brachial plexus Flashcards
Components of Brachial Plexus
VPR of C5-C8 and greater part of T1
Small contri-butions from C4 and T2
Contributions to the brachial plexus from the ventral primary rami of C4 and T2 can vary
Components of Brachial Plexus - C4 is large
This is a prefixed type of plexus.
T2 is frequently lacking
T1 contribution is reduced.
Components of Brachial Plexus - C4 is reduced or absent
postfixed type of plexus.
C5 contribution is usually reduced
T1 is larger than normal
T2 is always present
Organization of Brachial Plexus
Remember To Drink Cold Beer
Roots
Trunks
Divisions
Cords
Terminal Branches
Roots
VPR of C5-T1 (small contributions from C4 & T2)
Trunks
Upper - C5, C6
Middle - C7
Lower - C8, T1
Divisions
Anterior
Posterior
Terminal Branches
Musculocutaneous nerve
Median nerve
Ulnar nerve
Axillary nerve
Radial nerve
The trunks and divisions of the brachial plexus are located
in the posterior triangle of the neck, emerging from between scalenus anterior and scalenus medius.
where does the subclavian artery arrise
posterior triangle of the neck
between scalenus anterior and scalenus medius.
neurovascular compression syndrome result from
if the scalenus anterior and scalenus medius spasm, they may compress the nerves and artery
clavicle and subclavius muscle and the brachial plexus
The brachial plexus then passes behind them
what muscle does the brachial plexus lie on
upper part of serratus anterior and subscapularis muscles
C5 and C6 receive gray rami from
middle cervical ganglion
C7 and C8 receive gray rami from
the cervicothoracic ganglion
T1 receives gray rami from and sends white rami to
the cervicothoracic ganglion
Supraclavicular branch of the brachial plexus
branches arising from the roots or trunks (proximal to the clavicle),
Infraclavicular branch of the brachial plexus
branches arising from the cords (distal to the clavicle)
Supraclavicular Branches names
Dorsal scapular nerve
Long thoracic nerve
Suprascapular nerve
The nerve to subclavius
Dorsal Scapular Nerve segmental
C5 VPR
Dorsal Scapular Nerve pierces what
pierces scalenus medius
Dorsal Scapular Nerve runs with what nerve
runs with the dorsal scapular artery to the vertebral border of the scapula
Dorsal Scapular Nerve innervation
twig to levator scapulae
then runs deep to rhomboids major and minor to innervate both of those muscles.
Long Thoracic Nerve segmental
C5, C6, C7 VPR
Long Thoracic Nerve innervates
serratus anterior
Long Thoracic Nerve runs with
lateral thoracic artery
Suprascapular Nerve segmental
C5, C6
Suprascapular Nerve arrise from what part of the brachial plexus
upper trunk
Suprascapular Nerve path
runs deep to trapezius –> suprascapular notch under the superior transverse scapular ligament –> supraspinous fossa –> spinoglenoid notch –> infraspinous fossa
Suprascapular Nerve run with
suprascapular artery
travels over the transverse scapular ligament
Suprascapular Nerve muscular innervation
supraspinatus and infraspinatus
Suprascapular nerve cut innervation
sensory branches to the shoulder joint, AC joint and scapula
infraclavicular branches names
lateral and medial pectoral nerves
upper and lower subscapular nerves
thoracodorsal nerve
axillary nerve
musculocutaneous nerve
medial cutaneous nerves of the arm and forearm
median nerve
ulnar nerve
radial nerve
Lateral Pectoral Nerve segmental
C5, C6, C7
Lateral Pectoral Nerve from what part of the brachial plexus
the lateral cord
Lateral Pectoral Nerve innervates
deep surface of pectoralis major.
forms a loop with the medial pectoral nerve to supply pectoralis minor.
Medial Pectoral Nerve segmental
C8, T1
Medial Pectoral Nerve from what part of the brachial plexus
the medial cord
Medial Pectoral Nerve innervation
supplies pectoralis minor.
also sends some branches to supply pectoralis major.
Upper and Lower Subscapular Nerves
segmental
C5 and C6
upper subscapular nerve from what part of the brachial
posterior cord
upper subscapular innervation
subscapularis
lower subscapular nerve from what part of the brachial
posterior cord
lower subscapular nerve innervation
teres major and subscapularis.
Thoracodorsal Nerve segmental
C6, C7, C8
Thoracodorsal Nerve from what part of the brachial
posterior cord between the upper and lower subscapular nerves