nerves Flashcards
which ramus of the spinal nerve supply the limbs
ventral ramus
which spinal nerves contribute to the brachial plexus
C5, C6, C7, C8 and T1
what is a prefixed brachial plexus and a post fixed brachial plexus
pre - brachial plexus arises a little higher C4-C8
post - brachial plexus arises a little lower C6-8, T1-2
which ventral rami roots contribute to which trunks
C5 and 6 form superior trunks
C7 form middle trunk
C8 and T1 form inferior trunk
how do the trunks divide
they divide into anterior and posterior divisions
anterior divisions of the brachial trunks go to supply…
flexor muscles and the skin overlying them
posterior divisions of the brachial trunks go to supply…
extensor muscles and the skin overlying them
what do the divisions of the brachial plexus then divide into and how are they named
lateral, posterior and medial cords
named according to their relationship with the axillary arter
which brachial plexus divisions contribute to the lateral cord
anterior division of upper trunk and anterior division of middle trunk
which brachial plexus divisions contribute to the medial cord
the anterior division of the lower trunk
which brachial plexus divisions contribute to the posterior cord
all 3 posterior divisions come together to form the posterior cord
how do you orientate yourself with the terminal branches of the brachial plexus
the branch that pierces coracobrachialis is the musculocutaneous nerve (branch of the lateral nerve)
the median nerve arises from…
the medial and lateral roots of the medial and lateral cords
the ulnar nerve arises from…
the medial cord
which terminal branches of the brachial plexus supply the anterior compartment of the forearm
median and ulnar
which terminal branches of the brachial plexus supply the posterior compartment of the arm
radial
what are the ventral rami that contribute to the musculocutaneous nerve
C5-C7
what is the arrangement of the musculocutaneous nerve running down the arm
has biceps above it and coracobrachialis deep to it
which muscles does the musculocutaneous nerve supply
biceps
coracobrachialis
brachialis
what happens when the musculocutaneous nerve gets to the elbow
finishes with its motor supply
becomes superficial just lateral to the tendon of biceps –> changes its name to the lateral cutaneous nerve of the forearm (supplies skin overlying it)
which ventral rami contribute to the ulnar nerve
C8 and T1 and some contribution from C7
3 branches of the medial cord
ulnar nerve
medial cutaneous nerve of the arm
medial cutaneous nerve of the forearm
route of the ulnar nerve
descends in the anterior compartment of the arm medial to the artery, and then passes behind the medial epicondyle, between the two heads of of FCU, under the cover of FCU –> passes superificial to the flexor retinaculum –> palm of the hand
how can you damage the ulnar nerve
fracture of the medial epicondyle
which muscles of the upper limb does the ulnar nerve supply
- FCU
- medial half of FDP
- hand - splits to supply the superficial and deep neurovascular bundles
which dermatome does the ulnar nerve supply
the medial one and a half fingers front and back and the corresponding parts of the hand (C8)
which cords does the median nerve arise from
the medial root of the medial cord and the lateral root of the lateral cord
which ventral rami contribute to the median nerve
C5, C6, C7, C8 and T1
what is the arrangement of structures in the cubital fossa
tendon of biceps, brachial artery and then median nerve (most medial)
route of median nerve
crosses diagonally to the medial side of the artery and then slips beneath the fibrous arch of FDS lying in between the middle of the superficial and deep muscles –> cubital fossa –> straight down the middle of the forearm –> beneath flexor retinaculum
which muscles of the forearm does the median nerve supply
all of the anterior forearm that werent supplied by the ulnar nerve
- Pt, FCR, PL, FDS, PQ, PL and other half of FDP
which muscles of the hand does the median nerve supply
only the thenar eminence muscles and the lateral two lumbricals that are associated with the FDP that it supplies
which ventral rami contribute to the posterior cord
all of them
what are the two branches of the posterior cord
axillary and radial nerves
what is the anatomical relationship between axillary nerve, radial nerve and teres major
axillary nerve emerges onto the back of the arm above teres major, while radial nerve emerges below it
which ventral rami contribute to the axillary and radial nerves
axillary - C5-C6
radial - C5-T1
what does the axillary nerve supply
deltoid and teres minor
skin on the military badge area
what structure does a inferior dislocation of the shoulder joint endanger
axillary nerve
route of radial nerve
emerges onto posterior compartment beneath teres major and then runs diagonally across the posterior aspect of the humerus from medial to lateral and tucks under brachioradialis
what fracture endagers the radial nerve
fracture to the humerus in the midshaft
what does the radial nerve suply
the posterior aspect of the whole posterior forearm and the posterior side of the first 3.5 fingers except the nail beds
branches of the radial nerve
posterior interosseous nerve/deep branch
superficial branch
why is your radial nerve not endangered when you fracture your humerus
because the radial nerve gives off its branches right after the axilla
difference in innervation of the posterior interosseous nerve and the superficial branch of the radial nerve
posterior interosseous nerve - supplies posterior muscles
superficial branch - supplies the area of skin on the posterior surface of the hand of the first 3.5 fingers
Anteriorly: down the lateral side of your arm… from shoulder, mid shaft and elbow.. which nerves innervate there
axillary
radial
musculocutaneous
what innervates the anterior medial side of the upper limb
medial nerve
moving from the shoulder, down the lateral side of the arm and then back up the medial side… what are the ventral rami contributions??
C4, C5, C6, C7. C8, T1 and T2
ventral rami contributing to flexion and extension at the elbow
flexion - C5 and C6
extension - C7 and C8
what ventral rami contribute to pronation and supination
pronation - C7 and C8
supination - C6
what ventral rami contribute to waving (abduction and adduction of wrist)
T1
what ventral rami contribute to abduction and adduction of the shoulder joint
abduction - C5
adduction - C6-8
