Overview of Neck

1. Overview of Neck
Joins the head to the trunk and limbs (muscles, glands, arteries, veins, nerves, lymphatics, trachea, esophagus
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and vertebrae)
The main arterial blood flow (the carotid arteries)
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principal venous drainage (the jugular veins)
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Lymph from structures in the head and neck drain into cervical lymph nodes.
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Bones of Neck
Skeleton of the neck is formed by the cervical vertebrae, hyoid bone, manubrium of the sternum, and clavicles.
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Cervical Vertebrae;
7 cervical vertebrae: encloses the spinal cord and meninges.
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intervertebral (IV) articulations.
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The craniovertebral joints provide the necessary flexibility for the head.
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There are four typical cervical vertebrae (3rd–6th)
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There are three atypical cervical vertebrae (C1, C2, and C7).
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all cervical vertebrae include foramina transversaria.(except; vertebra C7, arteries and veins)
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Hyoid Bone
Lies in the anterior part of the neck (between the mandible and the thyroid cartilage.)
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not articulate with any other bone.
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Suspended by muscles that connect it to the mandible.
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Consists of a body and greater and lesser horns (L. cornua).
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Disorders of cervical region
Cervical Neck Pain;Causes include inflamed lymph nodes, muscle strain, protruding intervertebral (IV) discs.
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Fracture of hyoid bone; It causes the hyoid body to collapse on the thyroid cartilage.
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Fascia of the Neck
Structures, superficial fascia and deep cervical fascia.
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The cervical subcutaneous tissue (superficial cervical fascia) is a superficial layer of fatty connective tissue.
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It contains cutaneous nerves, blood and lymphatic vessels, superficial lymph nodes, and variable amounts of fat.
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Platysma
It’s a broad, thin sheet of muscle in the subcutaneous tissue of the neck.
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derived from mesenchyme in the 2nd pharyngeal arch facial nerve, CN VII.
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The platysma covers the anterolateral aspect of the neck.
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Acting from its superior attachment, the platysma tenses the skin, producing vertical skin ridges.
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Acting from its inferior attachment, the platysma helps depress the mandible and draw the corners of the mouth
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inferiorly.
As a facial expression muscle, the platysma serves to convey tension or stress.
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Deep Cervical Fascia
Consist 3 fascial layers (sheaths): investing, pretracheal, and prevertebral.
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1) Investing Layer;
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It Is the most superficial deep fascial layer.
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surrounds the entire neck deep to the skin and subcutaneous tissue.
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These muscles are derived from the same embryonic sheet of muscle (trapezius and sternocleidomastoid).
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are innervated by the same nerve (CN XI).
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attaches to the: occipital bone, temporal bones. Zygomatic arches, mandible, Hyoid bone.
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Just inferior to its attachment to the mandible and posterior to the mandible.
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2. The stylomandibular ligament is a thickened modification of this fascial layer.
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2) Pretracheal Layer;
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Its thin and limited to the anterior part of the neck.
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It includes a thin muscular part, which encloses the infrahyoid muscles, and a visceral part.(encloses thyroid
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gland, trachea, and esophagus)
3) Prevertebral Layer;
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It forms a tubular sheath for longus colli and longus capitis anteriorly, the scalenes laterally, and the deep
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cervical muscles posteriorly).
approximately at the T3 vertebra, it fuses with the anterior longitudinal ligament.
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4) Carotid Sheath Leyer
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Is a tubular fascial investment
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extends from the cranial base to the root of the neck.
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contains the: Common and internal carotid arteries, Internal jugular vein, Vagus nerve, Carotid sinus nerve.
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Retropharyngeal Space;
Is the largest and most important interfascial space in the neck.
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consists; visceral part of the prevertebral layer of deep cervical fascia and the buccopharyngeal fascia
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surrounding the pharynx superficially.
permits movement of the pharynx, esophagus, larynx, and trachea relative to the vertebral column during
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swallowing.
alar fascia; it is attached along the midline of the buccopharyngeal fascia from the cranium to the level of the C7
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vertebra and extends in the carotid sheath.
Superficial Structures Of Neck: Cervical Regions
is divided into four major regions.
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1) Sternocleidomastoid region; Sternocleidomastoid muscle, external jugular vein, greater auricular
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nerve.
It divides the neck into anterior and lateral cervical regions.
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A) Lesser supraclavicular fossa; inferior part of internal jugular vein
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2) Posterior cervical region; Trapezius muscle, cervical spinal nerve.
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3) Lateral cervical region;
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four muscles: splenius capitis, levator scapulae, middle scalene (L. scalenus medius), and posterior scalene (L.
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scalenus posterior).
The lateral cervical region is divided into a large occipital triangle superiorly and a small omoclavicular triangle
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lateral branches of the thyrocervical trunk, the third part of the subclavian artery, and part of the occipital artery.
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The cervicodorsal trunk (transverse cervical artery),the superficial cervical artery and the dorsal scapular artery.
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The external jugular vein (EJV), brachiocephalic vein, EJV receives the cervicodorsal, suprascapular, and
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anterior jugular veins.
The phrenic nerves contain motor, sensory, and sympathetic nerve fibers. (C3-C5)
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superficial cervical lymph nodes, drain into the deep cervical lymph nodes
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A) Occipital triangle; external jugular vein, cervical plexus of nerves, spinal accessory nerve
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B) Omoclavicular triangle; Subclavian artery, subclavian vein, suprascapular artery
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4) Anterior cervical region;
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A) Submandibular triangle; hypoglossal nerve, mylohyoid nerve, facial artery and nerve
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B) Submental triangle; Submental lymph nodes, small veins, anterior jugular vein
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C) Carotid triangle; carotid artery, internal jugular vein, vagus nerve, hypoglossal nerve, spinal accessory
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nerve
Carotid sinus: Innervated principally by the glossopharyngeal nerve (CN IX) through the carotid sinus nerve
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as well as by the vagus nerve (CN X), it is a baroreceptor (pressoreceptor)
Carotid body; Supplied mainly by the carotid sinus nerve (CN IX) and by CN X, it is a chemoreceptor.
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Branches;
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Ascending pharyngeal artery; sends branches to the pharynx, prevertebral muscles, middle ear, and
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3. cranial meninges.
Occipital artery; ends by dividing into numerous branches in the posterior part of the scalp.
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Posterior auricular artery: supply the adjacent muscles; parotid gland; facial nerve; and structures in the
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temporal bone, auricle, and scalp.
Superior thyroid artery; thyroid gland. In addition to supplying this gland, it gives off branches to the
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infrahyoid muscles and the SCM and gives rise to the superior laryngeal artery, supplying the larynx.
Lingual artery; giving branches to the posterior tongue.
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Facial artery: supplies the submandibular gland
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six branches of the carotid artery:
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1-2-3—one branch arises medially (ascending pharyngeal), superficial temporal artery
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two branches arise posteriorly (occipital and posterior auricular),
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three branches arise anteriorly (superior thyroid, lingual, and facial), Maxillary artery.
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Transverse cervical nerve (C2 and C3): supplies the skin covering the anterior cervical region.
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Hypoglossal nerve (CN XII): the motor nerve of the tongue.
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glossopharyngeal (CN IX) and vagus (CN X) nerves: in the submandibular and carotid triangles
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D) Muscular triangle; Sternothyroid muscle, thyroid and parathyroid gland
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