Neck Region

atlanto-occipital joint

Between the occipital condyles and facets on superior surfaces of lateral masses of atlas

Ligaments: anterior and posterior atlanto occipital membrane

flexion, extension and lateral flexion

action of atlanto-occipital joint

atlanto-acial joint

Between the odontoid and anterior arch of atlas

Between the lateral mases of the bones

apical ligament of atlanto-axial joint

apex of odontoid to anterior margin of foramen magnum

alar ligament of atlanto-axial joint

odontoid to medial of occipital condyle

cruciate ligament of atlanto-axial joint

transverse( attaching odontoid to anterior arch of atlas) and vertical parts (body to anterior margin of magnum)

membrane tectoria ligament of atlanto-axial joint

– continuation of posterior longitudinal ligament up to occipital bone in foramen magnum

rotation

action of atlanto-axial joint

joints of vertebral column below axis

Between the articular processes of two adjacent vertebrae

Joints between two vertebral body

Between the two adjacent bodies and disc (fibrocartilage)

hyoid bone

Single, U shape mobile bone in midline of neck

No articulation with other bones but is attached to the skull via stylohyoid ligament and to thyroid cartilage by thyrohyoid membrane

Forms base of tongue

larynx

organ that provides protective sphincter at the inlet of air passage

Responsible for voice production

Found below tongue and hyoid

Opens above into laryngeal part and below continues with trachea

Formed by cartilages that are held by ligament

thyroid cartilage

Largest cartilage of larynx

Consists of two laminae that meet in midline (laryngeal prominence)

Posterior : extends up into a superior cornu and down into inferior cornu

cricoid cartilage

Hyaline

Shaped like a signet ring with broad plate behind and shallow arch in front

Articulates with the inferior cornu of thyroid

Posteriorly it articulates with arytenoid cartilage

cricoid cartilage

Junction of larynx and trachea • Junction of pharynx and esophagus • Level of middle cervical sympathetic ganglion • Where inferior thyroid artery enters thyroid gland

arytenoid cartilage

Small and pyramid shape at back of larynx

articulate with cricoid cartilage

Parts: apex, base, vocal process, muscular process

superficial fascia

Thin layer of subcutaneous connective tissue that lies between the dermis of the skin and investing layer of deep cervical fascia

platysma

- wide thin subcutaneous sheet of striated muscle

action: tenses skin of the neck; draws corners of mouth inferiorly and assists in depressing mandible

deep cervical fascia

Divided into: Investing layer , pretracheal layer, prevertebral layer

Supports the viscera, muscles, vessels and lymph nodes

Fascial layers form natural cleavage planes through which tissues may be separated during surgery and limit spread of infections

investing (superficial) layer

surrounds entire neck deep to the skin and superficial cervical fascia

Enclose the trapezius and SCM

Encloses the submandibular gland, and parotid gland

sternocleidomastoid

key landmark in the neck dividing neck into anterior and posterior triangles

sternocleidomastoid

• action: unilateral: tilt head to its own side and rotates is so it is turned superiorly toward opposite side • bilateral: flexes neck

Torticollis (wry neck)

– lesion in the sternocleidomastoid muscle causing the head to turn to the side and face away from the affected side

congenital or acquired

Trapezius

large flat triangular muscle

action: superior fibers elevate scapula, middle fibers retract it and inferior fibers depress it

Pretracheal layer

– attached above the thyroid and cricoid cartilage

Also known as visceral layer

Extends into the thorax and blends with the fibrous pericardium

Blends with the carotid sheath and investing layer and surrounds the thyroid gland, gland to larynx, parathyroid gland, esophagus and infrahyoid muscles

prevertebral layer

covers the longus capitis and longus cervicis

Passes around the neck to be attached to ligamentum nuchae

Triangle forms a fascial floor and covers the sclenus anterior, medius and levator scapulae, splenius capitis and semispinalis capitis

prevertebral layer

• Enters thorax and blends with the anterior longitudinal ligament

Retrolayrngeal space

between pharynx and prevertebral fascia

carotid sheath

Tubular, fascial investment that extends from base of skull to root of neck

Blends with the investing, pretracheal and prevertebral layer

carotid sheath contents

Common and internal carotid arteries, Internal jugular vein, Vagus nerve, Deep cervical lymph nodes, Carotid sinus nerve, Sympathetic nerve fibers

Submental, Carotid, Digastric, Muscular

anterior triangle

supraclavicular, occipital

posterior triangle

carotid triangle contents

carotid sheath- external carotid artery and branches - Hypoglossal nerve - Superior root of ansa cervicalis - Accessory nerve - Thyroid - Larynx - Pharynx - Deep cervical nodes - Branches of cervical plexus

muscular triangle

sternothyroid and sternohyoid - Thyroid - Parathyroid glands

digastric triangle

Submandibular gland • Submandibular lymph nodes • Hypoglossal nerves • Mylohyoid nerve • Parts of facial artery and vein

submental triangle

Submental lymph nodes • Small veins that unite to form anterior jugular vein

suprahyoid muscles

Mylohyoid • Geniohyoid • Stylohyoid • Digastric

infrahyoid muscles

Sternohyoid • Omohyoid • Sternothyroid • thyrohyoid

cervical plexus

Formed by anterior rami of the first four cervical nerves

covered by the prevertebral layer of deep cervical fascia and related to internal jugular vein within the carotid sheath

Supplies skin and muscles of head, neck and shoulder

viscera of the neck

Thyroid Gland • Parathyroid glands • Trachea • Esophagus

thyroid gland

Consists of right and left lobes and isthmus • Very vascular organ • Sheath is derived from pretracheal layer of deep fascia

pear shape

thyroid lobe shape

Isthmus

– found on the 2nd – 4 th tracheal rings (thyroid)

pyramidal lobe

project up from isthmus usually to the left of midline (thyroid)

levator gladulae thyoideae

muscular band connecting pyramidal lobe to hyoid (thyroid)

thyroid

function: Secretes hormones thyroxine and triiodothyronine • Increase the metabolic activity of most cell in the body • Produce thyrocalcitonin that lowers level of blood calcium

goiter

abnormal enlargement of the thyroid gland

• May cause compression of trachea followed by dyspnea if located retrosternal

Hyperthyroidism

caused by excess circulating thyroxine or triiodothyronine

Myxedema

Hypothyroidism resulting from deficiency of thyroid hormone due to surgery or radioactive iodine

grave’s disease

– toxic multinodular ro solitary goiter caused by IgG antibodies against TSH receptor (vascular bruit, tachycardia, exophthalmos, orbital puffiness, diplopia, papilledema)

parathyroid

Small ovoid • Located to the posterior border of the thyroid gland lying within the fascial capsule • 2 pairs of glands

Superior parathyroid glands

lie at the level of the middle of the posterior or the thyroid

inferior parathyroid glands

found in the inferior pole of the thyroid gland

parathyroid hormone

function: controls concentration of calcium and phosphorous in the blood

Osteoclastic activity in bone thus mobilize bone calcium and increase calcium level in blood

Stimulates absorption of dietary calcium form small intestine and reabsorption of calcium in proximal convoluted tubule of kidney

Decrease reabsorption of phosphate in proximal convoluted tube of kidney

Secretion of hormone is controlled by calcium level

hypoparathyroidism

features include malaise, anorexia, nausea, vomiting and confusion • peptic ulceration and acute pancreatitis may be presenting symptoms

espohagus

Tubular structure 10 inches long

Continuous above with the laryngeal part of the pharynx opposite 6th cervical vertebra and passes diaphragm at level of 10th thoracic vertebra to join stomach

trachea

Mobile cartilaginous and membranous tube

Extends from inferior end of larynx at the level of 6th cervical vertebra and ends at the carina at the level of the sternal angle or at the T4-T5 IV disc where it divides into right and left principal (main) bronchus

Trachealis muscle

smooth muscle attached to the posterior free ends of the cartilage

Cricodthyroidotomy

insertion of tube in between the cricoid cartilage and thyroid cartilage • Complications: • Esophageal perforation • Bleeding (hemorrhage)

Tracheostomy

opening into the trachea in patients with severe laryngeal damage and infants with severe airway obstruction • Complications – • Hemorrhage • Nerve paralysis (recurrent laryngeal nerve) • Pneumothorax • Esophageal injury

root of the neck

Area of neck above the intlet into the thorax • Contains: scalene muscles (anterior, medius and posterior) • Subclavian artery and branches • Subclavian vein

subclavian artery

right subclavian arises from brachiocephalic artery and left subclavian comes from the arch of aorta

first part of subclavian artery

vertebral artery, thyrocervical trunk, inferior thyroid artery, superficial cervical and suprascapular arteries, internal thoracic artery

second part of subclavian artery

costocervical trunk, superior intercostal and deep cervical

axillary artery

third part of subclavian artery

thoracic duct

Begins in the abdomen and enters the thorax through the aortic opening in the diaphragm and ascends through the posterior mediastinum