Flash cards for ulnar nerve
Reading File
Finding Sources
Finding Sources
Reading File
Reading File
Reading File
Reading File
Reading File
Reading File
Reading File
Loading Image
Loading Image
I now have comprehensive content. Let me compile all the flashcards:
Here are your Ulnar Nerve Flashcards, sourced from Gray's Anatomy for Students, Bradley and Daroff's Neurology in Clinical Practice, and Miller's Review of Orthopaedics.
🃏 Flashcard 1 — Origin & Root Values
Q: What are the root values and cord origin of the ulnar nerve?
A: C8 and T1 roots, via the lower trunk and medial cord of the brachial plexus. It also travels alongside the medial brachial and antebrachial cutaneous sensory nerves.
🃏 Flashcard 2 — Course in the Arm
Q: What is the course of the ulnar nerve in the arm, and how many branches does it give there?
A: The ulnar nerve enters the arm medial to the axillary artery, passes through the medial intermuscular septum into the posterior compartment (anterior to the medial head of triceps), then passes posterior to the medial epicondyle into the forearm. It gives no branches in the arm.
🃏 Flashcard 3 — Course at the Elbow
Q: Describe the ulnar nerve's passage at the elbow.
A:
- Lies in the ulnar groove between the medial epicondyle and the olecranon process (a fibro-osseous tunnel)
- Just distal to the groove, it passes under the humeral-ulnar aponeurosis (tendinous arch of the two heads of flexor carpi ulnaris) - this forms the cubital tunnel
- First muscular branches here: to FCU and ulnar half of FDP
🃏 Flashcard 4 — Course in the Forearm
Q: What muscles does the ulnar nerve innervate in the forearm, and what cutaneous branches arise here?
A:
- Motor: Flexor carpi ulnaris (FCU) + medial half of flexor digitorum profundus (ring & little fingers)
- Cutaneous branches:
- Palmar branch (mid-forearm) → medial side of palm
- Dorsal branch (distal forearm, ~5-8 cm above wrist, passes deep to FCU tendon) → posteromedial hand and dorsum of little finger + medial ring finger
Neither dorsal nor palmar branch passes through Guyon's canal - important for localisation.
🃏 Flashcard 5 — Course at the Wrist / Guyon's Canal
Q: Describe the ulnar nerve's entry into the hand and its divisions in Guyon's canal.
A:
- Enters hand lateral to pisiform, superficial to flexor retinaculum, accompanied by ulnar artery (ulnar artery is lateral to the nerve)
- Guyon's canal is bounded by: pisiform (medial) + hook of hamate (lateral), covered by volar carpal ligament
- Divides into:
- Deep branch (motor) → hypothenar muscles, interossei, medial 2 lumbricals, adductor pollicis, deep head FPB
- Superficial branch (sensory) → little finger + medial half of ring finger (palmar)
🃏 Flashcard 6 — Motor Supply Summary
Q: List all muscles innervated by the ulnar nerve.
A:
| Region | Muscles |
|---|---|
| Forearm | FCU, FDP (ring + little) |
| Hypothenar | Abductor digiti minimi, Flexor digiti minimi, Opponens digiti minimi |
| Hand (deep) | All dorsal & palmar interossei (4+3), Medial 2 lumbricals (ring & little), Adductor pollicis, Deep head of FPB |
Mnemonic: "LOAF" gives median nerve muscles; everything else intrinsic = ulnar.
🃏 Flashcard 7 — Sensory Supply Summary
Q: What is the sensory distribution of the ulnar nerve?
A:
- Palmar branch (from forearm): medial side of palm (proximal)
- Dorsal branch (from forearm): posteromedial hand, dorsum of little finger + medial half of ring finger
- Superficial terminal branch (from Guyon's canal): palmar surface of little finger + medial half of ring finger
- Does NOT extend above the wrist (sensory loss above wrist suggests plexus/root lesion)
🃏 Flashcard 8 — Ulnar Claw Hand
Q: What is ulnar clawing, and why is it worse distally?
A:
- MCP joints of ring and little fingers hyperextended (lumbricals paralysed) + IP joints flexed (FDP intact) = "clawing"
- Paradox of the claw: Wrist lesions cause more clawing than elbow lesions because at the elbow, FDP to ring/little is also lost, so the flexor force at IP joints is reduced
- Clawing is limited to ring & little fingers because index & middle finger lumbricals are innervated by the median nerve
🃏 Flashcard 9 — Clinical Signs of Ulnar Nerve Palsy
Q: Name the 3 key clinical signs of ulnar nerve palsy and what each tests.
A:
| Sign | Description | Weak Muscle |
|---|---|---|
| Froment's sign | Thumb IP flexes during key pinch (FPL compensates) | Adductor pollicis |
| Jeanne's sign | Thumb MCP hyperextends during key pinch | Adductor pollicis |
| Wartenberg's sign | Little finger abducted/extended, catches on pocket | 3rd palmar interosseous |
Additional: atrophy of first dorsal interosseous is the most visible wasting.
🃏 Flashcard 10 — Cubital Tunnel Syndrome
Q: What is cubital tunnel syndrome? List the sites of compression.
A:
- Second most common entrapment neuropathy (after CTS)
- Compression of ulnar nerve at the elbow
- Mnemonic for sites (AO TEAM):
- Arcade of Struthers
- Osborne ligament (humeral-ulnar aponeurosis)
- Triceps (medial head)
- Epitrochleanconeus muscle (accessory)
- Aponeurosis of two heads of FCU
- Medial intermuscular septum
- Better surgical outcome if operated before motor symptoms appear
- No difference between in-situ decompression vs anterior transposition (Miller's Review of Orthopaedics)
🃏 Flashcard 11 — Ulnar Nerve at Elbow: Clinical Features
Q: What are the symptoms and signs of ulnar neuropathy at the elbow?
A:
- Sensory: Numbness/tingling in little + ring fingers, hypothenar eminence; dorsum of hand (dorsal branch area); does NOT extend above wrist
- Motor: Weak FCU, FDP (ring/little), intrinsic hand muscles; reduced grip; claw hand
- Wasting: First dorsal interosseous most noticeable
- Pain: Around elbow, tender to palpation; Tinel's sign at elbow
- Provocative test: Flexion-compression test
- EDX: Focal slowing (>10-15 m/s) or conduction block across elbow; elbow studies done at 70-90° flexion
🃏 Flashcard 12 — Guyon's Canal Zones
Q: What are the 3 zones of Guyon's canal and what is affected in each?
A:
| Zone | Lesion Type | Deficits |
|---|---|---|
| Zone 1 | Mixed (proximal to bifurcation) | Motor + sensory |
| Zone 2 | Deep branch (motor only) | Pure motor - intrinsic weakness, no sensory loss |
| Zone 3 | Superficial branch (sensory only) | Pure sensory - little/ring finger numbness |
- Common cause: extrinsic mass (ganglion, lipoma, aneurysm)
- Concurrent CTS: Guyon's canal decompressed automatically by TCL release
🃏 Flashcard 13 — Elbow vs Wrist Lesion: How to Differentiate
Q: How do you distinguish an ulnar nerve lesion at the elbow from one at the wrist?
A:
| Feature | Elbow | Wrist (Guyon's) |
|---|---|---|
| FCU weakness | Yes | No |
| FDP (ring/little) weakness | Yes | No |
| Dorsal hand sensation | Lost | Preserved (dorsal branch exits above wrist) |
| Medial forearm sensation | Normal (MABC) | Normal |
| Claw severity | Less (FDP also weak) | More (FDP intact - paradox) |
| Palmar sensation (hypothenar) | Lost | Depends on zone |
🃏 Flashcard 14 — Differentiating Ulnar Neuropathy from C8/T1 Root or Lower Trunk Plexopathy
Q: What features suggest a plexus/root lesion rather than ulnar neuropathy at the elbow?
A:
- Sensory loss extending > 3 cm above the wrist into the medial forearm/arm (territory of medial brachial and antebrachial cutaneous nerves)
- Weakness of median + radial C8 muscles: e.g., FPL (median) or long finger extensors (radial)
- These muscles are unaffected in isolated ulnar neuropathy
Sources: Gray's Anatomy for Students, pp. 881, 905, 936-937 | Bradley and Daroff's Neurology in Clinical Practice, pp. 2638-2640 | Miller's Review of Orthopaedics 9th Ed, p. 736
This is a shared conversation. Sign in to Orris to start your own chat.