PAROTID REGION AND FACIAL NERVE

DR PRATIK MISTRY

Parotid bed (mould)

PAROTID GLAND

Introduction Largest Meaning of “parotid” Para=around, otic=ear Inverted pyramid shape 25 gms

Coverings True capsule False capsule

(parotid sheath)

Presenting parts of the gland

Apex Base (upper surface) 3 surfaces- superficial (lateral),

anteromedial, anterolateral 3 borders- anterior, posterior and medial Parotid duct

Apex Directed below Overlap post belly of

digastric and appear in carotid triangle

Structures are:1. Cervical br of facial n.2. ant. division of retro-mandibular vein3. Formation of external jugular vein

Base Concave Related meatus and

t.m. joint Structures are:1. Temporal br of facial n.2. Superficial temporal vessels3. Auriculo-temporal n.

Superficial (lateral) surface

Covered by skin, superficial fascia, platysma, superficial lamella of parotid sheath

Fascia contain parotid L.N and branches of great auricular nerves

Antero-medial surface Grooved for ramus

and related with: Masseter muscle Mandibular ramus

and capsule of T.M. joint

Medial pterygoid muscle

Postero-medial surface Related with: Mastoid process and

sternocleidomastoid and post. belly of digastric

Styloid process and muscles

ICA and IJV Last four cranial

nerves Facial nerve

Anterior border Thin, rest on masseter Separate superficial and

antero-medial surfaces Structures are:1. Zygomatic n.2. Transverse facial vessel3. Upper buccal n.4. Parotid duct5. Lower buccal n.6. Marginal mandibular n.

Posterior border Rests on SCM Structures are:1. Post. auricular br of facial n.2. Post. auricular vessels

Medial border (pharyngeal border) Contact with pharynx

Processes of the gland Facial Accessory gland Pterygoid Glenoid Pre & post styloid

Structures passing Facial nerve and its branches Retro-mandibular vein External carotid artery Parotid LN

Pes anserinus Patey’s fasciovenous plane

Parotid duct (stenson’s duct)

5 cm and 3mm Union of 2 vertical ducts Course of duct (forward, medially, obliquely forward)

Blood supply Lymphatic drainage

Branches of ECA Veins into the external

jugular vein

Parotid LN Jugulodigastric LN

Nerve supply SYMPATHETIC Plexus around ECA

from superior cervical ganglion

Vasomotor in function

Produce mucous rich secretion

PARASYMPATHETIC Provide secretomotor

fibres to the gland Produce watery

secretion Very important

Secretomotor fibres of the gland

Clinical Anatomy Painful swelling Mumps Parotid abscess (Hilton’s method of

drainage) Mixed parotid tumour Parotidectomy Frey’s syndrome Parotid calculus and sialography

Parotitis

Mumps

Hilton’s method

Mixed parotid tumour

Sialography

Frey’s syndrome

FACIAL NERVE

Introduction 7th cranial nerve Mixed nerve with motor and sensory

root Arise from pons of brain stem Have motor, secretomotor components Carry taste sensations from ant 2/3 of

tongue Carry sensory fibres from auricle

Facial N.

Origin Motor nucleus Superior salivatory nucleus Inferior salivatory nucleus Spinal nucleus of trigeminal nerve

Course and relation Intracranial-intrapetrous Extracranial course

Extracranial part

Branches of distribution In the Facial canal N. To stapedius Chorda tympani

Below stylomastoid foramen

Post. Auricular N. To post. Belly of

diagastric N. To stylohyoid

In face Temporal Zygomatic Buccal Marginal mandibular Cervical

Clinical anatomy Supranuclear paralysis Nuclear paralysis Infranuclear paralysis

Infranuclear facial palsy (bell’s palsy) Wrinkles of forehead absent on

affected side Drooping of eyebrow Wide palpebral fissure. Unable to close the eyes, dry eye,

ectropion, Corneal reflex absent. Corneal ulcer Nasolabial fold absent During smiling, angle of the mouth

motionless. Triangular outline Food accumulate in the vestibule of

mouth on affected side Dribbling of saliva between lips on

affected side

Crocodile tear syndrome

Next lecturePosterior triangle of neck

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