Posterior Triangle of the Neck, Axilla, and Brachial Plexus

Question 1

Divisions of the posterior cervical triangle

Answer 1

Occipital triangle
Supraclavicular
Divided by omohyoid

Question 2

Borders of the Posterior Triangle of the Neck

Answer 2

SCM
Clavicle
Trapezius

Question 3

SCM (O, I, N, B, F)

Answer 3

O = Manubrium; Proximal Clavicle
I = Mastoid process; temporal bone 
N = Spinal Accessor 
B = Multiple
F = Individually, will tilt head toward shoulder on same side rotating head to turn face to opposite side; acting together, draw head forward

Question 4

Trapezius (O, I, N, B, F)

Answer 4

O = Vertebral spines; Occipital bone
I = Spine adn acromion of scapula; distal clavicle
N = Spinal accessory 
B = Transverse cervical - Superficial branch
F = Assists in rotating the scapula during abduction of humerus above horizontal; upper fibers - elevate, middle fibers - adduct, lower fibers - depress scapula

Question 5

Cervical Fascias

Answer 5

Enveloping layer of Deep Cervical Fascia
Pretracheal Fascia
Prevertebral Fascia
Carotis Sheath

Question 6

Retropharyngeal space

Answer 6

Located between Pretracheal and Prevertebral Fascai

Infection here is really dangerous bc space goes all the way to the thoracic cavity

Question 7

Scalene Muscles (I, F)

Answer 7

I = Cervical Nerves
F = Elevate ribs 1 and 2

Question 8

Between what scalenes does the brachial plexus pass?

Answer 8

Anterior and middle

Question 9

Levator Scapulae (O, I, N, B, F)

Answer 9

O = transverse processes of C1-C4
I = Superior angle of scapula; Medial border of scapula
N = Dorsal scapular, C3 and C4
B = Dorsal Scapular Artery 
F = Elevates Scapula

Question 10

Splenius Muscles (O, I, N, F)

Answer 10

O = Lower ligamentum nuchae, spinous processes of cervical and thoracic vertebrae
I = Transverse processes (cervicis), mastoid process and superior nuchal line (capitis)
N = dorsal rami of middle and lower cervical spinal nerves
F = extend, rotate, and laterally flex the head

Question 11

Contents of the Posterior Triangle

Answer 11

Cervical Plexus
Brachial Plexus (roots and trunks)
Branches of the Subclavian Artery 
Tributaries to the Jugulars
Posterior belly of omohyoid

Question 12

Cervical Branches (Cutaneous branches)

Answer 12

Lesses Occipital (C2)
Greater Auricular (C2-C3)
Transverse Cervical (C2-C3)
Supraclavicular (C4)

Question 13

Review Veins and Arteries

Answer 13

Slides 16-18

Question 14

The Phrenic Nerve crosses anterior to what muscle in the posterior triangle of the neck

Answer 14

Anterior Scalene

Question 15

Postaxial nerves

Answer 15

come from the posterior cord - axillary (shoulder muscles) and radial (arm and forearm)

Question 16

Preaxial nerves

Answer 16

come from the lateral and medial cords
musculocutaneous - arm
median - forearm
ulnar - hand

Question 17

Brachial plexus present in posterior triangle of the neck

Answer 17

Roots
Trunks
Dorsal Scapular N

Question 18

Branches of Roots

Answer 18

Dorsal scapular

Long thoracic

Question 19

Branches off Trunks

Answer 19

Suprascapular

Nerve to Subclavious

Question 20

Branches of Cords

Answer 20

Lateral Pectora - Lateral cord
Medial Pectoral - medial cord
Medial brachial cutaneous - medial cord
Medial antebrachial cutaneous - medial cord
Upper subscapular - posterior
Thoracodorsal - posterior
Lower supscapular - posterior

Question 21

Axilla

Answer 21

4 sides region - elongated
Transition from the posterior triangle of the neck to the upper limb
All nerves and blood vessels of the upper limb travel through here
Lots of fat

Question 22

Anterior Wall of Axilla

Answer 22

Pectoralis Major and Minor
Subclavius
Clavipectoral fascia

Question 23

Inlet of Axilla

Answer 23

Lateral margin of 1st rib
Clavicle
Superior margin of scapula

Question 24

Medial wall of Axilla

Answer 24

Upper thoracic wall

Serratus anterior

Question 25

Floor of Axilla

Answer 25

Skin of armpit | Laterally - open to arm

Question 26

Posterior wall of Axilla

Answer 26

Subscapularis Teres major Latissimus dorsi long head of biceps brachii

Question 27

Lateral wall of axilla

Answer 27

Intertubercular sulcus

Question 28

Contents of Axilla

Answer 28

Axillary sheath Cords of brachial plexus with branches supplying the walls Axillary artery and the main branches to the walls Deep veins of the upper limb

Question 29

Innervation of Pectoralis Major

Answer 29

Lateral and Medial Pectoral N

Question 30

Innervation of Pectoralis Minor

Answer 30

Medial Pectoral N

Question 31

Innervation of Subclavius

Answer 31

N. to Subclavius

Question 32

Serratus Anterior (F, I)

Answer 32

Hold scapula to thoracic wall Innervated by Long Thoracic Nerve If injured can lead to winging of scapula

Question 33

Innervation of infraspinatus

Answer 33

Suprascapular

Question 34

Innervation of Teres Minor (and Deltoid)

Answer 34

Axillary

Question 35

Innervation of Subscapularis

Answer 35

Upper and lower subscapular Nerves

Question 36

Innervation of Teres Major

Answer 36

Lower Subscapular

Question 37

Innervation of Latissimus Dorsi

Answer 37

Thoracodorsal

Question 38

Innervation of anterior wall of axilla

Answer 38

Medial and lateral cords

Question 39

Innervation of medial wall of axilla

Answer 39

long thoracic from roots of plexus

Question 40

Innervation of posterior wall of axilla

Answer 40

Branches from posterior cord

Question 41

Upper Plexus Injury

Answer 41

Excessive widening of angle between neck and shoulder C5-C6 Waiter's tip hand

Question 42

Lower Plexus injury

Answer 42

Excessive angle between trunk and upper limb C8-T1 Claw hand deformity

Question 43

When does the subclavian artery become the axillary artery?

Answer 43

After crossing lateral border of 1st rib

Question 44

When does the axillary artery become the brachial artery?

Answer 44

After artery crosses the inferior border of teres major

Question 45

Review Arteries

Answer 45

Slides 47 and 48

Question 46

Where is the cephalic vein and where does it drain

Answer 46

Laterally | Drains to the axillary artery vein through the deltopectoral triangle

Question 47

Where is the basilic vein and where does it drain

Answer 47

Medially | Drains to the medial intermuscular septum to join the brachial veins

Question 48

Where do cephalic and basilic veins communicate

Answer 48

Median cubital vein