3.3 Shoulder Complex (Neurovascular I)

Question 1

Brachial Plexus

Answer 1

(c5-T1)

Question 2

What are the subunits of the brachial plexus?

Answer 2

Real Texans Drink Cold Beer

Question 3

R(eal)

Answer 3

Roots/Rami (c5-T1- ventral ramus)

Question 4

T(exans)

Answer 4

Trunks:

• upper trunk (c5-c6) c4 may contribute
• middle trunk (c7)
• lower trunk (c8-T1) T2 may contribute

Question 5

D(rink)

Answer 5

DIVISIONS

• Anterior Division (c5-c7)
• Posterior Division (c5-T1)
• Anterior Division (c8-T1)

Question 6

C(old)

Answer 6

CORDS
-becomes cord when hits axillary artery
LATERAL / POSTERIOR / MEDIAL
* no anterior!

Question 7

Cutaneous N. of brachial plexus

-usually derived from branches of the _______

Answer 7

-CORDS

Question 8

CORDS subunits have:

Answer 8

• posterior cord
  
  • posterior cutaneous (PC)
• medial cord
  
  • medial cutaneous (MC)
• lateral cord
  
  • lateral cutaneous (LC)

*no anterior cutaneous, just anterior branches

Question 9

B(eer)

Answer 9

BRANCHES

• what used to be cord… terminal
• axillary n, musculocutaneous n., radial n., median n, ulnar n

Question 10

Cords and Branches of brachial plexus (c5-T1)

Answer 10

• wrap around AXILLARY ARTERY!
• Branches of posterior cord
  
  • Axillary N.
  • Radial N.

Question 11

Branches of the lateral and medial cord form….

Answer 11

“M”

Question 12

Lateral branch of “M” forms…

Answer 12

musculocutaneous N.

Question 13

Middle Branch of “M” forms..

Answer 13

median n. (comes from both cords)

Question 14

Medial Branch of “M” forms…

Answer 14

ulnar n.

Question 15

Root/Rami & Trunks of Brachial plexus innervate…

Answer 15

supraclavicular

Question 16

Cords and Branches innervate…

Answer 16

infraclavicular (arm)

Question 17

Rami of Brachial plexus (c5-T1)

-descend through….

Answer 17

• descend through interscalene space

- Between Anterior scalene & Middle Scalene mm.

Question 18

Trunks of Brachial plexus (c5-T1)

-located…

Answer 18

in posterior triangle of the neck

-bw sternocleidomastoid & trapezius mm. (pic?)

Question 19

Divisions of brachial plexus are located …

Answer 19

-posterior to clavicle

Question 20

Cords of brachial plexus are found…

Answer 20

• through Cervico-Axillary Canal
  - Thoracic Outlet
• Within Axilla
• Wrap around Axillary Artery

Question 21

Thoracic Outlet Syndrome (TOS)+

Answer 21

Superior Thoracic Aperture= Thoracic Outlet- Thoracic Inlet

(really should be cervicoaxillary syndrome) because refers to cervicoaxillary canal

Question 22

Thoracic Outlet Syndrome (TOS) Definition:

Answer 22

• impingement/compression of neurovascular structures
  - of Brachial plexus
  - of subclavian vessels

Question 23

Causes of TOS

Answer 23

• compression at interscalene space
  - anterior scalene (and middle) mm. tightness
• tightness, fibroses of PECTORALIS MINOR m.
  - occurs w/ repeated/prolonged overhead arm mvmts
• cervical rib compression @ c7 (before t1)
• costoclavicular approximation
  - compression between rib and clavicle (kyphosis)

Question 24

Sx. of vascular impingement

Answer 24

• bluish/pallor discoloration in hand
  
  • white= hand sign (no o2 in arteries)
• swelling in arm or hand (venous thoracic outlet syndrome?)
• pain and fatigue in shoulder and neck
  - pulsating lump above clavicle (anyeurism!)
• enlargement of venous arch of hand (veins enlarge)

Question 25

Sx. of plexus impingement

Answer 25

- pain, burning, parasthesia in: - neck & shoulder - forearm & hand - c8, T1 dermatome - mm. spasm, weakness in medial forearm - atrophy of intrinsic mm. of hand (ulnar n. innervates hand) - difficulty w/ fine motor skills

Question 26

TOS Tx:

Answer 26

PT - relaxation of mm. - build up postural mm. - NSAIDS to reduce inflammation - Meds - for P - anticoagulant/ thrombolytic - surgery - decompression surgery (mostly if vascular) - 1st rib or cervical rib removed, shaved

Question 27

Nerves exclusively innervating shoulder and arm mm.

Answer 27

- axillary n. - posterior cord - musculocutaneous n. - lateral cord