Upper Limb Flashcards
(35 cards)
Name the terminal branches of brachial plexus
Anterior division:
- lateral: musculocutaneous nerve
- medial: ulnar nerve
- lateral + medial: median nerve
Posterior division:
- radial nerve
- axillary nerve
What is proximal-distal gradient:
The more proximal muscles are innervated by the higher
segments (C5 and C6) and the more distal muscles are innervated by the lower segments (C8 and T1)
What is Erb-Duchenne Palsy?
Lesion of C5,6 roots (usually by separation of head and shoulder). Affects axillary, suprascapular, musculocutaneous nerves. Arm is medially rotated and adducted, forearm is extended and pronated. “Waiter’s tip”
What is Klumpke’s Palsy?
Lesion of C8, T1 roots (usually when upper limb is abducted above the head). Affects ulnar and median nerves. “Claw hand”. +- Horner syndrome
What is the function of musculocutaneous nerve?
- flex elbow
- supination
What is the function of Median nerve?
- wrist flexion (+ulnar)
- flexion of 1,2,3 digits
- thumb opposition
- sensory innervation of 1, 2, 3 1/2 digits on palm side
What is the function of Ulnar nerve?
- wrist flexion (weak, +median)
- flexion of 3, 4 digits
- adduction and abduction digits 2-5
- adduct the thumb
- sensor innervation of 1/2 4, 5 digits on both sides
What is the function of Axillary nerve?
- abduct shoulder 15° - 110° (deltoid muscle)
- lateral rotation of shoulder (teres minor m.)
What is the function of Radial nerve?
- extension of elbow, wrist, MP joints
- supination (supinator m.)
What is the function of Long thoracic nerve?
Innervation of m. serratus anterior (protracts and rotates scapula) => Lesion results in “winged scapula”
What is the function of suprascapular nerve?
Innervation of supraspinatus m. (abducts shoulder 0° - 15°) and infraspinatus m. (laterally rotates shoulder)
How does sensory innervation of the hand occur?
Palmar: - medial - ulnar nerve - lateral - median nerve Dorsal: - medial - radial nerve - lateral - ulnar nerve
Does carpal tunnel syndrome affect sensory innervation of the hand? Why?
No, because cutaneous branch of median nerve passes superficial to the carpal tunnel. Associated with edema during pregnancy
Name the possible causes and consequences of Radial nerve injury
1) Injury in axilla (Saturday night palsy, crutches, shoulder dislocation):
- loss of extension in elbow, wrist and MP joints
- sensory loss in posterior arm, forearm and dorsal of thumb
- “wrist drop”
2) Injury in arm (midshaft humerus fraction, lateral epicondyle, radial head dislocation):
- loss of extension in wrist and MP joints
- sensory loss in posterior forearm and dorsal of thumb
- “wrist drop”
3) Injury in wrist (laceration):
- sensory loss
- no motor loss
Name the possible causes and consequences of Median nerve injury
1) Injury in elbow (humerus fraction):
- loss of 1, 2, 3 digital flexion => hand of benediction
- loss of thumb opposition
- thenar atrophy
- loss of sensation (by median nerve)
2) Injury in wrist (carpal tunnel, laceration):
- thenar atrophy
- loss of sensation (if laceration)
- normal wrist and digital flexion
Name the possible causes and consequences of Ulnar nerve injury
Medial epicondyle, laceration, fracture of hook of hamate:
- loss of hypothenar muscles, 3,4 lumbricals muscles, all interossei and adductor policies muscle
- loss of abduction and adduction of digits 2-5
- “claw hand”
- sensory loss (by ulnar nerve)
Name the possible causes and consequences of Axillary nerve injury
Fracture of the surgical neck of the humerus, inferior dislocation of shoulder:
- loss of abduction of the arm to the horizon
- sensory lost over the deltoid muscle
Name the possible causes and consequences of Long thoracic nerve injury
Radical mastectomy, stab wound to the lateral chest: “winged scapula”
Name the possible causes and consequences of Suprascapular nerve injury
- loss of shoulder abduction between 0 and 15 degrees (supraspinatus
muscle) - weakness of lateral rotation of shoulder (infraspinatus muscle)
Name the possible causes and consequences of Musculocutaneous nerve injury
- loss of elbow flexion and weakness in supination
- loss of sensation on lateral aspect of the forearm
What’s the difference between Claw hand, hand of Benediction and Ape hand?
Claw hand:
- lesion of ulnar nerve => loss of 3,4 lumbricans m. => opposite muscles work => claw hand
- passive sign!
Hand of Benediction:
- lesion of median nerve ABOVE THE WRIST => loss of flexion of 1, 2, 3 digits while trying to make a fist
- active sign!
Ape (обезьяна) hand:
- carpal tunnel syndrom (lesion of median nerve) => thenar atrophy and loss of thumb abduction
How does arterial supply to the upper limb occur?
1) subclavian a.
2) axillary a.
- lateral thoracic a. (to mammary gland with long thoracic n. )
- subscapular a.
- posterior humeral circumflex a. (at surgical neck with axillary nerve)
3) brachial a.
- radial a. (deep palmar arch)
- ulnar a. (superficial palmar arch)
Which muscles form Rotator Cuff? Which of them is the most frequently damaged?
- supraspinal m.
- infraspinal m.
- teres minor m.
- subscapularis
(SIRS)
Supraspinal m. is the most frequently damaged
How does humerus dislocation occur?
inferior -> anterior -> superior
