Arm & Forearm Flashcards
Biceps Brachii long head origin
Supraglenoid tubercle of scapula
Biceps Brachii short head origin
Coracoid process of scapula
Biceps Brachii insertion
Radial (bicipital) tuberosity of radius
Biceps Brachii action
Flexes & supinates forearm (slight arm flexion)
Biceps Brachii supply
Musculocutaneous n & brachial vessels
Coracobrachialis origin
Coracoid process of scapula
Coracobrachialis insertion
Medial surface of middle of humerus
Coracobrachialis action
Flexes & adducts
Coracobrachialis supply
Musculocutaneous n & brachial vessels
Brachialis origin
Lower half of anterior humerus
Brachialis insertion
Ulnar tuberosity of ulna
Brachialis action
Flexes forearm
Brachialis supply
Radial & musculocutaneous nn & brachial vessels
Triceps Brachii long head origin
Infraglenoid tubercle of scapula
Triceps Brachii lateral head origin
Posterior shaft of humerus
Triceps Brachii medial head origin
Posterior shaft of humerus
Triceps Brachii insertion
Olecranon process of ulna
Triceps Brachii action
Extends forearm
Triceps Brachii supply
Radial n & deep brachial vessels
What is contained within the cubital fossa?
Biceps brachii tendon, brachial a, median n
What vein lies above the cubital fossa?
Median cubital vein
In the cubital fossa, what are the brachial a & median n protected by?
Bicipital aponeurosis
What are the boundaries of the cubital fossa?
Lateral: brachioradialis
Medial: pronator teres
Superior: line between humeral epicondyles
Floor: supinator & brachialis mm
What two muscles contract to promote pronation?
Pronator teres & Pronator quadratus
What two muscles contract to promote supination?
Supinator & Biceps Brachii
In pronation, how do the radius and ulna interact?
Radius crosses over ulna (opposite for supination)
For the anterior compartment of the forearm, what are the superficial muscles?
Flexor Carpi Ulnaris (FCU), Palmaris Longus, Flexor Carpi Radialis (FCR), Pronator Teres
For the anterior compartment of the forearm, what is the intermediate muscle?
Flexor Digitorum Superficialis
For the anterior compartment of the forearm, what are the deep muscles?
Flexor Digitorum Profundus, Flexor Pollicis Longus, Pronator Quadratus
What nerves are primarily responsible for innervating the anterior compartment of the forearm? From where do they derive?
Median and ulnar nn = C6, C7, C8, T1
C5 is not included because it is too proximal. We are now considering just the forearm
Flexor Carpi Ulnaris innervation & action
Ulnar n (mostly C8, but also C7 & T1) Flexor and adductor of wrist
Palmaris Longus innervation & action
Median n (C7, C8) Flexor of wrist
Flexor Carpi Radialis innervation & action
Median n (C6, C7) Flexor and abductor of wrist *Landmark = lateral position
Pronator Teres innervation & action
Median n path (C6, C7)
Pronates forearm
Flexor Digitorum Superficialis innervation & action (don’t forget joints)
Median n (mostly C8, but also T1) Flexor of metacarpophalangeal joint & proximal interphalangeal joint Flexor of wrist Made up of 4 tendons
Flexor Digitorum Profundus innervation & action (don’t forget joints)
Median & ulnar nn (mostly C8, but also T1)
Flexor of metacarpophalangeal joint & proximal & distal interphalangeal joints
Flexor of wrist
Made up of 4 tendons
Flexor Pollicis Longus innervation & action
Median n (C7, C8) Flexor of thumb
Pronator Quadratus innervation & action
Median n (C7, C8) Pronation
For the posterior compartment of the forearm, what are the superficial muscles?
Brachioradialis, Extensor Carpi Radialis Longus, Extensor Carpi Radialis Brevis, Extensor Digitorum, Extensor Digiti Minimi, Extensor Carpi Ulnaris, Anconeus
For the posterior compartment of the forearm, what are the deep muscles?
Supinator, Abductor Pollicis Longus, Extensor Pollicis Brevis, Extensor Pollicis Longus, Extensor Indicis
Brachioradialis action
Flexor at elbow
Lateral border of cubital fossa
Extensor Carpi Radialis Longus action
Extends & abducts wrist
Extends to base of metacarpal 2
Extensor Carpi Radialis Brevis
Extends & abducts wrist (more medial than Longus)
Extends to base of metacarpal 3
Extensor Digitorum
Extends fingers & wrist
Extensor expansion of digits 2-5
Extensor Digiti Minimi
Extends little finger
Extensor Carpi Ulnaris
Extends & adducts wrist (most medial)
Anconeus
Abducts ulna in pronation & extends elbow
Supinator action & innervation
Supinates; posterior interosseus n (C6, C7)
Abductor Pollicis Longus action & inneration
Abducts carpometacarpal jt thumb; posterior interosseus n (C7, C8)
Extensor Pollicis Brevis action & innervation
Extends metacarpophalangeal jt. thumb & extends metacarpometacarpal jt; posterior interosseus n (C7, C8)
Extensor Pollicis Longus action & innervation
Extends interphalangeal jt thumb, also metacarophalangeal & carometacarpal jts thumb; posterior interosseus n (C7, C8)
Extensor Indicis action & innervation
Extends index finger; posterior interosseus n (C7, C8)
What nerve is primarily responsible for innervating the posterior compartment of the forearm? From where does it originate?
Radial n; C5-C8
Where does posterior interosseus nerve come from?
It is a continuation of the deep branch of the radial nerve, after this has crossed the Supinator muscle
What does musculocutaneous nerve supply?
All of Biceps Brachii & medial part of Brachialis m
Between Biceps Brachii & medial part of Brachialis m, what nerve emerges? It is a continuation of what nerve?
Lateral Antibrachial Cutaneous nerve
Continuation of Musculocutaneous n
What does the Lateral Antibrachial Cutaneous n supply?
Skin of lateral forearm
Where does Median n run?
Between superficial & deep anterior forearm mm
What does Median n supply?
Most of anterior forearm mm
What branch of the Median nerve continues under carpal tunnel to supply the lateral hand? What kind of nerve is it?
Palmar branch
Cutaneous
What space does Median n enter?
Cubital Fossa
Where does Ulnar n run?
In cubital tunnel between medial epicondyle & olecranon
*Very superficial at this point (funny bone)
What does the Ulnar n supply?
Dives deep into medial forearm to supply it; continues over carpal tunnel to supply medial hand & deepest mm of hand
Does the Ulnar nerve travel superficial or deep to flexor retinaculum?
Superficial
Where does Radial n run?
With deep brachial a in radial groove of humerus (between lateral & medial heads of Triceps Brachii)
What does Radial n supply?
All of Triceps Brachii & lateral part of Brachialis
What do the branches of Radial n supply?
Superficial branch continues to supply skin on back of hand
Deep branch dives to supply mm of posterior forearm
Brachial a is a direct continuation of what artery?
Axillary
How does Brachial a run?
From inferior border of Teres Major to its bifurcation
What does Brachial a split into? Where?
Splits to radial and ulnar aa in cubital fossa
What branches are sent off at the bifurcation of Brachial a?
Deep brachial a & several muscular branches
Superior & inferior ulnar collateral aa
