Neuroanatomy Of UE Flashcards
SCM is one of two muscles innervated by what cranial nerve?
CN 11
Spinal accessory nerve
The CN11 provides motor innervation to SCM and what other muscle?
Trapezius
Name the three scalene muscles and their attachment points. Why are the anterior and middle scalenes most clinically significant?
Anterior - attaches to the 1st rib (scalene tubercle) *only scalene that attaches to scalene tubercle.
- Left subclavian vein passes anterior to anterior scalene!!
- Left subclavian artery passes in between anterior and middle scalene (if they tighten there will be limited BF = condition is called thoracic outlet syndrome)
Middle - O: posterior tubercles of the TP of C2-7
I: Upper surface of Rib 1
Posterior - O: posterior tubercles of the TP of C5-7
I: outer surface of rib 2
All N: by anterior divisions of nerves
Why would the area between the clavicle and first rib be clinically important
Big neurovascular bundle travels through.
It would Limit and compress BF or AP through that thoracic outlet.
What are the three neurovascular entrapment points?
Between anterior and middle scalene
Between clavicle and rib 1
Into pectoralis minor
The axillary artery can be found where?
Deep into the anterior shoulder
The brachial plexus is composed of what division
C5-T1
The musculocutaneous nerve is made up of three muscles (three muscle men). What nerve segments make this up portion of the brachial plexus?
C5, 6, 7
The axillary (circumflex nerve) is made up of what brachial plexus distributions?
C5, 6
What are the divisions of the radial nerve?
(C5, 6, 7, 8 (T1))
Innervates everything in the posterior compartment of the arm
What is the distribution of the median nerve?
((C5, C6, 7, 8, T1)
What three muscles does the musculocutaneous nerve intervene? Distributions
Biceps brachii, brachial is, and coracobrachialis (BBC)
What muscle can cause impingement on the axillary nerve causing loss of sensation over the deltoid?
Teres Minor
The radial nerve assists in additional innervation in what muscle? Causes what movement?
Brachialis
Supination
What nerve can get entrapped at pronation teres?
Medial nerve
T or F
Compression of the median nerve only happens at the carpal tunnel?
F
It can happen at three total locations including the carpal tunnel. Between bicep brachii and brachialis, or at pronator teres
Phrenic Nerve
O: B: (Branches from) N:
O: C3, C4, C5
B: pericardial nerve, phrenicoabdominal nerve
N: descends obliquely with the internal jugular vein, enters the thorax, and travels down each side of the mediastinum to innervate the pleura, pericardium, and diaphragm.
Brachial Plexus
Roots:
Trunks:
Divisions:
Cords:
Terminal Branches:
R: C5-T1
T: Superior, Middle, Inferior
D: Anterior and Posterior divisions
C: Lateral, Posterior, Medial
TB: Musculocutaneous, Axillary/Radial, Lateral root + Medial root = Median, Ulnar
Superior trunk of the brachial plexus stems from what roots?
C5, C6
Middle trunk of the brachial plexus stems from what roots?
C7
Inferior trunk of the brachial plexus stems from what roots?
C8, T1
What divisions and nerves stem from the superior trunk of the brachial plexus?
Anterior and posterior divisions
Suprascapular and subclavian nerve stem from the superior trunk
What divisions stem from the middle trunk of the brachial plexus?
Anterior and posterior divisions
What divisions stem from the inferior trunk of the brachial plexus?
Posterior and anterior divisions
What portions of the brachial plexus lead to the formation of the lateral cord?
C5-C7
Superior and Middle Anterior divisions make up the lateral cord
What portions of the brachial plexus lead to the formation of the posterior cord?
What nerves branch from this cord?
C5-T1
Superior, middle, and inferior posterior trunks with posterior divisions feed into the posterior cord
Upper and lower subscapular nerves, and thoracoacromial nerve branches from the posterior cord
What portions of the brachial plexus lead to the formation of the medial cord?
What nerves branch from this cord?
C8, T1
Inferior trunk
Anterior divisions into the medial cord
Branches from this cord are medial pectoral nerves, medial cutaneous nerve of arm, and medial cutaneous nerve of forearm.
What is the division of the musculocutaneous nerve and where does it stem from?
C5-7
Lateral cord anterior divison
Anterior divisions supply anterior ___________ compartments
Flexor
Posterior divisions supply posterior _______________ compartments
Extensor
Name the CORDS of anterior division and their roots and innervatation.
- Lateral cord
- lateral pectoral nerves (C5-7) —> pectoralis major
- musculocutaneous nerve (C5-7) —> lateral skin of forearm
- lateral cord (C5-7) contribution to median nerve (C5-T1) —> to flexors in forearm and some hand muscles - Medial Cord
- medial cord contribution to median nerve (C8, T1)
- medial pectoral nerve (c8, T1) —> pectoralis major and minor
- medial bronchial cutaneous nerve (T1) —> skin on medial arm
- medial antebrachial cutaneous nerve (C8 T1) —> skin on medial forearm
- ulnar nerve (C7-T1) —>CHECK THIS ONE LATER
Name the cord of the posterior division and its branches?
Posterior Cord
- upper subscapular nerve (C5, 6) —> subscapularis
- lower subscapular nerve (C5, 6) —> subscapularis and teres major
- thoracodorsal nerve(C6-8) —> latissimus dorsi
- Axillary nerve (C5, 6) —> deltoid, teres minor, LG of triceps brachii
- Radial nerve (C5-T1) —> triceps, anconeus, brachioradialis, extensors in forearm and skin of posterior upper limb
Phrenic Nerve
Musculocutaneous Nerve
Median nerve
Ulnar nerve
Radial nerve
Superficial Radial Nerve
Deep Radial Nerve
The lateral cord branches into what nerve and then goes into what muscle?
Lateral cord branches into the musculocutaneous and then innervates the coracobrachialis.
What nerve travels through the quadrangular space? What does it travel with?
Axillary nerve travels with the posterior humeral circumflex artery
How many anterior muscles are there of the forearm?
8 total
4 superficial (“Pass, Fail, Pass, Fail”)
1 intermediate
3 deep (muscles to complete a “punch”)
What 9 structure pass through the carpal tunnel?
8 tendons; 1 nerve
Flexor digitorum profundus tendons (4 tendons, one for each finger except the thumb)
Flexor Digitorum superficialis (4 tendons, one for each finger except the thumb)
Median Nerve: provides sensation to the palm side of the thumb, index, middle and part of the ring finger, and motor function of the hand
How many posterior muscles of the forearm are there?
Name these muscles and their groupings.
12 (4 groups of 3 muscles)
- Raidalis Group
1. BR = BrachioRadialis
2. ECRL = Extensor Carpi Radialis Longus
3. ECRB = Extensor Carpi Radialis Brevis
*Extensor Group
1. ED = Extensor Digitorum
2. EDM = Extensor Digiti Minimi
3. ECU = Extensor Carpi Ulnaris
*Pollicis Group
1. APL = Abductor Pollicis Longus
2. EPB = Extnsor Pollicis Brevis
3. EPL = Extensor Pollicis Longus
*Deep Group
1. A = Anconeus
2. S = Supinator
3. EI = Extensor Indicis
Name the innervations and names of the rotator cuff muscles.
Suprascapular Nerve = innervates supraspinatus, and Infraspinatus
Upper subscapular nerve = innervates the subscapularis
Lower Subscapular Nerve = innervates the Teres Minor
The cords are named due to their relationship with the 2nd part of the ______ ______.
Axillary Artery
Describe the medial brachial cutaneous nerve distribution.
T1 = skin on medial arm
Describe the medial antebrachial cutaneous nerve distribution.
(C8, T1) = skin on medial forearm
What muscle does the first 15-30 degrees of abduction of the humerus?
Supraspinatus
Innervated by the surprascapular nerve
Travels through the SCAPULAR NOTCH
Radial nerve innervates extensors of the elbow and what two flexors of the elbow?
Brachialis and brachioradialis
Thoracic Region Neurology
Thoracic region
• T1
• largest branch = part of brachial plexus • smallest branch = 1st intercostal nerve intercostal muscle and skin of
thoracic wall
• T2
• intercostobrachial nerve – arises like a lateral cutaneous nerve, but fails to
branch into anterior and posterior branches, pierces intercostal and serratus
anterior muscles, crosses axilla skin on medial side of brachium • 2nd intercostal nerve intercostal muscle and skin of thoracic wall
• T3 – T11
• 3rd – 11th intercostal nerves intercostal muscle and skin of thoracic wall
• T12 subcostal nerve intercostal muscle and skin of thoracic wall
• T1-L2/3 Sympathetic nerves (of the ANS)
• Much much more on this later
• Intercostal nerves 2-5 serratus posterior superior • Intercostal nerves 9-12 serratus posterior inferior
Intercostal nerves 2-5 innervate what muscle?
Serratus posterior superior
Intercostal nerves 9-12 innervate what muscle?
Serratus posterior inferior
Innervation of the trapezius
Accessory nerve (CN 11)
Serratus posterior superior innervation
Intercostal nerves 2-5
Innervation of teres minor?
Innervation of teres major?
T MINOR - axillary nerve
T MAJOR - lower subscapular nerve
