VISCERA OF THE NECK
The cervical viscera are disposed in three layers, named for
their primary function. Superficial to deep, they are the:
Endocrine layer: the thyroid and parathyroid glands.
Respiratory layer: the larynx and trachea.
Alimentary layer: the pharynx and esophagus
Endocrine Layer of Cervical Viscera
1. Thyroid Gland
lies deep to the sternothyroid and sternohyoid muscles, located
anteriorly in the neck at the level of the C5-T1 vertebrae
It consists primarily of right and left lobes, anterolateral to
the larynx and trachea.
The thyroid gland is the body's largest endocrine gland. It
produces thyroid hormone, which controls the rate of metabolism,
and calcitonin, a hormone controlling calcium metabolism. The
thyroid gland affects all areas of the body except itself and the
spleen, testes, and uterus.
Arteries of Thyroid Gland : the superior and inferior thyroid
arteries.
Veins of Thyroid Gland : Superior, middle and inferior thyroid
veins .
The lymphatic vessels of the thyroid gland run in the
interlobular connective tissue (near the arteries), they
communicate with a capsular network of lymphatic vessels. From
here, the vessels pass initially to prelaryngeal, pretracheal, and
paratracheal lymph nodes.
The prelaryngeal nodes the superior cervical lymph nodes,
The pretracheal and para-tracheal lymph nodes the inferior deep
cervical nodes.
Laterally, lymphatic vessels located along the superior thyroid
veins the inferior deep cervical lymph nodes. Some lymphatic
vessels may drain into the brachiocephalic lymph nodes or the
thoracic duct.
Nerves of Thyroid Gland: superior, middle, and inferior cervical
(sympathetic) ganglia .
2. Parathyroid Gland
The small flattened, oval parathyroid glands usually lie
external to the thyroid capsule on the medial half of the posterior
surface of each lobe of the thyroid gland, inside its sheath. Most
people have four parathyroid glands.
The hormone produced by the parathyroid glands, parathormone
(PTH), controls the metabolism of phosphorus and calcium in the
blood.
Arteries of Parathyroid Gland : inferior thyroid arteries, the
superior thyroid arteries; the thyroid ima artery; or the
laryngeal, tracheal, and esophageal arteries.
Veins of Thyroid Gland : thyroid plexus of veins
The lymphatic vessels : deep cervical lymph nodes and
paratracheal lymph nodes
Respiratory Layer of Cervical Viscera
The viscera of the respiratory layer, the larynx and trachea,
contribute to the respiratory functions of the body. The main
functions of the cervical respiratory viscera are as follows:
Routing air and food into the respiratory tract and esophagus,
respectively.
Providing a patent airway and a means of sealing it off
temporarily.
Producing voice.
3. Larynx
The larynx is located in the anterior neck at the level of the
bodies of C3-C6 vertebrae. It connects the inferior part of the
pharynx (oropharynx) with the trachea.
The larynx is the complex organ of voice production (the voice
box) composed of nine cartilages connected by membranes and
ligaments and containing the vocal folds.
Arteries of Larynx: The laryngeal arteries (branches of the
superior and inferior thyroid arteries). The superior laryngeal
artery (supply the internal surface of the larynx). The
cricothyroid artery (supplies the cricothyroid muscle). The
inferior laryngeal artery (supplies the mucous membrane and muscles
in the inferior part of the larynx)
Veins of Larynx: The laryngeal, The superior laryngeal vein
usually joins the superior thyroid vein and through it drains into
the IJV .The inferior laryngeal vein joins the inferior thyroid
vein or the venous plexus of veins on the anterior aspect of the
trachea, which empties into the left brachiocephalic vein.
Lymphatics of Larynx: The laryngeal lymphatic vessels superior
to the vocal folds accompany the superior laryngeal artery through
the thyrohyoid membrane and drain into the superior deep cervical
lymph nodes. The lymphatic vessels inferior to the vocal folds
drain into the pretracheal or paratracheal lymph nodes, which drain
into the inferior deep cervical lymph nodes .
Nerves of Larynx: The nerves of the larynx are the superior and
inferior laryngeal branches of the vagus nerves (CN X).
SUPERFICIAL STRUCTURES OF NECK: CERVICAL REGIONS
Terdapat empar regions dalam Neck
1. Sternocledomastoid Region
Dibentuk oleh SCM muscle, SCM muscle membagi setiap sisi leher
ke dalam anterior dan lateral cervical Regions (anterior and
posterior triangles).
SCM merupakan strap-like muscle yang punya two head tendon:
Rounded tendon of the sternal head yang attach ke manubrium
Clavicular head yang attach ke permukaan 1/3 superior
clavicle.
Kedua head tendon SCM dipisahkan oleh small triangular
depression, yaitu the lesser supraclavicular fossa.
Kedua tendon tersebut menyatu ke superior dengan arah oblique ke
cranium.
Superior SCM melekat di the mastoid process dari the temporal
bone dan the superior nuchal line of the occipital bone.
2. Lateral Cervical Region
- The lateral cervical region (posterior triangle) di batasi
oleh :
Anteriorly by the posterior border of the SCM.
Posteriorly by the anterior border of the trapezius.
Inferiorly by the middle third of the clavicle between the
trapezius and the SCM.
By an apex, where the SCM and trapezius meet on the superior
nuchal line of the occipital bone.
By a roof, formed by the investing layer of deep cervical
fascia.
By a floor, formed by muscles covered by the prevertebral layer
of deep cervical fascia.
The lateral cervical region dibagi menjadi dua segitiga oleh the
inferior belly of the omohyoid.: large occipital triangle
superiorly ( terdapat occipital artery dan nerve penting yaitu
spinal accessory (CN XI) dan a small omoclavicular triangle
inferiorly (The inferior part of the EJV lewat pada segitiga ini,
terdapat the subclavian artery).
ARTERIES IN LATERAL CERVICAL REGION: lateral branches of the
thyrocervical trunk, the third part of the subclavian artery, and
part of the occipital artery.
VEINS IN LATERAL CERVICAL REGION: The external jugular vein
(EJV) begins near the angle of the mandible (just inferior to the
auricle) by the union of the posterior division of the
retromandibular vein with the posterior auricular vein .
NERVES OF LATERAL CERVICAL REGION: The spinal accessory nerve
(CN XI)
LYMPH NODES IN LATERAL CERVICAL REGION:
Lymph from superficial tissues in the lateral cervical region
enters the superficial cervical lymph nodes that lie along the EJV
superficial to the SCM. Efferent vessels from these nodes drain
into the deep cervical lymph nodes, which form a chain along the
course of the IJV that is embedded in the fascia of the carotid
sheath.