Upper Limb Anatomy Flashcards
What is the path of the musculocutaneous nerve?
Branch of lateral cord of brachial plexus.
- penetrates coracobrachialus muscle
- passes obliquely between Biceps Brachii and Brachialis to the lateral side of the arm
- Pierces deep fascia lateral to the tendon of the biceps brachii ABOVE the elbow
- Continues into the forearm as the Lateral Cutaneous Nerve of the forearm
What 3 muscles are innervated by the musculocutaneous nerve?
- Coracobrachialis
- Biceps brachii
- Brachialis
What 3 muscles make up the Thenar Eminence?
- Abductor pollicis brevis
- Opponens pollicis
- Flexor pollicis brevis
Innervated by median nerve
What 3 muscles make up the Hypothenar eminence?
- Opponens digiti minimi
- Flexor digiti minimi brevis
- Abductor digiti minimi
What is the relation of the Serratus Anterior to the Long thoracic nerve?
The muscle lies MEDIAL to the Long Thoracic Nerve
What flexors in the forearm are innervated by the median nerve?
Flexor carpi radialis
Flexor digitorum superficialis
Flexor pollicis longus
Flexor digitorum profundus (radial half)
What is the motor supply of the median nerve in the hand?
LOAF
- Lateral 2 lumbricals
- Opponens pollicis
- Abductor pollicis brevis
- Flexor pollicis brevis
What does damage to the median nerve at the elbow result in?
- unable to pronate forearm
- weak wrist flexion
- ulnar deviation of wrist
- signs of carpal tunnel syndrome
What muscles of the forearms are innervated by the Radial Nerve (Posterior interosseous branch)?
- Supinator
- Brachioradialis
- Extensor carpi ulnaris
- Extensor pollicis longus AND brevis
- Abductor pollicis longus
What nerve lies laterally to the brachial artery at the level of the proximal humerus?
Median nerve
What are the borders of the anatomical snuffbox?
- Posterior (medial): Extensor pollicis longus
- Anterior: Extensor pollicis brevis and longus
- Proximal: Styloid process of radius
- Distal: apex of triangle
- Floor: Scaphoid and trapezium
Contains the radial artery
What are the clinical symptoms associated with ulnar damage at the elbow?
- Radial deviation of the wrist
- Clawing less in 4th and 5th digits
What are the 6 branches of the axillary artery?
Screw The Lawyer Save A Patient
1st part
- Superior thoracic artery
2nd part
- Thoracoacromial artery
- Lateral thoracic artery
3rd part
- Subscapular artery
- Anterior humeral circumflex artery
- Posterior humeral circumflex artery
What are the attachments of the Extensor retinaculum?
- Attaches at the pisiform and triquetral medially
- End of the radius laterally
What structures lie superficial to the Extensor retinaculum?
- Basilic vein
- Cephalic vein
- Dorsal cutaneous branch of ulnar
- Superficial branch of the radial
What structures pass deep to the extensor retinaculum?
Medial to lateral
- Extensor carpi ulnaris
- Extensor digiti minimi
- Extensor digitorum and extensor indicis
- Extensor pollicis longus
- Extensor carpi radialis longus
- Extensor carpi radialis brevis
- Abductor pollicis longus and Extensor pollicis brevis
What are the nerve roots of the median nerve?
C5-T1
What are the nerve roots of the axillary nerve?
C5 and C6
What is the path of the axillary nerve?
- Descends posterior to the axillary artery at lower border of subscapularis
- Passes through Quadrangular space with Posterior circumflex humeral vessels
- Divides into anterior and posterior branches
What are the nerve roots of the ulnar nerve?
C8, T1
What is supplied by the Deep branch of the ulnar nerve?
- Hypothenar muscles
- All interosseous muscles
- 3rd and 4th lumbricals
- Adductor pollicis
- Medial head of flexor pollicis brevis
What is a C5, C6 root lesion commonly known as and how does it present?
Erb’s palsy
- Loss of shoulder abduction (deltoid and supraspinatus paralysis)
- Loss of external rotation (infraspinatus paralysis)
- Loss of elbow flexion (biceps, brachialis, brachioradialis paralysis)
- Loss of forearm supination
At what point does the subclavian artery become the axillary artery?
As it crosses the lateral border of the first rib
What is the pathophysiology of Subclavian steal syndrome, how does it present and how is it treated?
Subclavian artery steno-occlusive disease PROXIMAL to origin of vertebral artery and is associated with flow reversal in the vertebral artery
Symptoms:
- dizziness (esp on exertion of arm)
- vertigo (esp on exertion of arm)
- arm pain
Management:
- percutaneous transluminal angioplasty
- stent
