6. BRACHIAL PLEXUS:
Brachial plexus is formed by the union of anterior rami of
C5, C6, C7, C8 and T1.
It provides the motor and sensory innervations to the upper limb.
10. BRACHIAL PLEXUS
Roots;
The ventral rami of spinal nerves C5 to T1 are referred to as the
roots of the plexus.
Trunks;
Shortly after emerging from the intervertebral foramina , these 5
roots unite to form three trunks.
The ventral rami of C5 & C6 unite to form the Upper Trunk.
The ventral ramus of C 7 continues as the Middle Trunk.
The ventral rami of C 8 & T 1 unite to form the Lower Trunk.
11.
12. BRACHIAL PLEXUS:
Divisions;
Each trunk splits into an anterior division and a posterior division.
The anterior divisions usually supply flexor muscles.
The posterior divisions usually supply extensor muscles.
13. Cords;
The anterior divisions of the upper and middle trunks unite to form
the lateral cord.
The anterior division of the lower trunk forms the medial cord.
All 3 posterior divisions from each of the 3 cords all unite to form
the posterior cord.
17. BRACHIAL PLEXUS:
Nerves that contain fibers from the superior rami of the
plexus (C5 and C6) innervates proximal muscles of
upper limb (shoulder muscles).
Nerves that contain fibers from the inferior rami of the
plexus (C8 and T1) innervates distal muscles of upper
limb (Hand muscles).
The ventral rami of the brachial plexus exhibit proximal
to distal innervation.
21. BRACHIAL PLEXUS:
Median nerve (C5 – T1)
a.Forearm;
Supplies the anterior compartment except 1.5 muscle by
ulnar nerve (Flexor carpi ulnaris and ulnar half of the
flexor digitorum profundus)
b.Hand;
Also supplies Thenar compartment, Opponens pollicis,
Central compartment and Lumbricals of Digit 2 & 3
• Flex wrist and all digits Pronation
• Opposition of thumb
• Flex MP joint and extend interphalangeal.
29. TERMINAL BRANCHES MUSCLES INNERVATED PRIMARY ACTION
Musculocutaneous nerve
(C5 - C6)
All muscles of the anterior
compartment of the arm.
Flex albow
Supination (bicep brachi)
Median nerve (C5 – T1) a.Forearm;
Anterior compartment except
1.5 muscle by ulnar nerve
(Flexor carpi ulnaris and
ulnar half of the flexor
digitorum profundus)
b.Hand;
Thenar compartment
Opponens pollicis
Central compartment
Lumbricals: Digit 2 & 3
Flex wrist and all digits
Pronation
Opposition of thumb
Flex MP joint and extend
interphalangeal (PIP and DIP)
joints of digits 2 & 3
30. Ulnar nerve (C8 – T1) a.Forearm;
Anterior compartment 1 ½
muscle not innervated by
the median nerve.
b.Hand;
Hypothenar compartment
Central compartment
Introssei muscle (Palmar
and Dorsal)
Lumbricals (Digit 4 and 5)
Adductor pollicis
Flex wrist (weak) and digits
4 and 5
Dorsal – Abduct digits 2-5
Palmar – Adduct digits 2-5
Assist lumbricals in MP and
IP extension of digit 2-5
Flex MP and extend PIP and
DIP joint of digit 4 & 5
Adduct the thumb
31. Axillary nerve (C5 – C6) Deltoid
Teres minor
Abduct shoulder 15 – 110
degree
Lateral rotation of shoulder
Radial nerve
(C5 – T1)
Posterior compartment
muscle of arm and forearm
Extend MP, wrist and elbow
Supination (Supinator
muscle)
32. COLLATERAL NERVES: MUSCLE OR SKIN INNERVATED:
Dorsal scapular nerve Rhomboids
Long Thoracic nerve Serratus Anterior – rotate scapula superiorly
Suprascapular nerve Supraspinatus – abduct shoulder 0 – 15°
Infraspinatus – laterally rotate shoulder
Lateral Pectoral nerve Pectoralis major
Medial Pectoral nerve Pectoralis major and minor
Upper subscapular nerve Subscapularis
Middle subscapular (thoracodorsal)
nerve
Latissimus dorsi
Lower subscapular nerve Subscapularis and teres major
Medial Brachial cutaneous nerve Skin of medial arm
Medial Anterobrachial cutaneous nerve Skin of medial forearm
33. BRACHIAL PLEXUS:
SENSORY INNERVATION:
The palm is mainly supplied by the median and ulnar nerve.
The median nerve supplies the lateral 3½ digit and adjacent area
of the lateral palm and the thenar eminence.
The Ulnar nerve supplies the medial 1½ digits and skin of
hypothenar eminence.
The Radial nerve supplies the skin of the dorsum in areas of first
dorsal web space, including the skin over the anatomic snuff box.
35. BRACHIAL PLEXUS:
LESIONS OF BRANCHES OF BRACHAIL PLEXUS:
Radial Nerve:
Axilla (Saturday Night Palsy)
Mid shaft of Humerus at radial groove or lateral elbow
Wrist (Lacerarion)
Median Nerve:
Elbow: (Supracondylar fracture of humerus)
Wrist: Carpal Tunnel or Laceration
Ulnar Nerve:
Elbow (Medial epicondyle)
Wrist (Laceration)
Fracture of Hook of hamate
36. BRACHIAL PLEXUS:
Axillary Nerve:
Fracture of the surgical neck of the humerus or
inferior dislocation of the shoulder.
Musculocutaneous Nerve:
Long thoracic Nerve:
Suprascapular Nerve:
43. “3M” comes off the medial cord.
Axillary Radial
Roots
Trunks
Divisions
Cords
Branches
C5 C6 C7 C8 T1
Upper Middle Lower
Musculocutaneous Median Ulnar
Lateral
Posterior
Medial
Upper subscapular
Lower subscapular
Thoracodorsal
Medial pectoral n.
Medial cutan. n. of arm
Medial cutan. n. forearm
SLOWSLOW
44. The lateral pectoral n. comes off the lateral cord.
Axillary Radial
Roots
Trunks
Divisions
Cords
Branches
C5 C6 C7 C8 T1
Upper Middle Lower
Musculocutaneous Median Ulnar
Lateral
Posterior
Medial
Upper subscapular
Lower subscapular
Thoracodorsal
Medial pectoral n.
Medial cutan. n. of arm
Medial cutan. n. forearm
Lateral pectoral n.
45. There are 4 supraclavicular branches.
Axillary Radial
Roots
Trunks
Divisions
Cords
Branches
C5 C6 C7 C8 T1
Upper Middle Lower
Musculocutaneous Median Ulnar
Lateral
Posterior
Medial
Upper subscapular
Lower subscapular
Thoracodorsal
Medial pectoral n.
Medial cutan. n. of arm
Medial cutan. n. forearm
Lateral pectoral n.
Dorsal Scapular n.
N. to subclavius
Suprascapular n.
Long
Thoracic n.
SLOW
46. That’s it! The Brachial Plexus
Axillary Radial
Roots
Trunks
Divisions
Cords
Branches
C5 C6 C7 C8 T1
Upper Middle Lower
Musculocutaneous Median Ulnar
Lateral
Posterior
Medial
Upper subscapular
Lower subscapular
Thoracodorsal
Medial pectoral n.
Medial cutan. n. of arm
Medial cutan. n. forearm
Lateral pectoral n.
Dorsal Scapular n.
N. to subclavius
Suprascapular n.
Long
Thoracic n.
47. Erb- Duchenne palsy
Injury to upper trunk and cord of
Brachial Plexus.
Occurrence:
Due to excessive increase in the angle between neck
and the shoulder.(Birth Injury, Fall on the shoulder)
Roots Involved:
C5 and C6
Muscles Involved:
Shoulder
Arm
57. Erb- Duchenne palsy
Clinical Appearance:
Motor Loss:
Adducted Shoulder
Medially Rotated Arm
Extended Elbow
Sensory Loss:
Lateral aspect of Upper Limb
58.
59.
60.
61. klumpke paralysis or Palsy
Injury to Inferior part of Plexus.
Occurrence:
Excessive abduction of arm.
Less common then Injury to Superior part of Plexus.
Roots Involved:
C8 and T1
62. klumpke paralysis or Palsy
Clinical Appearance:
Motor Loss:
Small muscles of Hand
Sensory Loss:
Medial aspect of Upper Limb
67. Anatomical Anomalies of the Brachial Plexus
• Prefixed plexus: Formed by the ventral
primary rami of C4 - 8
• Postfixed plexus: formed by the ventral
primary rami of C6-T2
*
*Rib 1 can impinge on the lower trunk of the
brachial plexus and create problems