Neurovascular Structures of the Upper Quarter

Question 1

What are the boundaries and contents of the anterior/posterior triangle of the neck?

Answer 1

Anterior Triangle of Neck:
Boundaries - anterior median line of the neck, inferior border of mandible, anterior border of sternocleidomastoid
Contents - hyoid bone + muscles, larynx, trachea, esophagus, submandibular salivary + thyroid glands, sympathetic trunk + cervicle ganglia, lymph nodes, ansa cervicalis, vagus and Hypoglossal nerves, carotid sheath
Posterior Triangle of Neck:
Boundaries - posterior border of sternocleidomastoid, anterior border of trapezius, middle third of clavicle
Contents - accessory nerve, nerves of cervical plexus, trunks of brachial plexus, subclavian artery, external jugular vein, lymph nodes, scalenes

Question 2

What is the carotid sheath and what is found within it?

Answer 2

Carotid sheath is a deep fascial sheath that envelops neurovascular structures and includes the common carotid artery, internal jugular vein, and vagus nerve

Question 3

What is the difference between the cervical plexus and brachial plexus?

Answer 3

Cervical - head, neck, and upper shoulder region
Brachial - arm, chest, shoulder, and hand

Question 4

What are the various nerves/nerve root levels that make up the cervical and brachial plexuses?

Answer 4

Cervical - anterior rami of C1-C4
Brachial - anterior rami of C5-T1

Question 5

What are the main blood vessels associates with the upper quarter, where are they found, and what is their significance?

Answer 5

Subclavian, beneath the clavicle, supplies blood to and from the upper limb, chest, neck, and brain
Axillary, armpit, provides blood to and from the shoulder and lateral thorax
Brachial, upper arm, supply blood to and from arm
Radial (lateral) + Ulnar (medial), forearm, supply blood to forearm and hand
Cephalic, lateral aspect of arm, important for IV
Basilic, medial aspect from hand to elbow, important for IV
Internal + External Jugular, along neck, drain blood from bran, neck, and head

Question 6

Various muscles innervated by the nerves of the brachial plexus?

Answer 6

C5-C7 Musculocutaneous Nerve innervates biceps brachii, brachialis, and coracobrachialis
C5-C6 Axillary Nerve innervates deltoid and teres minor
C5-T1 Radial Nerve innervates triceps brachii, ancones, brachioradialis, and extensor muscles of forearm
C5-T1 Median Nerve innervates forearm flexors, first 3 and 1/2 fingers
C8-T1 Ulnar Nerve innervates flexor carpi ulnas, medial half of flexor digitorum profundus, intrinsic hand muscles

Question 7

What is the difference between the supraclavicular and infraclavicular branches of the brachial plexus?

Answer 7

Supraclavicular - above clavicle, roots + trunks
Infraclavicular - below clavicle, cords

Question 8

What are the different types of brachial plexus lesions and how do they present themselves?

Answer 8

Superior Trunk Injury:
Erb’s Palsy
limited Elbow flexion + external rotation
C5-C6
presented as forceful lateral flexion of the neck with shoulder depression
Inferior Trunk Injury:
Klumpke’s Palsy
limited Hand extension
C8-T1
presented as forceful shoulder abduction

Question 9

What are the nerve root levels and skin locations for the upper extremity dermatomes?

Answer 9

C5 - Anterior Shoulder
C6 - Digit 1
C7 - Digit 3
C8 - Digit 5
T1 - Medial Forearm

Question 10

What are the nerve root levels and muscle actions for the upper extremity myotomes?

Answer 10

C5 - Shoulder Abduction
C6 - Elbow Flexion / Wrist Extension
C7 - Elbow Extension / Wrist Flexion
C8 - Thumb Extension / Finger Flexion
T1 - Finger Abduction

Question 11

What are the nerve root levels and actions associates with upper extremity reflexes?

Answer 11

C5 - Biceps, Elbow Flexion
C6 - Brachioradialis, Elbow Flexion
C7 - Triceps, Elbow Extension