Station 1: neurovasculature of limbs Flashcards

1
Q

Where does the subclavian artery become the axillary artery?

A

Lateral edge of rib 1 and enter into the axilla

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

Where does the axillary artery become the brachial artery?

A

Inferior margin of teres major muscle

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

Where does the brachial artery bifurcate into the radial and ulnar nerve?

A

Apex of cubital fossa at level of radial neck, underneath the brachialis muscle

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

What relation is the brachial artery to the tendon of biceps brachii?

A

Medial

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

Where is the median nerve in relation to the brachial artery?

A

Medial and anterior

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

Which is usually larger, the ulnar or radial artery?

A

Ulnar

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

Where are the radial and ulnar arteries located? What are the anatomical relations?

A

Forearm
Radial is lateral
Ulnar is medial

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

How are the radial and ulnar arteries injured?

What structures may also be injured?

A

Radial/ulnar fractures

Slitting of wrist

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

Where does the right subclavian artery arise from?

A

Brachiocephalic trunk

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

Where does the left subclavian artery arise?

A

Directly off the arch of the aorta

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

What could an axillary artery aneurysm compress?

A

The brachial plexus leading to neurological symptoms such as paraesthesia and muscle weakness

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

When could an axillary artery aneurysm occur?

A

As a result of atherosclerosis, thoracic outlet syndrome or trauma

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

If the brachial artery was completely blocked or severed, what would happen?

A

This causes a characteristic flexion deformity called Volkmann’s contracture.
Caused by: resulting ischaemia of the forearm can cause necrosis and paralysis of the muscles in the forearm. The affected muscles are replaced by scar tissue and shorten considerably.

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

Which part of the forearm does the radial artery supply?

A

The posterior aspect

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

Which part of the forearm does the ulnar artery supply?

A

The anterior aspect

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

What are the common sites for compression of the arteries of the upper limb to prevent haemorrhaging?

A

Subclavian artery:
At the 1st rib - downward pressure in angle between clavicle and inferior attachment of SCM

Axillary artery:
inferior part of lateral wall of axilla, compress against the humerus

Brachial artery:
compression against the medial humerus

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

What is the route of the basilic vein?

A

Originates from the dorsal venous network of the hand -> medial aspect of upper limb -> borders teres major -> moves deep into arm and combines with brachial vein to form the axillary vein

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

What is the route of the cephalic vein?

A

Originates from the dorsal venous network of the hand -> antero-lateral aspect of the upper limb, passing anteriorly at the elbow -> travels in the deltopectoral groove at the shoulder (between deltoid and pec major) -> enters axilla region via clavipectoral triangle -> in the axilla, cephalic vein terminates by joining the axillary vein

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

Which vein passes through the anatomical snuffbox?

A

Cephalic vein

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

Where do the cephalic and basilic vein connect? What is this vein called and what is commonly used for?

A

At the elbow, anteriorly at the cubital fossa, they are connected by the median cubital vein.
Commonly used for venipunctures.

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

What type of veins are the cephalic and basilic vein?

A

Superficial

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

Which spinal nerves make up the brachial plexus?

A

Anterior rami (divisions) of the cervical spinal nerves: C5, C6, C7, C8 and first thoracic spinal nerve T1

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

What is the brachial plexus divided up into?

Rugby Twats Drink Cold Beer

A

Roots, trunks, divisions, cords, branches

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

What are the roots of the brachial plexus?

A

C5, C6, C7, C8, T1 (anterior divisions)

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

How do the spinal nerves leave the spinal cord?

A

At each vertebral level, paired spinal nerves leave the spinal cord via the intervertebral foramina of the vertebral column.
Each nerve divides into the anterior and posterior nerve fibres. The roots of the brachial plexus are formed by the anterior divisions of the spinal nerves.
The posterior divisions go on to innervate the skin and musculature of the trunk.
The nerves then 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
26
Q

How are the trunks formed?

A

At the base of the neck, the roots converge forming three trunks:

Superior trunk - C5,C6 roots
Middle trunk - C7 root
Inferior trunk - C8, T1 roots

The trunks move laterally, crossing the posterior triangle of the neck

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

How are the divisions formed?

A

Each trunk divides into two divisions. One anteriorly and the other posteriorly, in relation to the mid clavicle.
The anterior divisions supply anterior compartment (flexors) and posterior divisions supply posterior compartment (extensors).
They 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
28
Q

How are the cords formed?

A

Once in the axilla, the divisions combine to form three cords. These are named due to their relation to the second part of the axillary artery.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

How is the lateral cord formed?

A

Anterior division superior trunk

Anterior middle trunk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How is the posterior cord formed?

A

Posterior division of the superior trunk
Posterior division of the middle trunk
Posterior division of the inferior trunk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How is the medial cord formed?

A

The anterior division of the inferior trunk

32
Q

The cords give rise to which major branches of the brachial plexus?

A
Musculocutaneous nerve
Median nerve
Ulnar nerve
Axillary nerve
Radial nerve
33
Q

Which nerve roots and cord supply the musculocutaneous nerve?

A

C5,C6,C7

Lateral cord

34
Q

What are the motor functions of the musculocutaneous nerve?

A

Muscles of anterior compartment: coracobrachialis, biceps brachii, brachialis (BBC)
Flexion of upper arm at shoulder and elbow, supination of forearm (biceps)

35
Q

What are the sensory functions of the musculocutaneous nerve?

A

Gives rise to lateral cutaneous nerve of the forearm - innervates skin of the lateral surface of the forearm

36
Q

Where is the musculocutaneous nerve commonly injured?

A

Uncommon, well protected within the axilla

Most common - stab wound to the axilla region

37
Q

What motor functions are affected in a musculocutaneous nerve injury?

A

BBC muscles
Flexion at shoulder is weakened (pec major)
Flexion at the elbow affected (brachioradialis)
Supination weakened (supinator muscle)

38
Q

What sensory functions are affected in a musculocutaneous nerve injury?

A

Loss of sensation over anterolateral side of the forearm

39
Q

Which nerve roots and cord supply the axillary nerve?

A

C5, C6

Posterior cord

40
Q

What are the motor functions of the axillary nerve?

A

Innervates teres minor (stabilises glenohumeral joint, externally rotates upper limb) and deltoid muscles (abduction of upper limb)

41
Q

What are the sensory functions of the axillary nerve?

A

Give rises to superior lateral cutaneous nerve of arm, innervates skin of inferior deltoid (regimental badge)

42
Q

Where is the axillary nerve most commonly damaged?

A

Trauma to shoulder or proximal humerus - such as fracture of humerus surgical neck, shoulder dislocation

43
Q

What motor functions are affected in a axillary nerve injury?

A

Paralysis deltoid and teres minor muscles - renders patient unable to adbuct the affected limb

44
Q

What sensory functions are affected in a axillary nerve injury?

A

Upper lateral cutaneous nerve of arm, resulting in loss of sensation over the regimental badge arm.

45
Q

What are the characteristic clinical signs of axillary injury?

A

Paralysed deltoid muscle rapidly atrophies, the greater tuberosity can be palpated in that area

46
Q

What are the roots of the median nerve?

A

C6 - T1 (some indiv have C5 fibres too)

From medial and lateral cords

47
Q

What are the motor functions of median nerve?

A

Flexor muscles in the anterior compartment of the forearm (except flexor carpi ulnaris and medial half of the flexor digitorum profundus)
Thenar muscles
Lateral two lumbricals in hand

48
Q

What are the sensory functions of the median nerve?

A

Give rise to palmar cutaneous branch ->
Lateral part of palm
Digital cutaneous branch -> lateral three and a half fingers on anterior/palmar surface of the hand

49
Q

How is the median nerve commonly injured?

A

Supracondylar fracture of the humerus (damage at the elbow)

Laceration just proximal to flexor retinaculum (damage at the wrist)

50
Q

What are the motor deficits when the median nerve is damaged at the elbow?

A

Flexors and pronators of forearm paralysed
= forearm constantly supinated and flexion is weak
Flexion of thumb prevented
Lateral two lumbricals affected - won’t be able to flex at MCP joints or extend at IP joints of index and middle fingers

51
Q

What are the sensory deficits when the median nerve is damaged at the elbow/wrist?

A

Lack of sensation over the areas that the median nerve innervates - lateral part of palm, lateral three and a half fingers on palmar aspect of hand

52
Q

What are the motor deficits when the median nerve is damaged at the wrist?

A

Thenar muscles and lateral two lumbricals are paralysed

Affects opposition of the thumb and flexion of the index and middle fingers

53
Q

Characteristic signs of median nerve damage

A

Thenar eminence wasted

Pt makes a fist -> little and ring fingers flex = shape of ‘hand of benediction’

54
Q

What are the roots of the radial nerve?

A

C5-T1

Posterior cord

55
Q

What is the sensory supply of the radial nerve?

A

Skin of posterior side of forearm, dorsal surface of lateral side of palm, lateral three and a half digits

56
Q

What is the motor supply of the radial nerve?

A
Triceps brachii (extends at elbow)
Majority of extensor muscles in the forearm (extends wrist and fingers and supinates forearm)
57
Q

How is the radial nerve damaged in the axilla region?

A

Dislocation at the shoulder joint

Fracture of the proximal humerus

58
Q

What are the motor and sensory deficits of damage to the radial nerve in the axilla?

A

Triceps, posterior compartment of forearm- unable to extend forearm, wrist and fingers
Unopposed flexion of wrist = wrist-drop

Loss of sensation over lateral and posterior upper arm, posterior forearm, dorsal surface of lateral 3.5 digits

59
Q

How is the radial nerve damaged in the radial groove?

A

Fracture of humeral shaft

60
Q

What are the motor and sensory deficits of damage to the radial nerve in the spiral groove?

A

Triceps weakened
Posterior forearm = wrist drop

Loss of sensation to dorsal surface of lateral 3.5 digits, associated palm area

61
Q

What are the MOI to damage to the radial nerve in the forearm and what would be the associated motor/sensory deficit?)

A

Stabbing/laceration to the forearm:
No motor, sensory loss of lateral 3.5 and palm dorsally

Fracture of radial head or posterior dislocation of radius:
Posterior forearm muscles, wrist drop doesn’t occur as extensor carpi radialis longus is unaffected and maintains some extension at the wrist
No sensory deficit

62
Q

What are the roots are the ulnar nerve?

A

C8, T1

Medial cord

63
Q

What are the motor functions of the ulnar nerve?

A

Muscles of the hand (except thenar muscles and two lateral lumbricals), flexor carpi ulnaris, medial half of flexor digitorum profundus

64
Q

What is the sensory innervation of the ulnar nerve?

A

Anterior and posterior surfaces of the medial one and half fingers, associated palm area

65
Q

Where is the ulnar nerve susceptible to injury?

A

Elbow and wrist

66
Q

How is the ulnar nerve commonly damaged at the elbow?

A

Medial epicondyle injury - such as a fracture

67
Q

What are the motor and sensory deficits when the ulnar nerve is damaged at the medial epicondyle?

A

Flexor carpi ulnaris and medial half of flexor digitorum profundus paralysed -> flexion of wrist can occur but is accompanied by abduction
Abduction and adduction of fingers can’t occur
Movement of little and ring fingers greatly reduced

Loss of sensation in anterior and posterior surfaces of the medial one and half fingers, associated palm area

Patient can’t grip paper placed between fingers

68
Q

What are the motor and sensory deficits when the ulnar nerve is damaged by laceration of the wrist?

A

Abduction and adduction can’t occur
Movement of little and ring finger reduced but muscles in forearm are unaffected

Just the palmar branch and superficial branch affected so sensory loss over palmar medial 1.5 fingers

Patient can’t grip paper and ulnar claw develops over long term

69
Q

What is ulnar claw?

A

Hyperextension of MCP joints of little and ring fingers (paralysis of lumbricals)
Flexion at ITP joins

70
Q

What is a upper brachial plexus injury? (Erb’s palsy/waiter’s tip)

A

Excessive increase in angle between neck and shoulder (stretch or tear of superior nerve roots) -> difficult birth of shoulder trauma
Nerves derived from C5 or C6 solely
Affected limb hangs limp, medially rotated, pronated

71
Q

What is a lower brachial plexus injury? (klumpke’s palsy/claw hand)

A

Excessive abduction of arm - person catching a branch when fall from tree
Nerves derived from T1 - median and ulnar
-> clawed hand appearance

72
Q

What is the function of anterior compartment of the forearm?

A

Flexion at wrist and fingers
Pronation
Innervated by ulnar and median nerve

73
Q

What is the function of the posterior compartment of the forearm?

A

Extension at the wrist and fingers
Supination
Innervated by the radial nerve

74
Q

What is the blood supply to the anterior compartment of the forearm?

A

Ulnar and radial artery

75
Q

What is the blood supply to the posterior compartment of the forearm?

A

Anterior and posterior interosseous arteries (branches of short common interosseous artery from the proximal artery)

76
Q

Why is compartment syndrome more common in the anterior compartment of the forearm?

A

Me don’t know