The Brachial Plexus Flashcards
What forms the brachial plexus?
The anterior rami of the spinal nerves
What are the different parts of the brachial plexus?
Roots, Trunks, Divsions, Cords and branches
What are the trunks and where do these come from?
Superior trunk= a continuation of the C5 and C6 roots
Middle trunk= a continuation of the C7 roots
Inferior trunk= a combination of the C8 and T1 roots
What are two types of divisions called?
Anterior and posterior divisions
What forms the different cords of the brachial plexus?
Lateral cord if formed by the anterior division of the superior trunk and the anterior division of the middle trunk
Posterior cord is formed by the posterior division of the superior trunk, the posterior division of the middle trunk and the posterior division of the inferior trunk.
Medial cord is formed by the anterior division of the inferior trunk
What are the Braches of the brachial plexus?
Musclocutanours nerve, the axillary nerve, the median nerve, the raidal nerve and the ulnar nerve
What are the roots of the musclocutaneous nerve?
C5, C6, C7
What are the roots of the axillary nerve?
Roots C5 and C6
What are the roots of the median nerve?
C6-T1
What are the roots of the radial nerve?
C5-C8 and T1
What are the roots of the ulnar nerve?
C8 and T1
What is the sensory distrubution of the musclocutaneous nerve?
Gives of the lateral cutaneous branch of the forearm, and the innervates the lateral half of the anterior forearm
What is the sensory innervation of the axillary nerve?
The regimental badge area
What are the sensory branches of the median nerve?
Gives of the palmar cutaneous, so the palm and the lateral 3.5 fingers of the forearm
What are the sensory functions of the radial nerve?
Posterior aspect of the arm
What are the senstory functions of the ulnar nerve?
Anterior and posterior surfaces of 1.5 fingers
How would you identify the brachial plexus in a cadaver?
Look for the M shape, and this consists of the muscultanous, median and ulnar nerves and then work from there.
What are the two other nerves that come of the roots of the brachial plexus?
The dorsal scapular nerve and the long thoraic nerve
What are the nerves that come from the trunks of the brachial plexus?
The suprascpaular nerve, the nerve to subcalvius
What are the extra nerves that come from the lateral cord of the brachial plexus?
The lateral pectroal nerve
What are the extra nerves that come from the medial cord of the brachial plexus?
the medial pectroa nerve, the medial cutaneous nerve of the arm, and the medial axillay nerve
What is Erbs Palsy?
An upper brachial plaexus injury, affecting the nerves from the C5 and C6 spinal roots
What causes the development of a erbs plasy?
When there is an excessive increase in angle between the neck and the shoulder
What are some of the nerves affected in Erbs palsy?
Musclocutaneous, axillary suprascapular and the nerve to the subcalvius
What are some of the musces that may be paralysed in a Erbs Palsy?
Supraspinatus, infraspinatus, subclvaius biceps brachi, brachialus, corcobrachilias, deltoid and teres minor
What are the motor functions which are lost in a Erbs palsy?
Abduction at the shoulder, lateral rotation of the arm, supination of the foreamt, and flexion at the shoulder
What are some of the symptoms of Erbs Palsy
Loss of sensation down the lateral side of arm, affected limb hangs weekly, medially roated by the action of pectoralis maor, and the postion known as the waiters tip is characterisitc of Erbs palsy.
What is Klumphke Palsy?
a lower brachila plexus injury, C8-T1
What can cause the development of a klumpke palsy?
Results from a excessive abduction of the arm.
What nerves are affected in a Klumpke palsy?
Nerves from a T1 root so the median and the ulnar nerves
Which muscles loose function in Klumpke Palsy?
All small muscles of the hand but flexion is usally unaffected
What sensory function is lost in Klupmke Palsy?
A loss in sensosry fucntion down the media side of arm
How would a patient present with Klumpke palsy?
Metocarpophalengeal joints are hyperextended, and interphalengeal joints are flexed giving a clawed appearance
