Anterior Forearm Flashcards
Anterior Forearm Osteology
Humerus (medial epicondyle is common flexor origin)
UIna (medial)
Radius (lateral)
Cutaneous Innervation of Arm, Forearm, Hand
Ulnar: medial hand, 4th and 5th digit and metacarpal
Musculocutaneous: Lateral forearm
Median: Palmar surface and dorsal lateral 3 digits
Radial Nerve: Dorsal tricep, forearm, lateral 3 digits
Axillary Nerve: dorsal shoulder region
Vasculature of the Arm & Forearm
Axillary a.
Brachial a.
deep brachial
middle collateral
radial collateral
superior ulnar collateral
inferior ulnar collateral
Blood supply to anterior forearm
ulnar artery
anterior interosseous artery
blood supply to posterior forearm
radial artery
recurrent interosseous artery
posterior interosseous artery
ulnar artery
Blood supply to anterior hand
superficial palmar arch (ulnar artery)
Deep palmar arch (radial artery)
Superficial Muscles of Anterior Forearm
Pronator teres
Flexor carpi radialis
Palmaris longus
Flexor carpi ulnaris
Intermediate muscles of Anterior Forearm
Flexor digitorum superficialis
Deep Muscles of Anterior Forearm
Flexor pollicis longus
Pronator quadratus
Flexor digitorum profundus
Pronator Teres
Origin: medial epicondyle of humerus
coronoid process of ulna
Insertion: middle of lateral surface of radius
Axns: pronates forearm
flexes forearm at elbow
Blood: ant. ulnar recurrent artery
Nerve: Median nerve (C6, 7)
Flexor Carpi Radialis
Origin: medial epicondyle of humerus
Insertion: base of 2nd metacarpal
Axns: flexes hand at wrist
abducts hand at wrist
Blood: ulnar artery
Nerve: Median Nerve (C6, C7)
Palmaris Longus (can be absent)
Origin: medial epicondyle of humerus
Insertion: flexor retinaculum (continuous w/ palmar aponeurosis)
Axns: flexes hand at wrist
tenses palmar aponeurosis
Blood: ulnar artery
Nerve: Median (C7, C8)
Flexor Carpi Ulnaris
Origin: medial epicondyle of humerus (humeral head)
Olecranon and posterior border of ulna (ulnar head)
Insertion: pisiform, hook of hamate, 5th metacarpal
Axns: flexes hand
adducts hand
Blood: ulnar artery
Nerve: ulnar nerve (C7, C8)
Flexor Carpi Ulnaris and Cubital Tunnel Syndrome
Ulnar nerve pinched in cubital tunnel (tendonous arch formed by ulnar and humeral head of FCU in elbow region)
Numbness and tingling in medial part of palm and medial digits
Flexor digitorum superficialis
Origin: medial epicondyle of humerus
superior 1/2 of ant. border of radius
Insertion: shafts of middle phalanges of medial 4 digits
Axns: flexes mid. phalanx at PIP joints
flexes prox. phalanx at MCP joints
Blood: Ulnar artery
Nerve: Median Nerve (C7, C8, T1)
Flexor digitorum profundus
Origin: prox. 3/4 of medial and anterior surfaces of ulna
interosseous membrane
Insertion: bases of distal phalanges of 2nd - 5th fingers
Axns: flexes distal phalanges at IP joints (power grip)
Blood: anterior interosseous artery
Nerve: median and ulnar nerves (C8, T1)
Flexor Pollicis Longus
Origin: ant. surface of radius and interosseous membrane
Insertion: base of distal phalanx of thumb
Axns: flexes thumb
Blood: anterior interosseous artery
Nerve: median nerve via ant. interosseous nerve (C8, T1)
Pronator quadratus
Origin: distal 1/4 of ant. surface of ulnar
Insertion: distal 1/4 of ant. surface of radius
Axns: pronates forearm
deep fibers bind radius and ulnar together
Blood: anterior interosseous artery
Nerve: median nerve via ant. interosseous nerve C8, T1
Anatomical Relationships
From lateral to medial (in anatomical position)
Superficial branch of radial nerve
Radial Artery
Median Nerve
Ulnar Artery
Ulnar Nerve
Slide 25
Ulnar Nerve Track
Posterior to medial epicondyle
Runs along medial forearm under flexor carpi ulnaris
Through Guyon’s canal lateral to pisiform
Enters and supplys most of intrinsic hand muscles
Ulnar Nerve and Artery Track
Run together (nerve medial)
artery under and just lateral to flexor carpi ulnaris
both run lateral to pisiform bone and Guyon’s canal
Median Nerve Track
Runs through pronator teres
Deep to flexor digitorum superficialis
between FDS and FD profundus
runs deep to flexor retinaculum through carpal tunnel
Radial Artery
Medial to superficial branch of radial nerve
nerve is lateral
runs under or just medial to brachioradialis
Anterior interosseous nerve and artery
run deep (posterior) to pronator teres
A 20 year old female is hit by a car while riding her bike. She sustains a concussion, a fractured mandible, and a broken arm. In the emergency department she has difficulty making a fist. Her hand and wrist are hyperextended. She is unable to flex her 4th and 5th digits. What part of her arm did she fracture? What nerve is injured?
Medial epicondyle of humerus (flexor origin)
Ulnar Nerve
Pg 769 in COA
