Grays Review II Flashcards
Wrist drop and weakness of grasp, but normal extension of elbow joint. No loss of sensation in the affected limb. Which nerve was most likely affected?
- Ulnar
- Anterior interosseus
- Posterior interosseus
- Median
- Superficial radial
PIN
The radial nerve travels between the heads of the triceps brachii in the arm, and then enters the cubital fossa, wher eit divides into the superficial and deep branch. The dep branch continues as the PIN, innervating extensors of the forearm. Wristdrop means radial, but sensation is intact so it can’t be superficial radial.
Flexion and supination of the forearm are severely weakened. She also hass loss of sensation on the lateral forearm. What neve was injured?
- Radial
- Musculocutaneous
- Median
- Laterla cord of brachial plexus
- Lateral cutaneous nerve of forearm.
Musculocutaneous.
Musculocutaneous innervates the biceps brachii, the most powerful supinator. It also innervates the anterior arm muscles, which flex the elbow joint. It also continues as the lateral cutaneous nerve to innervate the lateral forearm.
A woman was bitten on the thumb by a dog. The wound became infected and the infeciton spread into the radial bursa. The tendons of which muscle will most likely be affected?
- Flexor digitorum profundus
- Flexor digitorum superficialis
- Flexor pollicis longus
- Flexor carpi radialis
- Flexor pollicis brevis
Tenosynovitis of teh thumb may be spread through teh synovial sheath of the flexor pollicis longus tendon/radial bursa.
Whereas, tendons fo the flexor digitorum superficialis & profundus are envoloped in the ulnar bursa/synovial flexor sheath.
Can’t extend the left wrist, fingers, and thumb- but he can extend teh elbow. Sensation is lost in teh lateral half of the dorsum of the hand. What nerve has most likely been injured and where in the arm?
Radial, mid humerus.
It’s obviously radial because it innevates the extensor (posterior )compartments of the arm & fore arm. Elbow extension is intact if it can still supply the triceps brachii, so it’s fractured mid-humerus.
25
Injury to the radial nerve in the spiral groove would demonstrate which?
- Weakness of thumb abduction and thumb extension
- Weakness of thumb opposition
- Inability to extend the elbow
Weakness of thumb abduction and thumb extension.
This injury paralyzes the snuffbox (abductor pollicis longus muscle and both extensors of the thumb) and will lead to wrist drop (inability to extend wrist).
35
What artery arises form the brachial artery, accompanies the median nerve into the forearm, and anastomoses with the anterior ulnar recurrent artery?
Inferior ulnar collateral artery (from brachial artery)
He can’t abduct his arm more than 15 degrees and can’t rotate the arm laterally. He has a fracture of the humerus and sensory loss over the shoulder area. Where is the fracture?
- Fracture of the medial epicondyle
- Fracture of the glenoid fossa
- Fracture of the surgical neck of the humerus
- Fracture of the middle third of the humerus
Fracture of the surgical neck.
Abduction from 15- 90 degrees is the deltoid, innervated by the axillary nerve. Lateral rotation is the deltoid muscle, teres minor, and infraspinatus. The deltoid and the teres minor are both lost. The axillary nerve can be damaged at the surgical neck of the humerus.
How can you test lateral epicondylitis/tennis elbow?
Observe the presence of pain when the wrist is extended against resistance.
Someone has injury at the second part of the axillary artery. Luckily, there’ s arich collaterla pathway provided by teh anastomoses between which arteries?
Suprascapular & circumflex scapular
Suprascapular comes off the subclavian proximal to teh axillary artery; the subscapular artery is the major branch of the third par tof the axillary artery, giving off the thoracodorsal and circumflex scapular arteries. So, blood can flow fromthe circumflex in a retrograde direction into axillary artery
Fracture at the spinal groove of the humerus. A cast is placed and then 3 days later she complains of severe pain over her entire arm. The arm is swollen, pale, and cool. Radial pulse absent. Any movement causes severe pain.
What is this?
Compartment syndrome: increased pressure withina confined space by a fascial compartment -> impairs blood supply –> pale and loss of pulses distlal to compartment
A child fell while holding hands and walking with his two parents. Any movement of his right UE is painful and he holds it at hsi side with his elbow extended and forearm pronated. No hematomas or swelling. What structure was most likely injured?
Anular ligament!
This is nursemaid’s elbow: radial head slipped out because of the underdevelopment of the radial head and laxity of the anular ligament in children.
A guy got stabbed in the left posterior triangle of his neck. His left shoulder seems to be drooping lower than the right shoulder and the superior angle of the scapula juts otu slightly. Turning his head is symmetric. What nerve is most likely injured?
- Suprascapular nerve in supraspinous fossa
- Terminal segment of the dorsal scapular nerve
- Upper trunk of brachial plexus
- Spinal accessory nerve in the posterior cervical triangle
- Thoracodorsal nerve in the axilla
Spinal accessory nerve in the posterior cervical triangle
Woman has weak wrist extension and paraesthesia on the back of her arm & forearm. What spinal nerve was most likely injured?
Radial nerve –> C7
Post-op, a woman’s left shoulder droops; has weakness in turning his head to the right; impairment of abduction of her left upper limb to the level of the shoulder. What structure was injured?
- Suprascapular nerve
- Long thoracic nerve
- The junction of spinal nerves C5 and C6 of the brachial plexus
- Radial nerve
Spinal accessory nerve (CN XI) arises from C1-C4 rootlets that ascend through the foramen magnum to then exit the cranial cavity to innervate teh traps and sternocleidomastoid muscles –> head rotation and raising shoulders.
Fine motor function in the right hand is reduced, including opposition of the thumb; abduction & adduction of the digits; and interphalangeal joint extension. Also has anesthesia of the skin on the medial forearm.
Long flexor muscles of the hand and long extensors of the wrist are both normal.
What neural structure is most likely impaired?
- Median nerve
- Middle trunk of brachial pelxus
- Radial nerve
- Lower trunk of brachial plexus
- T1 ventral ramus
T1 ventral ramus
- provides sensation to medial forearm via medial antebrachial cutaneous nerve from medial cord
- Gives motor supply to all of the intrinsic muscles
- Because long flexors and intact, the median nerve and ulnar nerve are not injured.
- Extensors are intact, so radial nerve is fine.
A woman has winging of her left scapula and has difficulty raising her left arm above her head. A nerve was damaged. What was the origin of this damaged nerve?
- Upper trunk of brachial plexus
- Posterior division of middle trunk
- Ventral rami
- Posterior cord
- Lateral cord
It’s long thoracic, which paralyzed the serratus anterior –> protrusion of the medial border of the scapular. It originates form the ventrla rami of C5, C6, and C7
A man can abduct his arm and extend the forearm, and sensation in the forearm and hand is normal. However, hand grasp is very weak and he can’t extend his wrist against gravity. What was injured?
- Posterior cord of brachial plexus
- Radial nerve at the distal third of humerus
- Radial and ulnar
- Radial, ulnar, and median
- Radial and musculocutaneous
116
Radial nerve at the distal third of the humerus.
If he can extend his forearm, then his triceps brachii is fine. However, weakened hand grasp and wrist drop means the extensors in the forearm are malfunctioning. Yet, sensation is fine, so the superficial branch of the radial nerve are intact. The radial nerve separates into the superficial and deep branches at the distal third of the humerus.
A man falls directly on his shoulder. He has a vertical fracture through the entire length of the floor of the intertubercular sulcus of the right humerus. The muscle most likely affected is innervated by a nerve composed of which of the following nerve roots?
- C3 & C4
- C6-8
- C4 & C5
- C2-4
- C5-7
The lat dorsi attaches to the intertubercular sulcus of the humerus and is supplied by the thoracodorsal nerve (C6-8)
A man has a wound on his plam. He can’t touch teh pad of his index finger with his thumb, but can grib a sheet of paper between all fingers and has no loss of sensation on the skin of his hand. What nerve and branch was probably injured?
Recurrent branch of median n (thenar muscles)
A man has excruciating pain in his posterior forearm. When palpated 2cm distal and posteromedial to the lateral epicondyle, the pain is so bad he grimaces. What injury is most likely?
- Compression of ulnar nerve by flexor carpi ulnaris
- Compression of median nerve by pronator teres
- Compression of upserficial radial nerve by brachioradialis
- Compression of deep radial nerve by supinator
27
Compression of deep radial nerve by supinator
The deep branch of radial nerve travels between the two heads of the supinator and is located just medial & distal to the lateral epicondyle.
Whereas, the superficial radial nerve goes down the lateral aspect of the posterior forearm and would not cause pain due to pressure applied to the posterior forearm.
A maid was straightening a sheet when she caught the end of her index finger in a fold. She experienced sudden pain over the base of the terminal phalanx. Hours later, the end of her right index finger was swollen and she couldn’t completely extend the terminal IP joint. Which was most likely injured?
- Proper palmar digital branch of the median nerve
- The vinculum longa
- The insertion of the tendon of the extensor digitorum onto the base of the distal phalynx
- Insertion of hte flexor digitorum profundus tendon
- Insertion of the flexor digitorum superficialis tendon
Insertion of the tendon of the extensor digitorum onto the base of the distal phalanx
Accidentally injured the ulnar nerve at the wrist. Which would be lost?
- Flexion of the PIP at the pinky
- Adduction of the pinky
Adduction of the pinky because PADs are innervated by the deep ulnar nerve.
Flexion of the PIP at the pinky is from the flexor digitorum superficialis, innervated by median nerve.
A man can extend the metacarpophalangeal joints of all his fingers, but cannot extend the IP joints of the 4th and 5th digits and extension of the IP joints at the 2nd and 3rd digits is very weak. Sensation in hand is fine. What nerve was most likely injured?
- Radial nerve at elbow
- Median nerve at wrist
- Ulnar nerve mid forearm
- Deep branch of ulnar nerve
- Recurrent branch of median nerve.
Injuring the deep branch of ulnar nerve paralyzes all the interosseus muscles and the lumbrical muscles of digits 4 & 5.
Because extension of the MCP joints is normal (extensor digitorum), the radial nerve is fine. There’s some extension in digits 2 and 3 (lumbricals of 2 and 3), so median nerve is intact. If the ulnar nerve was injured midforearm, then sensation in the hand would be lost.
A man is cut across teh entire length of the distal transverse crease on teh anterior surface of the wrist. The cut is down to the surface of the flexor retinaculum, but not into it. Which of these deficits will be found?
- Weakend pronation of fore arm
- Inability to abduct thumb
- Weakened flexion of thumb
- Weakened opposition of the thumb
- Inability to adduct the thumb
Inability to adduct the thumb, because that’s deep ulnar nerve, which passes superficially to the flexor retinaculum.
