Upper Limb Anatomy Flashcards
What does the subclavian muscle do in relation to the clavicle and what is it innervated by?
It depresses the clavicle and is supplied by the upper trunk nerves
Where does the long head of the bicep insert?
Inserts into the Supraglenoid tubercle
Where does the long head of the tricep insert?
Infraglenoid tubercle
What are the 4 rotator cuff muscles where do they insert? (SITS)
Supraspinatus, Infraspinatus, Teres minor insert into the Greater Tubercle of the humerus. Subscapularus attaches to the Lesser Tubercle of the humerus
Which rotator cuff muscles are innervated by the Suprascapular nerve?
Supraspinatus + Infraspinatus
What two structures are liable to damage at the surgical neck of the humerus?
Axillary nerve and Humeral circumflex artery
Where is the Capitulum located and what does it articulate with?
Capitulum is found on the lateral epicondyle of the humerus and articulates with the head of the radius
What articulates with the olecranon fossa?
Olecranon process of the ulnar bone
Where is the deltoid tuberosity found?
Posterior humerus
What are the carpal bones? (from lateral to medial)
Scared Lovers Try Positions That They Can’t Handle
Scaphoid - Lunate - Triquetrum - Pisiform
Trapezium - Trapezoid - Capitate - Hamate
Which flexor muscle attaches to the pisiform bone?
Flexor carpi ulnaris
Which carpal bone can be damaged in a FOOSH leading to median nerve injury?
Dislocation/damage to the Lunate can cause injury to median nerve
What are the origins of Trapezius muscle and what is its function?
Originates from C7-T12 spinal processes and causes Scapula rotation
What does the accessory nerve (CN XI) supply and how is it tested?
Supplies Trapezius muscle and Sternocledomastoid (SCM) muscle.
Tested by shrugging shoulders
Which nerve supplies Latismuss Dorsi?
Thoracodorsal nerve
Where does Pectoralis minor and major attach to?
Major: Bicepital groove
Minor: Coracoid process
What is the function of the Pectoralis major muscle and which nerves is it innervated by?
Causes internal rotation of the arm and ADDuction of the arm
Innervated by medial and lateral pectoral nerves
Where does Pectoralis minor originate from and what is its innervation?
Originates from ribs 3-5 and is innervated only by the medial pectoral nerve
What is the function of the Teres major and what is it supplied by?
ADDuction and internal rotation and EXTension of the arm
Supplied by the Lower SUBSCAPULAR nerve
Where does the Teres major originate and attach?
Originates at the Inferior Scapula and attaches medially on the humerus
Where is the Quadrangular space and what are its borders
Found below the shoulder joint adjacent to the surgical neck of the humerus
Superior: Teres minor
Inferior: Teres major
Medially: Long head of triceps tendon
Laterally: Humerus
What are the contents of the Quadrangular space?
Axillary nerve - Humeral artery - Posterior humeral circumflex artery
What is the origin and insertion of the Coracobrachialis and what is its function?
Originates at the coracoid and inserts into mid humerus
Allows for flexion and adduction of the arm
Which nerve innervates the Coracobrachialis?
Musculocutaneous nerve (lateral cord)
Which 3 muscles does the musculocutaneous nerve innervate?
BBC
Biceps brachii - Brachialis - Coracobrachialis
What does the musculocutaneous nerve become in the forearm and what does it supply?
Continues into the forearm as the Lateral Cutaneous Nerve and provides sensory sensation to the lateral forearm
What is the origin and insertion of Brachialis?
Originates from mid humerus and inserts into the ulna tuberosity anteriorly
What is the blood supply to the triceps?
Profunda brachii artery
Which nerve supplies the flexors of the forearm and which muscle is the exception?
All flexor forearm muscles are innervated by the median nerve EXCEPT Flexor carpi ulnaris
Which muscle is involved in flexion of the proximal interphalangeal (PIP) joint and where does it insert?
Flexor digitorum superficialis (FDS)
Inserts in the base of middle phalanges and splits to allow passage for Flexor digitorum profundus (FDP)
Flexor Digitorum Profundus allows for flexion of DIP. What is its nerve supply?
Median anterior interosseous nerve and Ulnar nerve
What are the 3 main deep flexors of the forearm?
Flexor digitorum profundus - Flexor pollicis longus - Pronator quadratus
What is the nerve supply of the deep flexors of the forearm?
Median anterior interossesous nerve
What are the 5 deep extensors of the forearm?
- Supinator (inserts at dorsal lateral radius)
- Abductor policies longus (1st metacarpal base)
- Extensor policis brevis (inserts at prox thumb base)
- Extensor pollicis longus
- Extensor indices proprius (inserts at index finger)
What is the nerve supply of the deep extensors of the forearm?
Radial-posterior interosseous nerve
Which two extensors allow for extension of the wrist and where do they attach?
Extensor carpi radialis + Extensor carpi radialis brevis.
Insert into 2nd and 3rd metacarpal base respectively
What are the attachments of the Extensor Retinaculum?
Pisiform and Triquetrum medially
End of radius laterally
How many compartments are there beneath the extensor retinaculum?
5
What are the boundaries of the anatomical snuffbox in relation to the compartments beneath the extensor retinaculum?
Anterolateral: Compartment 1 (Abductor pollicis longus and Extensor pollicis brevis)
Posteromedial: Compartment 3 (Extensor pollicis longus)
What makes up the floor of the anatomical snuffbox?
Scaphoid and part of the Trapezium
Inflammation in which muscles causes pain at the base of the thumb and what is the name of this condition?
De Querrvains tenosynovitis
Inflammation of Abductor pollicis longus and Extensor pollicis brevis
Between which two muscles in the forearm does the radial nerve run?
Brachialis and Brachioradialis
What are the 4 Thenar muscles and what are their innervations?
- Abductor pollicis brevis (APB): Median nerve
- Opponent pollicis: Median nerve
- Flexor pollicis brevis (FPB): median and ulnar nerves
- Adductor pollicis (deep ulnar nerve)
Where are the extensor indices found?
Medial to Extensor digitorum within compartment 4 beneath the Extensor retinaculum
Which structure splits pronator teres and runs between Flexor digitorum superficial (FDS) and Flexor digitorum profundus (FDP)?
Anterior Interosseous nerve
What is the nerve root of the intrinsic muscles of the hand?
T1
What is the function of the dorsal and palmar interossei?
DAB - Dorsal does Abduction
PAD - Palmar does Adduction
How many dorsal and palmar interossei are there?
3 Palmar
4 Dorsal
What are the nerve supplies of the lumbricals and and interossei?
Lumbricals: Median (lateral) and Ulnar (medial)
Interossei: Ulnar nerve
What is the axillary artery a continuation of?
Subclavian artery
What are the main branches of the axillary artery?
Screw The Lawyer, Save A Patient
- Superior thoracic artery (medial serrates and pectoral muscles)
- Thoracoacromial artery (branches in Deltoid, Acromial, Pectoralis, Clavicular art.)
- Lateral thoracic artery
- Subscapular artery (gives rise to Thoracodorsal + circumflex scapular)
- Anterior humeral circumflex (supplies humeral head)
- Posterior humeral circumflex
Where does the axillary artery become the brachial artery?
Lower border of Teres major
What is the pathway of the median nerve in the upper arm?
Starts lateral to the brachial artery and crosses anteriorly over the mid humerus before continuing to the medial side of the brachial artery
What structures does ulnar artery lie on at the wrist?
FDP superficial to the flexor retinaculum
What are the branches of the ulnar artery?
- Deep palmar arch
- Superficial palmar arch
- Anterior interosseous artery
Which vein merges with the Basilic vein just prior to draining into the axillary vein?
Medial brachial vein
Where is the brachial plexus located?
Posterior triangle of the neck between Scalene anterior and Medius muscles
What are the roots of the brachial plexus?
C5-T1
Which trunk of the brachial plexus is most likely to be damaged in a clavicle fracture?
Inferior trunk (C8-T1)
What is the the nerve root of the Long thoracic nerve and what does it supply?
C5-7
Serratus anterior
Where are cords of the brachial plexus found?
Axilla
Cords are labelled in relation to the axillary artery
What are the 5 branches of the medial cord (C8-T1)
All begin with medial apart from 1
- Medial pectoral nerve (supplies pec major)
- Medial cutaneous nerve of the arm
- Medial cutaneous nerve of the forearm
- Medial part of median nerve
- Ulnar nerve
What are the 3 branches of the Lateral cord (C5-7)?
- Lateral pectoral nerve
- Lateral part of median nerve
- Musculocutaneous nerve (supplies BBC)
What are the branches of the Posterior cord (C5-T1)?
STARS
- Subscapular (upper) nerve
- Thoracodorsal nerve
- Axillary nerve
- Radial nerve
- Subscapular (lower) nerve
Which nerve gives sensation to the supraclavicular area?
Supraclavicular nerve (C4)
would remain intact in event of brachial plexus injury
Which muscles in the hand are innervated by the Median nerve?
LOAF
Lateral 2 lumbricals
Opponens pollicis
Abductor pollicis brevis
Flexor pollicis brevis
Which nerve supplies the forearm flexors and which additional muscles does this nerve supply in the arm?
All forearm flexors (except flexor carpi ulnas) are innervated by the median nerve
- Pronator quadratus
- Pronator teres
- Palmaris longus
Damage to which nerve would causes loss of pincer movement?
Anterior interosseous nerve
What are the motor innervations of the ulnar nerve?
MAFIA P
- Medial 2 lumbricals
- Adductor pollicis
- FDP + flexor carpi ulnaris
- Interossei
- Abductor and Opponens and Flexor digit minimi (hypothenar muscles)
- Palmaris brevis
What effects would you expect to see after damage to the ulnar nerve at the wrist?
- Loss of sensation in the medial hand
- Wasting and paralysis of Hypothenar muscles and intrinsic muscles
What would damage to the posterior interosseous nerve (PIN) cause?
Only finger drop
NO SENSORY LOSS
Ulnar damage at which point of the arm would cause radial deviation of the hand and clawing of 4th and 5th fingers?
Damage to the ulnar nerve at the ELBOW
What is the motor innervations of the radial nerve?
BEAST
Brachioradialis - Extensors - Aconeus - Supinator - Triceps
Which rotator cuff muscle is responsible for 0-15 degrees abduction of the shoulder?
Supraspinatus
What is the innervation of the breast?
Intercostal nerves (T4-6)
What is the arterial supply of the breast?
Internal mammary artery (60%)
External mammary artery
Anterior intercostal arteries
Where does the lymphatics from the breast drain into?
Axillary nodes
What are the borders of the axilla?
- Medially: Chest wall and Serratus anterior
- Laterally: Humeral head
- Floor: Subscapularis muscle
- Anteriorly: Lateral border of Pec major
Which nerves are at high risk for damage during a mastectomy?
- Long thoracic nerve (C5-7)
- Intercostal brachial nerve (parasthesia in armpits
- Thoracodorsal nerve
What are the medial and lateral boundaries of the cubital fossa?
Medial: Pronator teres
Lateral: Brachioradialis
What structures are present in the Cubital fossa (medial to lateral)?
Median nerve - Brachial artery - Brachial vein - Biceps tendon - Radial nerve
What is damaged in Erb’s palsy and what would a patient present with?
Damage to the Upper trunk (C5-6)
- Loss of sensation in radial aspect of arm
- Adduction and internal rotation of arm (due to paralysis of abductor muscles and infraspinatus and teres minor)
- Forearm extension and pronation (due to paralysis of forearm flexors and supinators)
VIT C & D
What are the 5 branches of the subclavian artery?
VIT C & D
- Vertebral artery
- Internal thoracic artery
- Thyrocervical trunk
- Costalcervical trunk
- Dorsal scapular artery
What is Klumbeks palsy?
Damage to the Lower trunk (C8-T1)
- Loss of sensation in ulnar aspect of lower arm
- Paralysis of all intrinsic muscles of hand
- Paralysis of wrist flexors (except flexor carpi radialis)
What is the dermatome of the lateral aspect of the forearm and thumb?
C6
What innervates Teres minor?
Axillary nerve
What forms the lateral border of Guyon’s canal (ulnar canal)?
Hamate
