The Brachial Plexus
By Samwel A Odede Ochieng
, Origin and formation of the brachial plexus
• The brachial plexus originates from the anterior rami of C5, C6,C7, C8 and T1. The anterior r
of these nerve roots unite in an organized manner to form trunks. C5 and C6 unite to form the
upper trunk, C8 and T1 unite to form the lower trunk while C7 remains as the only middle tru
• Each of the three trunks formed divide into an anterior and posterior divisions. The anterior
divisions of the upper trunk and the middle trunk unite to form the lateral cord. The anterior
division of the lower trunk remains alone as the medial cordand all the posterior divisions form
posterior cord.
• From the above description, we can see that the medial cord receives fibres from C8 and T1. E
though this is the case it is important to note that the medial cord frequently receives fibres fro
C7.
• There are two other variations in the formation of brachial plexus. The two variations are calle
prefixed plexus and a post fixed plexus.
By Samwel A Odede Ochieng
, Origin and formation of the brachial plexus
• The brachial plexus originates from the anterior rami of C5, C6,C7, C8 and T1. The anterior r
of these nerve roots unite in an organized manner to form trunks. C5 and C6 unite to form the
upper trunk, C8 and T1 unite to form the lower trunk while C7 remains as the only middle tru
• Each of the three trunks formed divide into an anterior and posterior divisions. The anterior
divisions of the upper trunk and the middle trunk unite to form the lateral cord. The anterior
division of the lower trunk remains alone as the medial cordand all the posterior divisions form
posterior cord.
• From the above description, we can see that the medial cord receives fibres from C8 and T1. E
though this is the case it is important to note that the medial cord frequently receives fibres fro
C7.
• There are two other variations in the formation of brachial plexus. The two variations are calle
prefixed plexus and a post fixed plexus.
