Brachial Plexus
Cutaneous Nerves
The sensory supply to a region of the body of a terminal nerve which can supply sensory nerves from multiple spinal nerves.
What nerves are considered to be infraclavicular branches?
Lateral pectoral, medial pectoral, Upper subscapular, thoracodorsal, lower supscapular, axillary, musculocutaneous, radial, median, ulnar, medial antebrachial cutaneous , and medial brachial cutaneous nerve.
What muscles does the dorsal scapular nerve innervate? (C5)
Levator scapulae, rhomboid major, rhomboid minor
What are the divisions of the brachial plexus called?
Anterior and Posterior divisions
Remember that the nerves of the terminal branch wrap around the _______________.
Axillary artery
What nerve innervates the Deltoid and teres minor? What is its cutaneous branch?
Axillary nerve (C5, C6) Su[erior lateral brachial cutaneous nerve
What are the peripheral nerves of the brachial plexus? (hint: the terminal branches)
Axillary nerve, Radial nerve, Musculocutaneous nerve, Median nerve, and Ulnar nerve
Where is the brachial plexus located?
Between the middle and anterior scalene muscles of the neck
What are the roots of the brachial plexus?
C5, C6, C7, C8, T1
What spinal nerves make up the brachial plexus?
C5, C6, C7, C8, T1
Ulnar nerve (C8, T1)
Innervates: flexor carpi ulanris, flexor digitorum profundus (half), plamaris brevis, flexor digiti minimi, abductor digit minimi, abductor digiti minimi, opponens digiti minimi, adductor pollicis, palmar interosseous muscles, dorsal interosseous muscles, 3rd and 4th lumbricals Cutaneous branches, deep branch of ulnar nerve, dorsal branch of ulnar nerve, dorsal digital nerves, common palmar digital nerves, proper palmar digital nerves
What are the two cutaneous nerves? (C8, T1)
Medial brachial cutaneous nerve and the medial antebrachial cutaneous nerve....area located on the medial side of the arm
Which nerves branch off the medial cord?
Medial pectoral nerve, medial brachial cutaneous nerve, Medial antebrachial cutaneus nerve
Dermatome
Refers to the region of skin innervated by GSA axons from a single spinal nerve root. useful in neurology for finding the site of damage to the spine
What nerve innervates the pronator muscles, palmaris longus, flexor muscles, abductor pollicis brevis, opponens pllicis, 1st and 2nd lumbricals? Cutaneous branches?
Median nerve: lateral cord (C6, C7) Medial cord (C8, T1) recurrent palmar branch of median nerve, common palmar digital nerves, and proper palmar digital nerves.
What muscle does the long thoracic nerve innervate? (C5, C6, C7)
Serratus anterior
What muscle does the nerve to subclavius innervate? (C5, C6)
Subclavius
What are the trunks of the brachial plexus called?
Superior, middle, and inferior trunks
What muscles does the suprascapular nerve innervate? (C5, C6)
Supraspinatus and infraspinatus
What muscle does the upper subscapular nerve innervate? (C5)
subscapularis
Which nerves branch off at superior trunk?
suprascapular nerve and nerve to subclavius
What muscles does the lower subscapular nerve innervate? (C6)
teres major and suscapularis
Which nerves branch off the posterior cord?
Upper subscapular nerve, thoracodorsal nerve, and Lower subscapular nerve
What nerve branches off the lateral cord?
lateral pectoral nerve
What muscle does the thoracodorsal nerve innervate? (C6-C7)
latissimus dorsi
Myotome
muscle mass that receives innervation from a single spinal nerve
What nerve innervates the coracobrachialis, biceps brachii, and brachialis? What is its cutaneous branch?
musculocutaneous nerve (C5, C6, C7) Lateral antebrachial cutaneous nerve
What are the names of the nerves that branch off at the root of the brachial plexus? Which one branches off C5 ONLY? Which one branches off C5 and is later joined by C6, and C7?
Dorsal Scapular nerve and Long thoracic nerve Dorsal Scapular nerve Long thoracic nerve
What nerves are part of the supraclavicular branches?
Dorsal scapular nerve, nerve to subclavius, suprascapular nerve, and long thoracic nerve
What are the cords of the brachial plexus called?
Lateral, posterior, and medial cords
What are the parts of the brachial plexus? Can you name them in order?
Root --> Trunks --> Divisions --> Cords --> Terminal branches (peripheral nerves)
What is the function of the brachial plexus?
To provide innervation to the muscles of the upper limp and surrounding tissues
What muscle does the lateral pectoral nerve innervate? (C5-C7)pect
pectoralis major
What muscles does the medial pectoral nerve innervate? (C8, T1)
pectoralis major and pectoralis minor
What are the common brachial plexus variations
prefixed brachial plexus: C4-C8 postfixed brachial plexus: C6-T2
Cutaneous Branches of posterior Rami
Provides cutaneous sensory innervation (GSA) to the back
What nerve innervates the Brachialis, tricepts brachii, anconeous, supinator, brachiradialis, Extensor muscles, and abductor? What are its cutaneous branches?
Radial nerve (C5-C8, T1) inferior lateral brachial cutaneous nerve, posterior brachial cutaneous nerve, posterior antebrachial cutaneous nerve, superfical branch of radial nerve