Is the first resistant structure that can be felt in the midline inferior to the chin.
Level of C3 vertebra.
Moves during swallowing.
Is suspended from the styloid process by stylohyoid ligaments.
Muscles connect the hyoid bone to the tongue, mandible, sternum, larynx, and pharynx.
Consequently, following fracture of the hyoid bone the fine balance of these muscles
would be disturbed, causing problems in breathing, speaking, and swallowing
Laryngeal Prominence
Formed by the thyroid cartilage.
More prominent in the male & rises with swallowing
Lies at the level of the C4 & 5 vertebrae.
It rises during swallowing.
Cricoid Cartilage
Can be felt inferior to the laryngeal prominence.
Level of C6 vertebra.
At C6- pharynx continues - esophagus and the larynx - trachea
Respiratory-Digestive
Block
Located anteriorly.
Contains the pharynx and larynx which form the
esophagus and trachea at the level of C6.
The contents are partially enclosed in a much thinner
sheath of fascia called the PRE-TRACHEAL FASCIA
Trachea in front and the esophagus behind together
enclosed in the thin pre-tracheal fascia, which also
encloses the thyroid gland.
The recurrent laryngeal nerve occupies the
groove between the trachea and esophagus.
Musculo-Vertebral
Block
Located posteriorly.
Consists of the cervical vertebrae and the muscles around them.
Plastered by a dense layer of PREVERTEBRAL FASCIA
The whole neck is enclosed in a
musculo-fascial tube composed of :
Sternomastoid muscle
Trapezius muscle
Investing Layer of Deep
Fascia of the neck
Carotid sheath: Fills in the angle between the
vertebral block and the respiratory-digestive block
Longus colli: Immediately in
front of the vertebral bodies.
Scalenus anterior: Arises from
the anterior tubercles of
transverse processes.
Scalenus medius & posterior: Arises
from the posterior tubercles.
Levator scapulae and deep muscles of the
neck arise further posteriorly.
Deep Fascia
of Neck
Investing layer.
Pre-tracheal fascia
Carotid Sheath
Prevertebral Fascia
MUSCLES!!
Sternocleidomastoid muscle
Digastric muscle
Omohyoid muscle
Subdivisions
of Neck
Posterior
Triangle
Anteriorly: Sternomastoid
Posteriorly: Trapezius
Apex: Meeting between trapezius & sternomastoid at the back of the skull.
Base: Middle third of the clavicle, between the attachment of sternomastoid and trapezius.
Anterior
Triangle
Boundaries
Anterior: Median line
Posterior: Sterno cleidomastoid
Base: Mandible + Line from angle to mastoid
Apex: Suprasternal notch
Subdivisions
Submandibular triangle.
Carotid triangle.
Muscular triangle.
Submental triangle.
Suprahyoid muscles
Digastric muscle
Stylohyoid
Above post belly of digastric muscle.
Extends between styloid process
& hyoid bone.
Mylohyoid
Extends between
mandible and hyoid bone.
Is attached to a midline raphe.
Geniohyoid: Extends between
mandible and hyoid bone.
Hyoglossus: Extends between hyoid bone & tongue.
Infrahyoid Muscles
Sternohyoid: Superficial to sternothyroid & thyrohyoid.
Between the manubrium & hyoid bone.
Omohyoid
Sternothyroid:Extends between the manubrium and the oblique line of thyroid cartilage.
Thyrohyoid: From the oblique line of the thyroid cartilage to the hyoid bone.
Ansa Cervicalis
Superficial to the carotid sheath
A loop formed by 2 components:
Superior Loop C1
(Descending Hypoglossi)
Inferior Loop from cervical plexus C2 and C3
Innervation: All infrahyoid
muscles except thyrohyoid (C1
through hypoglossal nerve