Download the median nerve

BRACHIAL
PLEXUS
BRACHIAL PLEXUS
The parts of the brachial plexus, from medial to lateral:
• 
• 
• 
• 
• 
ROOTS
TRUNKS
DIVISIONS
CORDS
BRANCHES
The parts of the brachial plexus
(from medial to lateral):
5 ROOTS
3 TRUNKS
6 DIVISIONS
3 CORDS
5 BRANCHES
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BRACHIAL PLEXUS
5 ROOTS
The roots of the brachial
plexus
are the
anterior
rami of
C5 to T1
The
roots
enter
the
posterio
r
triangle
of the
neck by
passing
between
the
anterior
scalene
and
middle
scalene
muscles
and lie
superior
and
posterio
r to the
subclavi
an
artery.
BRACHIAL PLEXUS
5 ROOTS  3 TRUNKS
The roots unite
to form the
trunks:
•  SUPERIOR
TRUNK: C5+C6
•  MIDDLE
TRUNK:
ONLY C7
• 
INFERI
OR
TRUNK:
C8+T1
BRACHIAL PLEXUS
5 ROOTS  3 TRUNKS  6 DIVISIONS
Each of the 3 trunks of the brachial plexus divides into 2 divisions:
•  anterior division
•  posterior division
The trunks pass trough
the posterior triangle of the neck.
The trunks pass laterally over Ist rib,
and enter the axilla.
BRACHIAL PLEXUS
5 ROOTS  3 TRUNKS  6 DIVISIONS
The trunks split into:
•  3 anterior divisions
•  3 posterior divisions
The 3 cords originate
from the 6 divisions
BRACHIAL PLEXUS
5 ROOTS

3 TRUNKS 6 DIVISIONS3 CORDS
THE CORDS:
•  LATERAL
•  POSTERIOR
•  MEDIAL
are related to the second part of the axillary artery
BRACHIAL PLEXUS
5 ROOTS  3 TRUNKS
è
6 DIVISIONS
è
3 CORDS
The posterior cord occurs posterior to the second part of the
axillary artery.
The posterior cord originates as the union of all three posterior
divisions.
It contains contribu[ons from all roots of the brachial plexus (C5
to T1)
BRACHIAL PLEXUS
5 ROOTS  3 TRUNKS
è
6 DIVISIONS
è
3 CORDS
The lateral cord results from the union of the anterior divisions of
the superior and middle trunks.
The lateral cord is placed lateral to the second part of
the axillary artery.
BRACHIAL PLEXUS
5 ROOTS  3 TRUNKS
è
6 DIVISIONS
è
3 CORDS
The medial cord is the con[nua[on of the anterior division of
the inferior trunk—it contains contribu[ons from C8 and T1.
The medial cord contains contribu[ons from
C8 and T1.
The medial cord is medial to the second part of the
axillary artery.
BRACHIAL PLEXUS
SCHEMA OF THE BRACHIAL PLEXUS
BRACHIAL PLEXUS
THE MUSCULOCUTANEOUS NERVE C5-C7
THE MUSCULOCUTANEOUS NERVE:
COURSE:
•  exits axilla by piercing corarobrachialis
•  descends between biceps brachii and brachialis (supply both)
•  exits laterally in forearm as lateral cutaneous nerve of forearm
MOTOR INNERVATION:
•  anterior flexor compartment of arm:
coracobrachialis, biceps brachii and brachialis muscles
SENSORY:
•  skin of the lateral aspect of the forearm
BRACHIAL PLEXUS
THE MUSCULOCUTANEOUS NERVE C5-C7
THE MUSCULOCUTANEOUS NERVE:
MOTOR INNERVATION:
•  anterior flexor compartment of arm:
coracobrachialis, biceps brachii and brachialis muscles
INJURY:
•  can not flex the elbow
BRACHIAL PLEXUS
THE AXILLARY NERVE:
COURSE:
•  exits axilla posteriorly
•  runs posterior to the SURGICAL NECK
INNERVATION:
•  glenohumeral (shoulder) joint
•  teres minor
•  deltoid muscle
SKIN:
•  skin of the superolateral arm
THE AXILLARY NERVE C5-C6
BRACHIAL PLEXUS
THE AXILLARY NERVE C5-C6
THE AXILLARY NERVE
MUSCLE INNERVATION:
•  teres minor
•  deltoid muscle
INJURY:
•  loss of abduc[on from 15-90
0
BRACHIAL PLEXUS
SCHEMA OF THE BRACHIAL PLEXUS
BRACHIAL PLEXUS
THE MEDIAN NERVE C6-T1
THE MEDIAN NERVE:
COURSE:
•  lateral to axillary artery
•  anterior to the elbow
THE MEDIAN NERVE: NO BRANCHES IN THE ARM
OR AXILLA!
COURSE:
•  supplies and passes between two heads of the pronator teres
muscle
•  the nerve is closed to the surface of the wrist
BRACHIAL PLEXUS
THE MEDIAN NERVE C6-T1
THE MEDIAN NERVE:
INNERVATION
FOREARM:
flexors of the wrist:
•  pronator teres,
•  flexor carpi radialis,
•  palmaris longus,
•  flexor digitorum
superficialis
Innervates most of the muscles in the
anterior compartment of the forearm
(except for: the flexor carpi ulnaris
muscle and the medial half of the flexor
digitorum profundus muscle, which are
innervated by the ulnar nerve).
BRACHIAL PLEXUS
THE MEDIAN NERVE C6-T1
THE MEDIAN NERVE:
THE BRANCHES (in the forearm):
•  Anterior interosseous nerve (major branch in the forearm)
•  Ar[cular branches
•  Muscular branches
•  Palmar cutaneous branch of the median nerve
BRACHIAL PLEXUS
THE MEDIAN NERVE C6-T1
THE MEDIAN NERVE
INNERVATION:
HAND:
•  two lateral lumbricals: 1st and 2nd
•  thenar eminence via the reccurent branch: opponens pollicis,
abductor pollicis brevis
SENSORY
•  lateral three and one-half fingers of palmar surface
•  superior dorsal apects (three and one-half finger[ps)
BRACHIAL PLEXUS
THE MEDIAN NERVE C6-T1
THE MEDIAN NERVE
INJURY
•  carpal tunnel syndrome – reduced the size of the carpal tunnel
•  lunate disloca[on
•  supra-epicondylar fracture of humerus
BRACHIAL PLEXUS
THE MEDIAN NERVE
The carpal tunnel syndrome causes:
MEDIAN TRAP
Myxedema (hypothyroidism)
Edema
Diabetes
Idiopathic
Acromegaly
Neoplasm
Trauma Rheumatoid arthri[s Amyloidosis Pregnancy
THE MEDIAN NERVE C6-T1
BRACHIAL PLEXUS
THE MEDIAN NERVE C6-T1
THE MEDIAN NERVE
The carpal tunnel syndrome:
•  any pathology that expands the contents of the tunnel will
compress the enclosed median nerve
•  tendoni[s of the flexor re[naculum from overuse – median nerve
entrapment
Findings:
•  numbness
•  [ngling or sensory loss
•  atrophy of thenar eminence
BRACHIAL PLEXUS
THE MEDIAN NERVE C6-T1
THE MEDIAN NERVE
INJURY OF THE MEDIAN NERVE
The median nerve controls the 1st & 2nd lumbricals, three thenar
muscles.
Addi[onally there may be thenar atrophy.
The hand of benedic[on is only apparent if the pa[ent is asked to make
a fist - pa[ent will be able to flex the lihle and ring fingers.
POPE'S HAND (HAND OF BENEDICTION)
BRACHIAL PLEXUS
SCHEMA OF THE BRACHIAL PLEXUS
BRACHIAL PLEXUS
THE RADIAL NERVE C5-T1
THE RADIAL NERVE:
COURSE:
•  posterior to brachial artery
•  runs with the profunda brachii artery
•  radial groove in humerus
•  con[nues inferiorly in the anterior compartment of the arm
•  between the brachialis and the brachioradialis
•  to the level of the anterior part of the lateral epicondyle of
humerus
BRACHIAL PLEXUS
THE RADIAL NERVE C5-T1
THE RADIAL NERVE:
MOTOR INNERVATIONS:
•  triceps
•  brachioradialis
MOTOR INNERVATIONS:
•  extensors of the wrist - posterior compartment of forearm: extensor
carpi radialis longus, extensor carpi radialis brevis, extensor
digitorum,extensor digi; minimi, extensor carpi ulnaris, supinator,
extensor indicis, abductor policis longus, extensor policis longus,
extensor policis brevis
BRACHIAL PLEXUS
THE RADIAL NERVE C5-T1
THE RADIAL NERVE - INNERVATION OF THE SKIN:
•  posterior arm and forearm
•  on dorsal hand - below the finger[ps of the medial three and one-half fingers
THE RADIAL NERVE INJURY may
be due to:
•  fracture of the body of humerus (radial groove)
•  saturday night palsy (compression of the nerve)
THE RADIAL NERVE
INJURY
RESULT IN
THE WRIST DROP
Pa[ent is not able to extend
the wrist and fingers in the MP
joints
BRACHIAL PLEXUS
THE RADIAL NERVE C5-T1
DORSAL BRANCH OF ULNAR NERVE
Skin of medial aspect of dorsum of hand and proximal por[ons of lihle
and medial half of ring finger
SUPERFICIAL BRANCH OF ULNAR NERVE
Palmaris brevis & sensa[on to skin of the palmar and distal dorsal
aspects of digit 5 and of the medial (ulnar) side of digit 4 and
proximal por[on of palm
DEEP BRANCH OF ULNAR NERVE
Hypothenar muscles, lumbricals of digits 4 and 5, all interossei,
adductor pollicis, and deep head of flexor pollicis brevis
BRACHIAL PLEXUS
SCHEMA OF THE BRACHIAL PLEXUS
BRACHIAL PLEXUS
THE ULNAR NERVE C7, C8-T1
THE ULNAR NERVE:
COURSE:
•  passes on the medial side of the brachial artery
•  descends between the medial intermuscular septum of the arm and
the medial head of triceps
THE ULNAR NERVE – NO BRANCHES IN THE ARM !
THE MEDIAN NERVE – NO BRANCHES IN THE ARM !
BRACHIAL PLEXUS
THE ULNAR NERVE C7, C8-T1
THE ULNAR NERVE:
COURSE:
•  passes posterior to the medial epicondyle and to the medial
olecranon to enter the forearm
•  passes superficial to the flexor re[naculum
(the median nerve under the flexor re;naculum)
•  enters the hand by passing through a groove between the pisiform
and the hook of the hamate – the ulnar canal (Guyon’s canal)
BRACHIAL PLEXUS
THE ULNAR NERVE C7, C8-T1
THE ULNAR NERVE:
INNERVATION OF FOREARM:
•  innervates medial flexors of the wrist: flexor carpi ulnaris and
medial part of the flexor digitorum profundus
INNERVATION OF HAND:
•  hypothenar eminence: abductor digi; minimi, flexor digi; minimi
brevis, opponens digi;
•  medial lumbrical muscles: 3rd and 4th lumbricals
•  all interosseous muscles of the hand: 1st – 4th dorsal interossei,
1st-3rd palmar interossei
THE ULNAR NERVE:
SKIN INNERVATION:
•  dorsal and palmar apsect of the hand for medial 1 ½ fingers
•  medial forearm
BRACHIAL PLEXUS
THE ULNAR NERVE C7, C8-T1
THE ULNAR NERVE INJURY may be
due to:
•  medial epicondyle fracture
•  fracture of the hook of hamate
THE ULNAR NERVE INJURY
RESULTS IN:
•  inability to abduct or adduct fingers
•  hypothenar atrophy
•  Ulnar Claw Hand:
•  loss of medial lumbricals
•  pa[ent tries to open hand and cannot extend 4th and 5th digits
BRACHIAL PLEXUS
VS
INJURY OF THE
MEDIAN NERVE
POPE'S HAND
(HAND OF
BENEDICTION)
the pa[ent is
asked to make a
fist: pa[ent will
be able to flex
the lihle and
ring fingers.
INJURY OF THE
ULNAR NERVE
ULNAR CLAW
HAND
pa[ent tries to
open hand and
cannot extend 4th
and 5th digits
DUPUYTREN CONTRACTURE OF PALMAR FASCIA
•  Its cause is unknown
•  The fibrous degenera[on of the longitudinal bands of the palmar
th
aponeurosis on the medial side of the hand pulls the 4th and 5
fingers into par[al flexion at the metacarpophalangeal and
proximal interphalangeal joints
•  The contracture is frequently bilateral and is seen in some men >
50 years of age
BRACHIAL PLEXUS
SENSORY INNERVATION OF THE HAND