anterior cervical triangle

which cervical vertebrae is Hyoid Bone located at

(C3)

which cervical vertebrae is thyroid cartilage located at

(C4-5)

Motor fibers from C1 and their innervation

(which also contributes to the superior limb of the Ansa Cervicalis) run along with CN XII in the same sheath but are not functionally part of it. These motor fibers eventually leave the sheath to innervate two muscles: the Geniohyoid and the Thyrohyoid muscles.

• Sternothyroid

- Lying beneath the sternohyoid. It arises from the manubrium of sternum and passes upward to attach to the oblique line on the lamina of the thyroid cartilage.

• Sternohyoid

- The long, thin sternohyoid muscle spans the entire distance between the manubrium of the sternum the hyoid bone as opposed to the sternothyroid and thyrohyoid muscles.

Superior thyroid artery

- The superior thyroid artery is the first branch of the external carotid artery. It descends, passing along the lateral margin of the thyrohyoid muscle, to reach the superior pole of the lateral lobe of the gland.

• Thyrohyoid

- The thyrohyoid muscle is deep to the omohyoid and sternohyoid. It spans the distance from the oblique line on the tracheal cartilage to the hyoid bone. The thyrohyoid muscle has variable functions depending on which bone is fixed. Generally, it depresses the hyoid, but when the hyoid is fixed (by suprahyoid muscles) it raises the larynx.

Sympathetic Trunk and Ganglia

-The chain ganglia are found immediately posterior to the carotid sheath and superficial to the prevertebral fascia. There are three. The inferior (or stellate) is at the level of C7. If the stellate ganglion merges with the first thoracic ganglion it is called the cervicothoracic). The middle (when present) is at the level of C6. The Superior is the largest ganglion and is at the level of C1-C2. memorize this good

superior thyroid artery

1st branch of the ECA anterior division supplies the superior pole and most of the rest of thyroid gland?? Arises just inferior to the greater horn of the hyoid bone, deep to infrahyoid muscles. It gives off Superior Laryngeal artery which goes between the hyoid bone and laryngeal cartilage through thyrohyoid membrane to supply the internal larynx

occipital artery

1st branch of the ECA posterior division Arises off the posterior side of the Ext. Carotid Artery at the level of the Facial a. Passes posteriorly along the inferior border of the posterior belly of the digastric. Is distributed to the scalp over the occiput. runs in groove between the mastoid process and the remainder of the skull

The lingual artery

2nd branch of the ECA anterior division enters the submandibular triangle to supply the floor of the mouth and tongue.

posterior auricular artery

2nd branch of the ECA posterior division Arises off the posterior side of the Ext. Carotid Artery at the level of the posterior belly of the digastric. Passes posteriorly along the superior border of the posterior belly of the digastric. Ascends posterior to the external acoustic meatus to supply regions around parotid gland, temporal bone, the auricle and the scalp.

Facial artery

3rd branch of the ECA anterior division Arises either in common with the lingual a or just superior to it. It passes superiorly over the digastric and stylohyoid muscles and the angle of the mandible. It loops anteriorly to pass in a groove in the submandibular gland. It is distributed to the face

The External Carotid Artery is said to give off ______branches.

8

The Submandibular Triangle.

Anterior Boundary- Ant. belly of the digastric; Posterior Boundary- Post. belly of the digastric; Superior Boundary- Inferior border of mandible Floor- Mylohyoid, Hyoglossus, Middle pharyngeal constrictor Contents- Submandibular Gland, Hypoglossal Nerve (CN XII), Nerve to the Mylohyoid, Facial Artery and Vein DR nelson states that sometimes this muscle is referred to as submandibular triangle

The Muscular Triangle

Anterior boundary- Median plane of the neck; Inferior Boundary- Anterior border of the Sternocleidomastoid muscle; Superior Boundary- Superior belly of the Omohyoid Floor- Thyroid and cricoid cartilages, Middle pharyngeal constrictor, Inferior pharyngeal constrictor Contents- Neck viscera including thyroid and parathyroid glands; Infrahyoid muscles, terminations of ansa cervicalis, Superior thyroid artery, Sup. laryngeal artery, internal and external laryngeal nn., Recurrent laryngeal n. and other important structures like lymphatics.

The Carotid Triangle

Anterior boundary- Superior belly of the Omohyoid; Posterior Boundary- Anterior border of the sternocleidomastoid muscle; Superior Boundary- Post. belly of the digastric Floor- Thyrohyoid, Middle pharyngeal constrictor, Inferior pharyngeal constrictor Contents- Carotid Sheath with Carotid A., Internal Jugular V., Vagus Nerve, Ansa Cervicalis.

A Variable Branch? what is it? Ascending Pharyngeal artery

Ascending Pharyngeal a.- Arises off the deep side of the junction between Internal and External Carotids. It Is small and difficult to see; you will probably tear it. It is distributed to pharyngeal muscles, prevertebral muscles, middle ear and meninges. As alluded to before, the Ascending Pharyngeal Artery is variable in its departure from the External Carotid Artery.

a 5 yo girl presented to the ED. the child complained of neck pain and suffered a fever but with no sire throat for 2 days subsequent to the periodontal procedure. the child vomited once, had a temperature of 101.7f, a pulse of 118 BPM, respiration were 24 per minute, and her BP was 122/65. a decreased ROM of the neck and right anterior cervical node were observed. the child refused to swallow. the child was seen by an ENT MD and she was admitted and started on IV clinda. she improved for 2-3 days and then worsened. she was admitted to surgery and subsequently made a full recovery after surgical intervention and an addition course of Abx. what is most likely the location of the infection in the 5 year old girl who presented in the ED? A- within the carotid sheath B-within the retropharyngeal space C-anterior to the pretracheal fascia D-posterior to the prevertebral fascia E-superficial to the investing fascia

B

a 20 yo woman has a stab wound in the superior region of the neck. the patient has lost sensation from the skin over anterior neck and the middle and anterior margin of the jaw. which of the following nerves is most likely injured? A- supraclavicular B-transverse cervical C-great auricular D-great occipital E-lesser occipital

B- transverse cervical

Fascial Spaces

Between the fascial layers in the neck are spaces that may provide a conduit for the spread of infection from the neck to the mediastinum Three spaces could be involved in this process

the Common Carotid Artery arises from the ___________________________ on the right and from the __________________________ on the left.

Brachiocephalic Trunk Aortic Arch

a 6 yo male child who had a complicated delivery has a permanently tilted head posture with the right ear near the right shoulder and the face turned upward into the left. what of the following muscles was most likely damaged during birth? A-anterior scalene B-omohyoid C-SCM D-trapezius E-platysma

C-sternocleidomastoid

Note that there are no anterior rami sensory branches from _________________ and that it has no sensory dermatome despite having a small suboccipital nerve

C1

inferior root of ansa cervicalis

C2-C3 supply the inferior omohyoid

which cervical vertebrae is the Cricoid Cartilage (C6) located at

C6

Cutaneous branches of the cervical plexus

Cutaneous (superficial) branches of the cervical plexus are visible in the posterior triangle as they pass outward from the posterior border of the sternocleidomastoid muscle. they include the lesser occipital, great auricular, transverse cervical, and supraclavicular nerves

a 16 yo boy has a painless neck mass that is tender with colds. he has a branchial cyst along the anterior border of the SCM at the middle third of the muscle below the mandibular angle. which nerve is least likely in danger from the cyst's excision? A-hypoglossal B-transverse cervical C-the superior root of ansa cervicalis D-the phrenic E-the great auricular

D the phrenic

maxillary artery

Distributed to intraoral and deep head structures.

an unconscious young man was taken to the ER following a knife fight. he had a superficial lateral neck wound. the severity of which didn't match the patients dire condition. which of the following dangers may have occurred? A- the external jugular vein was being held open by the deep cervical fascia B- the patient exhibited churning chest sounds C- the patient suddenly turned blue D- the patients heart began to fail suddenly E- all of the above

E

carotid sheath

Each carotid sheath surrounds the common carotid artery, the internal jugular vein, and the Vagus Nerve as these structures pass through the neck. The sheath is continuous inferiorly with the connective tissue around the great vessels of the heart. Superiorly, the carotid sheath is said to terminate at the level of the Thyroid Cartilage (~C4).

The Submental Triangle (unpaired; suprahyoid region)

Lateral Boundary- Anterior bellies of the right and left Digastric Muscles; Inferior Boundary- Body of the Hyoid; Apex- Symphysis menti Floor- Both Mylohyoids Contents- Ant. Jugular V., lymph nodes

• Omohyoid

Lateral to the sternohyoid muscle is the omohyoid muscle. This muscle consists of two bellies with an intermediate tendon in both the posterior and anterior triangles of the neck: the inferior belly begins on the scapula(just medial to the scapular notch), and the superior belly begins at the intermediate tendon and attaches to the hyoid bone. The intermediate tendon is attached to the clavicle, near its medial end, by a fascial sling.

medial/terminal branches of the external carotid artery

Maxillary and Superficial Temporal AA

relationship of posterior branches to posterior digastric

Note the relationship of the Occipital A. and the Posterior Auricular A. to the posterior belly of the Digastric Muscle. The Occipital Artery run first *below* and then behind the posterior belly of the Digastric muscle. It runs medial to the mastoid process which it groves and it pass backward toward the Occiput. The Posterior Auricular Artery runs just *above* the posterior belly of the Digastric muscle and the external acoustic meatus to take up its position behind the pinna of the ear.

Tributaries received by the external jugular vein along its course include the

Posterior External Jugular Vein (draining superficial areas of the back of the neck) and the Transverse Cervical and Suprascapular Veins (draining the posterior scapular region).

Anterior branches of external carotid artery

Superior thyroid, lingual, facial arteries

superficial temporal artery

Terminal branch of the Ext. Carotid. Distributed to temporal region. Remains somewhat superficial.

Anterior jugular veins

The anterior jugular veins, although variable and inconsistent, are usually described as draining the anterior aspect of the neck. These paired venous channels, which begin as small veins, come together at or just superior to the hyoid bone. Once formed, each anterior jugular vein descends on either side of the midline of the neck. Inferiorly, near the medial attachment of the SCM, each anterior jugular vein pierces the investing layer of cervical fascia to enter the subclavian vein.

cervical lymphatic drainage

The basic pattern of drainage is for superficial lymphatic vessels to drain to the superficial nodes. Some of these drain to the superficial cervical nodes on their way to the deep cervical nodes and others drain directly to the deep cervical nodes.

Carotid Body

The carotid body is a chemoreceptor located at the bifurcation of the common carotid artery. Carotid body monitors the blood's pH, pCO2, and pO2 and thereby modulates cardiovascular and respiratory function primarily through sympathetic tone. The Carotid Body is innervated by a branch of the CN IX and a branch of CN X Carotid SinuS - preSSure. Carotid bO2dy senses O2.

Carotid Sinus

The carotid sinus is a baroreceptor that senses changes in systemic blood pressure and is located in the adventitia of the carotid bulb of the internal carotid artery. Innervation is by a branch of CN IX). Carotid SinuS - preSSure. Carotid bO2dy senses O2

External jugular veins

The external jugular veins are formed posterior to the angle of mandible as the Posterior Auricular Vein and the retromandibular vein join. Once formed, the external jugular vein passes straight down the neck in the superficial fascia and is superficial to the SCM throughout its course, crossing it diagonally as it descends. Reaching the lower part of the neck, just superior to the clavicle and immediately posterior to the SCM, the external jugular vein pierces the investing layer of cervical fascia, passes deep to the clavicle, and enters the ***Subclavian Vein***

Infrahyoid muscles

The four infrahyoid muscles are in the muscular triangle. They attach the hyoid bone to inferior structures and depress the hyoid bone. They also provide a stable point of attachment for the suprahyoid muscles. Because of their appearance, they are sometimes referred to as the "strap muscles."

Inferior thyroid artery

The inferior thyroid artery is a branch of the Thyrocervical Trunk, which arises from the first part of the subclavian artery (to be discussed with the Posterior Triangle) . It ascends and reaches the inferior pole of the lateral lobe of the thyroid gland.

Venous and lymphatic drainage of the thyroid gland

Three veins drain the thyroid gland: The Superior Thyroid Vein primarily drains the area supplied by the superior thyroid artery; the Middle and Inferior Thyroid Veins drain the rest of the thyroid gland. The superior and middle thyroid veins drain into the internal jugular vein, and the inferior thyroid veins empty into the right and left brachiocephalic veins, respectively. Lymphatic drainage of the thyroid gland is to nodes beside the trachea (paratracheal nodes) and to deep cervical nodes inferior to the omohyoid muscle along the internal jugular vein.

In the carotid sheath the Common Carotid is _________________________ to the Internal Jugular Vein

anterior and slightly deep

the external carotid has 3 divisions before it divides into 8 branches. what are they?

anterior, posterior, medial/terminal

The Hypoglossal Nerve (CN XII) descends from its exit from the skull, coursing ___________________ and ______________________to the carotid arterial system.

anteriorly, inferiolateral

the supraclavicular nerves

are a group of cutaneous nerves from cervical nerves C3 and C4 that, after emerging from beneath the posterior border of the sternocleidomastoid muscle, descend and supply the skin over the clavicle and shoulder as far inferiorly as rib II has 3 sets medial intermediate and lateral

The Common Carotid Artery

arises from the Brachiocephalic Trunk on the right and from the Aortic Arch on the left. In the sheath, it is anterior and slightly deep to the Internal Jugular Vein. It branches into Internal and External Carotid Arteries. The Internal Carotid Artery has no branches in the neck but enters the skull through the Carotid Canal

The Internal Jugular Vein

begins at the base of the skull at the superior jugular bulb just below the Jugular Foramen. It receives lingual, facial and superior and middle thyroid veins. It ends by joining with the subclavian vein to form the brachiocephalic vein on either side. On the left side, at this junction, the veins are joined by the Thoracic Duct while on the right there may be a smaller lymphatic duct. In its lower extent, the Internal Jugular Vein can be found deep to the two heads of the SCM.

Retropharyngeal Space

between the buccopharyngeal fascia (on the posterior surface of the pharynx and esophagus) and the prevertebral fascia (on the anterior surface of the transverse processes and bodies of the cervical vertebrae), which extends from the base of the skull to the upper part of the posterior mediastinum;

Pretracheal Space

between the investing layer of cervical fascia (covering the posterior surface of the infrahyoid muscles) and the pretracheal fascia (covering the anterior surface of the trachea and the thyroid gland), which passes between the neck and the anterior part of the superior mediastinum; surround with orange in the pic

The carotid sinus and the carotid body are located at or near the

bifurcation of the common carotid artery into its internal and external branches

you will find the superior and inferior limbs of the Ansa Cervicalis on the surface of the ___________________ adjacent to the SCM and strap muscles.

carotid sheath

the great auricular nerve

consists of branches from cervical nerves C2 and C3, emerges from the posterior border of the sternocleidomastoid muscle, and ascends across the muscle to the base of the ear, supplying the skin of the parotid region, the ear, and the mastoid area;

• the transverse cervical nerve

consists of branches from the cervical nerves C2 and C3, passes around the midpart of the sternocleidomastoid muscle, and continues horizontally across the muscle to supply the lateral and anterior parts of the neck;

• the lesser occipital nerve

consists of contributions from cervical nerve C2, ascends along the posterior border of the sternocleidomastoid muscle, and distributes to the skin of the neck and scalp posterior to the ear;

Muscular (deep) branches of the cervical plexus

distribute to several groups of muscles. A major branch is the phrenic nerve, which supplies the diaphragm with both sensory and motor innervation. It arises from the anterior rami of cervical nerves C3 to C5. Hooking around the upper lateral border of the anterior scalene muscle, the nerve continues inferiorly across the anterior surface of the anterior scalene within the prevertebral fascia to enter the thorax.

sensory nerve supply to the cervical plexus

dorsal rami

buccopharyngeal fascia

from base of skull to mediastinum black line in the pic

The Sternocleidomastoid Muscle (SCM)

has two heads, one from the manubrium, the other from the clavicle. It inserts into the mastoid process. It is innervated by CN XI (Accessory Nerve) and by anterior rami of C2 and C3 (carrying) proprioceptive information. The SCM turns the head to the contralateral side. When the SCM work together, they lower the head.

At the level of the Common Carotid _____________________ branches into Internal and External Carotid Arteries.

hyoid bone C3-C4

omo means

in relation to the scapula

The Platysma

is a muscle of facial expression and is innervated by the Facial Nerve (VII). It is found within the superficial fascia, hence outside the (deep) investing fascia of the neck. It begins in the superficial fascia near the clavicle and runs upward to blend with muscles of the face. it is also analogous to sternocephallius in a horse -_-

• The Third Space is

is a potential space within the prevertebral layer covering the anterior surface of the transverse processes and bodies of the cervical vertebrae. This layer splits into two laminae to create a fascial space that begins at the base of the skull and extends through the posterior mediastinum to the diaphragm. This space is not as clinically important as the retropharyngeal space.. basically located between the prevertebral and vertebrae

The cervical plexus

is formed by the anterior (ventral) rami of cervical nerves C1 to C4, and possibly a contribution from the anterior ramus of cervical nerve C5. The cervical plexus consists of muscular (or deep) branches and cutaneous (or superficial) branches. The cutaneous branches are visible in the posterior triangle emerging from beneath the posterior border of the sternocleidomastoid muscle.

The Nerve Point of the Neck, Erb's point (punctum nervosum

is located on the posterior border of the sternocleidomastoid and is a place were four sets of nerves emerge. They are the Lesser Occipital, Great Auricular, Transverse Cervical, and Supraclavicular nerves, all of which are sensory parts of the cervical plexus that innervate the anterior and lateral neck. Deep and slightly inferior to this point lies the upper trunk of the Brachial Plexus.

The Ascending Pharyngeal Artery is variable in

its departure from the External Carotid Artery

deep cervical nodes

jugulodigastric node jugulo-omohyoid node

The Vagus Nerve (CN X)

located behind and between the Common Carotid Artery and the Internal Jugular Vein. The Vagus Nerve gives off Pharyngeal branches, and the Superior Laryngeal Nerve which initially courses deep to the External and Internal Carotid Arteries. The Superior Laryngeal Nerve will be discussed later. The Vagus Nerve gives off the Recurrent Laryngeal Nerve.

The Internal Carotid Artery has __________ branches in the neck but enters the skull through the Carotid Canal to be one of the major sources of blood supply to the brain.

no

superficial lymph nodes

occipital, mastoid, pre-auricular and parotid, submandibular, and submental nodes extra info below if you want some • Superficial lymph nodes -Five groups of superficial lymph nodes form a ring around the head and are primarily responsible for the lymphatic drainage of the face and scalp. Their pattern of drainage is very similar to the area of distribution of the arteries near their location. Beginning posteriorly these groups are: Occipital, Mastoid Nodes, Pre-auricular and Parotid, Submandibular and Submental Nodes. Drainage from the occipital and mastoid nodes passes to the superficial cervical nodes along the external jugular vein. Drainage from the pre-auricular and parotid nodes, the submandibular nodes, and the submental nodes passes to the deep cervical nodes.

Posterior branches of external carotid artery

occipital, posterior auricular

what are the three muscles that depress the hyoid bone?

omohyoid, sternohyoid and thyrohyoid

superior root of ansa cervicalis

originate from C1 and supply superior omohyoid, sternohyoid, sternothyroid.

The Posterior Triangle is bounded anteriorly by the ________________________, posteriorly by the _________________________, and inferiorly by the ________________________

posterior border of the sternocleidomastoid muscle anterior border of the trapezius muscles, middle third of the clavicle.

which 2 fascial spaces have continuation with the posterior mediastinum ?

retropharyngeal and third space

arterial supply to the thyroid gland

superior and inferior thyroid arteries

The (deep) investing layer (fascia)

surrounds the neck completely . It splits to surround the SCM, the strap muscles(scalene muscles ant, middle, post) and the Trapezius muscles. The (deep) investing fascia is attached superiorly to the skull and jaw and inferiorly to the scapula, acromion, clavicle, and the manubrium of sternum. (red and purple line in pic)

Pretracheal layer

surrounds the trachea, esophagus, and thyroid gland. The pretracheal fascia begins superiorly at the hyoid bone and ends inferiorly in the upper thoracic cavity. Laterally, this fascia continues and covers the thyroid gland and the esophagus. Posteriorly, the pretracheal layer is referred to as the buccopharyngeal fascia and separates the pharynx and the esophagus from the prevertebral layer.

• The prevertebral layer

surrounds the vertebral column and the muscles associated with it. The prevertebral fascia is attached posteriorly to the base of the skull. Anteriorly, the prevertebral fascia is attached to vertebrae CI to CVII.

. The ventral rami of the cervical plexus coalesce into

the Ansa Cervicalis.

Because of the density of the deep fascia in this region, bleeding resulting from tears in the External Jugular Vein at this point is sometimes difficult to control because

the fascia holds the torn vein(s) open).

The Anterior Triangle is bounded anteriorly by _____________________, posteriorly by the ______________________________, and superiorly by the ______________________________.

the median line of the neck anterior border of the sternocleidomastoid muscle inferior border of the mandible

subdivisions of the anterior triangle

the submandibular , submental (unpaired) , carotid and muscular triangles.

This larger anterior triangle can be divided into four smaller ones for descriptive purposes. These are

the submandibular, submental, carotid and muscular triangles.

The branch of the Superior Thyroid Artery piercing the________________________ is the Superior Laryngeal Artery.

thyrohyoid membrane

The Neck can be divided by the sternocleidomastoid muscle into

two large triangles: the Anterior and Posterior Cervical Triangles

motor nerve supply to the cervical plexus

ventral rami