How to Sketch the Nerve Branches

Drawing the nerve branches of the brachial plexus can be very helpful when you are learning anatomy of the human body. The brachial plexus is one of the most complex groupings of nerves in the entire body. It is important to learn what roots, trunks and cords certain nerves come from in order to diagnose and treat a patient. By drawing the plexus, you will be able to better understand where specific nerves are derived.

Instructions

• 1

  Make 5 short lines on the right side of your paper. They should be labeled (from top to bottom) C5, C6, C7, C8, T1. These will be representing the roots of the cervical nerves C5-C8 and the first thoracic nerve. Join C5 to C6 with a "<" shape to show that they come together. Continue C7 as a line by itself, and join C8 and T1 together as you did with C5 and C6.

• 2

  Draw a straight line coming off both "<" shapes and off the C7 extension. These are the three trunks of the brachial plexus. The top one is called the "superior" or "upper" trunk. The middle is referred to as the "middle" trunk, and the last one is the "inferior" or "lower" trunk.

• 3

  Next, draw two lines coming off each of the three trunks that looks like ">." This will represent the anterior and posterior divisions of the trunks. The superior and middle trunk will be labeled with "anterior" on top and "posterior" on bottom. The inferior trunk divisions will be labeled the opposite.

• 4

  Join the three posterior divisions together to form the "posterior cord." Join the anterior division of the superior trunk with the anterior division of the middle trunk to form the "lateral cord," and continue the anterior division of the inferior trunk to form the "medial cord."

• 5

  Draw another ">" shape coming off each of the three cords. Make sure they overlap so the lower line off the lateral cord meets up with the upper line of the medial cord, and the two lines coming from the posterior cord go on each side of that junction.

• 6

  Label these branches as follows: the lateral (top) branch of the lateral cord is the musculocutaneous nerve. The joining of the medial branch of the lateral cord and the lateral branch of the medial cord is called the median nerve. The lateral (top) branch of the posterior cord is the axillary nerve, and the medial branch of the posterior cord is the radial nerve. Finally, the medial branch of the medial cord is the ulnar nerve.