Brachial plexus Flashcards
the brachial plexus contains nerve roots from where
anterior (ventral) rami of C5-T1
axillary nerve is what roots
C5 C6
what would the implication of damaged C5 be in terms of the axillary nerve and deltoid
C6 fibres would still allow some innervation of deltoid - abduction of arm would be weaker but still possible
the brachial plexus is found where
in the axilla
the brachial plexus originates where
nerves originate from C5-T1 nerve roots in the neck and upper thorax (for T1)
where do the brachial plexus nerve roots lie
posterior triangle of neck
the brachial plexus nerve roots pass between what muscles
anterior and middle scalene
what innervation do the nerve roots of the brachial plexus receive
grey rami communicantes so carry post-ganglionic sympathetic fibres
what forms the superior trunk
C5 and C6
what forms the middle trunk
C7
what forms the inferior trunk
C8 and T1
the trunks of the brachial plexus pass where
over rib 1 and enter axilla
what makes up the phrenic nerve
C3 and C4 fibres from above the brachial plexus but also includes C5 fibres from C5 root
what other nerve gets its C5 component directly from this root
dorsal scapular nerve
what is the long thoracic nerve derived from
directly from C5 6 7 roots
what trunks give rise to nerves
middle and inferior do not, superior does
what nerves does the superior trunk form
suprascapular nerve
nerve to subclavius
the phrenic nerve innervates what
diaphragm
the dorsal scapular nerve innervates what
rhomboid major and minor
long thoracic nerve innervates what
serratus anterior
suprascapular nerve supplies
infraspinatus and supraspinatus
suprascapular nerve and nerve to subclavius roots
C5 6
nerve to subclavius innervates what
subclavius muscle
each trunk divides into an anterior and posterior ____ as they enter the axilla
division
all of the posterior divisions form the
posterior cord
the anterior division from the superior and middle trunks forms what
lateral cord
anterior division from inferior trunk forms
medial cord
what forms the posterior cord
all the posterior divisions of the trunks
what forms the lateral cord
anterior division of superior and middle trunk
what forms the medial cord
anterior division of inferior trunk
are there any peripheral nerves direct from the divisions
no
the 3 posterior divisions are the ultimate pathway for what
nerves assoc. with the posterior compartments of the arm and forearm
the 3 anterior divisions are the ultimate pathway for what
nerves assoc. with anterior compartments of the arm and forearm
what nerves will the anterior divisions form
musculocutaneous median and ulnar nerves
what nerves will the posterior divisions form
radial nerve and axillary nerve
what is the nerve of the posterior compartment of the arm and forearm
radial nerve
the cords are named dependent on what
relation to the axillary artery
which cord lies closer to the humerus
lateral cord