Brachial plexus

The brachial plexus may look difficult to draw, but here’s a shorthand way to draw the brachial plexus really fast.

Now that the nerves are all drawn, let’s begin labeling the brachial plexus, starting with the cervical and thoracic nerves - C5, C6, C7, C8, & T1.

The brachial plexus is also divided into roots, trunks, divisions, cords, and terminal branches.

The order can be remembered using the acronym “Remember To Drink Cold Beer.”

Then to remember the terminal branches, you can use the word “MARMU.” Which stands for the musculocutaneous, AXILLARY, radial, median, and ulnar nerves respectively.

Next, we can start labeling the collateral nerves starting with those that branch off the roots.

The dorsal scapular nerve branches off of the C5 root, and the long thoracic nerve arises from the C5, C6, and C7 roots.

The superior trunk has two collateral branches, the suprascapular and subclavius nerves.

And the cords have a total of 7 collateral branches.

The lateral cord gives rise to the lateral pectoral nerve.

The POSTERIOR cord gives rise to the upper, middle, and lower subscapular nerves.

And the medial cord gives rise to the medial pectoral, medial cutaneous nerve of the arm, and the medial cutaneous nerve of the forearm.

The nervous system is divided into the central nervous system, which includes the brain and spinal cord, and the peripheral nervous system, which is further divided into the somatic and the autonomic nervous systems.

Broadly speaking, the nervous system is split into an afferent and an EFFERENT division.

The afferent division brings sensory information from the outside into the central nervous system, and includes visual receptors, auditory receptors, and touch receptors.

On the other hand, the EFFERENT division brings motor information from the central nervous system to the periphery, ultimately resulting in contraction of skeletal muscles to trigger movement through the somatic nervous system, as well as contraction of the smooth muscles to trigger activity of the glands and organs through the autonomic nervous system.