Posterior Triangle of the Neck

What are the branches of the Subclavian Artery?

- Vertebral - Internal Thoracic - Transverse cervical (from thyrocervical trunk) -Suprascapular artery (from thyrocervical trunk) -Inferior thyroid artery (from thyrocervical trunk) -Costocervical trunk - A branch of subclavian that eventually divides into deep cervical and highest intercostal arteries. Dorsal scapular artery - A branch of the subclavian artery

What do the scalene muscles do?

- flex neck laterally - elevate ribs during forced inspiration

Is the phrenic nerve motor or sensory? What does it innervate?

- motor - innervates muscle of diaphragm "3,4,5 keep the diaphragm alive" - lies on anterior scalene

What are the scalene muscles innervated by?

- ventral ramii of cervical plexus

What are the components of the Carotid Sheath?

1. Common Carotid Artery 2. Internal Jugular Vein 3. Vagus Nerve

What four sensory nerves of the cervical plexus are in the "nerve point of neck?"

1. Greater Auricular 2. Lesser Occipital 3. Transverse Cervicle 4. Supraclavicular Nerves (medial, intermediate, lateral)

What are the four sensory nerves of the cervical plexus and where can you find their origin?

1. Greater Auricular 2. Lesser occipital 3. Transverse Cervicle 4. Supraclavicular (anterior, intermediate, lateral) - they originate at a point MID-POSTERIOR to SCM

What are the subdivisions of the posterior triangle of the neck?

1. Occipital 2. Sublcavian

Where are lymph nodes most highly numbered?

Along veins. Veins drain lymphatic system. - specifically internal and external jugular veins

What are the three scalene muscles?

Anterior Middle Posterior

The Phrenic nerve lies on which muscle?

Anterior Scalene

What structures is the thoracic duct near?

At juncture of left Internal Jugular Vein and left Subclavian.

What are some major structures near the anterior scalene?

Behind: Brachial Plexus Anterior surface: Phrenic Nerve On top going over first rib: Sublavian Vein (separated from artery which makes it good for IV placement)

What is located between the Anterior Scalene and Medial Scalene?

Brachial Plexus

The internal jugular vein joins with the subclavian to form what?

Brachiocephalic vein

Superficial Lymph drainage into External Carotid then enters...

Deep Venous system because external carotid opens to subclavian. - Important because in Cancer the lymph from the superficial system will drain to the deep system → greater spread of cancer

Where will lymph draining into internal jugular vein go?

Either Right Lymphatic Duct or Thoracic Duct

What causes Horner's Syndrome and what are common symptoms?

Enlargement of the Anterior Scalene (often due to whiplash) results in entrapment of the Sympathetic Trunk causing lack of communication back to brain. Symptoms: - constriction of pupil - lack of sweat on that side of face - ptosis (drooping of eyelid)

What does the thoracic duct drain?

Entier body except for right head, neck, and thorax above the diaphragm. - this includes lower extremities

The occipital artery is a branch of what?

External Carotid.

Where does the superficial lymphatic system drain?

External Jugular Vein

The greater auricular nerve can be expected to run with which vein?

External Jugular Vein.

Which vein is near the 4 sensory nerves of the cervical plexus?

External Jugular Vein.

Why is the anterior scalene known as the "key to the trunk of the neck?"

Find brachial plexus as well as many other nerves (phrenic, sympathetic trunk)

How is the Sympathetic Trunk distinguished as sympathetic?

Ganglion (cell bodies, grey matter) are present

What is the clinical implication of the Brachial Plexus being located between the Anterior Scalene and Medial Scalene?

If Anterior and Medial Scalene are enlarged or contracting uncontrollably, there can be entrapment of the Brachial Plexus. Especially common is problems in the C5-C6 innervations.

What forms the boundaries of the Subclavian division of the posterior triangle of the neck?

Inferior Belly of Omohyoid Clavicle SCM

The sympathetic trunk does what?

Innervates sympathetic muscles. - constricts or relaxes blood vessels etc

Where does the deep lymphatic system drian?

Internal Jugular Vein

What are the main components of the venous system in the posterior triangle?

Internal Jugular Vein (in carotid sheath) External Jugular Veing Subclavian Vein

Where is the lymphatic duct?

Junction of Right Subclavian and Right Internal Jugular Vein.

Cranial Nerve X innervates what muscle (that is most important in the head and neck section)?

Larynx (voice box)

Is the thoracic duct on the lect or right side of the body?

Left side

What muscle is the Sympathetic Trunk located near and what are the clinical implications of its location?

Located near Anterior Scalene. Clinical implications: if Anterior Scalene is enlarged (often due to whiplash) it can entrap the Sympathetic Trunk. Entrapment of the sympathetic trunk results in a lack of communication to the head. → Horner's Syndrome

What forms the boundaries of the occipital subdivision of the posterior triangle of the neck?

Posterior: Trapezius Anterior: SCM Inferior: Inferior Belly of Omohyoid

What are the boundaries of the Posterior Triangle of the Neck?

Posterior: Trapezius Anterior: Sternocleidomastoid Inferior: Clavicle

What does the right lymphatic duct drain?

Right head, neck, and thorax above the diaphragm. Thoracic Duct drains everything else.

What does Cranial Nerve XI (Accessory Nerve) Innervate?

SCM then Trapezius

The external jugular vein opens into what?

Subclavian

The lesser occipital nerve can be expected to be found posterior to what?

The Sternocleidomastoid

Which vein is commonly used for IV sites and why?

The Sublcavian Vein is used because it is very large and is separated from the artery. Allows for large catheter placement with minimal risk of hitting artery.

Thoracic Outlet Syndrome

Thoracic outlet syndrome (TOS) is a syndrome involving compression at the superior thoracic outlet[1] involving compression of a neurovascular bundle passing between the anterior scalene and middle scalene.[2] It can affect the brachial plexus (nerves that pass into the arms from the neck), and/or the subclavian artery or rarely the vein which does not normally pass through the scalene hiatus (blood vessels as they pass between the chest and upper extremity). Rarely a Pancoast tumour in the apex of the lung may be the cause. The compression may be positional (caused by movement of the clavicle (collarbone) and shoulder girdle on arm movement) or static (caused by abnormalities or enlargement or spasm of the various muscles surrounding the arteries, veins, and brachial plexus), a first rib fixation and a cervical rib

What are the attachments for the scalene muscles?

Transverse processes of Cervical Vertebrea Ribs

Why is the cervical plexus "point of the neck" a good place for anestesthia?

You can essentially numb the: - Greater Auricular - Lesser Occipital - Transverse Cervical - Suprascapular clavicular (medial, intermediate, anterior)