Brachial Plexus Flashcards Preview

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Flashcards in Brachial Plexus Deck (34):
0

Roots?
Trunks?
Divisions?
Cords?

5 roots
3 trunks
6 divisions
3 cords

1

Muscles in the anterior arm, anterior forearm, and hand that act mainly as FLEXORS are innervated by nerves that contain ANTERIOR DIVISION FIBERS

Musculocutaneous

Ulnar

Median

Lateral and Medial Pectoral Nerves

2

Muscles in the posterior arm and posterior forearm that act mainly as EXTENSORS are innervated by nerves that contain POSTERIOR DIVISION FIBERS

Axillary
Radial
Upper, Middle and Lower Subscapular Nerves

3

Branches of the brachial plexus

ROOTS

Roots:

DORSAL SCAPULAR (C5) - Rhomboids

LONG THORACIC (C5-C7) - Serratus Anterior

4

Branches of the brachial plexus

UPPER TRUNK

Upper trunk:

NERVE TO SUBCLAVIUS (C5 & C6)

SUPRASCAPULAR (C5 & C6)
- Supraspinatus Infraspinatus

5

Branches of brachial plexus

LATERAL CORD

Lateral cord:

LATERAL PECTORAL (C5-C7) - Pectoralis Major

MUSCULOCUTANEOUS (C5-C7)
- Coracobrachialis
- Biceps brachii
- Brachialis

LATERAL ROOT OF MEDIAN (C5, C6 & C7)

6

Branches of brachial plexus

MEDIAL CORD

Medial cord:

MEDIAL PECTORAL (C8-T1)
- Pectoralis Minor

MEDIAL CUTANEOUS NERVE OF ARM (C8-T1)

MEDIAL CUTANEOUS NERVE OF FOREARM
(C8-T1)

ULNAR (C8-T1)
MEDIAL ROOT OF MEDIAN (C8-T1)

7

Branches of brachial plexus

POSTERIOR CORD

Posterior cord:

UPPER SUBSCAPULAR (C5 & C6)
- Subscapularis

THORACODORSAL (C6, C7 & C8)
- Latissimus dorsi

LOWER SUBSCAPULAR (C5 and C6)
- Teres Major

AXILLARY (C5 and C6)
- Deltoid, Teres Minor

RADIAL (C5, C6, C7, C8 and T1)



8

Axillary nerve

Deltoid

Teres Minor

9

Musculocutaneous nerve

Anterior / Flexor compartment of arm

10

Radial nerve

Posterior / Extensor compartment of arm and forearm

11

Median nerve

Anterior / flexor compartment of forearm except FCU and FDP - medial

12

Ulnar nerve

Intrinsic muscles of hand

13

Tendon reflexes:

Biceps Brachii tendon reflex

Triceps tendon reflex

Brachioradialis tendon reflex

Biceps Brachii tendon reflex
- C5 and C6; flexion of the elbow joint by tapping the biceps tendon

Triceps tendon reflex
- C6, C7 and C8; extension of the elbow joint by tapping the triceps tendon

Brachioradialis tendon reflex
- C5, C6 and C7; supination of the radioulnar joints by tapping the insertion of the brachioradialis tendon

14

- Results from lesion of C5 and c6 ventral rami in the superior trunk of the plexus

- PROXIMAL musculature in the upper limb is mainly affected - muscles acting at the shoulder and at the elbow will be weakened

- upper limb is held in a "WAITER's TIP" position; arm is adducted, extended and medially rotated; forearm is probated and the carpal flexors flex the hand at the wrist

- altered sensation in lateral arm, forearm, thumb and index finger

ERB-DUCHENNE's SYNDROME

15

- Result from compression if the c8 and T1 ventral rami in the inferior trunk of the plexus

- DISTAL muscles in the upper limb innervated by C8 and T1 will be affected

- altered sensation in the medial hand, ring and little finger

- weakness of the intrinsic muscles of hand - combination of an "APE hand" and a "CLAW hand"

KLUMPKE's PARALYSIS

16

Most commonly injured as it courses superficial to the SERRATUS ANTERIOR on the lateral wall of the thorax

Patients cannot hold the vertebral border of the scapula flat against the back may have a "WINGING" of the vertebral border

Experience weakness in the ability to PROTRACT the scapula and difficulty in aria using arm above their head

Etiologies: thoracic surgery; Radical mastectomy; stab wounds

LONG THORACIC NERVE LESIONS

17

May be as a result of surgical procedures of the axilla

Patients may have difficulty in elevating the trunk and may have difficulty in using a crutch

Latissimus dorsi muscle is affected

THORACODORSAL NERVE LESIONS

18

May be injured as a result of a dislocation of the head of the humerus or by a fracture of thE SURGICAL NECK of the humerus

Patients may experience weakness in the ability to ABDUCT the arm and there may be altered sensation in the skin covering the DELTOID

weakness in LATERAL ROTATION because of weakness of Teres minor muscle

AXILLARY NERVE LESIONS

19

Uncommon

May be compressed as it passes through the Coracobrachialis muscle

Weakness in flexion of the forearm at the elbow and weakness in supination

MUSCULOCUTANEOUS NERVE LESION

20

As a result of a SPIRAL fracture of the MIDSHAFT of the humerus

"WRISTDROP"

Weakness in the ability to extend the hand at the wrist and a loss of extension at the MP joints of all digits

May experience pain and paresthesia in skin over the first dorsal interosseous muscle between the thumb and index finger

Supination may be weakened but not lost

Extension of the forearm is spared

RADIAL NERVE LESIONS

21

SUPRACONDYLAR fracture of the humerus
Compression between heads of pronator teres muscle

Altered cutaneous sensation - lateral 3 & 1/2 digits and thenar eminence

Weakness in flexion at wrist; flexion of lateral fingers and flexion of thumb

"HAND OF BENEDICTION" - index and middle fingers remain extended when attempting to flex in making a fist

MEDIAN NERVE LESION (PROXIMAL)

22

CARPAL TUNNEL SYNDROME
- LUNATE dislocation

Experience numbness and pain over the palmar aspects of thumb, index and middle fingers

Altered cutaneous sensation - lateral 3 &1/2 digits

"APE HAND" - weakness in OPPOSITION of thumb; remains adducted and extended

MEDIAN NERVE LESION (DISTAL)

23

MEDIAL EPICONDYLE fracture of the humerus

Altered cutaneous sensation - medial 1 & 1/2 digits and hypo thenar eminence

Weakness in flexion of medial fingers; flexion at wrist

ULNAR NERVE LESION (PROXIMAL)

24

Fracture of hook of HAMATE

altered sensation in skin of the medial aspect of the hand and digits

"CLAW HAND" - caused by weakness of the medial 2 lumbricals that flex the MP joints and extend the IP joints of the ring and little fingers

Weakness in the ability to abduct/adduct fingers (unable to hold a piece of paper between adjacent fingers)

ULNAR NERVE LESION (DISTAL)

25

Blood vessels of the BRACHIAL PLEXUS

Axillary artery

Brachial artery

Radial/Ulnar artery

Palmar arch

26

Artery that is continuation if subclavian artery

From 1st rib to TERES MAJOR

Axillary artery

27

Tendon of PECTORALIS MINOR divides the vessels into 3 parts

1st part

2nd part

3rd part

1st part: SUPERIOR THORACIC ARTERY (highest thoracic artery) supplies the muscles of the FIRST TWO INTERCOSTAL SPACES

2nd part: THORACOACROMIAL (pectoral, acromial, deltoid, clavicular) and LATERAL THORACIC

3rd part: SUBSCAPULAR ARTERY (largest branch); supplies subscapularis, teres major & latissimus dorsi; branches 1. thoracodorsal artery (along the thoracodorsal nerve and long thoracic nerve) supplies the anterior serratus muscle & 2. Circumflex scapular artery. ANTERIOR CIRCUMPLEX UMERAL & POSTERIOR CIRCUMPLEX HUMERAL

28

Veins of the Upper X

Cephalic vein --> Axillary vein

Basilic vein + Brachial vein = Axillary vein

Axillary vein --> Brachiocephalic

29

Posterior to styloid process of radius - ascends lateral side of Biceps brachii - reaches intraclavicular fossa - drains into axillary vein

CEPHALIC VEIN

30

Choice for central venous catheterization - increases in diameter and is in direct line with axillary vein

BASILIC VEIN

31

Between anterior & middle scalene muscles

Ventral primary rami (C5-T1)

32

Posterior triangle of the neck

Upper middle & lower trunks

33

5 major terminal branches

Musculocutaneous nerve (C5,6,7)

Axillary nerve (C5,6)

Radial nerve (C5,6,7,8,T1)

Median nerve (C5,6,7,8,T1)

Ulnar nerve (C8,T1)