Trace The Brachial Plexus
A nerve arises from anterior divisions of the superior & middle trunks à what cord & which terminal nerve could arise from that cord?
- Lateral cord
- Musculocutaneous
Patient has an injury to the ulnar nerve, which cord would be affected?
Medial cord
You find an injury on the posterior cord, which two terminal nerves may be affected?
- Axillary nerve
- Radial nerve
A patient has weakness of the deltoid & teres minor & decreased sensation over superolateral arm, which nerve is involved?
Axillary nerve
This nerve comes from lateral cord, contains roots C5-C7 & supplies muscles in anterior compartment of the arm, which nerve is it?
Musculocutaneous nerve
A patient has an injury affecting the posterior divisions of the superior & middle trunks (not inferior trunk), which cord contains fibers form these injured divisions?
A patient has a lesion involving the medial cord, which trunk & division would you say is affected?
- Inferior trunk
- Anterior division
A lesion affects the inferior trunk before it divides, which two cords could potentially contain fibers from that trunk?
- Medial cord
- Posterior cord
A patient has difficulty flexing the elbow because of weakness involving biceps/brachialis/coracobrachialis, which nerve most likely affected?
Musculocutaneous nerve
This nerve originates from posterior cord & contains fibers C5-C6 & innervates muscles involved in shoulder movement, which nerve is it?
Axillary nerve
You trace the fiber pathway: C6 --> superior trunk --> posterior division, what cord does that fiber enter?
Posterior cord
A patient has symptoms involving the radial nerve, fill in the pathway fully: radial --> ? --> ? --> ? --> roots
- Posterior cord
- Posterior divisions
- Superior/middle/inferior trunks
- C5-T1
A patient has a lesion affected the middle trunk, could this affect the lateral cord/posterior cord/both?
A patient has weakness of the triceps & wrist/finger extensors, you identify the nerve is radial nerve that’s affected, which cord & division are apart of this nerve?
- Posterior division
- Superior/middle/inferior trunks
This nerve has connections to both lateral & medial cords & contains fibers to all three trunks, which nerve am I?
Median nerve
A nerve is made from fibers traveling through the C5-C6 roots --> superior trunk --> posterior division à posterior cord, which terminal nerve is affected?
Axillary nerve
If the inferior trunk is impaired, where may the lesion be on which spinal nerves?
C8-T1
A patient has an injury to the C5-C6 roots, which cords could be affected?
- Lateral cord
- Posterior cord
A patient has weakness involving anterior forearm flexors/pronators along with thenar muscles & lumbricals, which nerve + cords affected?
- Median nerve
- Lateral + medial cords
This nerve originates from the posterior cord but unlike the axillary nerve, I receive fibers from all three trunks while innervating muscles involved in extension of the arm & forearm, which nerve am I?
Radial nerve
Trace this pathway: C8-T1 --> ? trunk --> anterior division à ? cord à ulnar nerve, fill in the two missing structures
- Medial cord
Which rami form the superior (upper) trunk?
C5-C6
The lateral cord is affected, which spinal nerves are affected?
C5-C7
A patient has weakness involving the flexor carpi ulnaris/ulnar half of flexor digitorum profundus/intrinsic hand muscles, identify nerve & which root affected
- Ulnar nerve
- C8-T1
This nerve originates from the medial cord & roots mainly C8-T1 (sometimes C7), which nerve am I?
Ulnar nerve