Download MBBS (Bachelor of Medicine, Bachelor of Surgery) Human Anatomy ppt lectures Topic 7 Brachial Plexus Notes. - anatomy ppt free download human anatomy ppt lectures, medicine notes ppt, anatomy handwritten notes pdf, mbbs 1st year anatomy notes pdf download, best anatomy notes pdf, human anatomy notes pdf, anatomy easy notes pdf, anatomy notes online, anatomy short notes, Anatomy ppt, Powerpoint Presentations and lecture notes.
Objectives
Spinal Nerves
Nerve Plexus
BP ? Origin & Relations
Formation
Parts of BP
Distribution - Nerve Supply ? areas
Anatomical Variations
Applied Anatomy
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Spinal Nerves
Spinal nerves attach to the
spinal cord via roots
Dorsal root
Has only sensory neurons
Attached to cord via rootlets
Dorsal root ganglion
Ventral root
Has only motor neurons
No ganglion - all cel bodies
of motor neurons found in
gray matter of spinal cord
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Spinal Nerves
31 pair
each contains thousands of nerve fibers
Al are mixed nerves have both sensory and motor
neurons
Connect to the spinal cord
Exit from SC ? Supplying the muscles & structures
of the body
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Spinal Nerves
8 pairs of cervical nerves from
C1 to C8
12 pairs of thoracic nerves
from T1-T12
5 pairs of lumbar nerves from
L1 to L5
5 pairs of sacral nerves from
S1 to S5
1 pair of coccygeal nerves
located at C zero (Co)
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Formation of Rami
Rami are lateral branches of a
spinal nerve
Rami contain both sensory and
motor neurons
Two major groups
Dorsal ramus
Neurons innervate the
dorsal regions of the
body
Ventral ramus
Larger
Neurons innervate the
ventral regions of the
body
Braid together to form
plexuses (plexi)
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Nerve Plexuses
Nerve plexus
A nerve plexus is nothing more than a
system or network of connected nerve
fibers that link spinal nerves with specific
areas of the body . A network of ventral
rami.
Ventral rami (except T2-T12)
Branch and join with one another
Form nerve plexuses
In cervical, brachial, lumbar, and sacral
re
gio
N n
o splexus formed in thoracic region of s.c.
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Branches
Dorsal Ramus
of
Neurons within muscles of trunk and back
Spinal
Nerves
Ventral Ramus (VR)
Braid together to form plexuses
Cervical plexus - VR of C1-C4
Brachial plexus - VR of C5-T1
Lumbar plexus - VR of L1-L4
Sacral plexus - VR of L4-S4
Coccygeal plexus -VR of S4&S5
Communicating Rami: communicate
with sympathetic chain of ganglia
Covered in ANS unit
12-8
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Brachial Plexus - Origin
Formed by ventral rami of spinal
nerves C5-T1
Five ventral rami form
Roots / Trunks that separate into
Divisions that then form
Cords that give rise to Branches
Major nerves
Axil ary
Radial
Musculocutaneous
Ulnar
Median
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Brachial Plexus
15 cms long ,spinal column to
axil a.
Brachial plexus is responsible for
cutaneous (sensory) and
muscular (motor) innervation of
the entire upper limb & pectoral
girdle.
It proceeds through the neck, the
axil a and into the arm.
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Relations - BP
In neck- posterior triangle,
being covered by skin,
Platysma, & deep fascia; where
it is crossed by supraclavicular
nerves, inferior belly of
Omohyoid, external jugular vein,
& transverse cervical artery.
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Relations - BP
When it emerges between
Scalene anterior &
medius
--* its upper part lies
above 3rd part of
subclavian artery,
* while trunk formed by
union of C8 & T1 is
placed behind artery.
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Relations - BP
Plexus next passes behind clavicle,
Subclavius, & transverse scapular vessels, &
lies upon 1st digitation of Serratus anterior, &
Subscapularis.
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Relations
In axilla it is placed
lateral to first portion of
axillary artery; it
surrounds 2nd part of
artery, one cord lying
medial to it, one lateral to
it, and one behind it; at
lower part of the axilla it
gives off its terminal
branches to upper limb.
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Anatomy CORD & BRANCH DIVISION
TRUNK
ROOT
Dorsal scapular N.
C4
Suprascapular N.
C5
UT
Lateral pectoral
C6
AD
RD
N.subclavius
PD
AL CO
A
C
PDD
7
MT
LATER
PD
C8
PD
MUSCULO CUTANEOUS
D
T
L
AD
T
AL ROOT
A
1
XILLARY
LATER
N. to latissimus
RADIAL NERVE POSTERIOR COR
M
dorsi
T2
EDIAL ROOT
MEDIAL COR
U. Subscapular
Long thoracic
L. Subscapular
MCF MCA Medial pectoral
MEDIAN NERVE
ULNAR NERVE
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Brachial Plexus Branches
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Brachial Plexus Branches
Branches of the Roots
?Long thoracic nerve(C5,C6,C7)
?Dorsal scapular nerve(C5)
?N. to longus colli & scaleni
Branches of Trunks
?Suprascapular nerve(C5,C6)
?Nerve to subclavius(C5,C6)
Branches of Lateral Cord
?Lateral Pectoral (C5-C7)
?Musculocutaneous (C5-C7)
?Lateral root of Median Nerve (C5-C7)
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Brachial Plexus Branches
Branches of Medial Cord
?Medial pectoral(C8-T1)
?Medial cutaneous nerve of arm(C8-T1)
?Medial cutaneous nerve of forearm(C8-T1)
?Ulnar nerve(C7,C8,T1)
?Medial root of median nerve(C8-T1)
Branches of Posterior Cord
?Upper subscapular (C5,C6)
?Thoracodorsal (C6-C8)
?Lower subscapular (C5,C6)
?Axil ary (C5,C6)
?Radial (C5-C8,T1)
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Muscles supplied by Brachial plexus
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Mode of Brachial Plexus Injuries
? Road traffic accident
? Penetrating injuries
? Surgical complications
? Birth Injuries
? Domestic violence and accidents
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Traumatic Brachial Plexopathies
Penetrating injury
? Infraclavicular plexus commonly affected
? Knife, gun shot etc
? Less common incident
? direct contact, hematoma pseudoaneurysm
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Traumatic Brachial Plexopathies
Closed traction injuries
? Supraclavicular injuries- forced
separation of head and shoulder
? Infraclavicular injuries- forced
separation of arm from the torso (hyper
abduction)
? Root avulsion- more serious
? Ventral roots are more prone to injury-
lesser calibers ,thinner dural sac
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Tractional Brachial Plexus
Injury
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Obstetric Brachial Plexopathies
Five pattern of injuries
C5,C6(Erb's palsy)
C5-T1 with some finger flexion sparing
C5-T1 with flail arm and Horner's syndrome
C5-T1 with Horner (Klumpke's palsy)
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Plexopathies
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Erb's Paralysis
? Injury of upper trunk at Erb's point, caused by traction
on arm at birth or due to accident
? Nerve root avulsion from cord, involved C5 & C6 causing
paralysis of deltoid, biceps, brachialis, brachioradialis &
supinator muscles
? Abduction, lateral rotation of arm & flexion &
supination of forearm lost
? Waiter's tip position (Adduction & medial rotation of
arm, extension of elbow and pronation of forearm)
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?Sensory loss over
the arm
Waiter's tip deformity
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Upper brachial plexus Erb-Duchenne palsy
? Results from excessive displacement of the head to the opposite side and
depression of the shoulder on the same side
Difficult labour
Motorcycle fal
Malposition of the upper
limb on the operation table
? Abrasions on the face and
shoulder show how this
motorcyclist pulled his entire
plexus apart
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Upper brachial plexus Erb-Duchenne palsy
The lesion produced is similar to that produced by a stab or bul et wound in the
neck affecting the superior trunk of the brachial plexus
Superior trunk
Neck wound
? Affects C5 & C6 roots or the superior
trunk
? suprascapular nerve, nerve to subclavius,
musculocutaneous, and axil ary nerves
are affected
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Upper brachial plexus Erb-Duchenne palsy
? Abduction, lateral rotation, and
flexion at the shoulder are
affected
? limb hangs by side adducted and
medially rotated by unopposed
pectoralis major
? forearm extended and pronated
because action of biceps is lost
? Affects C5 & C6 roots or the superior
trunk
? suprascapular nerve, nerve to subclavius,
musculocutaneous, and axil ary nerves
are affected
Waiter's tip position
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Klumpke's Paralysis
? Injury of lower trunk
? Caused due to hyper abduction of arm (extended arm
in a breech delivery, a fal on a outstretched arm)
? C8,T1 & some time C7 are involved
? Intrinsic muscles of hand & flexors of wrist(C6,C7,C8)
& fingers (C8,T1) are affected
? Claw hand deformity & anesthesia along the ulnar
border of the forearm & hand
? Horner's syndrome (injury to sympathetic fibers to
head & neck)
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Lower brachial
plexus
Klumpke palsy
results from excessive
? or when a person
abduction of the arm
falls from a height
as in during labor
grasping something
to save himself
? Cervical rib
Note the transverse process of C7
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Lower brachial plexus Klumpke palsy
Affects C8&T1
Claw hand
? Small muscles of the hand are
affected
Note wasting of dorsal interossei
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Klumpke's Paralysis
Horner's syndrome
Ptosis, myosis,enophthalmos and
loss of ciliospinal reflex
Claw hand deformity
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Supraclavicular Brachial Plexopathies
Burner syndrome (stinger syndrome)
? Forceful separation of head & shoulder ( lateral neck
extension & shoulder depression after a blunt force to
head & neck)
? Presented with unilateral sharp burning pain in neck
radiating to arm
? Classical C6 distribution,C5 may also affected
? Male sports person
? Permanent neurological dysfunction is rare
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Burner syndrome (Stinger syndrome)
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Winging of Scapula
? Serratus anterior stabilizes the
scapula
? Winging occurs due to
weakness in serratus anterior
? Injury to the nerve to serratus
anterior ( long thoracic nerve)
? Injury occurs during surgery or
due to infection
? Pushing and/or punching
defect
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Winging scapula:
?Injury to the long thoracic nerve
?Resulting from the blows on the
posterior triangle of the neck
?Serratus anterior muscle paralysed
?Inability to protract & rotate the scapula
during the abduction of the arm above the
head
?Medial border and inferior angle of the
scapula elevated
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Supraclavicular Brachial Plexopathies
Rucksack palsy ( cadet palsy, pack
palsy)
? Classical presentation ?pain
weakness associated with wearing a
backpack
? Sensory involvement and most are
due to demyelinating conduction
block (neuropraxia) of brachial plexus
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Cervical rib
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True neurogenic thoracic outlet
syndrome
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Thoracic outlet syndrome
? Compression of subclavian artery
and lower trunk of brachial
plexus in the area of the clavicle.
? This can happen when there is an
extra cervical rib
? There may be pain in neck &
shoulders, & numbess in the last 3
fingers & inner forearm.
? radial pulse may be easily
obliterated by movements of the
arm, particularly with arm
extended & abducted at shoulder.
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True neurogenic thoracic outlet syndrome
? Brachial plexus fibers compromised
by a translucent band extending
from rudimentary cervical rib to 1st
rib
? C8 and T1 fibers are mostly affected
? Presented with pain, paresthesia in
the neck shoulder and along the
medial border of hand
? Weakness of the muscles in the
hand
? symptom & sign of vascular
compromise
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True neurogenic thoracic outlet syndrome
Adson's Maneuver Allen's Test
Management-Surgical lysis of fibrous band or resection of
cervical rib
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Supraclavicular Brachial Plexopathies
Pancoast Syndrome
? Superior lobe carcinoma of
lung, mainly NSCC
? Compression of T1 as only
pleura separates lung from
T1
? Shoulder pain radiating in an
ulnar distribution down the
arm
Pancost tumor MRI
? Shoulder pain worse at night
? Associated with Horner
syndrome
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Pancoast Tumor
CT Chest- Pancoast Tumor Invading T1
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Infraclavicular Brachial Plexopathies
? Crutch palsy: radial nerve compression
? Midshaft clavicular fracture: medial cord
injury
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Nonspecific Brachial Plexopathies
Neuralgic Amyotrophy
? Frequently involves long thoracic, axil ary and
supraclavicular nerves
? Presenting feature: abrupt shoulder or upper
arm pain, often nocturnal onset
? Pain abates after 7-10 days
? 50% associated with infection
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1. The middle trunk of the brachial plexus is
formed by anterior rami of which spinal
cord segments?
a. C7
b. C6 and C7
c. C6
d. C5 and C6
e. C7 and T1
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2. Postoperative examination revealed that the
medial border and inferior angle of the left
scapula became unusually prominent
(projected posteriorly) when the arm was
carried forward in the sagittal plane,
especially if the patient pushed with
outstretched arm against heavy resistance
(e.g., a wall). What muscle must have been
denervated during the axil ary dissection?
A. Levator scapulae
b. Pectoralis major
c. Rhomboideus major
d. Serratus anterior
e. Subscapularis
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3. A person sustains a left brachial plexus injury in an auto accident.
After initial recovery the following is observed:
1) the diaphragm functions normally,
2) there is no winging of the scapula,
3) abduction cannot be initiated, but if the arm is helped through
first 45 degrees of abduction, patient can fully abduct arm.
From this amount of information and your knowledge of
formation of the brachial plexus where would you expect
injury to be:
a. Axil ary nerve
b. Posterior cord
c. Roots of plexus
d. Superior trunk
e. Suprascapular nerve
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4. In a case of Erb's palsy, where roots C5
and C6 of the brachial plexus are avulsed
(torn out) which muscle is paralyzed?
A. Latissimus dorsi
b. Pectoralis minor
c. Supraspinatus
d. Trapezius
e. Triceps brachii
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This post was last modified on 05 April 2022