Brachial Plexus

Question 1

The brachial plexus is a network of nerve fibres that supplies the ___ and ___ of the upper limb.

It begins in the _______ , passes through the ____, and runs through the entire _____

Answer 1

skin and musculature

root of the neck

axilla

upper extremity.

Question 2

The brachial plexus is formed by the anterior rami (divisions) of cervical spinal nerves __,___,___,____ and the _____

Answer 2

C5, C6, C7 and C8,

first thoracic spinal nerve, T1

Question 3

The brachial plexus is divided into five parts; ____,____,___,___, and ____

Answer 3

roots, trunks, divisions, cords and branches

Question 4

The ‘roots’ refer the (anterior or posterior ?) rami of the spinal nerves that comprise the brachial plexus. These are the anterior rami of spinal nerves C5, C6, C7, C8, and T1.

Answer 4

Anterior

Question 5

At each vertebral level, paired spinal nerves arise. They leave the spinal cord via the _____ foramina of the vertebral column.

Answer 5

intervertebral

Question 6

Each spinal nerve then divides into an ____ and _______ ramus.

The roots of the brachial plexus are formed by the ______ rami of spinal nerves ___-___ (the posterior divisions innervate the ___ and ____ of the ____ muscles).

After their formation, these nerves pass between the —— and ——— muscles to enter the base of the neck.

Answer 6

anterior and a posterior

anterior

C5-T1

skin and musculature

intrinsic back

anterior and medial scalene

Question 7

At the base of the neck, the roots of the brachial plexus converge to form three trunks. These structures are named by their relative anatomical location:

Superior trunk – a combination of ____roots.
Middle trunk – continuation of ___.
Inferior trunk – combination of _____ roots.

The trunks traverse (medially or laterally?) , crossing the ____ triangle of the neck.

Answer 7

C5 and C6

C7

C8 and T1

laterally

posterior

Question 8

Each trunk divides into two branches outside the posterior triangle of the neck.
T/F

Answer 8

F

Question 9

Divisions combine into cords in the ____ and are named based on their relative relation to the _____

Answer 9

Axilla

Axillary artery

Question 10

The lateral cord is formed by:

The ____ division of the ____ trunk
The _____ division of the ____ trunk

The posterior cord is formed by:
___________

The medial cord is formed by:
The ____ division of the _____ trunk.

Answer 10

anterior; superior

Anterior; middle

The posterior division of the superior trunk
The posterior division of the middle trunk
The posterior division of the inferior trunk

anterior; Inferior

Question 11

Musculocutaneous Nerve

Roots: _____

Motor Functions: Innervates the _____ muscles.

Sensory Functions: Gives off the ____ branch of the ___, which innervates the (medial or lateral?) half of the anterior forearm, and a small (medial or lateral?) portion of the posterior forearm.

Answer 11

C5, C6, C7.

brachialis, biceps brachii and coracobrachialis

lateral cutaneous

forearm
Lateral; lateral

Question 12

Axillary Nerve

Roots:_____
Motor Functions: Innervates the ____ and ____ muscles.
Sensory Functions: Gives off the _____ nerve of arm, which innervates the ____ region of the ____ (“____ area”).

Answer 12

C5 and C6.

teres minor and deltoid

superior lateral cutaneous

Lateral

deltoid

regimental badge

Question 13

Median Nerve

Roots: ____ . (Also contains fibres from __ in some individuals).

Motor Functions: Innervates most of the ___ muscles in the forearm, the ___ muscles, and the _____ lumbricals associated with the index and middle fingers.

Sensory Functions: Gives off the ____ branch, which innervates the ____ part of the palm, and the____ branch, which innervates the lateral ____ fingers on the ____ surface of the hand.

Answer 13

C6 – T1

C5

flexor

thenar

two lateral

palmar cutaneous; lateral

digital cutaneous; three and a half

anterior (palmar)

Question 14

Radial Nerve.

Roots: _____

Motor Functions: Innervates the triceps brachii, and the muscles in the posterior compartment of the forearm (which are primarily, but not exclusively, extensors of the wrist and fingers).

Sensory Functions: Innervates the ____ aspect of the arm and forearm, and the _____ aspect of the hand.

Answer 14

C5 – T1.

posterior

posterolateral

Question 15

Ulnar Nerve

Roots: ____

Motor Functions: Innervates the muscles of the hand (apart from the thenar muscles and two lateral lumbricals), flexor carpi ulnaris and ____ half of flexor digitorum ____

Sensory Functions: Innervates the anterior and posterior surfaces of the _____ fingers, and associated palm area.

Answer 15

C8 and T1.

medial

profundus

medial one and half

Question 16

The important structure to look for in a cadaver is an ‘ ___’ shape.

This is formed by the _____,____,____ nerves, usually (superficial or deep?) to the ____ artery.

Answer 16

M

musculocutaneous, median, and ulnar

Superficial

axillary

Question 17

2 minor nerves that comes from roots

2 minor nerves that comes from trunks

Answer 17

Dorsal scapular nerve ; Long thoracic nerve

Suprascapular nerve ; Nerve to subclavius

Question 18

Minor nerves from lateral cord of brachial plexus

Minor nerves from medial cord of brachial plexus

Answer 18

Lateral pectoral nerve

Medial pectoral nerve

Medial cutaneous nerve of arm

Medial cutaneous nerve of forearm

Question 19

Minor nerves from posterior cord of brachial plexus

Answer 19

Superior subscapular nerve

Thoracodorsal nerve

Inferior subscapular nerve

Question 20

Erb’s palsy refers to an injury to the _____ of the brachial plexus (typically ____).

It most commonly occurs as a result of a ____ injury during a difficult _____

Answer 20

upper roots

C5-6

stretching

vaginal delivery.

Question 21

Nerves affected in erbs palsy– the peripheral nerves derived from ____ roots are most affected.

This includes the ___,___,___,and____.

Answer 21

C5-6

musculocutaneous, axillary, suprascapular, and nerve to subclavius

Question 22

Muscles affected in erb’s palsy –

List 8

Answer 22

supraspinatus, infraspinatus, subclavius, biceps brachii, brachialis, coracobrachialis, deltoid and teres minor.

Question 23

Motor functions affected in erb’s palsy –

___uction at ____, _____ rotation of ___, __nation of ____, and _____ion at ____.

Answer 23

abd; shoulder

lateral; arm

supi; forearm

flex; shoulder

Question 24

Sensory functions affected in erb’s palsy –

sensation over the ____ aspect of upper limb (C5-6 dermatomes).

Answer 24

lateral

Question 25

The affected limb in erb’s palsy hangs limply, ____ rotated by the unopposed action of pectoralis major.

The forearm is ____ due to the loss of biceps brachii.

The wrist is ____ due to the normal tone of the wrist flexors relative to the weakened wrist extensors.

This is position is known as ‘ _____ ’ and is characteristic of Erb’s palsy.

Answer 25

medially

pronated

weakly flexed

waiter’s tip

Question 26

Klumpke’s palsy is an injury of the ____ of the brachial plexus (____).

It is most commonly associated with a difficult____

Answer 26

lower roots

C8-T1

vaginal delivery

Question 27

Erb’s palsy has a higher incidence rate than klumpke’s paralysis

T/F

Answer 27

T

Question 28

Nerves affected in klumpke’s paralysis–

the peripheral nerves derived from ___ root are most affected; the ____ and _____ nerves

Answer 28

T1

ulnar and median

Question 29

Muscles affected in klumpke’s paralysis –

the _____ muscles

Answer 29

intrinsic hand

Question 30

Sensory functions affected –

sensation along ____ side of upper limb (C8-T1 dermatomes).

Answer 30

medial

Question 31

The primary feature of Klumpke’s palsy is a ____ hand.

This occurs due to paralysis of the ___ muscles, which normally act to ___ the metacarpophalangeal joints (MCPJs) and ___ the interphalangeal joints (IPJs).

When paralysed, the fingers subsequently become ____ at the MCPJs and ___ at the IPJs, producing a ____ appearance.

Answer 31

clawed

lumbrical

flex

extend

extended

Flexed

clawed