7. Upper Limb (Part 2) Flashcards
(108 cards)
1
Q
What are the bones in the wrist and hand what do they articulate with?
A
- Carpals, Metacarpals, Phalanges (proximal, intermediate, distal)
- Carpals articulate with the radius at the wrist
2
Q
What kind of joint is the wrist joint?
A
Synovial condyloid joint (a.k.a. ellipsoid)
3
Q
What structures are involved in the wrist joint?
A
The joint is formed by articulations between the distal end of the radius and articular disc of the distal radioulnar joint with the proximal row of the carpal bones except the pisiform.
4
Q
Label this.
A
5
Q
Name all of the carpals, starting from the side of the thumb.
A
Distal: Trapezium, Trapezoid, Capitate, Hamate
Proximal: Scaphoid, Lunate, Triquetrum, Pisiform
6
Q
Give a good mnemonic for remembering the carpals.
A
Some lovers try positions that they can’t handle.
This gives the proximal then distal rows, each from lateral to medial side in the anatomical position.
7
Q
Out of the triquetrum and pisiform, which is on the palmar side of the hand?
A
Pisiform
8
Q
Describe how a scaphoid fracture might occur, symptoms and why it is dangerous.
A
- Occurs when falling onto outstretched hand
- Characterised by pain in the anatomical snuffbox
- In many people the blood supply to the scaphoid is only in the distal to proximal direction, so a fracture can cause avascular necrosis of the proximal portion of the scaphoid
9
Q
Describe what each of the carpals articulates with in the wrist joint.
A
- Scaphoid -> Articulates with radius
- Lunate -> Articulates with radius
- Triquetrum -> Articulates with articular disc
10
Q
The pisiform is a … bone.
A
Sesamoid
11
Q
What attaches to the pisiform?
A
Flexor retinaculum of the wrist
12
Q
What type of joint is the first carpometacarpal joint (base of thumb) and what movement does this allow?
A
Synovial saddle joint, allows opposition and reposition
13
Q
What movements are possible at the wrist joint?
A
The wrist joint is capable of flexion-extension, radial deviation and ulnar deviation, which may be combined to create a circumduction-like movement.
14
Q
What type of joint are the second, third, fourth and fifth carpometacarpal joints (between the wrist and the four fingers)?
A
Plane synovial joints
15
Q
What movement does the metacarpophalangeal joint of the thumb not allow?
A
Abduction/adduction - this is instead allowed by the first hypermobile carpometacarpal joint
16
Q
What type of joint are the second to fifth metacarpophalangeal joints and what movements does this allow?
A
Synovial ellipsoid joints, allow: - Flexion/extension - Abduction/adduction
17
Q
What type of joints are the distal and proximal interphalangeal joints and what stabilises them?
A
Synovial hinge joints, stabilised by collateral ligaments
18
Q
What are the movements of the pollux/thumb?
A
- Abduction (movement away from the hand along sagittal plane)
- Adduction (movement towards the hand along sagittal plane)
- Extension (movement away from the hand along the coronal plane)
- Flexion (movement towards and across the hand along the coronal plane)
- Opposition (UNIQUE, ability to touch little finger with thumb)
- Reposition (UNIQUE, ability to return hand to normal shape after opposition)
19
Q
Summarise where the flexors and extensors of the wrist and hand joints originate.
A
- Flexors -> At the medial epicondyle of the humerus, as the common flexor tendon.
- Extensors -> At the lateral epicondyle as the common extensor tendon.
20
Q
What is the carpal tunnel and what does it contain?
A
- A specialised fibro-osseous canal in the wrist joint
- It contains:
- 4 x tendons of flexor digitorum profundus (FDP)
- 4 x tendons of flexor digitorum superficialis (FDS)
- 1 x tendon of flexor pollicis longus (FPL)
- Median nerve
21
Q
What makes up the floor and roof of the carpal tunnel?
A
- Floor = Arch of the carpal bones
- Roof = Flexor retinaculum
22
Q
What are the names of the wrist and finger flexors you need to know?
A
- Flexor carpi radialis -> Flexes and abducts wrist
- Flexor carpi ulnaris -> Flexes and adducts wrist
- Flexor digitorum superficialis -> Flexes proximal and middle phalanges of fingers
- Flexor digitorum profundus -> Flexes distal phalanges of fingers
- Flexor pollicis longus -> Flexes thumb
23
Q
What is the flexor retinaculum?
A
It is a fibrous band above the carpals that forms the roof of the carpal tunnel. It is essentially a ligament.
24
Q
What nerves innervate what muscles in the hand and wrist?
A
- Wrist and finger extensors are innervated by the radial nerve.
- Medial wrist and finger flexors are innervated by the ulnar nerve.
- Lateral wrist, finger and thumb flexors innervated by the median nerve.
- All intrinsic muscles of the hand except the LOAF muscles are innervated by the ulnar nerve.
- LOAF muscles are innervated by the median nerve.
25
Describe the flexor carpi radialis, including function, attachments and innervation.
* Function: Flexes and abducts the wrist
* Origin: Common flexor tendon
* Insertion: Base of 2nd and 3rd metacarpal bones
* Innervation: Median nerve
26
Describe the flexor carpi ulnaris, including function, attachments and innervation.
* Function: Flexes and adducts the wrist
* Origin: Common flexor tendon and posterior border of ulna
* Insertion: Pisiform bone
* Innervation: Ulnar nerve
27
Describe the flexor digitorum superficialis, including function, attachments and innervation.
* Function: Flexes middle and proximal phalanges of medial four digits
* Insertion: Proximal part of middle phalanges
* Innervation: Median nerve
28
Describe the flexor digitorum profundus, including function, attachments and innervation.
* Function: Flexes distal phalanges of medial four digits
* Insertion: Distal phalanges
* Innervation: Ulnar half of this muscle is supplied by the ulnar nerve and the median nerve supplies the rest of the muscle.
29
Describe the flexor pollicis longus, including function, attachments and innervation.
* Function: Flexes thumb
* Insertion: Distal phalanx of thumb
* Origin: Flexor surfaces of radius and ulna
* Innervation: Median nerve
30
What are the flexors of the fingers contained in?
They are enclosed in a lubricating synovial sheath. These can, however, act as conduits through which infections can track.
31
What are the names of the wrist and finger extensors you need to know?
* Extensor digitorum -\> Extends fingers
* Extensor pollicis longus -\> Extends thumb
* Extensor pollicis brevis -\> Extends thumb
* Abductor pollicis longus -\> Abducts thumb and wrist
32
Describe the extensor digitorum, including function, attachments and innervation.
* Function: Extends fingers
* Origin: Common extensor tendon
* Insertion: Middle and distal phalanges of ulnar four digits
* Innervation: Radial nerve
33
Describe the extensor pollicis longus, including function, attachments and innervation.
* Function: Extends thumb
* Origin: Posterior surface of ulna and interosseus membrane
* Insertion: Distal phalanx of thumb
* Innervation: Radial nerve
34
Describe the extensor pollicis brevis, including function, attachments and innervation.
* Function: Extends thumb
* Origin: Posterior surface of radius
* Insertion: Proximal phalanx of thumb
* Innervation: Radial nerve
35
Describe the abductor pollicis longus, including function, attachments and innervation.
* Function: Abducts thumb and wrist
* Origin: Posterior surface of radius and ulna
* Insertion: Metacarpal of thumb
* Innervation: Radial nerve
36
Which nerve innervates all of the extensors of the wrist and fingers?
Radial nerve
37
Where is the anatomical snuff box? Why is it important?
* A triangular fossa on the lateral aspect of the dorsum of the hand, which can be “lit up” when the thumb is fully extended.
* This is an important anatomical landmark, as the radial artery crosses its floor obliquely.
* Fractures of the scaphoid typically cause tenderness on palpation of the anatomical snuffbox.
38
What makes up the borders of the anatomical snuff box?
* Medial border -\> Tendon of extensor pollicis longus
* Lateral border -\> Tendons of abductor pollicis longus and extensor pollicic brevis
* Floor -\> Scaphoid bone
39
Draw the position of the tendons, nerves and vessels at the wrist.
40
What is trigger finger?
* Inflammation of the tendon sheath of the flexor muscles can result in a swelling forming a knot or thickening in the tendon.
* As it passes through the tendon sheath there may be a clicking of the involved finger as the tendon eventually slips through.
* Eventually the finger may lock in the bent position.
* Splinting or the injection of anti-inflammatory drugs relieves the symptoms in the majority of cases.
41
What is mallet finger?
Rupture of the extensor tendon at the distal interphalangeal joint causes the joint to take on an abnormally flexed position. Whilst the joint can be extended passively this movement cannot be actively generated by the patient.
42
Which of the nerves is most likely to be injured in wrist drop?
Radial nerve (since it innervates the extensors of the wrist and fingers)
43
What is the palmar aponeurosis?
* The central part of the deep fascia of the palm which is a highly specialized thickened structure with little mobility.
* It is triangular in shape and it covers the underlying neurovascular and tendon structures.
44
What is the palmaris longus?
* The most superficial muscle of the superficial forearm flexors
* It is absent in around 14% of the population
45
What are palmar fascial spaces?
* Spaces of hand are formed by fascia and fascial septae.
* Fascia and fascial septae of the hand are arranged in such a manner that many spaces are formed.
* These spaces are important as they can get infected and distended with pus.
46
Where are the intrinsic muscles of the hand that control thumb movements found?
In the thenar eminence, found at the base of the thumb.
47
What are the muscles of the thenar eminence that you need to know?
* Flexor pollicis brevis -\> Flexes metacarpophalangeal joint of the thumb
* Abductor pollicis brevis -\> Abducts thumb
* Opponens pollicis -\> Opposes the thumb
* Adductor pollicis -\> Adducts thumb
48
Describe the flexor pollicis brevis, including function, attachments and innervation.
* Function: Flexes metacarpophalangeal joint of the thumb
* Origin: Flexor retinaculum and adjacent carpal bones
* Insertion: Proximal phalanx of thumb
* Innervation: Median nerve
49
Describe the abductor pollicis brevis, including function, attachments and innervation.
* Function: Abducts thumb
* Origin: Flexor retinaculum and adjacent carpal bones
* Insertion: Proximal phalanx of thumb
* Innervation: Median nerve
50
Describe the opponens pollicis, including function, attachments and innervation.
* Function: Opposes the thumb by 'swivelling' the first metacarpal on its saddle joint with the trapezium
* Origin: Flexor retinaculum and adjacent carpal bones
* Insertion: Metacarpal of thumb
* Innervation: Median nerve
51
Describe the adductor pollicis, including function, attachments and innervation.
* Function: Adducts thumb
* Origin: Capitate and third metacarpal (two heads)
* Insertion: Proximal phalanx of thumb
* Innervation: Ulnar nerve
52
What are lumbrical muscles?
Muscles responsible for flexion of the metacarpopharyngeal joints and extension of the interphalangeal joints of each finger.
53
What are the interossei?
* The dorsal interossei muscles, located between the metacarpals, abduct the fingers.
* Conversely, the palmar interossei muscles adduct the fingers.
* This can be remembered with the mnemonic: PAD and DAB (palmar adduction, dorsal abduction).
54
What are the intrinsic muscles of the hand innervated by?
* All intrinsic muscles of the hand except the radial two lumbricals, opponens pollicis, abductor pollicis brevis and flexor pollicis brevis (the “LOAF” muscles) are innervated by the ulnar nerve.
* The LOAF muscles are innervated by the median nerve.
55
What is carpal tunnel syndrome? What are the symptoms?
* Inflammation or trauma to the canal may cause entrapment of the median nerve.
* Symptoms:
* Numbness of the radial 3 ½ digits
* Atrophy of the thenar eminence of the hand.
* Classically, palmar sensation is spared due to a branch of the median nerve passing superficial to the flexor retinaculum.
* Treatment may involve a surgical incision to the flexor retinaculum to relieve compression.
56
What can lead to clawing of the hand?
* Lacerations to the wrist and subsequent ulnar nerve damage causes paralysis of most of the intrinsic hand muscles.
* Paralysis of the medial two lumbricals cause unopposed extensor muscle action (extensor digitorum) on the MCP joints of the 4th and 5th digits.
* Weakened extension of the interphalangeal joints due to lumbrical and interossei paralysis causes these joints to become flexed.
* Combined together, this lesion gives the hand a claw-like appearance.
57
Draw a diagram of the arterial supply of the upper limb.
58
What does the subclavian artery arise from?
From the brachiocephalic trunk on the right and directly from the arch of the aorta on the left.
59
Where does the subclavian artery pass?
The subclavian artery passes between the clavicle and first rib.
60
What does the subclavian artery become and when?
When the subclavian artery passes across the outer border of the first rib, it forms the axillary artery.
61
What does the axillary artery supply?
The axillary artery gives off branches to:
* Scapula
* Thoracic wall
* Posterior and anterior circumflex humeral arteries which wind around the (surgical) neck of the humerus.
62
What does the axillary artery become and when?
Below teres major the axillary artery is now called the brachial artery.
63
What does the brachial artery supply?
It gives off the profunda brachii artery, which supplies the posterior compartment of the arm.
64
Describe the superficial and deep palmar arches.
* The radial and ulnar arteries divide into superficial and deep branches, which form the superficial and deep palmar arches.
* The superficial arch lies more distal to the deep arch, and thus forms the digital arteries.
65
Describe the surface markings of the palmar arches.
* Superficial palmar arch -\> Distal border of a fully extended thumb.
* Deep palmar arch -\> Proximal border of a fully extended thumb, across the base of the metacarpal bones.
66
When can the brachial artery be damaged?
* In supracondylar fractures of the humerus.
* The median nerve is also likely to be damaged.
67
Describe the upper limb pulse points.
* Axillary pulse: located inferiorly of the lateral wall of the axilla
* Brachial pulse: located on the inside of the upper arm near the elbow
* Radial pulse: located on the lateral of the wrist
* Ulnar pulse: located on the medial of the wrist
68
Describe the venous drainage of the upper limb.
Superficial arteries:
* The dorsal venous arch of the hand drains to both the basilic (ulnar side) and cephalic (radial side) veins of the forearm.
* The cephalic and basilic veins connect via the median cubital vein at the anterior aspect of the elbow.
Deep veins:
* Above the elbow, the basilic vein joins with the brachial vein to become the axillary vein.
* The cephalic vein then drains in.
* The axillary vein then drains into the subclavian vein at the base of the neck.
69
Draw the venous drainage of the upper limb.
70
Name the superficial and deep veins of the upper limb.
Superficial:
* Dorsal venous arch of hand
* Basilic
* Cephalic
Deep:
* Axillary
* Subclavian
71
Describe the venepuncture and cannulation sites in the upper limb.
* Median cubital
* Cephalic (at the wrist)
* Subclavian vein for insertion of central venous lines
72
Describe the lymphatic drainage of the upper limb.
* Lymph drainage runs in parallel to the venous drainage, so that there are both superficial and deep lymphatic veins.
* Most superficial and deep vessels in the upper limb drain to the axillary lymph nodes, which surround the axillary artery.
* The lateral nodes drain most of the upper limb’s lymph, which then drain to the central nodes and ultimately the apical nodes.
* The axillary lymph nodes also drain the lymph vessels from the lateral quadrants of the breast.
73
What may be seen after drainage of the axillary lymph nodes?
Lymphoedema
74
What nerve roots innervate the upper limb (i.e. the brachial plexus)?
C5-T1
75
What is the brachial plexus formed by?
The anterior rami of spinal nerves C5-T1.
76
What do the anterior and posterior divisions of the brachial plexus supply?
* Anterior divisions supply the flexor muscles.
* Posterior divisions supply the extensors.
77
Draw the brachial plexus.
78
What are the different levels of the brachial plexus?
79
What are the end nerves of the brachial plexus?
* Musculocutaneous
* Axillary
* Median
* Radial
* Ulnar
80
What are some important branchings off from the brachial plexus that you need to know?
* Innervation of the serratus anterior (long thoracic nerve) arises from the roots
* Suprascapular nerve arises from the upper trunk of the brachial plexus
81
Name all of the nerve roots controlling the different upper limb movements.
82
What nerve roots control shoulder abduction and adduction?
* Abduction -\> C5
* Adduction -\> C6, C7, C8
83
What nerve roots control shoulder flexion and extension?
* Flexion -\> C5
* Extension -\> C6, C7, C8
84
What nerve roots control elbow flexion and extension?
* Flexion -\> C5, C6
* Extension -\> C6, C7, C8
85
What nerve roots control forearm pronation and supination?
* Pronation -\> C7, C8
* Supination -\> C6
86
What nerve roots control wrist flexion and extension?
* Flexion -\> C6, C7
* Extension -\> C6, C7
87
What nerve roots control finger flexion, extension, abduction and adduction?
* Flexion -\> C7, C8
* Extension -\> C7, C8
* Abduction -\> T1
* Adduction -\> T1
88
Describe the dermatomes of the upper limb.
* C4 = tip of shoulder
* C5 = regimental badge patch area
* C6 = lateral aspect of forearm and thumb
* C7 = middle finger
* C8 = little finger
* T1 = medial aspect of proximal forearm
89
Draw the dermatomes of the upper limb.
90
What are the effects of damage to the upper trunk of the brachial plexus?
* Loss of C5 and C6
* Main effects: Loss of shoulder abduction, lateral rotation and elbow flexion.
91
What are the effects of damage to the lower trunk of the brachial plexus?
* Loss of C8 and T1
* This mainly affects the hand
92
What does the musculocutaneous nerve innervate?
* Motor: Elbow flexors
* Sensory: Lateral forearm
93
What does the median nerve innervate?
* Motor: Forearm flexors (except ulnar FDP and FCU) and muscles of thenar eminence and lateral two lumbricals. -\> i.e. Lateral wrist, finger and thumb flexors + LOAF muscles.
* Sensory: Lateral palm and lateral three and a half digits on palmar surface
94
How may the median nerve be damaged?
* Supracondylar fractures of the humerus
* Cuts at the wrist
* Carpal tunnel syndrome
95
What does the ulnar nerve innervate?
* Motor: Ulnar half of flexor digitorum profundus, flexor carpi ulnaris and most intrinsic muscles of the hand (except LOAF).
* Sensation: Anterior and posterior surfaces of medial one and a half fingers and associated palm
96
What is the effect of damage to the ulnar nerve?
Clawing of the hand
97
What does the axillary nerve innervate?
* Motor: Teres minor and deltoid
* Sensory: Regimental badge area
98
How may the axillary nerve be damaged?
Dislocation of the shoulder
99
What does the radial nerve innervate?
* Motor: Elbow, wrist and finger extensors
* Sensory: Posterior aspect of forearm, dorsal surface of lateral side of palm and lateral three and a half digits
100
How may the radial nerve be damaged and what is the effect of this?
* Mid-shaft fracture of the humerus
* Results in wrist drop, with triceps function spared
101
What is Drunkards' palsy?
A compressive neuropathy of the radial nerve that occurs from prolonged, direct pressure onto the upper medial arm or axilla by an object or surface.
102
Draw a diagram to show the innervation of the main body compartments [although you don't need to know most of these probabaly].
103
Draw the sensory territories of the different upper limb nerves.
104
For the musculocutaneous nerve, draw a diagram to show which muscles are innervated by it.
105
For the median nerve, draw a diagram to show which muscles are innervated by it. [EXTRA?]
106
For the ulnar nerve, draw a diagram to show which muscles are innervated by it. [EXTRA?]
107
For the radial nerve, draw a diagram to show which muscles are innervated by it.
108
Describe the functional position of the forearm and hand.
* Wrist in 20-30° of extension and slight ulnar deviation.
* Fingers in 45-60° of MPC, 10-15° of PIP and 5-10°DIP flexion
* Thumb in 45° of abduction
