Limbs Arm Pathways Notes

1. Pathways of the Arm 
1. Blood Supply 
1. Aorta  aortic arch  L subclavian or brachiocephalic to R subclavian  axillary  brachial 
1. Ulnar collaterals 
2. Deep brachial 
1. Middle collateral 
2. Radial collateral 
2. Blood Drainage 
1. Basilic or cephalic  axillary  subclavian  brachiocephalic  SVC  RA
3. Nerve Supply 
1. Afferent 
1. Somatic 
1. Posterior and lateral arm via the radial nerve  posterior cord  superior, middle, and inferior trunks  C4-T1  dorsal roots  spinal cord
2. Anterior arm via medial cutaneous of the fore arm  medial cord  inferior trunk  C8-T1
3. Medial arm via medial cutaneous of arm  medial cord  inferior trunk  C8-T1
2. Autonomic 
1. N/A
2. Efferent 
1. Somatic 
1. Spinal cord C4-T1  ventral roots  brachial plexus  
1. Superior and middle trunks  lateral cord  musculocutaneous  muscles of anterior arm 
2. Autonomic 
1. Sympathetic 
1. IML of spinal cord  ventral roots  ventral rami of cervical plexus  white rami  cervical sympathetic ganglion  Ach synapse to postganglionic fiber  gray rami  ventral rami of brachial plexus  
1. Superior and middle trunks  lateral cord 
1. Musculocutaneous  anterior muscles 
2. Superior, middle and inferior trunks  posterior cord  radial nerve  posterior and lateral muscles, skin 
3. Inferior trunk  medial cord 
1. Medial cutaneous of forearm  anterior skin 
2. Medial cutaneous of arm  medial skin