Upper Limb Flashcards
1
Q
Pectoralis Major
A
Most superficial muscle of reigon. Large & fan shaped.
Function
Adducts & medially rotates the upper limb and draws the scapula anterioinferiorly. Clavicular head also acts individually to flex upper limb.
Innervation
Lateral & medial pectoral nerves
2
Q
Pectoralis Minor
A
Function
- Stabilises the scapula by drawing it anterioferiorly against the thoracic wall
- Protection of the scapula
- If arm & scapula are fixed, elevates the rib for deep breathing (runners etc)
Innervation
Medial pectoral nerve
3
Q
Serratus Anterior
A
Function
- Rotates the scapula, allowing arm to be held above 90o
- Holds scapula against rib-cage
Innervation
- Long thoraic nerve
4
Q
Subclavius
A
Small muscle underneath the clavicle, runs horizontally.
Function
- Anchors & depresses clavicle
- Provides minor protection to neurovasuclar structures underneath
Innervation
Nerve to Subclavius
5
Q
Clinical Relevance - Winging of Scapula
A
- Serratus anterior holds scapula against the ribcage
- If there is damage to the thoraic nerve then serratus anterior becomes paralysed
- The scapula gives a winged appearance, no longer being held against ribcage
- Long thoraic nerve palsy is most commonly down to traction issues, where the upper limb is stretched violently
6
Q
Trapezius
A
Superficial extrinsic muscle. Broad, flat & triangular
Function
- Upper fibres elevate scapula & rotates it during arm abduction
- Middle fibres retract scapula
- Lower fibres pull the scapula inferiorly
Innervation
Accessory nerve
7
Q
Latissimus Dorsi
A
Covers wide area of lower back, fibres converge into tendon (twist) that attaches to humerus
Function
Extends, adducts & medially rotates the upper limb
Innervation
Thoracodorsal nerve
8
Q
Levator Scapulae
A
Small, strap-like muscle
Function
Elevates the scapula
Retracts & rotates the scapula
Innervation
9
Q
Rhomboid Major
A
Situated inferiorly to the rhomboid minor
Function
Retracts & rotates the scapula
Innervation
Dorsal scapular nerve
10
Q
Rhomboid Minor
A
Situated superiorly to the major
Function
Retracts & rotates scapula
Innervation
Dorsal scapula nerve
11
Q
Clinical Relevance - Testing Accessory Nerve
A
- Accessory nerve damage is usually iatrogenic (due to a medical procedure e.g lymph node biopsy, jugular vein cannular)
- To test nerve, trapezius function can be assessed
- Ask patient ot shrug their shoulders
- Other features of damage include: muscle atrophy, asymmetrical neckline & partial paralysis of the sternocleidmastoid
12
Q
Deltoid
A
Can be divided into anterior, middle & posterior
Function
- Anterior fibres - flexion and medial rotation
- Posterior fibres - extension and lateral rotation
- Middle fibres - major abductor of the arm (takes over from supraspinatus, first 15o)
Innervation
Axillary nerve
13
Q
Teres Major
A
Function
Adducts the shoulder & medially rotates the arm
Innervation
Lower subscapular nerve
14
Q
Rotator Cuff
A
- A group of four muscles: supraspinatus, infraspinatus, subscapularis, teres minor
- Provides the glenohumeral joint with additional stability
- Collectively pulls the humeral head to the glenoid fossa
15
Q
Supraspinatus
A
Attachments
Originates: supraspinous fossa of the scapula
Attaches: greater tubercle of the humerus
Function
Abducts the arm 0-15o, assists deltoid for 15-90o
Innervation
Suprascapular nerve
16
Q
Infraspinatus
A
Attachments
Originates: Infraspinous fossa of scapula
Attaches: greater tubercle of the humerus
Function
Laterally rotates the arm
Innervation
Suprascapular nerve
17
Q
Subscapularis
A
Attachments
Originates: subscapular fossa, on costal surface of the scapula
Attaches: lesser tubercle of the humerus
Function
Medially rotates the arm
Innervation
Upper & lower subscapular nerves
18
Q
Teres Minor
A
Attachments
Originates: posterior surface of the scapula, adjacent to lateral border
Attaches: greater tubercle of the humerus
Function
Laterally rotates the arm
Innervation
Axillary nerve
19
Q
Clinical Relevance - Tendonitis
A
- Rotator cuff tendonitis refers to the inflamation of the tendons of the rotator cuff muscles
- Secondary to repetitive use of shoulder joint
- Supraspinatus most commonly affected - rubs and causes degenerative changes
- Conservative treatment: rest, analgesia & physiotherapy
- Severe cases: steriod injections & surgery
20
Q
Clinical Relevance - Suprascapular Ligament
A
- Can have ossification (calcification) which will compress the nerve/artery
- Can lead to atrophy of the intra/supraspinatus due to lack of innervation
21
Q
Biceps Brachii
A
Function
Supination of the forearm & flexes arm at elbow & shoulder
Innveration
Musculotaneous nerve
22
Q
Coracobrachialis
A
Function
Flexion of the arm at the shoulder & weak adduction
Innervation
Musculocutaneous nerve
23
Q
Brachialis
A
Function
Flexion at elbow
Innervation
Musculotaneous nerve, with contribution from radial nerve
24
Q
Clinical Relevance - Rupture of Biceps Tendon
A
- Long head of biceps brachii is a more common tendon to rupture
- When flexing elbow, characteristic is the ‘popeye sign’ - a bulge of the muscle belly
- Patient would not notice much weakness, due to brachialis & supinator muscle action
25
**Triceps Brachii**
Found in the posterior compartment of the upper arm. Made up of a long, lateral & medial head
**_Function_**
Extension of the arm at the elbow
**_Innervation_**
Radial nerve but in some individuals, long head is innervated by axillary nerve
26
**Flexor Carpi Ulnaris**
**_Function_**
Flexion & adduction at wrist
**_Innervation_**
Ulnar nerve
27
**Palmaris Longus**
**_Function_**
Flexion at wrist
**_Innervation_**
Median nerve
28
**Pronator Teres**
Forms the lateral border of the cubital fossa
**_Function_**
Pronation of forearm
**_Innervation_**
Median nerve
29
**Flexor Digitorum Superficialis**
Only muscle to make up the intermediate compartment - between superficial & deep layers
**_Function_**
Flexes metacarpophalangeal joints & proximal interphalangeal joints at 4 fingers
Flexes at wrist
**_Innervation_**
Median Nerve
30
**Flexor Digitorum Profundus**
**_Function_**
Only muscle that can flex interphalangeal finger joints
Flexes at metacarpophalangeal joints & at wrist
**_Innervation_**
Medial half (acts on little & ring finger) - ulnar nerve
Lateral half (middle & index finger) - anterior interosseous branch of median nerve
31
**Flexor Pollicis Longus**
Lies laterally to the Flexor Digitorum Profundus
**_Function_**
Flexes at the interphalangeal & metacarpophalangeal joint of the thumb
**_Innervation_**
Median nerve
32
**Pronator Quadratus**
**_Function_**
Pronates the forearm
**_Innervation_**
Median nerve
33
**Brachioradialis**
Paradoxical muscle - origin & innervation of an extensor muscle but is actually a flexor
**_Function_**
Flexes at elbow
**_Innervation_**
Radial nerve
34
**Extensor Digitorum**
**_Functions_**
Extends medial four fingers at MCP & IP joints
**_Innervation_**
Radial nerve (deep branch)
35
**Extensor Carpi Radialis Longus & Brevis**
**_Function_**
Due to position, able to extend & abducts the wrist
**_Innervation_**
Radial nerve
36
**Extensor Digiti Minimi**
Thought to originate from the extensor digitorum muscle - in some people they are fused together. Anatomically:
**_Function_**
Extends the little finger & contributes to extension at the wrist
**_Innervation_**
Radial nerve (deep branch)
37
**Extensor Carpi Ulnaris**
**_Function_**
Due to position, able to extend & adduct at wrist
**_Innervation_**
Radial nerve (deep branch)
38
**Aconeus**
Blended with fibres of the triceps brachii & the two muscles can be indistinguishable
**_Function_**
Extends & stabilises the elbow joint
Abducts the ulna during pronation of forearm
**_Innervation_**
Radial nerve
39
**Clinical Relevance - Tennis Elbow**
* Tennis Elbow aka Lateral Epicondylitis is inflammation of the posterium of the lateral epicondyle
* Peak age of onset: 40-50 years old
* Caused by repeated use of the supericial extensor muscles
* Strains their common tendious attachment to the lateral epicondyle
40
**Supinator**
Lies on the floor of the cubital fossa
**_Attachments_**
First head originates: lateral epicondyle of humerus
Second head originates: posterior surface of ulna
Inserts: together into posterior surface of radius
**_Function_**
Supinates forearm
**_Innervation_**
Radial nerve (deep branch)
41
**Abductor Pollicis Longus**
**_Function_**
Abducts the thumb
**_Innervation_**
Radial nerve (posterior interosseous branch)
42
**Extensor Pollicis Longus**
**_Function_**
Extends all joints of thumb: carpometacarpal, metacarpophalangeal & interphalangeal
**_Innervation_**
Radial nerve (posterior interossesous branch)
43
**Extensor Indicis Proprius**
**_Function_**
Extends the index finger
**_Innervation_**
Radial nerve (posterior interosseous branch)
44
**Clinical Relevance - Wrist Drop**
* Sign of radial nerve injury, proximal to elbow
Two common characteristic sites of damage:
* Axilla - injured via humeral dislocations/fractures
* Radial groove of humerous - injured via a humeral shaft fracture
In an event of a radial nerve lesion, all muscles in the extensor compartment of forearm get paralysed.
The flexor muscles remain unaffected (innervated by median nerve). Unopposed flexion at the wrist joint = wrist drop
45
**Thenar Muscles**
* Three short muscles located at the base of the thumb
* Bellies produce a bulge, thenar eminence
* Responsible for fine movements of the thumb
* All muscles innervated by the median nerve
46
**Opponens Pollicis**
Largest & lies underneath other two muscles
**_Function_**
Opposes the thumb by medially rotating and flexing the metacarpal on the trapezium
**_Innervation_**
Median nerve
47
**Abductor Pollicis Brevis**
**_Function_**
Abducts the thumb
**_Innervation_**
Median nerve
48
**Flexor Pollicis Brevis**
**_Function_**
Flexes the metacarpophalangeal (MCP) of thumb joint
**_Innervation_**
Median nerve. Deep head is innervated by the deep branch of ulnar nerve
49
**Hypothenar Muscles**
* Produce hypothenar eminence - muscular protusion on medial side of palm (base of little finger)
* Ulnar nerve innervates the three muscles
50
**Opponens Digiti Minimi**
Lies deep to other hypothenar muscles
**_Function_**
Rotates the little finger metacarpal towards the palm, producing opposition
**_Innervation_**
Ulna nerve
51
**Abductor Digiti Minimi**
Most superficial of hypothenar muscles
**_Function_**
Abducts little finger
**_Innervation_**
Ulna nerve
52
**Flexor Digiti Minimi Brevis**
Lies laterally to the abductor digiti minimi
**_Function_**
Flexes the MCP joint of little finger
**_Innervation_**
Ulnar nerve
53
**Lumbricals**
* Four lumbricals in hand, associated with a finger
* Crucial to finger movement - linking extensor tendons to flexor tendons
* Denervation of these muscles is basis for the unlar claw & hand of benediction
**_Function_**
Flexion at the MCP joint & extension at the interphalangeal (IP) joints of each digit
**_Innervation_**
Lateral two (index & middle): median nerve
Medial two (little & ring): ulnar nerve
54
**Dorsal Interossei**
Most superficial of all dorsal muscles - can be palpated on the dorsum of hand (4 in total)
**_Function_**
* adduct the fingers at MCP joint
* assist lumbricals in the flexion at MCP joints & extension of IP joints
**_Innervation_**
Ulnar nerve
55
**Palmar Interossei**
* three palmar interossei muscles
* located anteriorly on hand
**_Function_**
Adducts fingers at the MCP joint
**_Innervation_**
Ulnar nerve
56
**Palmaris Brevis**
Small thin muscle found superficially in the subcutaneous tissue of the hypothenar eminence
**_Function_**
* wrinkles skin of the hypothenar eminence
* deepens curvature of hand, improving grip
**_Innervation_**
Ulnar nerve
57
**Adductor Pollicis**
Large triangular muscle with two heads. Radial atery passes anteriorly through the space between two heads, forming deep plamar arch.
**_Function_**
Adductor of thumb
**_Innervation_**
Ulnar nerve
58
**Axilla Region Borders**
Apex - first rib, scapula, clavicle
Lateral wall - humerus
Medial wall - serratus anterior & thoracic wall (ribs & intercostal muscles)
Anterior wall - pectoralis major, minor & subclavius muscles
Posterior wall - subscapularis, teres major & lattisimus dorsi
59
**Axilla Reigon Contents**
* Axillary artery - 3 parts, one medial, one lateral & one posterior to pectoralis minor (medial & posterior travel in axilla)
* Axillary vein
* Brachial plexus
* Axillary lymph nodes
* Biceps brachii (short head)
* Coracobrachialis
60
**Clinical Relevance**
_Thoracic Outlet Syndrome_
* vessels & nerves of axilla may become compressed between bones in the apex
* common causes - trauma, repetitive motion, cervical rib
* presents with pain in the affected limb (dependent on nerve), tingling, muscle weakness & discolouration
_Lymph Node Biopsy_
* 75% of lymph from breast drains into the axilla lymph nodes
* Biospy to test for cancer, removal to prevent spreading (axillary clearance)
* Long thoraic nerve may become damaged, resulting in winged scapula
61
**Cubital Fossa Borders**
Lateral border - brachiodialis muscle
Medial border - pronator teres muscle
Superior border - hypothetical line between epicondyles of humerus
Floor - proximally by brachialis, distally by supinator muscle
Roof - consists of skin & fascia, reinforced by bicipital aponeurosis
62
**Cubital Fossa Contents**
* Radial nerve
* Biceps tendon
* Brachial artery
* Median nerve
Mneumonic - Really Need Beer To Be At My Nicest
63
**Clinical Relevance - Cubital Fossa**
**_Brachial Pulse & Blood Pressure_**
* Can be felt immeadiately when palpating medial to the biceps tendon in the cubital fossa
* When measuring blood pressure, stethoscope must be placed here to heat korotkoff sounds
**_Venepuncture_**
* Medial cubital vein located superficially in roof
* Connects basilic & cephalic veins
* Can be accessed easily - common site for venepuncture
**_Supracondular Fractures_**
* common in young people falling on hyper-extended elbow (sometimes flexed)
* displaced fracture fragments may impinge & damage cubital fossa
* direct damage/post-fracture swelling can cause lack of forearm blood supply from brachial artery
* ischaemia can cause Volkmann-s ischaemic contracture - uncrontrolled flexion of hand as flexors become short
* also can be damage to median or radial nerves
64
**Carpal Tunnel Borders**
* Narrow passageway found on anterior portion of wrist
* Entrance to palm for several tendons & median nerve
**_Carpal Arch_**
concave on palmar side, forming base & sides of carpal tunnel
lateral - scaphoid & trapezium tubercles
medial - hook of hamate & pisiform
**_Flexor Retinaculum_**
thick connective tissue that forms roof
turns carpal arch into tunnel by briding space between the medial & lateral parts
originates on lateral side & inserts into medial side of carpal arch
65
**tCarpal Tunnel Contents**
**_Tendons_**
* the tendon of flexor pollicis longus
* four tendons of flexor digitorum profundus
* four tendons of flexor digitorum superficialis
8 tendons surrounded by a single synovial sheath, 1 (flexor pollicis longus) surrounded by it's own synovial sheath
Sheaths allow free movement of tendons
**_Median Nerve_**
* once it passes through the carpal tunnel, splits into two branches: reccurent branch & palmar digital nerves
* palmer digital nerves give sensory innervation to palmer skin, dorsal nail beds & lateral 3 1/2 digits
* palmer digital nerves give motor innervation to lateral two lumbricals
* recurrent branch supplies thenar muscle group
66
**Clinical Relevance - Carpal Tunnel Syndrome**
* Caused by compression of median nerve in carpal tunnel
* Most common mononeuropathy & can be caused by thickening of ligaments & tendon sheaths
* Left untreated can cause weakness to thenar muscles
* Clinical features include: numbness, tingling & pain along median nerve (forearm). Often wakes patients in sleep & is worse in mornings
67
**Anatomical Snuffbox Borders**
Ulnar (medial) border: tendon of extensor pollicis longus
Radial (lateral) border: tendons of extensor pollicis brevis & abductor pollicis longus
Proximal border: styloid process of the radius
Floor: carpal bones, scaphoid & trapezium
Roof: skin
68
**Anatomical Snuffbox Contents**
* Radial artery (pulse can be palpated in some individuals)
* Superficial branch of the radial nerve - found in skin & subcutaneous tissue
* Cephalic vein
69
**Clinical Relevance - Scaphoid Fracture**
* Most commonly fractured carpal bone (FOOSH - falling on outstreched hand)
* Causes pain & tenderness in anatomical snuffbox
* Risk of avascular necrosis - 'retrograde blood supply' at distal end that may interrupt blood supply to proximal part rendering it avascular
* Scaphoid is supplied by two vascular branches of radial artery - volar branch is weaker than dorsal branch
* avascular necrosis (death of bone tissue) can cause non-union (failure to heal fractures properly)
* Having a missed scaphoid fracture makes patient more likely to develop osteoarthritis of wrist in later life
70
**Muscle Groups (& Blood Supply) - Anterior Compartment of Forearm**
Pronators of Wrist
* pronator teres & quadratus
* median nerve
Flexors of Wrist
* flexor carpi ulnaris & radialis
* ulnar nerve
Flexors of Fingers
* flexor digitorum profundus & superficialis
* median nerve (flexor digitorum profundus is also innervated by ulnar nerve)
Flexors of Thumb
* flexor pollicis longus & brevis
* median nerve
_General Blood Supply_
Anterior Arm = brachial artery & veins
Anterior Forearm = radial/ulnar arteries & venae comitantes
71
**Clinical Relevance - Tendon Injuries Hand**
* Tendons of the digits may be severed when the hand is injured
* To find out what tendons have been damaged, the patient should be asked to flex the fingers at both the distal & proximal interphalangeal joints:
If there is movement only in the distal phalanges - flexor digitorum superficialis damaged
If there is movement in the only middle phalanges - flexor digitorum profundus damaged
If no movement at all - both damaged
72
**Clinical Relevance - Linburg-Comstock**
* Common anatomical variation in the hand - involuntary flexion of the index/middle finger when flexing thumb
* Caused by extra tissue holding tendons together so they cannot move independently
* Opperation to remove tissue possible - important for musicians
* Another common anatomical variation is the presence of a palmaris longus (seen when wrist flexed & thumb and little finger opposed)
73
**Hand Innervation**
* Medial side (1/2 ring & little finger) innervated by ulnar nerve
* Lateral side (thumb, index, middle & 1/2 ring finger) is innervated by median nerve
* Ring finger is innervated by both nerves
74
**Carpal Tunnel Syndrome Tests**
**_Phalen's_**
* flex wrists maximally & push dorsal side of hands together for 1 minute
* if tingling is felt on lateral side of hand (thumb to 1/2 ring finger) carpal tunnel syndrome can be concluded
* pressure on median nerve
**_Tinel's_**
* tap over carpal tunnel at wrist & whole distribution of median nerve from index finger to elbow
* Positive test if tingling or numbness is felt on the lateral fingers (thumb to 1/2 ring finger) - median nerve damage
75
**Clinical Relevance - Allen's Test**
* shows anastomotic nature of the palmar arches - if there is a likely obstruction in the median or ulnar artery
* open & close hand quickly several times then squeeze hand tightly (clench fist)
* with thumbs, compress radial & ulnar arteries
* open hand & release one thumb (one artery at a time)
* if blood flows into hand quickly - healthy artery
* compare with other hand to see if an artery is impared
76
**Supination VS Pronation**
* Supination is a stronger movement - supinator muscles (supinator & biceps brachii) are larger & more developed so are more powerful and don't tire easily
* Pronation is a weaker movement - pronator muscles are smaller & weaker (pronator teres & quadratus) so forearm will tire easily
* Reason why screws require an anti-clockwise movement (supination) to tighten
77
**Muscle Groups - Hand**
Lumbricals
* flex metacarpophalangeal joints & extend interphalangeal joints
* median & ulnar nerve
Palmar Interossei
* adducts digits 2-4
* ulnar nerve
Dorsal Interossei
* abducts digits 2-4
* ulnar nerve
Thenar Muscles
* fine movements of thumb
* median nerve
Hypothenar Muscles
* abducts, flexes and rotates 5th digit
* ulnar nerve
78
**Clinical Relevance - Venous Patterns**
* Important for venepuncture & intravenous access
* Cephalic & basilic veins are most prominent and superficial
* Basilic vein is larger than cephalic vein so is usually the most common vessel used for intravenous access (however there is anatomical variation between patients)
79
**Interossei**
Palmar Interossei
* anterior compartment of hand
* adduct digits
* PAD - Palmar interossei ADduct
Dorsal Interossei
* Posterior compartment of hand
* adbucts digits
* DAB - Dorsal interossei ABduct
80
**General Nerves & Veins**
Radial
* mainly extensor muscles
Median
* mainly flexor muscles
* thenar muscles
* 1st two lumbricals (little & ring)
Ulnar
* mainly intrinsic muscles of hand (hypothenar)
Musculotaneous
* three main muscles of anterior arm
81
**Extensor Retinaculum**
* thickened fibrous band that traverses wrist
* holds extensor tendons in position
* prevents bow-stringing - if reticulum was torn, tendons would come more superior & take the shortest route when digits extend
82
**Tendons in Digits**
* Two tendons & muscle bellies in the index (2nd) and little (5th) finger - move independently/more freely
* Interconnections in the dorsal of the hand - middle (3rd)/ ring (4th) finger cannot move alone as easily
83
