Download Region 15: Anterior Forearm and Wrist Cutaneous Vessels

Region 15: Anterior Forearm and Wrist
Cutaneous Vessels
--Cephalic Vein
*From: lateral aspect of the dorsal venous network
*To: axillary vein
--Basilic Vein
*From: medial end of the dorsal venous network
*to: axillary vein (with brachial veins)
--Median cutibal vein
*Obliquely across elbow to join the cephalic and basilic veins
*distal lateral (cephalic) to proximal medial (basilic)
--Median antebrachial vein
*ascends in the middle of the anterior aspect of the forearm between the
cephalic and basilic veins
*From: superficial venous palmar arch
*To: joins with basilic vein (may also branch and form with cephalic vein)
Cutaneous peripheral nerves
--Lateral antebrachal cutaneous nerve
*From: terminal branch of the musculocutaneous nerve
*Branches into posterior and anterior branches
*Supplies: skin on lateral side of forearm
*Runs with: cephalic vein
--Medial antebrachial cutaneous nerve
*From: medial cord
*Branches into posterior and anterior branches
*Supplies: skin on anterior and medial surfaces of the forearm
*Runs with: basilic vein
--Superficial radial nerve
*From: radial nerve
*To: runs behind brachioradialis to posterior forearm
--Dorsal cutaneous branch of ulnar nerve
*From: ulnar nerve
Deep Fascia
--Palmar carpal ligament: anterior thickening of the antebrachial fascia , continuous
with the extensor retinaculum
--Flexor retinaculum: aka transverse carpal ligament, distal to the palmar carpal
ligament at a deeper level, fibers run , thickening of antebrachial fascia
*Extends between the anterior prominences of the outer carpal bones and
converts the anterior concavity of the carpus into the carpal tunnel
--Palmar aponeurosis: fibers run in superior to inferior direction
Bursa
--Ulnar bursa: surrounds 8 tendons, extends to pinky
--Radial bursa: extends into midthumb
Injuries
--Scaphoid bone: most commonly fractured
--Lunate bone: most common subluxated (usually anterior into tunnel)
Muscles of the Anterior Forearm
--Superficial First Layer (4): pronator teres, flexor carpi radialis, Palmaris longus,
flexor carpi ulnaris
Pronator Teres
O
I
Inn.
Act.
BS
Not
Ulnar head: coronoid process of ulna
Humeral head: medial epicondyle of humerus (common flexor origin)
Middle of convexity of lateral surface of radius
Median nerve
Pronates forearm (at elbow)
Flexes forearm (at elbow)
Radial artery
Median n. runs b/w the 2 heads, if compressed similar symptoms as carpal tunnel
syndrome
Flexor Carpi Radialis (FCR)
O Medial epicondyle of humerus
nd
rd
I Base of 2 and 3 metacarpal
Inn. Median nerve
Flexes hand (at wrist)
Act. Abducts hand (at wrist)
Flexes forearm (at elbow)
BS Radial artery
Not Radial a. runs b/w this muscle and brachioradialis m.
Palmaris Longus
O Medial epicondyle of humerus
I Distal half of flexor retinaculum and apex of palmar aponeurosis
Inn. Median nerve
Flexes hand (at wrist)
Act. Flexes forearm (at elbow)
Tenses palmar aponeurosis
BS Radial or ulnar artery
Not Missing in 12%, lies on top of median n. in forearm
Flexor Carpi Ulnaris (FCU)
O
I
Humeral head: medial epicondyle of humerus
Ulnar head: olecranon of ulna and posterior border (via aponeurosis)
Pisiform, hook of hamate, 5th metacarpal (pH5)
Inn. Ulnar nerve
Flexes hand (at wrist)
Act. Adducts hand (at wrist)
Flexes forearm (at elbow)
BS Posterior ulnar recurrent artery
--Second/Intermediate Layer: flexor digitorum superficialis
Flexor Digitorum Superficialis (FDS)
Humeroulnar head: medial epicondyle of humerus and coronoid process of ulna
Radial head: superior half of anterior border of radius
I Shafts (bodies) of middle phalanges of medial four fingers
Inn. Median nerve
O
Flexes middle phalanges at proximal interphalangeal joints
Flexes proximal phalanges at metacarpophalangeal joints
Act. Flexes forearm (at elbow)
Flexes hand (at wrist)
BS Radial and ulnar arteries
Goes through tunnel with 2nd and 5th tendons below 3rd and 4th
Not
Fibrous arch at proximal end
--Third/Deep Layer (2): flexor digitorum profundus, flexor pollicis longus
Flexor Digitorum Profundus
O
I
Inn.
Act.
BS
Not
Proximal three quarters of medial and anterior surfaces of ulna and interosseous
membrane
Medial part: bases of distal phalanges of 4th and 5th fingers
Lateral part: bases of distal phalanges of 2nd and 3rd fingers
Medial part: Ulnar nerve
Lateral part: Anterior interosseous nerve (from median nerve)
Flexes at distal interphalangeal joints, PIP, MCP, and wrist
Ulnar artery, anterior interosseous artery
Pierces FDS and splits it into 2
Flexor Pollicis Longus
O Anterior surface of radius and adjacent interosseous membrane
I Base of distal phalanx of thumb
Inn. Anterior interosseous nerve
st
Act. Flexes phalanges of 1 digit
BS Anterior interosseous artery
Not Passes in between the 2 sesamoid bones
--Fourth Layer: pronator quadratus
Pronator Quadratus
O Distal quarter of anterior surface of ulna
I Distal quarter of anterior surface of radius
Inn. Anterior interosseous nerve
Pronates forearm (initiates pronation, prime mover)
Act.
Deep fibers hold radius and ulna together
BS Anterior interosseous artery
Nerve Supply to the Anterior Compartment
--Ulnar nerve (supplies 1 ½ mm.)
*Passes lateral to pisiform bone
--Median nerve (supples 4 mm)
*Branches:
--Ant. interosseous n. (2 ½ m): passes deep to pronator quadratus
Arterial Supply to the Anterior Compartment
--Ulnar artery
*From: terminal branch of brachial artery
*Branches:
--Common interosseous artery (branching into ant. and post.
interosseous aa.)
--Radial artery
*From: terminal branch of brachial artery
Region 16: Anterior Hand
Cutaneous peripheral nerves
--palmar cutaneous branch of the median nerve
*Passes over: flexor retinaculum
*1-3, lat. 4 digits supplied by common and proper digital branches
--3 common (first common has 3 proper)
--palmar cutaneous branch of the ulnar nerve
*Passes over: flexor retinaculum
*med. 4, 5 digits supplied by common and proper digital branches
--1 common (to 2 proper) and 1 proper
**More muscle, less skin
--superficial branch of radial nerve
Deep fascia
--Flexor retinaculum: thickening of deep fascia to form the carpal tunnel
*Lateral attachments: trapezium
*Medial attachments: hook of hamate
--Thenar fascia: palmar fascia on the lateral side of palm (over thumb muscles)
--Hypothenar fascia: palmar fascia on the medial side of palm (over pinky muscles)
--Palmar aponeurosis: central part of palmar aponerosis, thick, tendinous, triangular
*continues to blend with fibrous digital sheaths, superficial transverse
metacarpal ligaments transverse the aponeurosis at the distal end at to
form
the base of the palmar aponeurosis
*proximal end continuous with flexor retinaculum and Palmaris longus
tendon
--fibrous digital sheaths: thickening of fascia over palmar sides of digits 2-5
*Cruciate part: where the joints are
*Anular part: shafts of phalanges
--Septas:
*Medial fibrous septum: extends deeply from the medial border of the
palmar aponeurosis to the 5th metacarpal
--Medial to this septum: hypothenar/medial compartment
*Lateral fibrous septum: extends from lateral border of palmar aponeurosis
to the 3rd metacarpal
--Lateral to this septum: thenar/lateral compartment
--Compartments
*Hypothenar: 3 hypothenar muscles
*Thenar: 3 thenar muscles
*Central: flexor tendons, lumbrical muscles, superifical palmar arterial arch,
and digital vessels and nerves
*Adductor: adductor pollicis
*Interosseous: contains interosseous muscles
--Potential Spaces
*Midpalamar and Thenar: bounded by fibrous septa passing from the edges
of the palmar aponeurosis to the metacarpals, lateral fibrous septum
separates the 2 spaces (midpalamar space more medial)
--Midpalmar space is continuous with the anterior compartment of
the forearm via the carpal tunnel
--Eminences
*Thenar eminence: at the base of the thumb
*Hypothenar eminence: proximal to the base of the 5th finger
Carpal Tunnel
--Boundaries
*Roof: flexor retinaculum, flexor carpi radialis tendon
*Medially: hook of hamate, pisiform
*Laterally: trapezium, scaphoid
*Floor: hamate, capitate, trapezoid, little trapezium
--Contents
*4 flexor digitorm superficials tendons, 4 flexor digitorum profudus tendons,
1 flexor pllicus longus, median nerve
Guyon’s Tunnel
--Contains: ulnar artery and ulnar nerve
Tests
--Allens test for radial and ulnar contributation to superficial and deep palmar arches
--Wrist drop: Radial nerve damage
--Pope’s Blessing: median nerve injury
--Ape hand: Trauma to median nerve
--Claw hand 1st and 2nd fingers: Results from: distal lesion of ulnar nerve
Muscles of the Anterior Hand
--Thenar Muscles: opponens pollicis, abductor pollicis brevis, flexor pollicis brevis,
adductor pollicis
Opponens pollicis
O Flexor retinaculum and tubercles of scaphoid and trapezium
st
I Lateral side of 1 metacarpal
Inn. Recurrent branch of median nerve
Oppose thumb, draws 1st metacarpal medially to center of palm and rotates it
Act.
medially
BS Superficial palmar branch of radial artery
Abductor pollicis brevis
O
I
Inn.
Act.
BS
Flexor retinaculum and tubercles of scaphoid and trapezium
Lateral side of base of proximal phalanx of thumb
Recurrent branch of median nerve
Abducts thumb (away from palm/toward ceiling), helps oppose it
Superficial palmar branch of radial artery
Flexor pollicis brevis
O Flexor retinaculum and tubercles of scaphoid and trapezium
I Lateral side of base of proximal phalanx of thumb
Superficial head: recurrent branch of medial nerve
Inn.
Deep head: deep branch of ulnar nerve
Act. Flexes thumb (crosses over palm)
BS Superficial palmar branch of radial artery
Adductor pollicis
Oblique head: bases of 2nd and 3rd metacarpals, capitate, adjacent carpals
Transverse head: anterior surface of shaft of 3rd metacarpal
I Medial side of base of proximal phalanx of thumb
Inn. Deep branch of ulnar nerve
Act. Adducts thumb toward lateral border of palm
BS Deep palmar arterial arch
st
Not Muscle in 1 interosseous space with DAB
O
--Hypothenar muscles: abductor digiti minimi, flexor digiti minimi, opponens digiti
minimi, Palmaris brevis
Abductor digiti minimi
O Pisiform
th
I Medial side of base of proximal phalanx of 5 finger
Inn. Deep branch of ulnar nerve
th
Act. Abducts 5 finger, assists in flexion of its proximal phalanx
BS Deep palmar branch of ulnar artery, dorsal carpal branch of ulnar artery
Flexor digiti minimi brevis
O Hook of hamate and flexor retinaculum
th
I Medial border of 5 metacarpal
Inn. Deep branch of ulnar nerve
th
Act. Flexes proximal phalanx of 5 finger
BS Deep palmar branch of ulnar artery, dorsal carpal branch of ulnar artery
Opponens digiti minimi
O Hook of hamate and flexor retinaculum
th
I Medial border of 5 metacarpal
Inn. Deep branch of ulnar nerve
Draws 5th metacarpal anterior and rotates it, bringing 5th finger into opposition
Act.
with thumb
BS Deep palmar branch of ulnar artery, dorsal carpal branch of ulnar artery
Palmaris Brevis
O Flexor retinaculum
I Skin
Inn. Superficial branch of ulnar nerve
Wrinkles skin of eminence, deepening the hollow of the palm, aiding in palmar
Act.
grip (function: protect ulnar nerve)
BS Superficial palmar branch of ulnar artery
--Short muscles: lumbricals, dorsal interossei, palmar interossei
Lumbricals
O
I
Inn.
Act.
BS
1 and 2: lateral 2 tendons of flexor digitorum profundus (as unipennate muscles)
3 and 4: medial three tendons of flexor digitorum profundus (as bipennate
muscles)
Lateral sides of extensor expansions of 2nd to 5th fingers
1 and 2: median nerve
3 and 4: deep branch of ulnar nerve
Flex metacarpophalangeal joints
Extend interphalangeal joints of 2nd to 5th fingers
Branches of superficial and deep palmar arterial arches
Dorsal Interossei (4)
O Adjacent sides of 2 metacarpals (as bipennate muscles)
nd
th
I Bases of proximal phalanges; extensor expansions of 2 to 4 fingers
Inn. Deep branch of ulnar nerve
Abducts 2nd to 4th fingers from axial line; act with lumbricals in flexing
Act.
metacarpophalangeal joints and extending interphalangeal joints
BS Deep palmar arterial arch
Not More lateral and deeper
Palmar Interossei (3)
nd
th
th
O Palmar surfaces of 2 , 4 , and 5 metacarpals (as unipennate muscles)
nd
th
th
I Bases of proximal phalanges; extensor expansions of 2 , 4 , and 5 fingers
Inn. Deep branch of ulnar nerve
Adducts 2nd, 4th, and 5th fingers toward axial line, assist lumbricals in flexing
Act.
metacarpophalangeal joints and extending interphalangeal joints
BS Deep palmar arterial arch
Not More medial and superficial
Nerve Supply of Anterior Hand
--Recurrent median nerve
*From: median nerve
--Deep ulnar nerve
*From: ulnar nerve
--Median nerve
Arterial Supply of Anterior Hand
--Radial artery
*From: terminal branch of brachial artery
*Runs: between 2 heads of adductor pollicis
*Branches: dorsal branch gives off princeps pollicis and radialis indicis aa.
--Superficial palmar arch
*From: terminal branch of ulnar artery (superficial palmar branch of ulnar a.)
*Joined by: superficial palmar branch of radial a. (passes over or through
thenar muscles)
*Branches into: common palmar (to proper) digital aa.
--Deep palmar arch
*From: terminal branch of radial artery (deep palmar branch of radial a.)
*Joined by: deep palmar branch of ulnar artery
*Branches: palmar metacarpal arteries