BRACHIAL PLEXUS
DISSECTION
After cleaning the branches of the axillary artery, proceed to clean the brachial plexus. It is formed by the ventral primary rami of the lower four cervical (CS—C8) and the first thoracic (T1) nerves. The first and second parts of the axillary artery are related to the cords; and third part is related to the branches of the plexus. Study the description of the brachial plexus before proceeding further.
The origin of the plexus may shift by one segment either upward or downward, resulting in a prefixed or postfixed plexus respectively.
In a prefixed plexus, the contribution by C4 is large and that from T2 is often absent.
The plexus consists of roots, trunks, divisions, cords and branches.
Roots
These are constituted by the anterior primary rami of spinal nerves C5—C8 and T1, with contributions from the anterior primary rami of C4 and T2.The origin of the plexus may shift by one segment either upward or downward, resulting in a prefixed or postfixed plexus respectively.
In a prefixed plexus, the contribution by C4 is large and that from T2 is often absent.
Comments
Post a Comment
If you have any doubts,please let me know.