• Describe the Structure of the brachial plexus

R-read - Roots

T-that - Trunk

D-damn - Divisions

C-cadaver - Chord

B-Book - Branches

there is a lateral, posterior and medial strand of the brachial plexus and within them they have different sections as detailed above ^

the Brachial plexus has 3 main sections but within the sections there are branches that branch from specific sections of certain parts of the brachial plexus, the main 3 sections are the Lateral posterior and medial strands they start off as Roots from spinal nerves then 2 spinal nerves join to create a trunk, after this divisions occur where there is a cross over of one or more spinal nerves to each section of the brachial plexus (the crossover just adds to the section it touches it does not take away from what was already present) after divisions chords are present which include the spinal nerves from the divisions that just passed. after chords the branches occur, the lateral and medial sections continue onwards and also form a midline division creating an M shape the lateral straight is connected to the musculocutaneous nerve

the middle straight (made from division) connects the median nerve

the medial straight connects the ulnar nerve

the original posterior section of the brachial plexus then branches off into the radial and axillary nerve which are posterior nerves

• Describe features of the Brachial plexus – from roots to terminal branches

Lateral segment

begins roots with C5 and C6 then becomes a lateral trunk when C6 and C5 nerves join together (C5 C6 lateral trunk) the trunk then becomes divisions in the case of the lateral segment the nerves of the lateral trunk (C5 & C6) diverge to join the posterior segment and the posterior C7 nerve joins the lateral segment. after division has taken place chords are established which include every spinal nerve that has joined the segment to this point and in the case of the lateral chord this includes C7,C5,C6 the lateral segment then continues to become the musculocutaneous nerve and also has a division to a middle point (joins with the medial nerve) to create the median nerve

Posterior Segment

roots begin with C7 the posterior trunk includes only C7 spinal nerve, at divisions the C7 spinal nerve joins the lateral chord and the lateral division including C5 & C6 joins the posterior segments chord, simultaneously the medial division (from the medial segment) joins the posterior segment which includes T1 and C8 nerves resulting in the posterior chord including T1,C8,C7,C5,C6 the posterior chord then becomes two branches of the posterior segment creating the radial and axillary nerves