Brachial Plexus Flashcards
Brachial plexus consists of
Roots
Trunks
Divisions
Cords Branches
Roots constitute of what
Anterior primary Rami of spinal nerves C5-T1
With contributions from C4 and T2
Root C5and C6 form
Upper trunk
Root C7 forms
Middle trunk
Root C8 and T1 forms
Lower trunk
The trunks lie where
They lie in the neck between the scalenus anterior and scalenus medius covered by axillary sheath from prevertebral fascia
The trunks divide into how many divisions
2 divisions , ventral and dorsal and they join to form cords
Lateral cord is formed by
Union of ventral divisions of upper and middle trunks
Medial cord is formed by
Ventral division of lower trunk
Posterior cord is formed by
Dorsal divisions of upper, middle and lower trunks
List the branches of the roots
Long thoracic nerve or nerve to serratus anterior(C5-C7)
Dorsal scapular nerve or nerve to rhomboids(C5)
Branches to longus and scaleni muscles (C5-C8)
Phrenic nerve (Main root is from C4 ,C5 contributes little )
Dorsal scapular nerve supplies
Rhomboids
Long thoracic nerve supplies
Serratus anterior
Phrenic nerve
Sole motor nerve supply to the diaphragm
Upper trunk gives how many branches
2
List the branches of upper trunk
Suprascapular(C5-C6)
Nerve to subclavius (C5-C6k
Suprascapular nerve supplies
Supraspinatus and Infraspinatus
Nerve to subclavius supplies
Subclavius muscle
Lateral cord has how many branches
3
List the branches of lateral cord
Lateral pectoral
Musculocutaneous
Lateral root of median nerve
All C5-C7
Lateral pectoral nerve supplies
Pectoralis major and minor
Musculocutaneous supplies
Muscles of anterior arm which includes….. Mention them
Lateral root of median nerve
It joins the medial root of median nerve forming median nerve
Median nerve supplies muscles of anterior compartment of forearm and thenar eminence.
Branches of medial cord are how many
5
List branches of medial cord
Medial pectoral (C8-T1)
Medial cutaneous nerve of arm(C8-T1)
Median cutaneous nerve of forearm(C8-T1)
Ulnar nerve(C8-T1)
Median root of median nerve (C8-T1)
Pectoralis major and minor
Carries sensory impulse from a small area of medial side of arm
Medial cutaneous nerve of arm
Carries sensory impulse from a large area of medial side of forearm
Medial cutaneous nerve of forearm
Ulnar nerve supplies
Hypothenar eminence
15 intrinsic muscles of palm
One an half muscles of anterior forearm
Joins lateral root of median nerve and gets distributed with branches of median nerve
Median root of median nerve
Posterior cord has how many branches
5
List them
Upper subscapular C5-C6
Lower subscapular C5-C6
Nerve to latissimus dorsi C6-C8
Axillary or circumflex C5-C6
Radial C5-C8, T1
Supplies subscapularis muscle
Upper subscapscular and Lower Subscapular
Supplies teres major
Lower subscapular
Supplies deltoid and Teres minor
Axillary or circumflex nerve
What is the thickest branch of brachial plexus
Radial nerve
Radial nerve supplies
3 heads of triceps brachii
12 muscles on posterior forearm
Upper limb is supplied near the trunk by
Supraclavicular branches of cervical plexus
Intercostobrachial branch of 2nd intercostal nerve
Blood supply to brachial plexus
Vertebral artery
Thyrocervical trunk with its branches
Suprascapular artery
Transverse cervical arteries
Site of Erbs paralysis
Erbs point- located in upper trunk of brachial plexus.6 nerves meet there.
Cause of injury
Undue separation of the head
from the shouder which can be seen in
1 Birth injury
2.Fall on the shoulder
3. During anaesthesia.
Nerve root involved
Mainly C5
Partly C6
Muscles paralysed
Mainly biceps brachii,
deltoid,
brachialis
brachioradialis.
Partly supraspinatus,
infraspinatus
supinator
Deformity and position of limb
The deformity is known as’policeman’s tip hand’
Arm: Hangs by the side; it is adducted and medially
rotated.
Forearm: Extended and pronated.
What movements are lost
.Abduction and lateral rotation of the arm at
shoulder joint.
• Flexion and supination of the forearm.
• Biceps and supinator jerks are lost.
• Sensations are lost over a small area over the
lower part of the deltoid.
Klumpkes paralysis
Site of injury
Lower trunk of the brachial plexus.
Cause
Undue abduction of the arm, as in
clutching something with the hands after a fall from a
height, or sometimes in birth injury.
Nerve root involved
Mainly T1
Partly C8
Muscles paralyzed
Intrinsic muscles of the hand (T1).
•Ulnar flexors of the wrist and fingers (C8)
Deformity of hand
Claw hand .
Injury to serratus anterior other name
Nerve of bell
Cause
1 Sudden pressure on the shoulder from above.
2 Carrying heavy loads on the shoulder.
Deformity
Winging of the scapula, i.e. excessive
prominence of the medial border of the scapula.
Disability
Loss of pushing and punching actions.
During
attempts at pushing, there occurs winging of the
scapula
•Overhead abduction of shoulder girdle is partly
affected due to intact trapezius muslce.
Clinical Problem 1
A patient came with inability to: (i) abduct right
shoulder, (ii) flex elbow joint, and (iii) supinate the
forearm
•What is the site of injury of the nerves?
•What is the point called?
•What are the nerves affected?
The site of injury is called Erb’s point.
Six nerves are involved:
i.Ventral ramus of cervical five segment of
spinal cord
ii.Ventral ramus of cervical six segment of spinal
cord
These two rami join to form the upper trunk.
iii.Suprascapular nerve from upper trunk
iv.Nerve to subclavius from upper trunk
v.Anterior division of upper trunk
vi.Posterior division of upper trunk
These divisions give fibres to deltoid, brachialis,
biceps brachii, supinator, so the arm cannot be
abducted.
The elbow is extended and forearm is
pronated.
This paralysis is called Erb’s paralysis.
