Final Exam--Blue Boxes Flashcards
Paralysis of Serratus Anterior
Caused by injury to long thoracic nerve
Medial border of scapula moves laterally and posteriorly away from thoracic wall (winged scapula)
serratus anterior unable to rotate the glenoid cavity superiorly so upper limb cannot abduct above horizontal position
Triangle of Auscultation
Gap in musculature that makes it easier to listen to lungs
Borders: superior Latissimus dorsi, medial scapula, inferolateral trapezius
Enlarged when crossing arms across chest
6th, 7th ribs, 6th intercostal space subcutaneous
Injury of spinal accessory nerve (spinal accessory nerve palsy)
ipsilateral weakness when shoulders are elevated (shrugged) against resistance
Thoracodorsal nerve injury (C6-C8)
At risk during surgery of inferior axilla, during mastectomies when axillary tail of breast removed, and during surgery on scapular lymph nodes
at posterior wall of axilla and enters at medial surface of Lat. dorsi
Paralysis of lats leads to being unable to raise trunk with upper limbs and unable to use axillary crutch bc shoulder is pushed superiorly by it (aka injury leads to loss of active depression of scapula)
Injury to dorsal scapular nerve
nerve to rhomboids
scapula on affected side will be located farther from the midline than that on the normal side
Injury to axillary nerve (C5-C6)
Deltoid atrophies, flattened shoulder, slight hollow around acromion, loss of sensation over lateral side of proximal arm (bc axillary n gives rise to lateral cutaneous nerve of arm)
usually injured when surgical neck of humerus is injured bc thats where this nerve wraps around; Can also be injured during dislocation of glenohumeral joint or by compression from incorrect crutches use
Fracture–Dislocation of Proximal humeral epiphysis
caused by a direct blow or indirect injury of shoulder of child or adolescent bc joint capsule of glenohumeral joint, reinforced by rotator cuff (tendon of the SITS muscles) is stronger than epiphyseal plate
In severe fractures, shaft of humerus is displaced but humeral head retains its relationship with glenoid cavity of scapula
Rotator Cuff Injuries
Supraspinatus tendon is most commonly ruptured
Rotator Cuff injuries resutl in instability of glenohumeral joint
Degenerative tendonitis of rotator cuff is common, esp in older people
Variations of Brachial Plexus:
Aside from the normal C5-T1 contributions, what other nerve roots can contribute to the brachial plexus? What is each of the conditions called when a different nerve root contributes?
Anterior rami of C4 or T2 can contribute
If plexus goes from C4-C8=PREFIXED brachial plexus
if it goes from C6-T2=POSTFIXED brachial plexus=inferior trunk of plexus can be compressed by 1st rib producing neurovascular symptoms in upper limb
Variations of Brachial Plexus: What other variations are seen?
Variations in trunks, divisions and cords or combination of branches
Ex: lateral or medial cords may receive fibers from anterior rami inferior or superior to usual levles, respectively
Variations of Brachial Plexus:
What remains always the same regardless of the variations in brachial plexus?
Terminal branches remain unchanged
Also, even though a nerve (like the median nerve) may have two medial roots, the components of the nerve are the same (impulses arise from the same place and reach the same destination whether they go through one or two roots)
Brachial plexus injuries: complete paralysis vs. incomplete paralysis
complete: no movement detectable
incomplete: not all muscles paralyzed so person can move but movements are weak
Brachial plexus injuries: superior brachial plexus injuries (C5-C6)
caused by excessive increase in the angle between the neck and shoulder (thrown from motorcycle or horse and lands on shoulder that separates neck and shoulder. Then, shoulder hits something and stops while head and trunk continue moving)
Injury to superior trunk of brachial plexus
waiter’s tip position–limb hangs by side in medial rotation
Upper brachial plexus injury can also occur in neonates when excessive stretching of neck occurs during delivery
Consequences of Superior brachial plexus injury
Erb-Duchenne palsy
paralysis of muscles supplied by C5-C6: deltoid, biceps, brachialis
symptoms: adducted shoulder, medially rotated arm and extended elbow, loss of sensation to lateral elbow
heavy backpack can cause microtrauma to superior trunk causing motor and sensory deficits due to musculocutaneous and radial nerves
Backpackers palsy
superior brachial plexus injury producing muscle spasms and severe disability in hikers who carry backpacks for long periods
Acute brachial plexus neuritis (brachial plexus neuropathy)
neurological disorder of unknown cause characterized by sudden onset of severe pain around shoulder; pain starts at night and is followed by muscle weakness and atrophy (neurologic amyotrophy)
Brachial neuritis
often preceded by URI, vaccination or trauma; nerve fibers are from superior trunk of brachial plexus
Compression of cords of the brachial plexus
caused by hyperabduction of arm during overhead tasks like painting
cords impinged between coracoid process and pectoralis minor tendon
Symptoms: numbness, paresthesia, erythema and hand weakness, ischemia of upper limb and distension of superficial veins
Result from compression of AXILLARY nerve & vessels!!
Klumpe paralysis: inferior brachial plexus injury (C8-T1)
occurs when uper limb suddenly pulled superiorly (ex: grasping something to break a fall or baby’s upper limb pulled excessively during delivery)
short muscles of hand are affected and CLAW HAND results!!
Brachial plexus block
Anesthesia around axillary sheath
sensation blocked in all deep structures of upper limb and kin distal to middle of arm
combined with occlusive tourniquet technique and allows for operation on upper limb without general anesthetic
Can use interscalene, supraclavicular and axillary approach or block
bicipital myotatic reflex
positive response confirms integrity of musculocutaneous nerve and C5,C6 spinal cord segments
Prolonged response indicates central or peripheral NS disease or metabolic disorders like thyroid disease
Biceps Tendinitis
Inflammation of biceps tendon caused by repetitive microtrauma (throwing, tennis etc)
Tight, narrow or rough intertubercular sulcus may irritate and infame tendon producing tenderness and crepitus
Dislocation of tendon of long head of biceps
occurs in young people during traumatic separation of proximal epiphysis of humerus
can also occur in older people with history of biceps tendinitis
popping or catching felt during arm rotation
Rupture of tendon of long head of biceps
caused by wear and tear of inflamed tendon as it moves back and forth in intertubercular sulcus of humerus; can be caused by forceful flexion against excessive resistance (weights) but more likely caused by prolonged tendinitis
occurs in individuals older than 35; tendon is torn from its attachment at supraglenoid tubercle; snap/pop
detached muscle belly forms ball near center of distal anterior arm
repetitive overhead movements=swimmers, baseball pitchers
Interruption of blood flow in brachial artery
best place to compress brachial artery to control hemorrhage=medial to humerus near middle of arm bc ulnar and radial arteries will still receive sufficient blood through the anastomoses around the elbow
If there is collateral circulation around the elbow, why can it still be problematic if brachial artery is occluded?
bc it causes paralysis of muscles from ischemia of elbow and forearm within a few hours
Ischemic compartment syndrome
Muscles and nerves can tolerate upto 6 hrs of ischemia. Then, fibrous scar tissue replaces necrotic tissue and causes muscles to shorten permanently producing flexion deformity
Flexion of fingers and wrist results in loss of hand power due to irreversible necrosis of forearm flexors
Absence of Pectoralis muscles
Anterior axillary fold (formed by skin and fascia over inferior pec major) is absent and nipple more inferior than usual
Poland syndrome: Both pectoralis major and minor are absent; breast hypoplasia and absence of two to four rib segments also seen
Injury to musculocutaneous n.
typically inflicted by weapon like a knife
results in paralysis of coracobrachialis, biceps, and brachialis
Weak flexion may occur at glenohumeral joint bc musculocutaneous n affecting long head of bicpes and coracobhacialis
Flexion of elbow and supination greatly weakened but not lost bc of brachioradialis and supinator (radial n)
Loss of sensation of lateral forearm supplied by lateral antebrachial cutaneous n supplied by musculocutaneous n.
Injury to radial n in arm
causes paralysis of triceps, brachioradialis, supinator, and extensor muscles of wrist and fingers and loss of senstion in areas of skin supplied by radial n; if injured in radial groove, triceps not totally paralyzed bc only medial head and distal posterior forearm affected
WRIST DROP seen–inability to extend wrist and fingers at metacarpophalangeal joint; wrist assumes partly flexed position
Venipuncture in cubital fossa
Cubital fossa=site for blood sampling, transfusion, IV injections bc of assessibility of veins–median cubital vein–crosses bicipital aponeurosis (grace Deux tendon)
median cubital vein also site for cardiac catheters to get blood samples from great vessels and chambers of heart and also can be used for coronary angiography
Variation of veins in cubital fossa
20% of people: Median antebrachial vein (median vein of forearm) divides into median basilic v which joins basilic v of arm and median cephalic v that joins cephalic v
Creates an M by cubital veins; both median cubital and median basilic vein crosses SUPERFICIAL to BRACHIAL ARTERY from which it is separated by bicipital aponeurosis
good for drawing blood but NOT for injecting drugs bc of danger of injecting it into brachial a.
