FACE – Anatomy
After reading this post you will know the following about anatomy of face:
- Characteristic features of skin of face.
- Muscles of face , their action and nerve supply.
- Facial artery and other arteries supplying face.
- Tributaries of facial vein.
- Sensory nerve supply of face.
- Terminal branches of facial nerve and anatomical basis of bell’s palsy.
- Tributaries of facial vein.
- Anatomical basis of dangerous area of face.
- Lymphatic drainage of face.
Q. What is the extent of face?
Ans. Extent of face
- Superiorly : hairline
- Inferiorly : chin and base of the mandible
- Laterally : auricle
SKIN OF FACE
Q. What are the characteristic features of skin of face?
- Is highly vascular and elastic.
- Contains large number of sweat and sebaceous glands ( is common site for acne ).
- Is lax except on nose where it is attached to the underlying cartilages ( laxity of the skin facilitates rapid spread of edema)
- Provides insertion to the muscles of facial expression.
|Deep fascia is absent in face except over the parotid gland and masseter muscle (parotido-masseteric).|
MUSCLES OF FACE
Q. Enumerate the muscles of face (facial expression)and write their action.
Ans. Muscles of facial expression are arranged around three orifices palpebral fissure, nostrils and mouth.
|Muscle around palpaberal fissure||Orbicularis oculi||Orbital part||Closes eyelids tightly( winking, protection from light)|
|Palpaberal part||Closes eyelids gently ( blinking or sleep)|
|Lacrimal part||Dilates lacrimal sac and helps and aids in drainage of lacrimal fluid .|
|Corrugator supercilii||Produce vertical lines in the forehead|
|Levator palpabrae superioris||Elevate the upper eyelid|
|Muscles around nose||Procerus||Produces transverse wrinkles over the bridge of the nose|
|Compressor naris||Compresses the nasal aperture|
|Dilator naris||Draws the ala downwards and laterally, thus assists in widening the nasal aperture.|
|Depressor septi||Widens the nasal aperture.|
|Muscles around mouth||Muscles attached to upper lip||Labial part of levator labii superioris alequae nasi||Elevates upper lip|
|Levator labi superioris||Elevates and everts upper lip|
|Zygomaticus minor||Elevates upper lip|
|Muscles converging at angle of mouth||Levator anguli oris||Raises the angle of mouth|
|Zygomaticus major||Pulls the angle of mouth upwards and laterally|
|Depressor anguli oris||Draws the angle of mouth downwards and laterally|
|Risorius||Pulls the angle of mouth laterally|
|Muscle attached to lower lip||Depressor labii inferioris||Draws the lower lip downwards|
|Platysma||Draws down the lower lip and angle of mouth|
|Mentalis||Protrudes or everts the lower lip (although it is not attached to lower lip)|
|Orbicularis oris||Closes the mouth|
Q. Name the muscles responsible for various facial expressions.
|Frowning||Corugator supercilii and procerus|
|Grief||Depressor anguli oris|
|Anger||Dilator naris and depressor septi|
|Muscles of facial expression are derived from the 2nd pharyngeal arch and are therefore supplied by facial nerve.|
Q. Write origin, insertion, action and nerve supply of buccinator.
Ans. a. Buccinator : it is quadrilateral shaped muscle of cheek occupying the interval between maxilla and mandible.
|Buccinator||Upper fibers-Outer surface of maxilla opposite molar teeth||Upper lip|| Compresses the cheek against teeth and gums. This preventing accumulation of food in the vestibule of mouth.
Helps in whistling, blowing.
|Buccal branch of facial nerve|
|Middle fibers-Pterygomandibular raphe||Fibers decussate at angle of mouth and upper fibers pass to lower lip , lower fibers to upper lip.|
|Lower fibers – Outer surface of mandible opposite molar teeth||Lower lip|
- Structures piercing buccinator muscle:
- Parotid duct
- Buccal branch of mandibular nerve
- Paralysis of buccinator muscle: Paralysis of buccinator muscle (in facial palsy – injury to facial nerve) , food tends to accumulate in the vestibule of mouth.
FACIAL ARTERY – ORIGIN, COURSE & BRANCHES
Q. Describe origin, course and branches of Facial artery:
- Is the anterior branch of external carotid artery.
- It arises in the carotid triangle
- Its course is divided into two parts – Cervical and facial.
- Cervical part :
- Is closely related to submandibular gland .
- gives four branches – Ascending palatine, tonsillar, glandular and submental.
- Facial part:
- Enters face by crossing base of mandible at the anteroinferior angle of the masseter.
- It then runs upwards and forwards towards angle of mouth (1.25cm. lateral to angle of mouth).
- Then ascends by the side of the nose up to the medial angle of the eye.
- Terminates by anastomosing with the dorsal nasal branch of the ophthalmic artery.
- It gives four named branches viz. inferior labial, superior labial, lateral nasal and angular and many muscular branches.
|Facial artery pulsations can be felt at the base of the mandible at the anteroinferior angle of masseter.
Facial artery is tortuous throughout its course. The cervical part is tortuous to adapt to the movement of pharynx during deglutition and facial part is tortuous to adapt to the movements of mandible, lips and cheek.
Q. Describe cause and signs and symptoms of Bell’s palsy.
Bell’s palsy: A lesion of facial nerve usually at stylomastoid foramen results in ipsilateral paraysis of facial muscles. The symptoms of Bell’s palsy include:
- Asymmetrical face
- Loss of horizontal wrinkles on forehead
- Inability to close eye
- Loss of corneal reflex
- Absence of nasolabial fold
- Inability to show teeth
- Drooling of saliva from corner of mouth
- When the person tries to smile the angle of mouth of the normal Side moves upwards and laterally
Q. Draw labeled diagram of following.
- Sensory innervation of face
- Terminal branches of facial nerve
- Arteries supplying face
- Facial vein
- Lymphatic drainage of face
- Components of lacrimal apparatus
SENSORY AND MOTOR SUPPLY OF FACE
Ans. a. Sensory innervation of face : Skin of face is supplied by the three subdivisions of trigeminal nerve. A small part over the angle of mandible is supplied by great auricular nerve (Ventral rami of C2,C3).
- Branches of ophthalmic nerve: Supply skin of forehead, upper eyelid, dorsum of nose including tip and scalp as far as vertex.
- Palpebral branch of lacrimal
- External nasal
- Branches of maxillary nerve: Supply skin of lower eyelid, side of nose, upper lip and upper part of cheek and anterior part of temporal region.
- Zygomatico facial
- Branches of mandibular nerve:Supply lower lip lower part of cheek and posterior part of temporal region.
Terminal branches of facial nerve
ARTERIES SUPPLYING FACE
TRIBUTARIES OF FACIAL VEIN
LYMPHATIC DRAINAGE OF FACE
Lymphatic drainage of face:Lymphatics from face drain into following three groups of lymph nodes:
- Preauricular / superficial parotid lymph nodes:
- Lateral part of forehead, lateral half of eyelids and lateral half of cheek.
- Submandibular lymph nodes: Medial part of forehead, medial half of eyelids, nose, upper lip, lateral part of lower lip and medial part of cheek.
- Submental lymph nodes: Central part of lower lip and chin.
Components of lacrimal apparatus
- Lacrimal gland and ducts
- Conjunctival sac
- Lacrimal puncta and canaliculi
- Lacrimal sac
- Nasolacrimal duct
DANGEROUS AREA OF FACE
Q. Give anatomical basis of dangerous area of face.
Ans. The dangerous area of face includes the upper lip, lower part of nose and adjoining cheek. The infection from a boil on the dangerous area of face may spread from facial vein to cavernous sinus along the following route.
1. Facial vein -> Deep facial vein-> Pterygoid plexuses of veins -> emissary veins-> cavernous sinus
2. Facial vein-> ophthalmic vein -> cavernous sinus
*Facial vein and its communicating veins do not possess valves , therefore blood can flow in both directions.