vertical wrinkles of the forehead.

Nasalis

Sphincter-like muscle of the nose
Function: Compresses the nasal cartilages
Responsible for "flaring" of the nostrils.

Levator Labii Superioris

Raises the upper lip
Involved in movements such as facial expressions, actions of disgust, expressions of sadness, nasal flaring, retching (vomiting) and to show oral content.
Origin is on the lateral aspect of the nose and extends to the zygomatic bone.

Levator Anguli Oris

The happy muscle, making the corners of our mouth turn upwards into a smile.

Zygomaticus Major & Minor

Both muscles are involved in elevating the upper lip to generate a smile.

Risorius

A very thin and delicate muscle that pulls the lips horizontally creating a large, but insincere smile.

Orbicularis Oris

The circular muscle around our mouth
Brings our lips together.

Boundaries of Scalp

Extends from the superciliary arches anteriorly to the external occipital protuberance and superior nuchal lines posteriorly
Down to the ears and zygomatic arches laterally

Scalp Layers

Skin
Connective tissue
Aponeurosis
Loose areolar tissue
Pericranium
The first three layers are intimately bound together and move as a unit.

Scalp Skin ('S')

Thick and hairy
Firmly attached to the epicranial aponeurosis through dense fascia
Abundant sebaceous glands
Sebaceous cysts are common

Scalp Connective Tissue ('C')

Fibrous and dense, containing blood vessels and nerves
Binds skin to subjacent aponeurosis
Wounds bleed profusely as blood vessels are prevented from retraction by fibrous tissue.
Bleeding is stopped by applying pressure against the bone
Subcutaneous hemorrhages are not extensive due to dense fascia
Inflammation causes little swelling but more pain

Scalp Aponeurosis ('A')

Anteriorly frontal belly and posteriorly occipital belly of occipitofrontalis muscle
Frontal belly originates from skin of forehead and mingled with orbicularis oculi muscle
Occipital belly originates from lateral 2/3 of superior nuchal line
It gaps if cut transversely and should be stitched

Scalp Loose Areolar Tissue ('L')

Extends anteriorly into the eyelids as frontalis has no bony attachment
Posteriorly to superior nuchal line
On each side to superior temporal line
Bleeding causes generalized swelling of the scalp
Dangerous layer of the scalp as emissary veins open here and carry any infections inside the brain (venous sinus)
Bleeding leads to black eye
Caput succedaneum in newborn

Arterial Supply of Scalp

In front of the auricle, the scalp is supplied from before backwards by the:
- Supratrochlear: Branches of ophthalmic artery
- Supraorbital: branch of internal carotid artery
- Superficial temporal arteries: branch of the external carotid artery.
Behind the auricle, the scalp is supplied from before backwards by the:
- Posterior auricular
- Occipital (tortuous) arteries, both of which are branches of the external carotid artery.

Lymphatic Drainage of Scalp

Lymph vessels in the anterior part of the scalp and forehead drain into the submandibular lymph nodes.
Drainage from the lateral part of the scalp above the ear is into the superficial parotid (preauricular) nodes.
Lymph vessels in the part of the scalp above and behind the ear drain into the mastoid nodes.
Vessels in the back of the scalp drain into the occipital nodes.

Black Eye

Collection of blood in the layer of loose connective tissue causes generalized swelling of the scalp.
The blood may extend anteriorly into the root of the nose and into the eyelids (as frontalis muscle has no bony origin) resulting in a black eye.

Lymph Glands

Submental
Submandibular
Buccal and mandibular
Preauricural
Occipital

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Description

Explore the intricate structures of the face, including boundaries, skin characteristics, superficial and deep fascia, and facial muscles. This quiz provides an overview of the vital elements that contribute to facial anatomy and its functions in expression and sensation.