the brachial plexus is the one of the nervous pleus in the body it provide the nerve supply for all structures in the upper limb

1. Brachial plexus and axillary
lymph node
Dr. Mohammed Mahmoud Mosaed

2. Functions of the nerves in the upper
limb
• The nerves entering the upper limb provide the
following important functions:
• 1. Sensory innervation to the skin and deep
structures, such as the joints;
• 2. Motor innervation to the muscles;
• 3. Influence over the diameters of the blood
vessels by the sympathetic vasomotor nerves;
• 4. Sympathetic secretomotor supply to the
sweat glands

3. The brachial plexus
• The brachial plexus is a complicated
plexus formed by the nerves at the root
of the neck
• This allows the nerve fibers derived
from different segments of the spinal
cord to be arranged and distributed
efficiently in different nerve trunks to
the various parts of the upper limb

4. The brachial plexus
• The brachial plexus is formed in the
posterior triangle of the neck by the
union of the anterior rami of the 5th ,
6th , 7th , and 8th cervical and the 1st
thoracic spinal nerves.
• The plexus can be divided into
roots, trunks, divisions, and cords.

5. • The plexus can be divided into roots,
trunks, divisions and cords.

8. Root of the brachial plexus
• The roots of the brachial plexus
is formed by the union of the
anterior rami of the 5th , 6th , 7th ,
and 8th cervical and the 1st
thoracic spinal nerves

10. Trunks of the brachial plexus
• The roots of C5 and 6 unite to
form the upper trunk.
• The root of C7 continues as the
middle trunk.
• The roots of C8 and T1 unite to
form the lower trunk.
• Each trunk then divides
into anterior and posterior
divisions.

11. Cords of brachial plexus
• The anterior divisions of the upper
and middle trunks unite to form the
lateral cord,
• the anterior division of the lower trunk
continues as the medial cord
• the posterior divisions of all three
trunks join to form the posterior cord

13. Relation of the cords to the axillary artery
• First part of the artery
• All three cords of the brachial plexus lie above and
lateral to the first part of the axillary artery.
• Second part of the artery
• The medial cord lies on the medial side of the second
part of the artery.
• The posterior cord lies behind the second part of the
artery,
• The lateral cord lies on the lateral side of the second
part of the artery.
• Third part of axillary artery
• Most branches of the cords that form the main nerve
trunks of the upper limb continue this relationship to
the artery in its third part

15. The axillary sheath
• The roots, trunks, and
divisions of the brachial
plexus reside in the lower
part of the posterior
triangle of the neck.
• The cords become
arranged around the
axillary artery in the axilla.
Here, the brachial plexus
and the axillary artery and
vein are enclosed in the
axillary sheath

16. Branches of the brachial plexus
• Roots
• Dorsal scapular nerve (C5)
• Long thoracic nerve (C5, 6, and 7)
• Upper trunk
• Nerve to subclavius (C5 and 6)
• Suprascapular nerve (supplies the
supraspinatus and infraspinatus
muscles)

17. Branches of the cords
• From the lateral cord
• musculocutaneous nerve (C5,6).
• lateral pectoral nerve (C5,6).
• lateral root of median nerve (C5,6,7).
• From the medial cord
• Medial pectoral nerve (C8 ,T1)
• Medial cutaneous nerves of arm (C8 ,T1).
• Medial cutaneous nerves of forearm(C8 ,T1).
• Ulnar nerve(C7, 8 ,T1)
• Medial root of median nerve (C8 ,T1).
• From the posterior cord
• Upper subscapular nerves (C5,6).
• lower subscapular nerves (C5,6).
• Nerve to latissimus dorsi (thoracodorsal nerve) (C 6, 7,8).
• Axillary nerve(C5,6).
• Radial nerve (C5,6,7,8,T1).

18. Branches of the Brachial Plexus
Found in the Axilla
• The nerve to the subclavius (C5 and 6)
supplies the subclavius muscle.
• The long thoracic nerve (C5, 6, and 7)
enters the axilla by passing down over the
lateral border of the first rib. It supplies the
serratus anterior muscle
• The lateral pectoral nerve supplies the
pectoralis major muscle
• The medial pectoral nerve supplies and
pierces the pectoralis minor muscle, and
supplies the pectoralis major muscle

19. • The musculocutaneous nerve arises from the
lateral cord of the brachial plexus, supplies the
coracobrachialis muscle
• The lateral root of the median nerve is joined by
the medial root to form the median nerve trunk
which passes downward on the lateral side of the
axillary artery. The median nerve gives off no
branches in the axilla
• The medial cutaneous nerve of the arm (T1) is
joined by the intercostobrachial nerve (lateral
cutaneous branch of the second intercostal nerve).
It supplies the skin on the medial side of the arm.
• The medial cutaneous nerve of the forearm
arises from the medial cord of the brachial plexus
and descends in front of the axillary artery

20. • The thoracodorsal nerve arises from the posterior
cord of the brachial plexus and runs downward to
supply the latissimus dorsi muscle.
• The axillary nerve is one of the terminal branches
of the posterior cord of the brachial plexus. It turns
backward and passes through the quadrangular
space. Having given off a branch to the shoulder
joint, it divides into anterior and posterior branches
• The radial nerve is the largest branch of the
brachial plexus and lies behind the axillary artery It
gives off branches to the long and medial heads of
the triceps muscle and the posterior cutaneous
nerve of the arm. The latter branch is distributed to
the skin on the middle of the back of the arm

21. Cutaneous innervation of the upper limbs
• Cutaneous innervation refers to the area of the skin which is supplied by a
specific nerve.
• Arm and shoulder
• Supraclavicular nerves
• upper lateral cutaneous nerve of arm (Axillary nerve).
• lower lateral cutaneous nerve of arm –(branch from radial nerve).
• Intercostobrachial nerve
• Medial cutaneous nerve of arm (from the medial cord)
• Posterior cutaneous nerve of arm
• Forearm
• Lateral cutaneous nerve of forearm (branch of musculocutaneous nerve).
• Medial cutaneous nerve of forearm (branch of medial cord).
• Posterior cutaneous nerve of forearm (branch of radial nerve).
• Hand
• Superficial branch of the radial nerve (dorsal digital branch)
• palmar digital branch from the median nerve
• Superficial branch of ulnar nerve (palmar digital branch)

23. Dermatomes of the upper limb

24. Lymph Nodes of the Axilla
The axillary lymph nodes (20 to 30 in
number) drain lymph vessels from:
• The lateral quadrants of the breast
• The superficial lymph vessels from the
thoracoabdominal walls above the level
of the umbilicus
• The vessels from the upper limb

25. The axillary lymph node
• The lymph nodes are arranged in 5 groups
• 1. Anterior (pectoral) group
• 2. Posterior (subscapular) group
• 3. Lateral group
• 4. Central group
• 5. Apical group:

26. • 1. Anterior (pectoral) group:
• Lying along the lower border of the pectoralis minor
behind the pectoralis major,
• these nodes receive lymph vessels from the lateral
quadrants of the breast and superficial vessels from the
anterolateral abdominal wall above the level of the
umbilicus.
• 2. Posterior (subscapular) group:
• Lying in front of the subscapularis muscle,
• these nodes receive superficial lymph vessels from the
back, down as far as the level of the iliac crests.
• 3. Lateral group:
• Lying along the medial side of the axillary vein,
• these nodes receive most of the lymph vessels of the
upper limb.

27. • 4. Central group:
• Lying in the center of the axilla in the axillary fat,
• these nodes receive lymph from the above three
groups.
• 5. Apical group:
• Lying at the apex of the axilla at the lateral border
of the first rib,
• these nodes receive the efferent lymph vessels
from all the other axillary nodes.
• The apical nodes drain into the subclavian lymph
trunk.
• On the left side, this trunk drains into the thoracic
duct;
• On the right side, it drains into the right lymph trunk.

29. Infraclavicular (deltopectoral)
group
• These nodes are not strictly axillary
nodes because they are located outside
the axilla.
• They lie in the groove between the
deltoid and pectoralis major muscles
and receive superficial lymph vessels
from the lateral side of the hand,
forearm, and arm