i want 25 mutiple choice questions that covers different aspects of the all of the following information : Nerves of the upper limb
• The upper limb is supplied by a nervous network called the brachial plexus.
• This plexus is made by the merging of the anterior rami from the lower four cervical nerves and the first thoracic nerve (C5-T1).
• The plexus is anatomically divided into roots, trunks, divisions, cords and finally, the terminal branches.Terminal branches of the brachial
plexus:
1. The musculocutaneous nerve: innervates the
anterior compartment of the arm + the skin of the lateral
side of the forearm.
2. The axillary nerve: innervates the deltoid, and teres
minor muscles. Provides sensory innervation for the shoulder
joint and the skin covering region of the deltoid muscle.
3. The median nerve: innervates the anterior
compartment of the forearm (except for the flexor carpi
ulnaris and medial half of the flexor digitorum profundus),
the thenar eminence (opponens pollicis, abductor pollicis
brevis, flexor pollicis brevis), lateral 2 lumbricals , and the
skin of the lateral hand.4. The radial nerve: innervates the posterior
compartments of the arm and forearm, skin of
posterior arm, forearm and the dorsolateral part of
the hand.
5. The ulnar nerve: innervates the flexor carpi
ulnaris and medial half of the flexor digitorum
profundus, the hypothenar eminence (opponens
digiti minimi, abductor digiti minimi, flexor digiti
minimi brevis), palmaris
brevis, medial 2
lumbricals,
dorsal
and
palmar
interossei, adductor pollicis, and the skin of the
medial hand.The axillary nerve
• Origin: continuation of the
posterior cord.
• Spinal roots: C5 and C6.
• Course:
It
travels
through
the quadrangular space together
with the posterior circumflex
artery and vein.• It is a mixed nerve.
• Sensory functions: Gives rise to the
upper lateral cutaneous nerve of arm,
which innervates the skin over the
lower deltoid (‘regimental badge
area’).
• Motor functions: Innervates the teres
minor and deltoid muscles.Axillary nerve injury
• Causes:
1. Dislocation of the shoulder joint.
2. fracture of the surgical neck of the humerus.
3. During shoulder operations,
• Symptoms&signs:
Paralysis of the deltoid and teres minor muscles
• Weakness of arm abduction
• Wasting of the deltoid muscle
• Anaesthesia (loss in sensation) of the area of the skin posterior to
the deltoid muscle
• Deformty: Atrophy of the deltoid muscle results in a loss of the
normal rounded appearance of the shoulder, which gives the
shoulder a flattened appearance.Musculocutaneous nerve
• Origin& root value: from the lateral cord
of the brachial plexus (C5-C7).
• Course: pierces coracobrachialis then
between the brachialis and the biceps
brachii muscle.
• emerges lateral to biceps brachii. It then
continues as the lateral cutaneous nerve of
the forearm that supplies the anterolateral
skin of the forearm.• Branches:
1. motor: biceps brachii, brachialis,
coracobrachialis (BBC).
2. sensory: lateral cutaneous nerve
of the forearm.
3. articular: elbow jointMedian nerve
• Origin and nerve roots: is formed by the union of
1. the medial root from the medial cord
2. lateral root from the lateral cord.
• It contains fibres from roots of spinal nerves C6-T1, but
in some individuals it can also contain fibers from C5.
• Course: It runs downward on the lateral side of the
brachial artery.
• At the middle of the arm, it crosses the brachial artery
from lateral to medial and continues downward on its
medial side.56BRANCHES OF THE MEDIAN
NERVE IN THE FOREARM
• Muscular: To
• Pronator teres,
•
Flexor carpi radialis,
• Palmaris longus,
•
Flexor digitorum superficialis.
• Palmar cutaneous branch:
• It arises at the distal part of
forearm.. It descends superficial
to flexor retinaculum to supply
skin of the lateral 2/3 of the
palm.
• Articular: To elbow joint.
• Anterior interosseous nerve:
• Descends between flexor pollicis
longus and flexor digitorum
profundus, anterior to the
interosseous membrane.
• It supplies : FPL+PQ+ lateral half
of FDP.
• It gives an articular branches to
wrist & distal radioulnar joint.
57Median nerve in the palm • It enters the palm through the carpal tunnel, deep to the flexor retinaculum. • Branches:
• Muscular: To ( 5 Muscles). • Abductor pollicis brevis. • Flexor pollicis brevis. • Opponens pollicis (deep to the above 2 ms.).
Thenar
Eminenece Ms.
• Lateral 2 lumbrical (1st & 2nd ). • Digital cutaneous branches : • Cutaneous branches to the palmar aspect of the lateral 3 ½ fingersLESION OF MEDIAN NERVE
I- ABOVE THE ELBOW
• Weakness of flexion of wrist due to
paralysis of flexor carpi radialis &
palmaris longus.
• Loss of pronation due to paralysis of
pronator teres & pronator quadratus.
• Loss of flexion of middle phalanges
of medial 4 fingers due to paralysis
of flexor digitorum superficialis.
• Loss of flexion of terminal phalanges
of index & middle fingers due to
paralysis of lateral ½ of the
flexor digitorum profundus.LESION OF MEDIAN NERVE
I- ABOVE THE ELBOW (Continued)
• Loss of flexion of thumb due to
paralysis of flexor pollicis longus &
brevis
• Loss of opposition of thumb due to
paralysis of opponens pollicis.
• Flatting of the thenar eminence due to
atrophy of thenar muscles.
• The characteristic deformity in the
hand ‘APE HAND’ because the thenar
eminence is flattened and the thumb
is hyperextended.
• Loss of cutaneous sensations on the
hollow of palm of hand + palmar
surfaces of lateral 3 ½ fingers.LESION OF MEDIAN NERVE
II- ABOVE THE WRIST
• Loss of opposition of thumb due
to paralysis of opponens pollicis.
• Flattening of the thenar
eminence due to atrophy of
thenar muscles.
• The characteristic deformity ‘APE
HAND’ is present.
• Loss of cutaneous sensations on
the palmar surfaces of the lateral
3 ½ fingers.CARPAL TUNNEL SYNDROME
• It results from compression of median
nerve in the carpal tunnel.
• Slight flattening of thenar eminence due
to wasting of ms. of thenar eminence
supplied by median nerve.
• This is accompanied by burning pain or
‘pin and needles’ and diminished
cutaneous sensations on palmar aspect of
lateral 3 ½ fingers.
• No paresthesia occurs over the thenar
eminence (because this area of skin is
supplied by palmar cutaneous branch of
median N. arises in the distal part of
forearm and descends superficial to the
flexor retinaculum..ULNAR NERVE C 8 &T1
• Origin: • From the medial cord of the brachial plexus(C*&T1).
• sometimes carry C7 fibers as well.
• It runs downward on the medial side of the brachial artery as far as the middle of the arm.
• At the insertion of the coracobrachialis, it pierces the medial intermuscular septum and, accompanied by the superior ulnar collateral artery, to enter the posterior compartment of the arm.
• At the elbow, it passes behind the medial epicondyle.
• It has no branches in the arm. 64ULNAR NERVE
in the Forearm
• It continues downward
to enter the forearm
between the two heads
of the flexor carpi
ulnaris.
• It runs down the
forearm between FCU
and FDP.
• In the lower half of the
forearm it lies medial to
the ulnar artery.ULNAR NERVE in the Forearm
• Branches: • Muscular: To 1 ½ muscles. • Flexor carpi ulnaris. • Medial ½ of FDP • Articular: To elbow joint. • Dorsal or posterior cutaneous branch:
• To the dorsal surface medial 1/3rd of the hand and 1½ fingers.
• Palmar cutaneous branch : to supply skin of medial 1/3rd of the palm of hand.ULNAR NERVE in the
Hand
• Enters the palm
superficial to the flexor
retinaculum, close to
the lateral border of
pisiform bone.
• Then it divides into
superficial & deep
branches.
• Superficial branch:
• It supplies palmaris
brevis & palmar aspect
of the medial 1½
fingers.LESION OF ULNAR NERVE ABOVE ELBOW
• Weakness of flexion of wrist due to paralysis of
flexor carpi ulnaris.
• Loss of flexion of terminal phalanges of ring &
little fingers due to paralysis of medial ½ of flexor
digitorum profundus.
• Paralysis of all interossei & medial 2 lumbricals
(3rd &4th ).
Atrophy
hypothenar
muscles
of
• The characteristic deformity is called ‘
partial claw hand’.
• Atrophy of hypothenar muscles.
• The fingers are hyperextended at
metacarpophalangeal joints and flexed at
interphalangeal joints in the ring & little finger.
• Loss of adduction of hand & thumb due to
paralysis of flexor carpi ulnaris & adductor pollicis.LESION OF ULNAR NERVE ABOVE ELBOW
• Loss of cutaneous
sensations on the
front & dorsum of
medial 1/3 of hand +
medial 1 ½ fingers.LESION OF
ULNAR NERVE
ABOVE WRIST
• It leads to paralysis of
intrinsic muscles of hand as
described above.
• The deformity is called
‘claw hand’
• Loss of cutaneous sensations
of medial 1 ½ fingers.
Test for Palmar interossei
for adduction of fingers.
Test for adductor &
opponens pollicis.Radial nerve
• Origin and nerve roots: The radial nerve is the
largest nerve of the upper limb. It originates as
the terminal branch of the posterior cord of
the brachial plexus (C5,6,7,8 &T1).
• Course: The radial nerve arises in the axillary
region and descends down along the posterior
surface of the humerus.
• It then passes through the cubital fossa and
terminates in the posterior compartment of the
forearm, by dividing into two terminal
branches:
superficial
and deep (motor).
(sensory)• Branches:
• Muscular: the posterior muscles of the
arm and forearm (triceps brachii,
anconeus, brachioradialis, ECRL,ECRB,
extensor digitorum, extensor digiti
minimi, extensor carpi ulnaris, supinator,
abductor pollicis longus, extensor pollicis
brevis, extensor pollicis longus, extensor
indicis)• Cutaneous:
1. Posterior cutaneous nerve of the arm
(posterior surface of the arm).
2. inferior lateral cutaneous nerve of the arm
(lower outer aspect of the arm) .
3. posterior cutaneous nerve of the forearm
(posterior aspect of the forearm).
4. dorsal aspect of the lateral third of the hand
5. dorsal aspect of the lateral three and half
fingers of the hand except the distal
phalenges.Radial nerve injury
(Radial nerve palsy)
• Due to its length, the radial nerve is the most commonly
injured nerve of the upper extremity.
• Causes:
1. fractures of the humerus.
2. The nerve can also be injured when it is "overused" (e.g.
sports-related injuries) or
3. compressed (e.g. improper use of crutches).
• Symtoms&signs:
The most known presentation of radial nerve palsy is the
"wrist drop". due to the paralysis of the posterior
forearm muscles (extend the wrist).• The sensory loss will depend on the
anatomical location of the injury.
• For example, if the nerve is injured in the axillary
region, the sensory loss will be located at the
lateral arm and the posterior aspect of the
forearm radiating to the radial aspect of the hand
and digits.
• This is seen commonly with "Saturday night
palsy" (e.g. when the arm is resting on the chair
for a long time compressing the nerve).Upper Brachial Plexus trunk Injury
(Erb’s Palsy)
• Erb’s palsy refers to an injury to the upper
roots of the brachial plexus (typically C5-6).
• It most commonly occurs as a result of a
stretching injury during a difficult vaginal
delivery.
• Nerves affected: the peripheral nerves
derived from C5-6 roots are most affected.
This includes the musculocutaneous, axillary,
suprascapular, and nerve to subclavius.• Muscles affected:
supraspinatus,
infraspinatus,
subclavius, biceps brachii, brachialis, coracobrachialis,
deltoid and teres minor.
• Motor functions affected: abduction at shoulder,
lateral rotation of arm, supination of forearm, and
flexion at shoulder.
• Sensory functions affected: sensation over the lateral
aspect of upper limb (C5-6 dermatomes).
• The affected limb hangs medially rotated by the
unopposed action of pectoralis major. The forearm is
pronated due to the loss of biceps brachii. The wrist is
weakly flexed due to the normal tone of the wrist
flexors relative to the weakened wrist extensors. This is
position is known as ‘waiter’s tip’ and is
characteristic of Erb’s palsy.Lower Brachial Plexus trunk Injury
(Klumpke’s Palsy)
• Klumpke’s palsy is an injury of the lower
roots of the brachial plexus (C8-T1).
• It is also most commonly associated with a
difficult vaginal delivery but has a much lower
incidence than Erb’s palsy.
• Nerves affected: the peripheral nerves
derived from T1 root are most affected; the
ulnar and median nerves• Muscles affected: the intrinsic hand muscles • Sensory functions affected:
sensation along medial side of upper limb (C8-T1 dermatomes).
• The primary feature of Klumpke’s palsy is a complete claw hand.
• This occurs due to paralysis of the lumbrical muscles, which normally act to flex the metacarpophalangeal joints (MCPJs) and extend the interphalangeal joints (IPJs). When paralysed, the fingers subsequently become extended at the MCPJs and flexed at the IPJs, producing a clawed appearance