3. Spinal Nerves
31 pairs of spinal nerves
are attached to the spinal
cord.
8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal
Each spinal nerve divides
into a dorsal and ventral
ramus. 3Cleyson Mupfiga HUB117 2011
4. Brachial Plexus
The brachial plexus is a network of nerves
formed by the union of the anterior rami
(branches) of C5 – C8 & T1 spinal nerves.
It originates in the neck, passes laterally &
inferiorly over the first rib & enters the axilla
(arm pit).
All major nerves of the upper limb originate
from parts of the brachial plexus.
Divided into ROOTS, TRUNKS, DIVISIONS,
and CORDS. BRANCHES emerge to supply the
upper limb.
4Cleyson Mupfiga HUB117 2011
15. Upper
Middle Trunks
Lower
Roots (ventral rami):
Upper subscapular
Lower subscapular
Thoracodorsal
Medial cutaneous
nerves of the arm
and forearm
Long thoracic
Medial pectoral
Lateral pectoral
Nerve to subclavius
Suprascapular
Dorsal scapular
Posterior
divisions
Anterior
divisions
Lateral
PosteriorCords
Medial
Axillary
Musculo-
cutaneous
Radial
Median
Ulnar
Posterior
divisions
Trunks Roots
C4
C5
C6
C7
C8
T1
(a) Roots (rami C5 – T1), trunks, divisions, and cords
16. Brachial Plexus Injuries
16Cleyson Mupfiga HUB117 2011
Upper brachial plexus
injuries: “waiter’s tip
position”
Lower brachial plexus
injuries: short muscles of
the hand are affected >
“clawhand”
17. Nerve Injury
17
Anaethesia: loss of sensation; may
be pathological or induced to facilitate
surgery or other medical treatment.
Paraesthesia: abnormal sensation
e.g. tingling or burning.
Cleyson Mupfiga HUB117 2011
Provides the following important functions: (1) sensory innervation to the skin & deep structures; (2) motor innervation to muscles; (3) influence over diameter of blood vessels by sympatetic vasomotor nerves; (4) sympathetic secretomotor supply to the sweat glands.
