Week 10: Nerve Supply of the Upper Limb Flashcards
What is the definition of a spinal segment?
A section of the spinal cord with its associated pair of (left and right) nerve roots
What nerves are found in the dorsal root?
sensory nerves
What nerves are found in the ventral root?
motor nerves
What nerves are in the dorsal ramus?
sensory and motor nerves
What nerves are in the ventral ramus?
sensory and motor nerves
What muscles do the dorsal ramus supply?
back muscles and overlying skin
What muscles do the ventral ramus supply?
anterior trunk and limbs and the overlying skin
What nerves are in the spinal (mixed) nerve?
sensor and motor nerves
What are the features of the brachial plexus?
ventral rami, trunks, divisions, cords, branches
What are the ventral rami?
C5, C6, C7, C8, T1
Where do the ventral rami exit the neck?
between the anterior and middle scalene muscles
What are the three different trunks of the brachial plexus?
upper, middle, lower
Where are the trunks of the brachial plexus found?
between the scalene muscles and inferior to the clavicle
How many divisions are there?
2 from each trunk, one anterior and one posterior
Where do the divisions of the brachial plexus occur?
superior to the clavicle
What are the cords of the brachial plexus called?
lateral, posterior and medial
Which divisions make up the lateral and medial cords?
anterior
What are the branches of the brachial plexus?
musculocutaneous nerves, median nerve, ulnar nerve, axillary nerve and radial nerve
What is the root value of the musculocutaneous nerve?
C5,6,7
What muscles do the musculocutaneous nerve suply?
coracobrachialis, biceps brachii, brachialis
What is the root value of the median nerve?
C5,6,7,8, T1
What muscles does the median nerve supply?
pronator teres, pronator quatratus, flexors of the wrist, fingers and thumb (EXCEPT flexor carpi ulnaris and medial half of flexor digitorum profundus), thenar muscles and lateral 2 lumbricals
What is the root value of the ulnar nerve?
C8, T1
What muscles does the ulnar nerve supply?
flexor carpi ulnaris and medial half of flexor digitorum profundus, intrinsic muscles of the hand (hypothenar muscles, medial 2 lumbricals, adductor pollicis and all interossei)
What is the root value of the radial nerve?
C5,6,7,8 T1
What muscles do the radial nerve supply?
triceps brachii, brachioradialis, anconeus, supinator, extensors of the wrist and fingers, extensors of the thumb, abductor pollicis longus
What is the root value of the axillary nerve?
C5,6
What muscles does the axillary nerve supply?
deltoid and teres minor
What muscles does the dorsal scapula nerve supply?
rhomboid minor and major and levator scapulae
What muscle does the long thoracic nerve supply?
serratus anterior
What is the root value of the suprascapular nerve?
C5,6
What muscles does the suprascapular nerve supply?
supraspinatus and infraspinatus
What muscles do the upper and lower subscapular nerve supply?
subscapularis and teres major (lower subscapular nerve)
What muscles does he thoracodorsal nerve supply?
latissimus dorsi
What muscle does the lateral pectoral nerve supply?
pectoralis major
What muscles does the medial pectoral nerve supply?
pectoralis major and minor
What are the nerves that supply the shoulder joints?
axillary, suprascapular, subscapular, lateral pectoral, musculocutaneous
What are the nerves that supply the elbow joints?
musculocutaneous, median, ulnar, radial
What are the nerves that supply the wrist joints?
median, radial, ulnar
What is a myotome?
a group of muscles supplied by a single nerve root
What myotome produces abduction and lateral rotation of the shoulder?
C5
What myotomes produce adduction and medial rotation of the shoulder?
C6,7,8
What myotomes produces elbow flexion?
C5,6
What myotomes produces elbow extension?
C7,8
What myotomes produce supination of the radioulnar joints?
C6
What myotomes produce pronation of the radioulnar joints?
C7,8
What myotomes produce flexion and extension of the wrist?
C6,7
What myotomes produce flexion and extension of the digits?
C7,8
What myotomes produce adduction, abduction and opposition of the digits?
C8, T1
What is a dermatome?
an area of skin supplied by a single nerve root
What occurs when there is a nerve lesion?
nerve supply is lost in the regions distal to the lesion, the muscles, skin and joints in that area are no longer innervated
