Brachial Plexus/ Axillary Region/Forearm

Fractures of the radius and ulna

Fractures in one bone often cause a dislocation of the nearest joint because the bones are attached by the interosseous membrane

During the difficult birth of a baby, the physician pulled on the baby's head while the shoulder was still in the birth canal. The procedure caused a traction injury of the brachial plexus. What spinal nerves were most likely affected? A. C2 and C3 B. C3 and C4 C. C4 and C5 D. C5 and C6 E. C6 and C7

D. C5 and C6

A 19-year-old man was thrown from his motorcycle into a tree after hitting a deer. Although he appeared not to be seriously injured, his neck felt sore shortly after the accident. He came to see his family physician because his upper extremity was limp, and his forearm and hand pronated. Upon physical examination, the patient was unable to flex, abduct or laterally rotate his arm, and there was a loss of flexion at the elbow joint. A lack of sensation was detected on the lateral surface of his arm and forearm. Which of the following muscles was probably least affected by the nerve injury? A. Biceps brachii B. Brachialis C. Infraspinatus D. Pectoralis major E. Supinator

D. Pectoralis major

A 17-year-old male is brought to the emergency department following an injury while playing football. X-rays revealed a transverse fracture of the humerus 1 inch proximal to the epicondyles. What nerve is most frequently injured by the jagged edges of the broken bone at this location? A. Axillary nerve B. Median nerve C. Musculocutaneous nerve D. Radial nerve E. Ulnar nerve

D. Radial nerve

During a difficult breech delivery of a large baby, strong lateral flexion of the infant's trunk and neck was performed to deliver the head. Complete loss of sensation and complete paralysis of the right limb was evident from the time of birth. In addition, the infant's right eyelid drooped. What part of the brachial plexus was likely injured? A. Cords B. Divisions C. Dorsal rami D. Roots E. Trunks F. Terminal branches

D. Roots

During the difficult birth of a baby, the physician pulled on the baby's head while the shoulder was still in the birth canal. The procedure caused a traction injury of the brachial plexus. What is the usual clinical appearance of the upper limb when this injury of the brachial plexus occurs? A. The upper limb is abducted and laterally rotated B. The upper limb is abducted and medially rotated C. The upper limb is adducted and laterally rotated D. The upper limb is adducted and medially rotated E. The arm is extended and forearm flexed

D. The upper limb is adducted and medially rotated

The median Nerves supplies all of the superifical forearm muscles, except with one of the following? A. Pronator teres B. Flexor carpi radialis C. Flexor carpi radialis D. Parlmaris longus E. Flexor digitorum superficialis F. Flexor carpi ulnaris

F. Flexor carpi ulnaris

complete paralysis of the brachial plexus

no movement is detected

incomplete paralysis of the brachial plexus

not all muscles are paralyzed, the person can move, but the movements are weak compared to the normal side

ulna fractures

occur more when trauma occurs at elbow

radial fractures

occur more when trauma occurs from falls on hands

which muscles if absent in 14% of individuals?

palmaris longus

Dislocation of the Elbow Joint

posterior dislocation: occurs when children fall on their hands with their elbows flexed, the ulnar collateral ligament is often torn

smiths fracture

reverse colles fracture, usually caused by a fall on the dorsum of the hand with the wrist flexed

A 36-year-old man was painting the ceiling in a large room of his home when he felt pain and tingling in his right shoulder and in the proximal part of his right arm. When being examined by his family physician, the physician raised the man's limb above the shoulder and noted that the radial pulse decreased when examined. After holding the limb above the shoulder for several minutes, the man said he felt pain and some tingling around the shoulder. Both cyanosis and distension of the superficial limb veins was noted. Compression of what structure is responsible for the decreased radial pulse? A. Axillary artery B. Deep brachial artery C. Radial artery D. Suprascapular artery E. Ulnar artery

A. Axillary artery

A 36-year-old man was painting the ceiling in a large room of his home when he felt pain and tingling in his right shoulder and in the proximal part of his right arm. When being examined by his family physician, the physician raised the man's limb above the shoulder and noted that the radial pulse decreased when examined. After holding the limb above the shoulder for several minutes, the man said he felt pain and some tingling around the shoulder. Both cyanosis and distension of the superficial limb veins was noted. Compression of what structure is responsible for the pain and tingling around the shoulder? A. Axillary nerve B. Dorsal scapular nerve C. Radial nerve D. Suprascapular nerve E. Thoracodorsal nerve

A. Axillary nerve

During a difficult breech delivery of a large baby, strong lateral flexion of the infant's trunk and neck was performed to deliver the head. Complete loss of sensation and complete paralysis of the right limb was evident from the time of birth. In addition, the infant's right eyelid drooped. What is the name of the eyelid syndrome? A. Horner syndrome B. Kleinfelter syndrome C. Poland syndrome D. Raynaud syndrome E. Thoracic outlet syndrome

A. Horner syndrome

A 19-year-old man was thrown from his motorcycle into a tree after hitting a deer. Although he appeared not to be seriously injured, his neck felt sore shortly after the accident. He came to see his family physician because his upper extremity was limp, and his forearm and hand pronated. On physical examination the patient was unable to flex, abduct or laterally rotate his arm, and there was a loss of flexion at the elbow joint. A lack of sensation was detected on the lateral surface of his arm and forearm. What part of the brachial plexus was injured in this man? A. C4 and C5 B. C5 and C6 C. C6 and C7 D. C7 and C8 E. C8 and T1

B. C5 and C6

A 44-year-old woman's husband noticed that his wife's right scapula protruded abnormally when she pushed against the wall during her stretching exercises. Several weeks earlier she had had surgical dissection of her right axilla for the removal of lymph nodes for staging and treatment of breast cancer. She also had difficulty raising her right arm above her head. What nerve was probably injured? A. Intercostobrachial nerve B. Long thoracic nerve C. Pectoral nerves D. Suprascapular nerve E. Thoracodorsal nerve

B. Long thoracic nerve

A 44-year-old man is admitted to the hospital after a bar fight in which his right arm was severely injured. Radiographic examination of the arm reveals an oblique fracture of the humerus. Physical examination of the patient revealed he was unable to extend his forearm or wrist. The damaged nerve was composed of nerve fibers from what spinal cord segments? A. C5,C6 B. C5, C6, C7 C. C5, C6, C7, C8, T1 D. C7, C8, T1 E. C8, T1

C. C5, C6, C7, C8, T1

A 78-year-old woman attempted to open a stuck double-hung window by lifting the lower window frame. She experienced a sudden pain in her shoulder, suggesting involvement of the rotator cuff. What movement of the upper extremity produces pain in rotator cuff injuries? A. Adduction B. Abduction C. Extension D. Flexion E. Lateral rotation

C. Extension

A 29-year-old male, right-handed house painter visits his family physician because of pain in his right upper limb and slight tingling and numbness in all of his digits, but especially in the fourth and fifth digits when he reaches high over his head to paint. Radiographic studies reveal the presence of a cervical rib and accessory scalene musculature. Which of the following structures is most likely compressed when he reaches high to paint? A. Axillary artery B. Brachiocephalic artery C. Lower trunk of the brachial plexus D. Subclavian artery E. Superior trunk of the brachial plexus

C. Lower trunk of the brachial plexus

An 85-year-old woman fell when attempting to cross the street and injured her left arm when hitting the curb. X-rays showed a midshaft fracture of the humerus. Which pair of structures was most likely injured at the fracture site? A. Axillary nerve and posterior humeral circumflex artery B. Median nerve and brachial artery C. Radial nerve and deep brachial artery D. Suprascapular nerve and suprascapular artery E. Thoracodorsal nerve and thoracodorsal artery

C. Radial nerve and deep brachial artery

During a yearly physical exam, a 54-year-old construction worker complained of pain over the right shoulder. Abduction of the right upper extremity caused considerable discomfort, and palpation of the deltoid muscle produced pain. Imaging studies of the shoulder revealed intermuscular inflammation extending over the head of the humerus. Which of the following structures was inflamed? A. Axillary sheath B. Glenohumeral joint cavity C. Subacromial bursa D. Subscapular bursa E. Teres minor muscle

C. Subacromial bursa

A 10-year-old boy fell from his bicycle and suffered shoulder trauma that stretches the upper trunk of the brachial plexus. Which of the following signs or symptoms would the boy most likely have as a result of the injury? A. Inability to shrug the shoulder against resistance B. Weakness in the ability to abduct and adduct the fingers C. Weakness in the ability to flex the forearm at the elbow D. Weakness in the ability to protract the scapula E. Wrist drop

C. Weakness in the ability to flex the forearm at the elbow

During a difficult breech delivery of a large baby, strong lateral flexion of the infant's trunk and neck was performed to deliver the head. Complete loss of sensation and complete paralysis of the right limb was evident from the time of birth. In addition, the infant's right eyelid drooped. What caused his right eyelid to droop? A. Loss of parasympathetic nerve fibers B. Loss of somatic motor nerve fibers C. Loss of somatic sensory nerve fibers D. Loss of sympathetic postganglionic nerve fibers E. Loss of sympathetic preganglionic nerve fibers

E. Loss of sympathetic preganglionic nerve fibers

A 50-year-old police officer presents complaining of right shoulder pain that arose 2 weeks after subduing a suspect. He recalls that the individual yanked very aggressively on his arm, but he really didn't have much pain at the time. The arm is weak and he has pain with abduction. You find significant atrophy of the supraspinatus and infraspinatus muscles. What structure was injured in this altercation? A. Axillary nerve B. Biceps tendon C. Glenohumeral ligament D. Superior glenoid labrum E. Suprascapular nerve

E. Suprascapular nerve

A 35-year-old baseball pitcher told his catcher and manager that he felt a gradual onset of shoulder pain. He continued to pitch but had to stop because of pain and weakness. A MRI revealed a tear in the pitcher's rotator cuff. What part of the rotator cuff usually tears? A. Biceps (long head) muscle B. Infraspinatus muscle C. Coracobrachialis muscle D. Subscapularis muscle E. Supraspinatus muscle

E. Supraspinatus muscle

A 78-year-old woman attempted to open a stuck double-hung window by lifting the lower window frame. She experienced a sudden pain in her shoulder, suggesting involvement of the rotator cuff. Which of the following muscles is NOT part of the rotator cuff? A. Infraspinatus muscle B. Subscapularis muscle C. Supraspinatus muscle D. Teres minor muscle E. Teres major muscle

E. Teres major muscle

During the difficult birth of a baby, the physician pulled on the baby's head while the shoulder was still in the birth canal. The procedure caused a traction injury of the brachial plexus. Which of the following muscles was least affected or paralyzed in this individual? A. Biceps brachii B. Deltoid C. Brachialis D. Brachioradialis E. Triceps brachii

E. Triceps Brachii

A 32-year-old male is brought to the emergency department with injuries to his right elbow after falling while rock climbing. X-rays of the right elbow revealed a fracture of the medical epicondyle. Which of the following nerves was likely injured in this fall? A. Anterior interosseous nerve B. Deep branch of the radial nerve C. Median nerve D. Superficial branch of the median nerve E. Ulnar nerve

E. Ulnar nerve

Avulsion of the medial epicondyle

can result from a fall in children that causes severe abduction of the extended elbows. can lead to the epicondyle not fusing with distal end of the humerus, can cause traction injury of the ulnar nerve

bursitis of the elbow

caused by excessive pressure and friction, subuctaneous olecranon bursitis, also known as dart thrower's elbow/miner's elbow

Pronator Syndrome

compression of the median nerve by the pronator teres muscle, onset is usually after repeated elbow movements: chopping wood, cleaning fish, etc. presents as chronic aching sensation localized to the forearm with pain occasionally radiating into the elbow

upper brachial plexus injury: Erb-Duchenne palsy

injury to C5-C6, occurs with an increase angle between the neck and shoulder during a fall or delivery of a baby. Clinical features: adducted arm, medial rotation of arm, extended elbow, waiter's tip position of hand (See C5-C6 innervation)

What is the material that connects the radius and ulna?

interosseous membrane

colles fracture

involves the distal end of the radius with displacement of the distal radius posteriorly/dorsally

Lower brachial plexus injury: klumpke paralysis

less common than upper brachial plexus injuries. injury to C8-T1 spinal roots, occurs when the upper limb is suddenly pulled superiorly or a baby's limb is pulled excessively during delivery. Clinical features: atrophy of the intrinsic (short) muscles of the hand=claw hand

Which of the following is a clinical manifestation of injury to the lower brachial plexus? Loss of intrinsic hand movements Unable to flex the forearm at the elbow joint Unable to extend the forearm at the elbow joint Unable to abduct the upper extremity Unable to adduct the upper extremity

loss of intrinsic hand movements

Injury to axillary Nerve

the deltoid atrophies (shoulder takes on flattened appearance) when axillary nerve(C5-C6) is severly damaged. it is usually injured during fracture to surgical neck of humerus or dislocation of the glenohumeral joint.

What part of the hand does the ulnar nerve supply?

the medial side of the hand, pinky and part of ring finger

Skier's thumb

the rupture or chronic laxity of the collarteral ligament of the 1st MP joint. caused by hyperextension of thumb

What does the nerve roots C6 supply?

thumb, lateral/radial side of arm

What forms the roof of the carpal tunnel?

transverse carpel ligament/flexor retinaculum, serves to hold the flexor muscles in the carpal tunnel

Cubital tunnel Syndrome

ulnar nerve is compressed in the cubital tunnel. Presents as numbness, tingling of the medial part of the palm and pinky and ring finger

postfixed brachial plexus

variation in brachial plexus, where the superior root is C6 and the inferiormost root is T2

prefixed brachial plexus

variation in brachial plexus, where the superiormost root of the plexus is C4 and the inferiormost root is C8

C5-C6

ventral rami supply the lateral rotators: infraspinatus and teres minor, and the abductors: supraspinatus and deltoid