Branchial Plexus and Compartments Flashcards
where on the spine does the brachial plexus join together ?
C5 - T1
what are the five portions of the brachial plexus ?
root
trunks
divisions
cords
branches
what’s an acronym to remember the five portions of the brachial plexus ?
really thirsty drink cold beer
what are the roots of the brachial plexus ?
C5 - T1
what are the trunks of the brachial plexus ?
upper, middle and lower
what are the divisions of the brachial plexus ?
anterior and posterior
what are the cords of the brachial plexus ?
lateral, medial and posterior
what are the branches of the brachial plexus ?
- axillary
- radial
- musculocutaneous
- median
- ulnar
what muscles are innervated by the axillary nerve ?
teres minor and deltoid (C5 - C6)
what muscles are innervated by the radial nerve ?
posterior compartments (C5 - T1)
what muscles are innervated by the musculocutaneous nerve ?
arm flexors (C5 - C7)
what muscles are innervated by the median nerve ?
forearm flexors (C5 - T1)
what muscles are innervated by the ulnar nerve ?
forearm flexors (C8 - T1)
in the brachial plexus, between extensors and flexors, which face the front/back ?
extensors to the back and flexors to the front
which brachial plexus division are extensors ?
radial and axillary
which brachial plexus divisions are flexors ?
musculocutaneous, median and ulnar
which vertebral bodies combine to form the upper trunk ?
C5 - C6
which vertebral bodies combine to form the middle trunk ?
C7 (on its own)
which vertebral bodies combine to form the lower trunk ?
C8 - T1
what nerve comes off of the upper trunk ?
the supra scapular
what nerve comes off of the lateral cord ?
lat. pectoral
what nerve comes off of the posterior nerve ?
thoracodorsal, upper and lower subscapular
what nerve comes off of the medial cord (anterior division) ?
med. pectoral
when C5, C6 and C7 roots all come together, what does that form ?
long thoracic
what nerve comes off of the medial cord ?
med cutaneous arm and med cutaneous forearm
what branch comes off of the lateral cord ?
musculocutaneous nerve
what branch comes off of the posterior cord ?
axillary and radial nerve
what branch comes off of the medial branch ?
ulnar nerve
what branch comes off of both the lateral and medial branch ?
median nerve
where are the extensor compartment nerves anatomically located ?
posterior aspect of the upper limb
what two muscles does the axillary innervate ?
deltoids and teres minor
why is the radial nerve so important ?
essentially does everything on the extensor side of the upper limb
what nerve only innervates muscles in the arm ?
musculocutaneous
what two nerves split a lot of the muscles they innervate ?
median and ulnar
the coracobrachialis, biceps branchii and brachialis are all innervated by what nerve ?
musculocutaneous
what nerves are multi segmental (meaning that information from multiple roots recombined throughout the plexus to form a single nerve)
plexus and peripheral nerves
which two nerves are formed from C5 - T1 ?
radial and median
what are the two brachial plexus injuries ?
- klumpke paralysis
- erb-duchenne palsy
which roots does erb-duchenne palsy affect ?
C5 - C6
which roots fors klumpke paralysis affect ?
(C8 - T1)
what is erb-duchenne palsy ?
excess angle between neck + shoulder
what is klumpke paralysis ?
excess angle between arm and body, usually overhead
what brachial plexus injury is describes by “excess angle between arm and body, usually overhead”
klumpke paralysis
what brachial plexus injury is describes by “excess angle between neck + shoulder”
erb-duchenne palsy
what is the outcome of erb-duchenne palsy ?
waiter’s tip
- musculocutaneous + axillary nerve impaired
- paralysis of : deltoid, biceps + brachialis
- limb medial rotation + adduction, extended elbow, pronated foreaem
what is the outcome of klumke paralysis ?
poor ulnar nerve function
- decease arm and hand movement
- loss of sensation to medial, distal hand
between klumpke paralysis and erb-duchenne palsy, which is more common ?
erb-duchenne palsy is way more common
what is the main function of the brachial plexus ?
provides sensory and motor innervation to the upper limb (anything to do with upper limb)
how are limb compartments seperated ?
by fibrous sheaths
what layers around the outside of the whole shank ?
fascia layer
is flexion of the arm towards the front or back ?
front
is flexion of the arm towards the front or back ?
back
in the upper body are flexors / extensors the anterior or posterior part of the body ?
flexors = anterior
extensors = posterior
what nerve is going to supply everything on the medial aspect (pinky side) ?
ulnar nerve
what muscles does the median nerve innervate ?
- pronator teres
- flexor pollicis longus
- pronator quadratus
- thenar muscles
- lumbricals to digits 2, 3
- flexor digitorum profundus
- flexor digitorim superficialis
- palmaris longus
- flexor carpu radialis
what muscles does the musculocutaneous nerve innervate ?
- biceps brachii
- brachialis
- coracbrachialis
what muscles does the ulnar nerve innervate ?
- flexor carpi ulnaris
- flexor digitorum profundus
- palmar interossei
- adductor pollicis
- dorsal interossei
- palmaris brevis
- hypothenar muscles
- lumbricals to digits 4 and 5
what muscles does the radial nerve innervate ?
- triceps brachii (lateral, long and medial head)
- supinator
- extensor carpi ulnaris
- extensor digiti minimi
- extensor digitorum
- brachioradialis
- extensor carpi radialis longus
- extensor carpi radialis brevis
- posterior interosseous nerve
- abductor pollicis longus
- extensor pollicis brevis, longus
- extensor indicis
what is compartment syndrome ?
fibrous sheaths surrounding compartments dont stretch, if damage + swelling occurs pressure can build up
what are two common sites of compartment syndrome ?
shank and forearm
what are the four compartments in the leg ?
- anterior
- lateral
- deep
- posterior
what can cause compartment syndrome ?
chronic overuse
what is the 5 step cycle of compartment syndrome ?
pain, tauma/increased blood flow, swelling/bleeding, increased pressure, decreased blood/nerve supply
what is fasciotomy ?
term for the surgery that’s performed to release the pressure inside of these compartments
what is the term used for the surgery that is performed to release the pressure inside of these compartments
fasciotomy
what do compartments do ?
define groups of muscles within the limbs
how do muscles within a compartment typically act ?
synergistically on a joint
how is each compartment supplied ?
each compartment is supplied by it’s own neuromuscular bundle (there is a common nerve, artery and vein that supplies that group of muscles)
