Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

► Med Misc 25 > The Brachial Plexus > Flashcards

The Brachial Plexus Flashcards

1
Q

What is the brachial plexus?

A

A network of nerve fibres that supplies the skin and musculature of the upper limb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Where does the brachial plexus begin?

A

In the root of the neck

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where does the brachial plexus pass?

A

Through the axilla, and enters the upper arm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the brachial plexus formed by?

A

The anterior rami (divisions) of the cervical spines C5-8, and the first thoracic spinal nerve, T1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the brachial plexus divided into to aid explanation?

A

Roots, trunks, divisions, cords and branches

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the functional difference between the parts of the brachial plexus?

A

None

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What do the roots refer to?

A

The beginning of the brachial plexus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the roots of the brachial plexus formed by?

A

The spinal nerves C5, C6, C7, C8 and T1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What happens at each vertebral level?

A

Paired spinal nerves arise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How do paired spinal nerves leave the spinal cord?

A

Via the intervertebral foramina of the vertebral column

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What happens when the paired spinal nerves have left the spinal cord?

A

Each nerve divides into the anterior and posterior nerve fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How are the roots of the brachial plexus formed?

A

By the anterior divisions of spinal nerves C5-T1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What happens to the posterior divisions of the spinal nerves C5-T1?

A

They go on to innervate the skin and musculature of the trunk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What happens to the anterior division of spinal nerves C5-T1 after their formation?

A

They pass between the anterior and medial scalene muscles to enter the base of the neck

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What happens at the base of the neck?

A

The roots of the brachial plexus converge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is formed when the roots of the brachial plexus converge?

A

Three trunks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the trunks of the brachial plexus named based on?

A

Their anatomical position

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the three trunks of the brachial plexus?

A

Superior trunk
Middle trunk
Inferior trunk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What does the superior trunk consist of?

A

A combination of C5 and C6 roots

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does the middle trunk consist of?

A

A continuation of C7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What does the inferior trunk consist of?

A

A combination of C8 and T1 roots

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What happens once the trunks have been formed?

A

They begin to move laterally, crossing the posterior triangle of the neck

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What happens within the posterior triangle of the neck?

A

Each trunk divides into two branches

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What happens to the two branches formed from the trunks of the brachial plexus?

A

One division travels anteriorly (towards the front the body) and the other posteriorly (towards the back of the body)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What happens once the divisions have been formed?

A

The divisions leave the posterior triangle and pass into the axilla region

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What happens once the anterior and posterior divisions have entered the axilla?

A

They combine together to form three nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

How are the three nerves formed by the trunks of the brachial plexus named?

A

By their position relative to the axillary artery

28
Q

What are the three cords formed from the trunks of the brachial plexus?

A

Lateral
Posterior
Medial

29
Q

What is the lateral cord formed by?

A

The anterior division of the superior trunk

The anterior division of the middle trunk

30
Q

What is the posterior cord formed by?

A

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

31
Q

What is the medial cord formed by?

A

The anterior division of the inferior trunk

32
Q

What do the cords give rise to?

A

The five major branches of the brachial plexus

33
Q

Where do the cords give rise to the major branches of the brachial plexus?

A

In the axilla and proximal aspect of the upper limb

34
Q

What happens to the major branches of the brachial plexus?

A

They continue into the upper limb to provide innervation to the muscles and skin present

35
Q

What are the major branches of the brachial plexus?

A 
Musculocutaneous nerve
 Axillary nerve
 Radial nerve
 Ulnar nerve
 Median nerve
36
Q

What is the M structure found when looking for the brachial plexus in a dissection formed by?

A

The musculocutaneous, median and ulnar nerves, arranged around the brachial artery

37
Q

What does the brachial plexus have in addition to the 5 major branches?

A

A number of smaller nerves that arise

38
Q

What nerves arise from the roots of the brachial plexus?

A

Dorsal scapular nerve

Long thoracic nerve

39
Q

What nerves arise form the trunks of the brachial plexus?

A

Suprascapular

Nerve to subclavius

40
Q

What nerves arise from the lateral cord of the brachial plexus?

A

Lateral pectoral nerve

41
Q

What nerves arise from the medial cord of the brachial plexus?

A

Medial pectoral nerve
Medial cutaneous nerve of arm
Medial cutaneous nerve of forearm

42
Q

What nerves arise from the posterior cord of the brachial plexus?

A

Superior subscapular nerve
Thoracodorsal nerve
Inferior subscapular nerve

43
Q

What is an intact brachial plexus vital for?

A

Normal function of the upper limb

44
Q

What are the major types of injuries that can affect the brachial plexus?

A

Upper brachial plexus injury

Lower brachial plexus injury

45
Q

What does an upper brachial plexus injury affect?

A

The superior roots

46
Q

What does a lower brachial plexus injury affect?

A

The inferior roots

47
Q

When does Erb’s palsy commonly occur?

A

Where there is excessive increase in the angle between the neck and the shoulder

48
Q

Why does excessive increase in the angle between the neck and the shoulder result in Erb’s Palsy?

A

It stretches (or can tear) the nerve roots, causing damage

49
Q

What can Erb’s Palsy occur as a result of?

A

Difficult birth Shoulder trauma

50
Q

What nerves affected by Erb’s Palsy?

A

Nerves derived solely from C5 or C6 roots- musculocutaneous, axillary, suprascapular and nerve to subclavius

51
Q

What muscles are paralysed in Erb’s Palsy?

A

Supraspinatus, infraspinatus, subclavius, biceps brachii, brachialis, coracobrachialis, deltoid and teres minor

52
Q

What motor functions are lost or greatly weakened in Erb’s Palsy?

A

Abduction at the shoulder
Lateral rotation of the arm
Supination of the forearm
Flexion at shoulder

53
Q

What sensory functions are lost in Erb’s Palsy?

A

Loss of sensation down lateral side of arm

54
Q

Why is the a loss of sensation down the lateral side of the arm in Erb’s Palsy?

A

Because this covers the sensory innervation of the axillary and musculocutaneous nerve

55
Q

What happens to the affected limb in Erb’s Palsy?

A

The affected limb hangs limply, medially rotated

56
Q

Why is the limb medially rotated in Erb’s Palsy?

A

Due to the unapposed action of the pectoralis major

57
Q

Why is the forearm pronated in Erb’s Palsy?

A

Due to the loss of the biceps brachii

58
Q

What is the characteristic position of Erb’s Palsy?

A

‘Waiters tip’

59
Q

What does a lower brachial plexus injury result from?

A

Excessive abduction of the arm

60
Q

What is a lower brachial plexus injury called?

A

Klumpke Palsy

61
Q

How does the incidence of Klumpke Palsy differ from Erb’s palsy?

A

It is much lower

62
Q

What nerves are effected in Klumpke Palsy?

A

Those derived form the T1 root- ulna and median nerves

63
Q

What muscles are paralysed in Klumpke Palsy?

A

All the small muscles of the hand

64
Q

Why are the flexor muscles in the forearm not paralysed in Klumpke Palsy?

A

Although they are supplied by the ulna and median nerve, they are innervated by different roots

65
Q

What sensory functions are lost in Klumpke Palsy?

A

Loss of sensation along medial side of arm

66
Q

What is the characteristic appearance of Klumpke Palsy?

A

Hand has a clawed appereance

67
Q

What gives the hand a clawed appearance in Klumpke Palsy?

A

The metacarpophalangeal joints are hyperextended, and the interphalangeal joints are flexed

► Med Misc 25 (69 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions