NEUROVASCULAR SUPPLY OF THE UPPER LIMB Flashcards
what is the brachial plexus?
a complex inter communicating network of nerves formed by spinal nerves C5, C6, C7, C8, and T1. supplies the upper limb
where does the brachial plexus supply? exceptions?
- supplies all SENSORY information to the upper limb and most of the axilla — except for an area of the medial upper arm and axilla (supplied by the intercostobrachial nerve T2)
- supplies all MOTOR information to the muscles of the upper limb and shoulder girdle — except for the trapezius (supplied by the spinal accessory nerve XI)
what is the brachial plexus divided into?
roots, trunks (each trunk has anterior and posterior divisions) , divisions, cords
what forms the upper/superior trunk?
the roots of C5 and C6
what forms the middle trunk?
the roots of C7
what forms the lower/inferior trunk?
the roots of C8 and T1
what forms the lateral cord?
the anterior divisions of the upper and middle trunks
what forms the medial cord?
the anterior division of the inferior trunk continues as the medial cord
what forms the posterior cord?
the posterior divisions of all trunks form the posterior cord
what forms the long thoracic nerve?
formed by the posterior aspect of the ventral rami of C5, C6, and C7
where does the long thoracic nerve pass?
it passes through the apex of the axilla posterior to the other components of the brachial plexus
branches of what artery supplies the brachial plexus?
the subclavian artery
blood supply of the roots of the brachial plexus
vertebral artery, anterior and posterior spinal arteries
blood supply of the trunks and divisions of the brachial plexus
ascending and deep cervical arteries, superior intercostal artery
blood supply of the cords of the brachial plexus
axillary artery
describe the musculocutaneous nerve
= a major peripheral nerve of the upper limb
= the terminal branch of the lateral cord of the brachial plexus
- nerve roots: C5-C7
- emerges at the inferior border of the pectoralis minor
what are the motor and sensory functions of the musculocutaneous nerve?
- MOTOR = innervates the muscles in the anterior compartment of the arm (BBC)
- SENSORY = the nerve gives rise to the lateral cutaneous nerve of the forearm which innervates the skin of the anterolateral aspect of the forearm
describe the axillary nerve
= a major peripheral nerve of the upper limb
= a direct continuation of the posterior cord from the brachial plexus
- nerve roots: C5 and C6
- formed within the axilla
- it is posterior to the axillary artery in the axilla and anterior to the subscapularis muscle
- exits axilla at the inferior border of the subscapularis via the quadrangular space
- passes medially to the surgical neck of the humerus where it divides into 3 terminal branches