Exam 2 Material

At which cervical vertebra level does the trachea begin?

Approximately CV7

Through which structure does the vagus nerve travel in the neck?

Carotid sheath

What action does the sternocleidomastoid muscle perform bilaterally?

Flexes the neck

What action does the sternocleidomastoid muscle perform unilaterally?

Rotates head to contralateral side

What actions does the SCM perform?

Unilateral contraction rotates the head to the contralateral side; bilateral contraction flexes the neck.

What anatomical structures are found in the root of the neck?

Trachea, esophagus, thyroid and parathyroid glands, thoracic duct, right lymphatic duct

What are the actions of the anterior scalene muscle?

Bilaterally: neck flexion; assist forced inhalation; Unilaterally: lateral flexion

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

Anterior: posterior border of the SCM, Posterior: anterior border of the trapezius, Inferior: clavicle

What are the boundaries of the posterior triangle?

Posterior border of SCM, anterior border of trapezius, and clavicle.

What are the branches of the 1st part of the subclavian artery?

Vertebral artery, internal thoracic artery, thyrocervical trunk

What are the contents of the root of the neck?

Subclavian vessels, common carotid arteries, internal jugular veins, phrenic nerve, vagus nerve, recurrent laryngeal nerve, sympathetic chain, trachea, esophagus, thyroid and parathyroid glands, thoracic duct, and apex of the lungs

What are the key branches of the brachial plexus in the posterior triangle?

Dorsal scapular nerve, nerve to subclavius, suprascapular nerve, and long thoracic nerve

What are the key contents of the posterior triangle?

CN XI, external jugular vein, branches of the subclavian artery, trunks of the brachial plexus, cutaneous branches of the cervical plexus

What are the major structures that pass between the anterior and middle scalene muscles?

Subclavian artery and roots of the brachial plexus

What are the subtriangles of the posterior triangle?

Occipital triangle and omoclavicular (supraclavicular) triangle.

What are the superior and inferior limits of the neck?

Superior limit: lower border of the mandible; Inferior limit: jugular notch, sternoclavicular joint, clavicle, acromion, CV7.

What are the symptoms of arterial thoracic outlet syndrome?

Cold, pale hand with pain during overhead arm motions

What are the symptoms of neurogenic thoracic outlet syndrome?

Pain, weakness in shoulder and arm, tingling in fingers, muscle atrophy

What are the symptoms of venous thoracic outlet syndrome?

Edema, blueness of hand/arm, pain/tingling, prominent veins in shoulder and neck

What are the two triangles of the neck?

Anterior triangle and posterior triangle

What branches does the thyrocervical trunk split into?

Inferior thyroid artery, transverse cervical artery, suprascapular artery

What branches supply the skin of the neck?

Cutaneous cervical plexus branches (C2-C4)

What can spinal accessory nerve injury cause?

Trapezius weakness, shoulder droop, and difficulty abducting the arm above horizontal

What divides the neck into anterior and posterior triangles?

The sternocleidomastoid (SCM) muscle.

What do supraclavicular nerves (C3-C4) supply?

The inferior posterior triangle, upper thorax, and shoulder region

What do the supraclavicular nerves innervate?

Skin over the clavicle and upper chest

What does external jugular vein distension indicate?

Elevated venous pressure

What does the brachial plexus form from?

Ventral rami of C5-T1

What does the carotid sheath contain?

Carotid vessels, internal jugular vein, vagus nerve, deep cervical lymph nodes.

What does the great auricular nerve (C2-C3) supply?

The parotid region, auricle, and angle of the mandible

What does the lesser occipital nerve (C2) supply?

The mastoid region and scalp posterior to the auricle

What does the phrenic nerve supply?

Motor to the diaphragm

What does the prevertebral layer of deep cervical fascia surround?

The vertebral column and closely related muscles

What does the right lymphatic duct drain?

Right upper limb, shoulder, right upper thorax, right head/neck

What does the spinal accessory nerve (CN XI) supply?

SCM and trapezius

What does the subclavian artery arise from on the left?

The aortic arch

What does the subclavian artery become at the lateral border of rib 1?

The axillary artery

What does the subclavian vein join to form the brachiocephalic vein?

Internal jugular vein

What does the superficial cervical fascia contain?

Fat, cutaneous nerves, platysma, superficial veins.

What does the thoracic duct drain?

Everything else except what the right lymphatic duct drains

What does the transverse cervical nerve (C2-C3) supply?

The anterior neck

What does the transverse cervical nerve innervate?

Skin of the anterior triangle of the neck

What does the vertebral artery supply?

Brain and brainstem

What forms the brachial plexus?

Ventral rami of C5-T1

What forms the external jugular vein?

The posterior division of the retromandibular vein and the posterior auricular vein

What forms the floor of the posterior triangle?

Muscles including splenius capitis, levator scapulae, posterior scalene, middle scalene, and anterior scalene

What forms the interscalene triangle?

Bounded by 1st rib, anterior scalene muscle, and middle scalene muscle

What forms the roof of the posterior triangle?

Investing layer of deep cervical fascia.

What innervates the anterior scalene muscle?

Branches from C4-C7 VPR

What innervates the omohyoid muscle?

Ansa cervicalis (C1-C3).

What innervates the platysma muscle?

Cervical branch of facial nerve (CN VII)

What is a cervical rib?

A congenital extra rib that may increase the risk of neurovascular compression

What is a risk associated with the spinal accessory nerve during surgery?

It is vulnerable due to its superficial course in the posterior triangle

What is contained in the interscalene triangle?

Roots of the brachial plexus and the 3rd part of the subclavian artery.

What is Erb's point?

Approximately midway on the posterior border of SCM, marking the emergence of cutaneous branches of the cervical plexus.

What is the anterior limit of the root of the neck?

Superior border of the manubrium

What is the boundary of the root of the neck?

Superior thoracic aperture

What is the clinical relevance of the posterior triangle and root of the neck anatomy?

It is applied to various clinical scenarios involving the neck and thorax.

What is the clinical significance of the external jugular vein (EJV) distension?

Assessed at 45° recline; distension above clavicle suggests elevated venous pressure

What is the course of the internal jugular vein?

Begins at jugular foramen, runs laterally in carotid sheath, joins subclavian vein to form brachiocephalic vein

What is the course of the vagus nerve (CN X)?

Inside the carotid sheath, anterior to the subclavian artery

What is the course of the vagus nerve in the neck?

Inside carotid sheath, anterior to subclavian artery, medial to phrenic nerve

What is the function of the great auricular nerve?

Innervates skin towards the angle of the mandible and parotid region

What is the function of the lesser occipital nerve?

Innervates skin behind the ear

What is the function of the phrenic nerve?

Motor innervation to the diaphragm

What is the function of the platysma muscle?

Tenses neck skin and depresses angle of the mouth

What is the function of the superficial cervical fascia?

It encircles the neck and contains fat, cutaneous nerves, and the platysma muscle.

What is the inferior limit of the neck?

Anterior: jugular/suprasternal notch, sternoclavicular joint, clavicle, and acromion process; Posterior: CV7

What is the innervation of the platysma?

Cervical branch of the facial nerve (CN VII).

What is the innervation of the sternocleidomastoid muscle?

Motor: spinal accessory nerve (CN XI); Sensory and proprioception: C2 and C3 VPR

What is the insertion of the anterior scalene muscle?

Scalene tubercle of rib 1.

What is the insertion of the omohyoid muscle?

Hyoid bone.

What is the insertion point of the SCM?

Mastoid process.

What is the insertion point of the sternocleidomastoid muscle?

Mastoid process

What is the key landmark in the posterior triangle?

Anterior scalene muscle

What is the lateral limit of the root of the neck?

Rib 1

What is the most common type of thoracic outlet syndrome?

Neurogenic, accounting for approximately 90% of cases

What is the origin of the anterior scalene muscle?

Anterior tubercles of transverse processes of CV3-CV6.

What is the origin of the omohyoid muscle?

Superior border of scapula.

What is the origin of the sternocleidomastoid (SCM)?

Manubrium and medial clavicle.

What is the origin of the sternocleidomastoid muscle?

Manubrium and sternal end of the clavicle

What is the posterior limit of the root of the neck?

Body of TV1

What is the relationship between the prevertebral fascia and the axillary sheath?

The prevertebral fascia follows the brachial plexus and subclavian vessels into the axillary sheath.

What is the relationship of the esophagus to the trachea?

The esophagus passes posterior to the trachea

What is the role of the anterior scalene muscle?

It serves as a key landmark for surrounding structures in the posterior triangle.

What is the sensory innervation from the phrenic nerve?

From parietal peritoneum in right upper quadrant of the abdomen

What is the significance of the pretracheal fascia?

It allows for the spread of infection between the neck and thorax.

What is the significance of the prevertebral fascia?

It continues to the axilla as the axillary sheath, allowing spread of infection.

What is the structure of the omohyoid muscle?

Formed from two bellies connected with an intermediate tendon

What is the superior limit of the neck?

Lower border of the mandible

What is the venous angle?

The junction between internal jugular vein and subclavian vein

What is thoracic outlet syndrome (TOS)?

Compression of the brachial plexus and/or subclavian vessels

What is thoracic outlet syndrome?

Compression of brachial plexus and/or subclavian vessels between scalene muscles or at a cervical rib

What is torticollis?

A condition where the head tilts toward the affected side and the chin rotates to the opposite side

What muscle divides the posterior triangle into two sub-triangles?

Inferior belly of omohyoid muscle

What muscle of facial expression is found in the neck?

Platysma muscle

What muscles are covered by the prevertebral fascia in the posterior triangle?

Splenius capitis, splenius cervicis, levator scapulae, posterior scalene, middle scalene, anterior scalene.

What nerve crosses the anterior surface of the anterior scalene muscle?

Phrenic nerve

What spinal nerve levels innervate the skin of the neck?

C2, C3, C4 VPR

What structures are anterior to the anterior scalene?

Prevertebral fascia, subclavian vein, phrenic nerve, ascending cervical artery, transverse cervical artery, suprascapular artery, and omohyoid.