Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

MMB (Meera) > [007] The Axilla And Brachial Plexus > Flashcards

[007] The Axilla And Brachial Plexus Flashcards

1
Q

What is the axilla and why is it important?

A

The axilla is an area of transition, allowing the passage of nerves and blood vessels from the body into the arm - it is the gateway between the trunk and neck and the upper line

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

What is the structure of the Axilla?

A

It is roughly pyramidal in shape: 4 walls, a floor, an inlet (apex of the pyramid)

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

What are the boundaries of the axillary inlet formed from?

A

• The anterior margin = clavicle

• The medial margin = superior margin of rib 1

• the posterior margin= superior margin of the scapula lateral to the coracoid process

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

What 3 components make up the anterior wall of the Axilla?

A

• Pectoralis major and minor muscles
• susclavius muscle
• Clavipeltoral fascia

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

What 3 components make up the medial wall of the Axilla?

A

• Thoracic wall (ribs, intercostal muscles)
• Serratus anterior muscles
• Long thoracic nerve and intercostobrachial nerve

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

What is the base of the Axilla?

A

The skin of the armpit

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

What is the lateral wall of the Axilla made up of?

A

The intertubercular sulcus of the humerus

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

What are the 3 components of the posterior wall?

A

• Subscapularis
• Latissimus dorsi
• Teres major muscle
• Long head of the triceps

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

What are the 4 apertures in the Axilla?

A
  1. Suprascapular foremen
  2. Quandrangular space
  3. Triangular space
  4. Triangular interval
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What 2 components make up the suprascapular foramen?

A

The suprascapular nerve and the superior transverse scapular ligament

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

Which 2 muscles are innervated by the subscapular nerve?

A

The supraspinatus and infraspinatus muscles

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

Which 2 components pass through the greater scapular notch (spinoglenoid notch)?

A

The subscapular nerve and artery

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

Which 4 components make up the quandrangular space?

A

• Superiorly: interior margin of the teres minor muscle
• Laterally: surgical neck of the humerus
• Medially: lateral margin of the long head of the triceps
• Inferiorly: superior margin of the teres major muscle

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

Which 2 structures pass through the quandrangular space?

A
  1. The axillary nerve which innvervates the deltoid and teres minor
  2. The posterior humeral circumflex artery
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Why are the axillary nerve and posterior humeral circumflex artery at risk if the humerus is fractured?

A

As both of these structures go through the quadrangular space and run tightly around the back of the surgical neck of the humerus

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

What structure passes through the triangular space?

A

The circumflex scapular artery

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

Where is the triangular space?

A

Medial to the quadrangular space

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

Which 2 structures pass through the triangular interval?

A

• The radial nerve
• The profunda brachii artery

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

What is a risk for the structures that pass through the space created by these muscles?

A

Sometimes, if these muscles become inflamed and undergo hypertrophy they may compress the nerves/arteries that pass through the space and impact their functioning

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

What are the 2 muscles within the Axilla?

A
  1. Coracobrachialis
  2. Biceps brachii
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the origin of the coracobrachialis?

A

The coracoid process of the scapula

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

What is the insertion of the coracobrachialis?

A

The medial side of the humerus

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

Which nerves innervate the coracobrachialis?

A

C5 - C6 (musculocutaneous nerves)

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

What is the origin of the short head of the biceps brachii?

A

The coracoid process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is the origin of the long head of the biceps brachii?
The supraglenoid tubercle
26
What is the insertion of the biceps brachii?
The 2 heads combine to insert onto the radial tuberosity of the forearm
27
Which nerves innervate the biceps brachii?
C5 - C6 (musculocutaneous nerves)
28
What are the 3 parts of the subclavian artery that supplies the arm?
The SUBCLAVIAN ARTERY passes over the 1st rib and changes into the AXILLARY ARTERY. The axillary artery passes out of the Axilla and past the lower boundary of latissimus dorsi and teres major it changes to the BRACHIAL ARTERY.
29
What are the borders to the 3 parts of the axillary artery?
1st part: between the first rib and the pectoralis minor 2nd part: deep to the pectoralis minor 3rd part: between the pectorals minor and the lower boundary of teres major
30
How many branches come off each part of the axillary artery?
1st part: one branch 2nd part: two branches 3rd part: three branches
31
What is the branch that comes eff the first part of the axillary artery and what does it supply?
The superior thoracic artery which supplies the upper medial and anterior axillary walls
32
What are the two arteries that branch off the second part of the axillary artery?
The thoracoacromial artery and the lateral thoracic artery
33
What does the thoracoacromial artery branch into and what does it supply?
Clavicular Acromial Deltoid Pectoral Cadavers Are Dead People It supplies blood to the anterior wall of the axilla and chest
34
What does the lateral thoracic artery supply?
The lateral side of the thorax, pectoralis minor and the serratus anterior and medial axillary walls
35
What are the three branches that come off the third branch of the axillary artery?
1. The subscapular artery 2. The anterior humeral circumflex artery 3. The posterior humeral circumflex artery
36
What does the subscapular artery branch into?
1. The circumflex scapular artery - passes through the triangular space 2. The thoracodorsal artery
37
What are the paths of the anterior and posterior humeral circumflex arteries?
The anterior humeral circumflex artery goes around the front of the surgical neck of the humerus. The posterior humeral circumflex artery goes around the back of the surgical neck (through the quadrangular space) Both these arteries anastomose to form a loop around the surgical neck of the humerus - dangerous in case of a humeral fracture at the surgical neck
38
What is the pathway from the subclavian to the axillary artery?
Subclavian > thyrocervical trunk > suprascapular artery > circumflex scapular > subscapular artery > axillary artery
39
What is a pathway from the subclavian artery to the axillary artery?
Subclavian > transverse cervical artery > deep branch of transverse cervical artery /dorsal scapular > circumflex scapular artery > subscapular artery > axillary artery
40
Label the numbers in the diagram.
1. Superior thoracic artery 2. Thoraco-acromial artery 3. Subscapular artery 4. Anterior humeral circumflex artery 5. Posterior humeral circumflex artery 6. Circumflex scapular artery 7. Thoracodorsal artery 8. Lateral thoracic artery
41
Within the arm and forearm the vein is known as (1) vein, when it crosses the (2) muscle, it becomes the (3) vein, then finally when it crosses the lateral border of the (4) it becomes the (5) vein.
1. Basilic 2. Teres major 3. Axillary 4. Rib 1 5. Subclavian
42
Within the arm and forearm, the vein is known as the (1) vein, when it crosses the (2) muscle it becomes the (3) vein, then finally when it crosses the lateral border of the (4) it becomes the (5) vein.
1. Basilic 2. Teres major 3. Axillary 4. First rib 5. Subclavian
43
What lymph nodes are responsible for draining the upper limb and adjacent areas?
The axillary lymph nodes
44
What are the 5 groups of axillary lymphatics?
1. Pectoral 2. Lateral (humerus) 3. Apical 4. Central 5. Subscapular
45
Which rein rums superiorly under the surface of the hard to drain the lateral and posterior parts of the hand?
Cephalic vein
46
Which node receives most of the lymphatic drainage of the arms?
The humeral node
47
Where does the axillary vein run compared to the axillary artery?
The vein is anteriomedial to the artery
48
Where does the cephalic vein run and where does it drain into?
Between the deltoid and pectoralis major in the deltopectoral groove It drains into the axillary vein and drains the upper limb superficially
49
Why are the axillary lymph nodes important in breast cancer?
As they are responsible for 75% of the breast drainage and the axillary process of the axilla may enter the axilla
50
What is a plexus?
A way to connect the innervation of nerves of different spinal levels into one peripheral nerve
51
Which spinal levels contribute to the brachial plexus?
The ventral rami of spinal levels C5 - T1
52
What type of plexus is the brachial plexus and what kind of innervation does it provide to the upper limb?
It is a somatic plexus and provides sensory and motor innervation to the upper limb
53
What two areas are not innervated by the brachial plexus?
The trapezius and the regiments badge area
54
What innervates the regiments badge area?
The intercostobrachial nerve
55
What nerve innervates the trapezius?
Cranial nerve (XI)
56
What does the brachial plexus also carry?
Sympathetic fibres to the blood vessels, sweat glands and erector pili Carries grey rami T2-T6
57
What type of innervation is not present in the upper limb?
Parasympathetic
58
Where do the roots and trunks of the brachial plexus lie?
Between the anterior and middle scalene muscles and inferior to the subclavian artery
59
What is the order of the veins, arteries and brachial plexus at the neck?
Vein, artery, brachial plexus (VAP)
60
What are the branches of the C5 root?
The dorsal scapular nerve (only C5), long thoracic nerve and a contribution to the phrenic nerve
61
What are the branches of the roots C6-C7?
Long thoracic nerve
62
What does the dorsal scapular nerve innervate?
The rhomboid muscle and part of the levator scapulae
63
What does the long thoracic nerve innervate?
The serratus anterior
64
What clinical sign will patients with a damaged long thoracic nerve present with?
A winged scapula
65
Which roots is the superior trunk of the brachial plexus a combination of?
C5 and C6
66
Which root is the middle trunk of the brachial plexus a combination of?
C7
67
Which roots is the inferior trunk of the brachial plexus a combination of?
C8-T1
68
What are the two branches coming off the superior trunk?
The suprascapular nerve and the nerve to the subclavius
69
What does the suprascapular nerve innervate?
The supraspinatus and the infraspinatus muscle After travelling through the suprascapular foramen
70
What do the anterior divisions of the superior and middle trunk combine to form?
The lateral cord
71
What do the posterior divisions of the superior, middle and inferior trunk combine to form?
The posterior cord
72
What does the anterior division of the inferior trunk form?
The medial cord
73
What are the branches of the lateral cord?
1. Musculocutaneous nerve 2. Lateral pectoral nerve 3. Median nerve
74
What are the branches of the posterior cord?
1. Axillary nerve 2. Radial nerve 3. Inferior subscapular nerve 4. Thoracodorsal nerve 5. Superior subscapular nerve
75
What are the branches of the medial cord?
1. Medial pectoral nerve 2. Medial cutaneous nerve of the arm 3. Medial cutaneous nerve of the forearm 4. Median nerve 5. Ulnar nerve
76
What are the 4 terminal nerves?
1. Musculocutaneous nerve 2. Median nerve 3. Radial nerve 4. Ulnar nerve
77
What does the lateral pectoral nerve (coming off the lateral cord) innervate?
Pectoralis major
78
What does the musculocutaneous nerve (terminal nerve of the lateral cord) innervate?
All the muscles of the anterior compartment of the arm (coracobrachialis, brachialis, biceps brachii) Sensory innervation to the forearm
79
What does the lateral root of the median nerve (terminal nerve of the lateral cord) innervate?
All the flexor muscles in the anterior compartment of the forearm (except flexor carpi ulnaris and part of flexor digitorum profundus) Thenar muscles Lateral lumbricals (digits 3 and 4) Sensory innervation of the lateral part of palm + digits 5,4,3 + 1/2 of 2
80
What does the medial pectoral nerve (from the medial cord) innervate?
Pectoralis major Pectoralis minor
81
What does the medial cutaneous nerve of the arm (from the medial cord) innervate?
The skin over the medial side of the distal part of the arm The floor of the axilla
82
What does the medial cutaneous nerve of the forearm (medial cord) innervate?
The skin over the medial surface from the forearm down to the wrist
83
What does the medial root of the median nerve innervate?
Same as lateral root of the median nerve
84
What does the ulnar nerve (terminal nerve of the medial cord) innervate?
Flexor carpi ulnaris and the medial half of flexor digitorum profunda Medial palmar surface (sensory innervation)
85
What does the superior subscapular nerve (branch of the posterior nerve) innervate?
Subscapularis
86
What does the thoracodorsal nerve (branch of the posterior nerve) innervate?
Latissimus dorsi
87
What does the inferior subscapular nerve (branch of the posterior nerve) innervate?
Subscapularis Teres major
88
What does the axillary nerve (branch of the posterior nerve) innervate?
Deltoids Teres minor Regiment's badge
89
What does the radial nerve (branch of the posterior nerve) innervate?
All muscles in the posterior compartment of the arm and forearm
90
PLEASE KNOW THIS
91
What is Erb's Palsy or Waiter's tip caused by?
Traumatic lateral neck bending
92
What trunk is affected?
Superior trunk (C5 - C6)
93
What nerves are damages in Erb's Palsy?
Suprascapular nerve Dorsal scapular nerve Axillary nerve Musculocutaneous nerve Radial nerve
94
What is Klumpke's Palsy caused by?
Hyperabduction of the arm (e.g. grabbing to stop falling)
95
What is a clinical sign of Klumpke's Palsy?
Claw hand presentation
96
Which nerve is damaged in Klumpke's Palsy?
Ulnar nerve (C8-T1)
97
What causes wrist drop/saturday night palsy?
Fracture of humerus Compressed radial nerve Improper use of clutches
98
What causes the wrist drop?
Loss of extensors (triceps, brachioradialis, supinator and extensors of wrist and fingers)
99
What are the clinical signs of damage to median nerve?
Hand of Benediction/Pope’s Blessing or Hand
100
What causes Hand of Benediction/Pope’s Blessing or Hand?
Loss of finger and wrist flexors, thenar muscles, and 1st and 2nd lumbricals
101
What causes deltoid paralysis?
Injury to axillary nerve
102
What are the clinical signs of deltoid paralysis?
Inability to abduct arm beyond 15 degrees Flat shoulder (Atrophy of deltoid, rounded contour of shoulder flattens) Loss of sensation over regimental badge

MMB (Meera) (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions