Neuroanatomy Of The UE (MODULE 2A) Flashcards
Muscular and cutaneous branches of the brachial plexus:
Which Muscular branches innervate parts of the body wall or limbs that consist of bone, tendon/ligament, muscle, and vessels?
GSA -
GVA -
GSE -
Postganglionic GVE axons -
Which cutaneous branches innervate the skin?
GSA axons - joint receptors, proproceptors, other nociceptors
GVA axons - primarily arising in vascular elements responding pressure
GSE axons - innervating skeletal muscles cells
Postganglionic GVE axons - sympathetic innervation of the vessels serving the muscles, bones and surrounding soft tissues.
SKIN INNERVATION:
GSA axons - high and low threshold fibers (mechanoreceptors, thermoreceptors chemoreceptors, and nociceptors)
GVA axons - primarily vascular pressure
Postganglionic GVE axons - sympathetic innervation of the vessels, erector pili, and the sweat glands
The “roots” or VPR intertwine and reassert to become?
Trunks: upper, middle, and lower
Divisions: Anterior and Posterior
Cords: lateral medial and posterior
Main branches: axillary, musculocutaneous, median, ulnar and radial
During MSR testing; what are the grade for muscle strength? 0-5
0 - complete paralysis
1 - flicker of contraction
2 - contraction only with gravity eliminated
3 - contraction against gravity only
4 - contraction against gravity and slight resistance
5 - Normal contraction against normal resistance
*reflexes are evaluated on a + scale, there ++ is normal
Name the muscle tests, reflex test, and sensory test in correlation with C5.
Muscle test: Deltoid
PR: Axillary
Reflex test: Biceps
RP: Musculocutaneous
Sensory test: C5 Dermatome
Name the muscle tests, reflex test, and sensory test in correlation with C6.
Muscle test: biceps brachii, and wrist extensors
PR: Musculocutaneous and posterior interosseous
Reflex test: brachioradialis
PR: radial nerve
Sensory test: C6 Dermatome
Name the muscle tests, reflex test, and sensory test in correlation with C7.
Muscle tests: Triceps brachii, and wrist flexors
PR: radial and median
Reflex Test: Triceps
PR: Radial
Sensory Test: C7 Dermatome
Name the muscle tests, reflex test, and sensory test in correlation with C8.
Muscle Test: Finger flexors
PR: Median (and ulnar)
Reflex test: finger flexor reflex
PR: median
Sensory test: C8 Dermatome
Name the muscle tests, reflex test, and sensory test in correlation with T1.
*Interossei
Muscle test: Finger adductors and/or abductors
PR: Ulnar
Reflex test: None
Sensory Test: T1 Dermatome
Which of these make up the complete brachial plexus?
A. VPR of C5-T1
B. VPR of C5-C8
C. DPR of C5-T1
A
Spinal injuries may impact a structure that could not be involved in injuries of the lower lumbar spine. What is it?
A. The spinal ligaments
B. The spinal cord
C. DPR of the spinal nerves
D. VPR of the spinal nerves
B
The integrity of spinal nerves is tested using three major indicators. What are these?
Muscle strength, reflex reaction, and dermatomal distribution of sensation
Axons are classified on the basis of their function and distribution. Which answer inclues ALL axon components of the VPR?
A. GSA, GVA, GSE, and preganglionic GVE sympathetic
B. GSA, GVA, preganglionic sympathetic
C. GSA, GVA, GSE, and postganglionic GVE sympathetic
C
Muscular branches of the brachial plexus innervate:
A. Muscles, tendons, ligaments, bone fascia, and BV
B. Muscles, tendons, and bone, only
C. Muscles and BV, only
D. Muscles, skin, and sweat glands
A
Muscular branches of the brachial plexus consist of what types of functional axons?
A. GSE, only
B. GSE, GSA, GVA, and postganglionic sympathetic
C. GSE and postganglionic sympathetic, only
B
When evaluating the integrity of the C5 spinal nerves, what joint function will be most affected?
A. Digits
B. Shoulder
C. Elbow
D. Wrist
B
Integrity of the C5 spinal nerves is tested by evaluating the strength of the ____________
Wrist extensors
Finger flexors
Wrist flexors
Deltoid
Biceps brachii
Deltoid
The peripheral route for the muscle tested in the C5 MSR is the __________ nerve
Radial
Ulnar
Media
Axillary
Posterior interossei
Axillary
Integrity of the C6 spinal nerves is tested by evaluating the reflex of the_________ muscle
Brachioradialis
Finger flexors
Deltoid
Triceps
Biceps brachii
Brachioradialis
Integrity of the C7 spinal nerves is evaluated by evaluating the strength of which TWO muscles?
Triceps
Interossei
Wrist extensors
Finger flexors
Biceps brachii
Wrist flexors
Deltoid
Triceps
Wrist flexors
The peripheral route for the innervation of the T1 muscle strength test is the _________ nerve
Median
Axillary
Radial
Ulnar
Musculocutaneous
Ulnar
Which of the following choices best describes the Dermatome pattern of C8?
Medial arm to just below the elbow
Lateral arm to elbow
Medial forearm to tip of the fifth digit
Lateral forearm to the tip of the thumb
Medial forearm to tip of the fifth digit
When performing the muscle tested for C6, the doctor applies resistance to the patient;s effort of:
Finger flexion
Shoulder abduction
Elbow extension
Elbow flexion
Elbow flexion
When performing the muscle tested for the median nerve peripheral route of C7, the doctor applies resistance to the patient’s effort of:
Finger flexion
Wrist extension
Wrist flexion
Finger abduction
Wrist flexion
What is Thoracic Outlet Syndrome? This can occur in what three ways. List and describe these.
TOS - The thoracic outlet syndrome is a grouped of symptoms arising not only from the upper extremity, but also from the chest, neck, and shoulders. The symptoms are produced by a positional, intermittent compression of the brachial plexus and/or subclavian artery and vein.
Costoclavicular Syndrome - Clavicle compressing vessels and nerves from the neck. NOTE: this condition is caused by entrapment of the BV between the clavicle and the first rib. It can be related to clavicular fracture, subluxation / fixation of the clavicle, and spasming of the Subclavius muscle.
Scalene-anticus syndrome - Scalenes compressing artery and nerves from the neck. NOTE: Injuries of the vertical spine: sprain — strain types of injuries, as well as respiratory distress conditions such as: asthma, pneumonia, emphysema, COPD, and others. Further, anxiety can cause TOS due to breathing from the neck area instead of using the diaphragm affectively. Pt will exhibit transient signs of arm parenthesis and weakness in all areas of the arm, both sides of the hand. These symptoms come and go with neck movements and breathing difficulty.
Hyperabduction Syndrome - Pectoralis minor compressing vessels and nerves from the neck. NOTE: Pectoralis minor entraps the BV as it passes between the coracoid process of the scapula and tha ttachemets of the pectoralis minor on ribs 3-5. This muscle can be over-stretched in hyperabductions of the upper extremity, wearing heavy backpacks or other things pulling the shoulder back.
What test is associated with anterior scalene syndrome?
Adson’s Test
Neuro component symptoms are going to include reproduction of the parenthesis and weakness that the pt has experienced.
What test is associated with Costoclavicular syndrome?
Costoclavicular maneuver
This condition is caused by entrapment of the BV/nerves between the clavicle and the first rib. Can be related to clavicular fracture, subluxation/fixation of the clavicle, and spasming of the Subclavius muscle
Pt is going to assume a position that is going to further approximate the clavicle and the subclavian and the first rib. Pt will stick chest out (this will push rib towards clavicle, pull shoulder girdle back and down and tuck the chin to the chest. Doc will be check radial pulse.
What test is associated with hyperabduction syndrome?
Wright’s Test
Tests for Pectoralis Minor Syndrome
The medial pectoral nerve can potentially get impinged in causes of this syndrome.
Have pt UE and passively move it up (abduction and extension) and back while palpating the radial pulse in wrist. Have pt breath in deep.
The long thoracic and dorsal scapular nerves are ____________ divison nerves.
Posterior
Long thoracic = innervates Serratus anterior
Dorsal scapular = innervates rhomboid major, minor, Levator scapulae
What nerves are derived from the roots?
Dorsal Scapular nerve (C5) - posterior division nerve rhomboid major and minor, Levator scapulae
Long thoracic nerve (C5, 6, 7) - Serratus anterior
What muscles are innervated by the dorsal scapular nerve? What actions do these muscles do to the scapula?
Innervates the Levator scapulae, rhomboideus minor, and rhomboideus major.
These muscles elevate and retract the scapula.
Name the long thoracic roots.
The long thoracic nerve innervates what muscle?
What does this muscle do?
C5-C7
Serratus anterior
Stabilizer of the scapula. Acts in throwing activities.
What nerves arise from the trunks?
Suprascapular nerve: anterior divisions, C5-6
C5 - mostly supraspinatus
C6 - Mostly Infraspinatus
Nerve to the Subclavius: anterior divisions, C5-6
What travels through the suprascapular notch?
What damages can occur at this point?
- Suprascapular notch is a small indentation at the superior border of the scapula. Through this notch, the suprascapular nerve and suprascapular artery travel.
- Entrapment of the nerve within the suprascapular notch
- A major or repetitive trauma
- Neuralgic amyotrophic (parsonage - turner syndrome)
What travels through the quadrangular space?
And
What make up the borders of the quadrangular space?
Posterior circumflex humeral artery AND Axillary nerve
QS
Superior: inferior margin of teres minor
Inferior: superior margin of teres major
Lateral: surgical neck of humerus
Medial: lateral margin of long head of triceps
for reference - Anterior: subscapularis
What travels through the triceps hiatus (lower triangular space)?
- Profunda brachii artery
- Radial nerve
Name three causes that could lead to suprascapular nerve syndrome. (Suprescapular nerve entrapment)
- Entrapment of nerve within the suprascapular notch
- Major or repetitive trauma
- Neurological amyotrophic
Name the trunks of the brachial plexus.
Upper, middle, lower
Name the nerves derived from the roots of the brachial plexus.
Long thoracic C5-7
Dorsal scapular nerves C5
Thoracic outlet syndrome includes three major classifications. Which is the one caused by entrapment at the pectoralis minor?
A. Scalenes anticus syndrome
B. Costoclavicular syndrome
C. Hyperabduction syndrome
D. Hypoadduction syndrome
C
Which of these tests, when postitive, is indicative of scalenes anticus syndrome?
A. Eden’s
B. Adson’s
C. Wright’s
D. Constoclavicular
B
What are the symptoms of thoracic outlet syndrome? Choose the best answer.
A. Pain in the UE, only
B. Weakness in the UE, only
C. pain and weakness of the muscles supporting the head
D. transient parenthesis and weakness in the UE
D
The dorsal scapular nerves arise is derived from _______ segment’s and innervates______ muscles.
A. C5; rhomboid major and minor and Levator scapulae
B. C5; Levator scapulae, only
C. C5-6; Serratus anterior and rhomboid major and minor
A
The long thoracic nerve is derived from ____ segment(s) and innervates ______ muscles.
A. C5, 6; Serratus anterior and rhomboid major and minor
B. C5-7; Serratus anterior,only
C. C5-6; Levator scapulae, only
D. C5; rhomboid major and minor and Levator scapulae
B
The dorsal scapular nerve is tested using _______ test
A. Scapular wining
B. Position of attention
C. Shoulder flexion
B
T or F
There is no cutaneous innervation pattern for either the dorsal scapular nor long thoracic nerve?
T
The dorsal scapular nerves arise can be impinged by:
A. Spasming of the middle scalene muscle
B. Pressure on the suprascapular notch
C. Pressure at the pectoralis minor
A
The “reach test” is used in evaluation of the _______ muscle and the _____ nerve.
Long thoracic
Serratus anterior Stabiliser
The suprascapular nerve arises from the ______ trunk and innervates ________
A. Upper; supraspinatus and Infraspinatus
B. Middle; subscapularis
C. Middle; rhomboid major
D. Upper; supraspinatus, only
A
The nerve to he subclavius arises from ______ spinal segment(s) and functions in ____
A. C5-7; movements of the humerus
B. C5; stabilisation of the scapula
C. C5-6; stabilization of the clavicle
C
The suprascapular nerve is entrapped:
A. At the supraspinatus notch
B. By humeral fracture
C. By fracture of the scapular spine
D. Following pathologies of Ramsay-Hunt syndrome
A
Name the three cord divisions. These cords are named for their relationship to what vessel?
Lateral, posterior, medial
Relationship to the subclavian artery
Name the divisions of the lateral, posterior, and medial cords.
Lateral = C5-7 (anterior)
Posterior = C5-T1 (posterior)
Medial = C5-C8 (anterior)
Name the branches of the lateral cord and the muscles these nerves innervate.
Lateral Pectoral Nerve (C5-6)
- Pectoralis major
Musculocutaneous Nerve (C5-7
- coracobrachialis (C5-7)
- brachialis (C5-6)
- biceps brachii (C5-6)
=CBB
Contribution to he medial cord/Median nerve
T or F
The musculocutaneous nerve is the large branch of the lateral cord.
T
The cutaneous contribution of the musculocutaneous nerve is referred to as ______ ________ _________ ______. This distribution goes to where?
Lateral Antebrachial Cutaneous Nerve
Distribution to he lateral forearm, largely from C6. The C6 Dermatome continues down to the thumb and includes the web.
T or F
The muscular test for C6 is the biceps and the reflex test for C5 is also the biceps
T
The lateral antebrachial cutaneous provides the cutaneous innervation for the ______ ______ _______.
Lateral anterior forearm
A pt comes in and reports pain. The loss of sensation ends at the wrist and then it gets picked up again at the thumb. What nerve is the issue?
Musculocutaneous nerve
If the pt cannot feel forearm, thumb, tip of thumb, then it is a C6 nerve issue.
What does a C6 MSR test look for: (if injured what will be affected?)
Muscle:
Reflex:
Sensory:
Muscle - Biceps
Reflex - Brachioradialis
Sensory - to the tips of the thumbs and index finger
Name the muscle(s), reflex affected, and cutaneous distribution associated with the musculocutaneous nerve.
Muscle(s) - flexion of the forearm by the biceps and brachialis
Reflex affected - Biceps
Cutaneous distribution - Lateral anterior and posterior ante brachium to the wrist
The lateral cord of the brachial plexus is derived from:
A. VPR of C5, and C6
B. Upper trunk components, only
C. Upper and middle trunk anterior divisions of C5-7
C
What are the three main branches of the lateral cord?
Lateral pectoral nerve
Contribution to the medial cord
Musculocutaneous nerve
The cords of the brachial plexus are named with represent to their position relative to the:
A. Aorta
B. Anterior and middle scalene muscles
C. Subclavian artery
D. Pectoralis minor muscle
C
The lateral pectoral nerve innervates the ______ muscle
Pectoralis major
The musculocutaneous nerve innervates ______ muscles?
Biceps brachii, brachialis, coracobrachialis
T or F
The lateral pectoral nerve, via small anstomosing branches with the medial pectoral nerves innervates the pectoralis minor as well as the pectoralis major
T
Which of these muscles innervated by the musculocutaneous nerve receives a contribution from C7 as well as C5 and C6?
A. Coracobrachialis
B. Biceps brachii
C. Brachialis
D. All of the above
A
The musculocutaneous nerve distributes the MSR reflex for:
A. C6
B. C5 and C6
C. C5
D. C7
C
Entrapment of the musculocutaneous nerve occurs at two sites. These include:
A. Between the anterior and middle scalene muscles
B. At the pectoralis minor and clavicle
C. At the pectoralis major
D. Between the biceps and brachialis
D
One way to distinguish C6 spinal nerve entrapment from musculocutaneous nerve entrapment is to compare:
A. The relative strength of the pectoralis major to the muscle strength of the biceps brachii
B. The briskness of the biceps reflex of the right arm to that of the left arm
C. The dermatomal and the cutaneous distributions of parenthesis experienced by the pt
C
Name the branches of the medial cord. (5 branches)
- Median nerve (largest)
- Ulnar nerve
- Medial cutaneous nerve of the forearm
- Medial cutaneous nerve of the arm
- Medial pectoral nerve
Name the divisions of the medial pectoral nerve. What muscles does this nerve innervate? Where can entrapment occur?
C8-T1
- Innervates Pectoralis major and minor
- Entrapment can occur with pectoralis minor injuries and spasms
The referred pain patterns in the medial brachial and antebrachial cutaneous nerves are associated with ___________ ________ and _________.
(Condition)
Myocardial infarction and angina
What is the largest nerve in the upper extremity? What is this nerves root distributions? Innervates what muscles?
Median nerve (C5-T1)
This nerve innervates the flexors of the wrist and fingers, as well as pronator of the forearm.
The main muscular branch of the median nerve innervates what muscles?
- Pronator teres
- Flexor carpi radialis
- Palmaris longus
- Flexor Digitorum superficialis
The anterior interosseous nerve (branch of the median nerve) innervates what muscles?
All Italians Feed Families Pizza (Punch Muscles)
*Anterior interosseous nerve
- Flexor Digitorum profundus I and II
- Flexor pollicis longus
- Pronator quadratus
The recurrent branch (little branches in the hand) of the median nerve innervates what muscles?
AFOFS
Always Find Opposing Fingers (1) Sketchy (2)
- Abductor pollicis brevis
- Flexor pollicis brevis
- Opponents pollicis
- First lumbrical
- Second lumbrical
List the superficial muscles (main muscular branch) of the anterior forearm.
Innervated by what nerve?
Name the syndrome associated with this region.
- Pronator Teres (C5-6)
- Flexor carpi radialis (C6-7)
- Palmaris longus (C7-8
- Flexor digitorum superficialis (C7-T1)
Innervated by median nerve
Possible Entrapment: carpal tunnel, flexor digitorum superficialis tunnel, pronator teres heads (possible between brachialis and biceps brachii but highly unlikely)
Name the deep muscles of the anterior forearm and their innervation.
Muscles to complete a “punch”
- Flexor digitorum Profundus
- Flexor Pollicis longus
- Pronator quadratus
- Innervated by the anterior interosseous branch of the median nerve
Explain anterior interosseous nerve syndrome (AINS).
What can cause this?
What test checks for this?
AINS is a condition caused by compression or injury to the anterior interosseous nerve (a branch of median nerve). The AIN supplies motor function to several muscles in the forearm, which are crucial for movement of the thumb and index finger.
AIN innervates the:
1. Flexors pollicis longus - responsible for flexing the thumb
2. Flexor digitorum profundus - specifically the lateral half, which flexes the distal phalanges of the index and middle fingers.
3. Pronator quadratus - responsible for pronating the forearm.
Cause: Compression or entrapment - This is the most common cause, which may occur at various points along the course of the nerve in the forearm, especially near the pronator teres muscle or in a tight facial band.
Test: Pinch test (OK sign) for median nerve innervates
Name the three muscles of the Thumb: Median Nerve.
About Flexing Openly
Abductor pollicis brevis
Flexor pollicis brevis
Opponents pollicis
Why would flexion of the thumb be a bad test for median nerve entrapment vs ulnar nerve entrapment?
Because of the dual innervation of the muscle of the flexor pollicis brevis. Flexion of the thumb is innervated by both nerves.
T or F
Lumbricals 1 and 2 are innervated by the median nerve and lumbricals 3 and 4 are innervated by the ulnar nerve.
T
T or F
If you have carpal tunnel syndrome you should not have weakness of the fingers
T
Will have pain but no weakness because muscle bellies are more proximal to carpal tunnel.
The palmar cutaneous branch travels on top of the carpal tunnel and not through. What does this mean?
In carpal tunnel syndrome, they should not have parenthesis of the palm of the hand. This would only happen in pronator teres syndrome. Digital cutaneous sensory would also happen in pronator teres syndrome.
In carpal tunnel syndrome we would just have digital cutaneous branch problems. We would not have palmar cutaneous branch problems because the nerve passes over the tunnel.
T or F
The palmar cutaneous branch of median nerve would be involved in carpal tunnel syndrome.
F
Because it does not pass through the tunnel (under the transverse carpal ligament)
The ulnar nerve (C8-T1) innervates what muscles? What are the cutaneous branches?
U (Ulnar) Feel Fricken Sore?
Branch = SUN Peanut Butter (1)
Branch = FLAP OAF (7)
Muscular Innervation of Ulnar Nerve:
- Flexor Carpi Ulnaris
- Flexor Digitorum Profundus 3 and 4
- Sensory to digits 1/2 4 and 5
Branch #1 - Superficial Ulnar Nerve
- Palmaris Brevis
Branch #2 - Deep Ulnar Nerve
- Flexor pollicis brevis - deep hand
- Adductor Pollicis
- Palmar and Dorsal Interossei
- Lumbricals 3 and 4
- Opponens Digiti Minimi
- Adbuctor Digiti Minimi
- Flexor Digiti Minimi
What is the Tunnel of Guyon? What nerve can be entrapped here?
Space between the hook of the hamate and pisiform where the ulnar nerve passes through.
Ulnar nerve entrapment = can result in loss of sensation in 5th digit and half of 4th.
The Froment’s paper test is testing what muscle? Looking for what neurological deficiency?
Adductor pollicis, in this test you are specifically looking at the ability of the thumb to adduct, not that DIP to flex.
Ulnar nerve
Regarding the interossei muscles:
The Dorsal interossei are ___________
Whereas, the palmar Interossei muscles are ____________
Dorsal interossei = Abductors
Palmar interossei = Adductors
*Look at pictures of cutaneous distribution of Ulnar, Median, and Lateral nerve!!!!!!
The medial cord of the brachial plexus is derived from:
A. VPR of C5-C7, only
B. DPR of C5-7
C. Upper and middle trunk components, only
D. CPR of C5-T1, anterior divisions of all three trunks
D
The THREE main branches of the medial cord are…
Ulnar nerve
Medial pectoral nerve
Median nerve
The medial cord exhibits two separate cutaneous nerves. One of these is the: ___________ nerve.
A. Lateral antebrachial cutaneous
B. Medial cutaneous nerve of the arm
C. Posterior antebrachial cutaneous
D. Superficial radial
B
The medial pectoral nerve innervates the ____________ muscle.
A. Pectoralis minor
B. Teres minor
C. Lateral pectoral
A
The median nerve has three main muscular branches. These are ________ nerves.
A. Anterior interosseous, recurrent median, and ulnar
B. Main muscular, posterior interosseous, and recurrent median
C. Main muscular, anterior interosseous, and recurrent median
C
T or F
The main muscular branches of the median nerve can be entrapped between the two heads of the pronator teres.
T
Which of these muscles innervated by the median nerve receive contributions C8 and T1, only?
A. Flexor pollicis longus
B. Abductor pollicis brevis
C. Pronator teres
D. Flexor carpi radialis
B
The median nerve distributes the MSR reflex for:
A. C5
B. C6
C. C7
D.C8
D
Entrapment of the median nerve occurs at two important sites. These are?
A. Between the two heads of the pronator teres and at the carpal tunnel
B. At the superficial flexor arch and at the Tunnel of Guyon
C. Between the two heads of the pronator Teres and at the Arcade of Struthers
A
One way to distinguish entrapment of the median nerve at the pronator teres (PTS) from entrapment at the carpal tunnel (CTS) would be:
A. The briskness of the finger flexor reflex would be normal in PTS but descreased in CTS
B. Use the pinch test, this would be normal in PTS but abnormal in CTS
C. In PTS, the pt would have parenthesis of the palm, where in CTS they would not
D. Strength of the flexor pollicis longus would be affected in PTS and the strength of the ADDuctor pollicis would be affected in CTS
C
The ulnar nerve can be entrapped:
A. Between the two heads of the biceps brachii
B. Between the long head and lateral head of the triceps brachii
C. As it passes around the lateral epicondyle of the humerus
D. Posterior to the fascia spanning the pisiform and hook of the hamated
D
Choose THREE muscles innervated by the ulnar nerve:
Flexor pollicis brevis
Pronator teres
Flexor digiti minimi
Adductor pollicis
Flexor digitorum superficialis
Flexor pollicis brevis
Flexor digiti minimi
Adductor pollicis
The cutaneous distribution of the ulnar nerves includes the: _________
A. Lateral hand and thumb anteriorly
B. Medial hand, anterior and posteriorly
C. Tips of the tale real digits
D. Lateral forearm
B
The test for the adductor pollicis is:
A. Froment’s paper sign
B. The sign of OK
C. Phalen’s test
D. The pinch test
A
Looking at the ability for the thumb to adductor. Not the DIP to flex. If the thumb cannot adduct then there is an ulnar nerve problem.
The Interossei muscles are innervated by _______ nerve
A. Anterior interosseous
B. Recurrent median
C. Ulnar
C
What are the four major nerves associated with the posterior cord?
Upper and lower subscapular nerves
Thoracodorsal nerve
Axillary nerve
Radial nerve
The upper subscapular nerve innervates what muscles?
The lower subscapular nerve innervates what muscles?
USN - subscapularis, posterior divisions
C5, 6
LSN - subscapularis (C5) and teres major (C6)
What muscle does the thoracodorsal nerve innervates?
Latissimus dorsi
Posterior divisions
C6-8
The axillary nerve comes from what division and innervates what muscles?
Posterior divison (C5, 6)
Innervates teres minor, deltoid (tricep long head)
Compare C5 Root Damage to Quadrangular Space Syndrome
Motor
C5 Root Damage - Deltiod paresis, mild
Quad. SS - Deltiod / teres minor paresis and atrophy; moderate to severe
Reflex
C5 Root Damage - Mild hyporeflexia, the biceps reflex is rarely lost
Quad. SS - not affected
Sensory
C5 Root Damage - Lateral shoulder / C5 Dermatome parenthesia
Quad. SS - lateral shoulder and proximal arm paresthesia
Pain findings
C5 Root Damage - Neck pain, radicular pain, cervical compression increases pain, neck traction increases pain
Quad. SS - Pain in the quad space; pain on internal rotation of the shoulder
Other:
C5 Root damage - shoulder rgirdle muscles should be checked for weakness as well
Quad SS - surgical neck of the humerus fracture can contribute to
Name the muscular branches of the brachium, and antebrachium, cutaneous branches.
Slide 17* Unit 6
Brachium - long heads triceps (C7,8); Anconeus (C7, 8)
Antebrachium -
*Radial nerve: Brachioradialis C5, 6; Supinator C6; Extensor carpi radialis longus C6, 7
*Posterior Interosseus Nerve (DEEP RADIAL) the rest of the extensors of the wrist and hand
Cutaneous Branches:
Brachium - the lower lateral cutaneous nerve and the posterior breachial cutaneous nerve
Antebrachium - the posterior antebrachial cutaneous nerve and the superficial radial nerve
The triceps are innervated by what nerve?
Axillary nerve - long heads of triceps
Radial nerve - lateral head and medial head of triceps
The radial nerve innervates what superficial muscles of the antebrachium?
The posterior interosseous nerve innervates what muscles of the antebrachium?
Radial nerve -
- Brachioradialis
- Supinator
- Extensor carpi radialis longus
Posterior Interosseus nerve -
- Extensors carpi radialis brevis
- Extensors carpi ulnaris
- Extensor digitorum
- Extensor digiti minimi
Name the deep muscles of the antebrachium.
EEEA
Ext. indicis
Ext. pollicis longus
Ext. pollicis brevis
Adbuctor pollicis longus
Upper arm radial nerve palsy: AKA “Saturday Night Palsy” involves what?
Compression of the radial nerve innervates the spiral groove of the humerus, or damage to the nerve innervates humeral fracture.
Radial Tunnel Syndrome (RTS): AKA Supinator Syndrome involves what?
Persistent pain around the lateral epicondyle, often misdiagnosed as lateral epicondyle, often misdiagnosed as lateral epicondylitis. Pain may be dull and diffuse in the dorsal antebrachium, often due to repetitive pronation / supination;
Pain, not weakness
What does posterior interosseous nerve syndrome (PINS) involve?
Bowling PINS at the ARCADE
Site of compression is at the arcade of frohse, and weakness is the principle symptom. Weakness of wrist, fingers, and thumb extension; particularly the 3rd digit extension.
No sensory changes, just weakness of wrist, fingers, thumb extension, and aching pain during activity.
What does superficial radial nerve compression involve?
Wartenberg’s palsy
The most common cause of superficial radial nerve palsy is wearing tight wrist bands.
Can cause numbness on posterior side of hand and from digits 1-3 1/2
The posterior cord of the brachial plexus is derived from:
A. VPR of C5-T1, posterior divisions of all three trunks
B. DPR of C5-7
C. VPR of C5-7
A
Choose THREE main branches of the posterior cord:
Anterior interosseous nerve
Radial nerve
Thoracodorsal nerve
Axillary nerve
Medial pectoral nerve
Radial nerve
Thoracodorsal nerve
Axillary nerve
The radial nerve exhibits a cutaneous nerve as its terminal branch. It is the _______ nerve.
A. Lateral antebrachial cutaneous
B. Superficial radial
C. Posterior interosseous
D. Posterior antebrachial cutaneous
B
The lower subscapular nerve innervates these muscles:
A. Teres major, supraspinatus
B. Subscapularis, teres minor
C. Subscapularis, teres major
D. Subclavius, teres major
C
There are four rotator cuff muscles. These muscle provide fine movements of the humerus at the shoulder. These are supported by large muscles like the deltoid and the ________ which is innervated by the thoracodorsal nerve.
A. Teres major
B. Serratus anterior
C. Supraspinatus
D. Latissimus dorsi
D
T or F
The posterior interosseous nerve can be entrapped at the Arcade of Frohse
Bowling PINS at the Archade
T
The radial nerve distributes the MSR reflex for:
A. C5
B. C6
C. C7
D. C8
C
Entrapment of the radial nerve at the radial groove causes which one of these conditions?
A. Posterior interosseous nerve syndrome
B. Carpal tunnel syndrome
C. Wartenberg’s syndrome
D. Saturday Night palsy
D
One way to distinguish radial nerve (RT) entrapment from posterior interosseous nerve syndrome (PINS) would be:
A. In RT, the pt exhibits wrist drop, where in PINS they would exhibit loss of finger extension, especially of the third digit
B. The strength of the abductor pollicis longus would be affected in PTS but not in RT
C. The biceps reflex would be affected in RT but not in PINS
A
The axillary nerve can be entrapped at the _____________
Quadrangular space
Choose THREE muscles innervated by the ulnar nerve:
Flexor digiti minimi
Flexor digitorum superficialis
Adductor pollicis
Pronator teres
Flexor Pollicis Brevis
Flexor digiti minimi
Adductor pollicis
Flexor pollicis brevis
When testing the latissimus dorsi, the arm and thumb should be:
A. Arm: abducted and no rotation; thumb pointed anteriorly
B. Arm: adducted and internally rotated; thumb: pointed posteriorly
C. Arm: abducted and internally rotated; thumb: neutral position
B
The triceps is innervated by:
A. Both axillary and radial nerves
B. Radial nerve
C. Aciallary nerve
A
Damage to the superficial radial nerve results in:
A. Weakness of the Abductor pollicis longus muscle
B. Paresthesia / numbness of the posterior thumb and hand
C. Paresthesia of the palm and anterior thumb
D. Weakness of the extensor digiti minimi muscle
B
Neruopraxia
Axonotomesis
Neurotmesis
Slight ding
Compression causing weakness
Worst transaction; paralysis
Name and describe the muscular innervations and cutaneous distribution of the Musculocutaneous nerve.
Biceps brachii
Brachialis
Corabcobrachialis
Lateral Antebrachial cuteneous N. = Sensory branch covering the lateral spect of the forearm
Name and describe the muscular innervations and cutaneous distribution of the axillary nerve.
Teres Minor
Deltoid
Triceps (long head)
Lateral Brachial cutaneous Nerve = (Superior) sensory for skin over lateral aspect of the shoulder
What two nerves branch from the median nerve?
What muscles do these nerves innervate?
Remember: AI - Punch muscles & Raccoons - Obtain Abundant Food
Branch 1: Anterior Interosseous Nerve
- Flexor digitorum profundus 1 and 2
- Flexor pollicis Longus
- Pronator Quadratus
Branch 2: Recurrent Branch of Median
- Opponons Pollicis
- Adbuctor pollicis brevis
- Flexor pollicis brevis
What muscles does the Radial Nerve innervate?
Think Always Be Exercising
What are the two nerve branches from the radial nerve?
Super Posture!
Radial Nerve Innervates:
- Triceps
- Anconeus
- Brachioradialis
- Extensor Carpi Radialis Longus
Branch #1 - Superficial Radial Nerve
Branch #2 - Posterior Interosseous Nerve / Deep Radial Nerve
The Superficial Radial Nerve provides sensory to what?
Sensory to dorsal of digits 1, 2, 3 1/2
The Posterior Interosseous Nerve / Deep Radial Nerve Innervate what muscles?
7 sEa’s
—> Supinator
1. Extensor Carpi Radialis brevis
2. Extensor Digitorum
3. Extensor Carpi Ulnaris
4. Extensor Digiti Minimi
5. Extensor Pollicis Brevis
6. Extensors Pollicis Longus
7. Extensor Indicis
—> Abductor Pollicis Longus
Radial tunnel Syndrome (RTS): AKA Supinator Syndrome involves what?
How is this Different from Posterior Interosseus Nerve Syndrome (PINS)?
RTS: persistent pain around the lateral epicondyle, often misdiagnosed as lateral epicondylitis (tennis elbow). Pain may be dull and diffuse in the dorsal ante-brachium, often due to repetitive pronation/supination. PAIN, NOT WEAKNESS
PINS: Site of compression at the Arcade of Frohse, and weakness is the principle symptom. WEAKNESS of wrist, fingers, and thumb extension; particularly the 3rd digit extension. NO sensory changes, only aching pain during activity.
