Head - Neck Anatomy Lecture
Head - Neck Anatomy Lecture
Head - Neck Anatomy Lecture
TOPIC
Head-Neck Anatomy
HEAD & NECK ANATOMY: Topic List
SL. No. Topic Name
1. Triangles of neck
2 Carotid sheath
3 Subclavian artery
4 Carotid vessels
5 Trigeminal nerve
6 Facial nerve
7 Foramina of skull
8 lacrimal apparatus
9 Tongue
10 Salivary glands
11 Tonsils
12 Larynx
13 Vagus Nerve
14 External ear
15 Middle ear cavity
16 Cervical Lymph nodes
17 Thyroid gland
18 Parathyroid glands
19 Cervical Plexus
20 Pharyngeal arch & pouches
Triangles of Neck
Anterior Triangle
• Boundaries: Is bounded by the anterior • Contents:
border of the sternocleidomastoid, the • Submental triangle: Submental lymph
anterior midline of the neck, and the
inferior border of the mandible. Has a node, commencement of anterior
roof formed by the platysma and the jugular vein
investing layer of the deep cervical • Submandibular / Digastric triangle:
fascia. Submandibular gland, submandibular
LN, facial vein & artery, Mylohoid
vessels & nerve, part of hypoglossal
• Subdivision: Is further divided by the nerve
omohyoid anterior belly and the
digastric anterior and posterior bellies • Carotid triangle: Carotid sheath
into the digastric (submandibular), contents
submental (suprahyoid), carotid, and • Muscular triangle: Muscles; beneath
muscular (inferior carotid) triangles. its floor lies thyroid, larynx, trachea &
esophagus
Posterior Triangle
• Palatine Tonsil: Lies on each side of the oropharynx in an interval between the palatoglossal and
palatopharyngeal folds.
• Is highly vascular, receiving blood from the ascending palatine and tonsillar branches of the facial
artery, the descending palatine branch of the maxillary artery, a palatine branch of the ascending
pharyngeal artery, and the dorsal lingual branches of the lingual artery.
• Is innervated by branches of the glossopharyngeal nerve and the lesser palatine branch of the
maxillary nerve.
• Tubal (Eustachian) Tonsil: Is a collection of lymphoid nodules near the pharyngeal opening of the
auditory tube.
• Lingual Tonsil: Is a collection of lymphoid follicles on the posterior portion of the dorsum of the
tongue.
Palatine tonsillectomy
• is surgical removal of a palatine tonsil.
• During tonsillectomy, the glossopharyngeal nerve may be injured,
causing loss of general sensation and taste sensation of the posterior
one-third of the tongue.
• It may cause severe hemorrhage, which may occur from the branches
of the facial, ascending pharyngeal, maxillary, and lingual arteries or
paratonsillar veins
Palatine tonsillectomy
LARYNX:CARTILAGES
• Thyroid Cartilage: Is a single hyaline cartilage that forms a median elevation called the laryngeal
prominence (Adam's apple), which is particularly apparent in males.
• Cricoid Cartilage: Is a single hyaline cartilage that is shaped like a signet ring. Is at the level of CV 6
and articulates with the thyroid cartilage. Its lower border marks the end of the pharynx and larynx.
• Epiglottis: Is a single elastic cartilage. Is a spoon-shaped plate that lies behind the root of the
tongue and forms the superior part of the anterior wall of the larynx. Its lower end is attached to
the back of the thyroid cartilage.
• Arytenoid Cartilages: Are paired elastic and hyaline cartilages. Are shaped liked pyramids, with
bases that articulate with and rotate on the cricoid cartilage. Have vocal processes, which give
attachment to the vocal ligament and vocalis muscle, and muscular processes, which give
attachment to the thyroarytenoid muscle and the lateral and posterior cricoarytenoid muscles.
• Corniculate Cartilages Are paired elastic cartilages that lie on the apices of the arytenoid
cartilages.Are enclosed within the aryepiglottic folds of mucous membrane.
• Cuneiform Cartilages: Are paired elastic cartilages that lie in the aryepiglottic folds anterior to the
corniculate cartilages.
LARYNX: CAVITIES AND FOLDS
• The laryngeal cavity is divided into three portions by the vestibular and vocal folds: the vestibule,
ventricle, and infraglottic cavity.
• Vestibule : Extends from the laryngeal inlet to the vestibular (ventricular) folds.
• Ventricles: Extend between the vestibular fold and the vocal fold.
• Infraglottic Cavity: Extends from the rima glottidis to the lower border of the cricoid cartilage.
• Rima Glottidis : Is the space between the vocal folds and arytenoid cartilages. Is the narrowest
part of the laryngeal cavity.
• Vestibular Folds (False Vocal Cords) : Extend from the thyroid cartilage above the vocal ligament
to the arytenoid cartilage.
• Vocal Folds (True Vocal Cords) : Extend from the angle of the thyroid cartilage to the vocal
processes of the arytenoid cartilages. Contain the vocal ligament near their free margin and the
vocalis muscle, which forms the bulk of the vocal fold. Are important in voice production because
they control the stream of air passing through the rima glottidis.
VAGUS NERVE
Recurrent laryngeal nerve
• Innervates all of the intrinsic muscles of the larynx except the cricothyroid, which is innervated by the external
laryngeal branch of the superior laryngeal branch of the vagus nerve.
• Supplies sensory innervation below the vocal cord. Has a terminal portion above the lower border of the cricoid
cartilage called the inferior laryngeal nerve.
• Lesion of the recurrent laryngeal nerve could be produced during thyroidectomy or cricothyrotomy or by aortic
aneurysm and may cause respiratory obstruction, hoarseness, inability to speak, and loss of sensation below the vocal
cord.
Superior Laryngeal Nerve
• Is a branch of the vagus nerve and divides into the internal and external laryngeal branches.
• Oval Window (Fenestra Vestibuli): Is pushed back and forth by the footplate of the stapes
and transmits the sonic vibrations of the ossicles into the perilymph of the scala vestibuli in
the inner ear.
• Round Window (Fenestra Cochlea or Tympani: Is closed by the secondary tympanic
(mucous) membrane of the middle ear and accommodates the pressure waves transmitted
to the perilymph of the scala tympani.
Boundaries of the Tympanic Cavity
• Roof : tegmen tympani.
• Floor : jugular fossa.
• Anterior : carotid canal.
• Posterior : mastoid air cells and mastoid antrum through the aditus ad
antrum.
• Lateral : tympanic membrane.
• Medial : lateral wall of the inner ear, presenting the promontory formed
by the basal turn of the cochlea, the fenestra vestibuli (oval window), the
fenestra cochlea (round window), and the prominence of the facial
canal.
Cervical Lymph Nodes : Levels
LYMPHATIC DRAINAGE OF THE HEAD AND NECK
• The lymph nodes of the head and neck are divided into two groups: a circular chain of nodes around the base of the skull,
and the deep and superficial cervical chains accompanying the large veins of the neck
• The circular chain consists of seven groups of nodes lying along the upper attachment of the deep cervical ‘polo neck’
fascia. All are palpable when enlarged.
● Occipital – around the occipital artery; drain the posterior scalp and adjacent neck.
● Posterior auricular – on the mastoid process; drain the external acoustic meatus, the posterior auricle and the adjacent
scalp.
● Superficial parotid – in front of the tragus; drain the external meatus, the front of the auricle and the adjacent scalp.
● Deep parotid – within the parotid gland; drain the anterior scalp, infratemporal region, orbit, lateral eyelids, upper molar
teeth, external acoustic meatus and parotid gland.
● Retropharyngeal – between the pharynx and the upper cervical vertebrae; drain the upper pharynx and adjacent
structures.
● Submandibular – between the mandible and submandibular gland; drain the anterior nasal cavities, tongue, teeth and
gums, submandibular and sublingual glands, and all the face apart from the lateral eyelids and the medial part of the lower l ip
and chin.
● Submental – behind the chin on mylohyoid; drain the tip of the tongue, the floor of the mouth and the lower lip and chin
The deep cervical chain lies around the internal
jugular vein
Named nodes in the chain are the:
● Jugulodigastric – behind the mandible;
drains the tonsil and lateral part of the
tongue.
● Jugulo-omohyoid – between the internal
jugular vein and the superior belly of
omohyoid; drains the tongue via the
submental and submandibular nodes.
● Para- and pretracheal – lie along the
inferior thyroid vessels; drain the trachea
and thyroid gland. Efferent vessels may
pass to mediastinal tracheobronchial
nodes.
Deep Cervical Nodes
• The deep cervical nodes form a vertical chain along the course of the
internal jugular vein within the carotid sheath .They receive lymph
from all the groups of regional nodes. The jugulodigastric node, which
is located below and behind the angle of the jaw, is mainly concerned
with drainage of the tonsil and the tongue. The juguloomohyoid
node, which is situated close to the omohyoid muscle, is mainly
associated with drainage of the tongue. The efferent lymph vessels
from the deep cervical lymph nodes join to form the jugular trunk,
which drains into the thoracic duct or the right lymphatic duct
THYROID GLAND
• Consists of right and left lobes connected by the isthmus, which usually crosses the
second and third (or second, third, and fourth) tracheal rings.
• An inconstant pyramidal lobe, a remnant of the thyroglossal duct, extends upward
from the isthmus, usually to the left of the midline, and may be anchored to the
hyoid bone by a fibrous or muscular band known as the levator glandulae
thyroideae.
• Artery Supply: supplied by the superior and inferior thyroid arteries and
sometimes the thyroid ima artery, an inconsistent branch from the brachiocephalic
trunk.
• Venous Drainage: Drains via the superior and middle thyroid veins to the internal
jugular vein and via the inferior thyroid vein to the brachiocephalic vein.
• Lymph drainage: The lymphatics from the thyroid gland drain to deep cervical
nodes. A few pass into prelaryngeal, pre- and paratracheal nodes, and a few drain
directly into the thoracic duct.
• Nerve supply Sympathetic (vasoconstrictor) nerves from the superior, middle and
inferior cervical ganglia accompany the thyroid arteries.
Clinical Notes :
• Swellings of the Thyroid Gland and Movement on Swallowing
• The thyroid gland is invested in a sheath derived from the pre tracheal
fascia, This tethers the gland to the larynx and the trachea and explains why
the thyroid gland follows the movements of the larynx in swallowing. This
information is important because any larynx in swallowing. This information
is important because any pathologic neck swelling that is part of the thyroid
gland will move upward when the patient is asked to swallow.
Sensory Phrenic nerve (C3, 4, 5) Pericardium, mediastinal parietal pleura, and pleura and
peritoneum covering central diaphragm
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