Download Lecture Upper limb II 2010

Upper Limb, part II
Cubital fossa, Forearm, and Hand
Objectives:
1. Bones and joints of the upper limb
2. Fascial compartments of arm, forearm and hand
3. Special areas of upper limb - cubital fossa,
wrist, carpal tunnel, anatomical snuffbox
4. Arteries and veins of upper limb
5. Nerves innervating upper limb
humerus
radius
ulna
carpal bones
metacarpal bones
{
phalanges
Radiolulnar joints
Which carpal bone is the most
commonly fractured? scaphoid
Wrist (radiocarpal joint)
Intercarpal joints
Carpometacarpal and
intermetacarpal joints
Carpometacarpal joint
of the thumb
Metacarpophalangeal joints
Interphalangeal joints
-Why is the scaphoid the most
commonly fractured carpal bone?
-- due to palming a floor after a fall
Responsible for
wrist rotation
Carpal bones:
Proximal row of carpals
(from lateral to medial):
1. scaphoid bone S
2. lunate bone L
3. triquetrum bone T
4. pisiform bone P
Distal row of carpals
(from lateral to medial):
1. trapezium bone T
2. trapezoid bone T
3. capitate bone C
4. hamate bone
H
Hand movements
Flexion - Extension
Abduction - Adduction
*Be sure to reference
the anatomical position*
Compartmentalization = Functionally
related groups of muscles are enclosed
within compartments defined by thick layers
of deep fascia and intermuscular septa that
attach to the bone. Compartments contain
muscles sharing a common function (action)
and a common innervation.
FLEXORS
ARM
compartment
anterior
}
biceps brachii,
musculocutaneous n.
coracobrachialis
brachial a.
brachialis
EXTENSORS
triceps brachii
}
radial n.
profunda brachii a.
posterior
FOREARM
compartment
FLEXORS
median and
ulnar nn.
ulnar and
radial aa.
anterior
}
flexors,
pronators,
palmaris longus
brachioradialis
radial n.
radial a.
EXTENSORS
extensors,
supinator,
abductor
radial n.
posterior
interosseus a.
}
posterior
Forearm muscles - anterior/flexor-pronator compartment
Three functional groups:
1. Muscles which pronate the forearm and hand
*pronator teres
*pronator quadratus
2. Muscles that flex the hand
*flexor carpi radialis/abduct
*flexor carpi ulnaris/adduct
*palmaris longus
3. Muscles that flex the digits
*flexor digitorum superficialis (FDS)
*flexor digitorum profundus (FDP)
*flexor pollicis longus
Superficial group (5):
*pronator teres
*flexor carpi ulnaris
*flexor carpi radialis
*palmaris longus
*flexor digitorum spf.
(FDS)
Deep group (3):
Flexor carpi ulnaris and medial half of FDS are
innervated by ulnar nerve
First two lumbricals, thenar muscles and … are
innervated by the median nerve
.: pronator quadratus
.: flexor digitorum prof.
(FDP)
.: flexor pollicis longus
Teres: round
5 superficial muscles
1. Pronator teres
2. Flexor carpi
radiales
3. Flexor carpi
ulnaris
4. Palmaris longus
muscle
5. Flexor digitum
superficialis
Flexor digitorum
superficialis
Flexor carpi ulnaris
Palmaris longus
Radial artery
Tendon of flexor
carpi radialis
Forearm muscles - posterior/extensor-supinator compartment
Three functional groups:
1. Muscles that extend the hand
*extensor carpi radialis longus/abduct
*extensor carpi radialis brevis/abduct
*extensor carpi ulnaris/adduct
2. Muscles that extend the digits
*extensor digitorum
*extensor digiti minimi
*extensor indicis
3. Muscles that extend the thumb
*extensor pollicis longus EPL
*extensor pollicis brevis EPB
*abductor pollicis longus ABL/abduct
Superficial group:
*extensor carpi radialis brevis
extensor carpi radialis longus
*extensor carpi ulnaris
*extensor digitorum
*extensor digiti minimi
brachioradialis
Deep group:
supinator
EPL
EPB
APL
extensor indicis
5
4
8
1.
2.
3.
4.
5.
6.
7.
8.
3
7
Brachioradialis
Extensor carpi radialis longus
Extensor carpi radialis brevis
Abductor policis longus
Extensor pollicis brevis
Extensor digitorum
Extensor digiti minimi
Extensor carpi ulnaris
2
6
1
Lateral epicondyle
Cubital fossa - borders and contents
Borders: (4; it’s a “cube)
* medially - pronator teres m.
* laterally – brachioradialis m.
* the roof – deep fascia, subcutaneous tissue, and skin
* the floor – supinator m. laterally and brachialis m. medially.
Contents from medial to lateral side: (5)
* median n.
* bifurcation of the brachial a.
* (deep) accompanying veins of the arteries
* tendon of biceps brachii m.
* radial n. and its branches (within the floor of the fossa)
Superficially, in the subcutaneous tissue overlying the fossa:
*median cubital vein (connects cephalic vein to basilar vein)
*medial and lateral antebrachial (forearm) cutaneous nerves
Superficial branch
of radial nerve
Brachial artery
Tendon of biceps brachii
Biceps brachii
Brachioradialis
Median nerve
Medial epicondyle
Pronator
Muscles of the hand – 4 compartments
1. Thenar compartment:
* abductor pollicis brevis
* flexor pollicis brevis
* opponens pollicis
Thenar: a raised fleshy area on
the palm of the hand near the
base of the thumb
median n. – recurrent branch
2. Adductor compartment:
* adductor pollicis
ulnar n. – deep branch,
3. Hypothenar compartment:
* abductor digiti minimi
* flexor digiti minimi
* opponens digiti minimi
ulnar n. – deep branch
4. Central compartment:
1st and 2nd median n. – digital branches
3rd and 4th ulnar n. – deep branch
* interossei- 3 PAD and 4 DAB ulnar n. – deep branch
* lumbricals :
Palmar aponeurosis{
Hypothenar fascia
Palmaris brevis
Flexor pollicis brevis
Abductor pollicis brevis
Thenar fascia
1st lumbrical
1st dorsal interosseous
Superficial palmar branch
Adductor pollicis
Abductor digiti minimi
Palmaris brevis
Ulnar artery
Pisiform bone
Flexor pollicis brevis
Abductor pollicis brevis
Superficial branch of radial artery
Radial artery
Short muscles of the Hand
Flex the digits at the
metacarpophalangeal joints
and extend the interphalangeal
joints.
Abduct the digits
(4 DAB)
Adduct the digits
(3 PAD)
 Lumbricals:
 .: What do they do?

They flex the digits at the metacarpophalangeal joints and extend
the interphalangeal joints
 Abductor: Dorsal interossei muscles
 How many are there? 4
 Hence, 4 DAB
 Adductor: Palmar interossei
 How many are there? 3
 Hence, 3 PAD
 Metacarpophalangeal joints are the knuckle joints
Carpal tunnel is the space between the carpal bones and the flexor
retinaculum. The flexor retinaculum (transverse carpal ligament) is
a thick connective tissue ligament that bridges the space between the
medial and lateral side of carpal arch.
Structures that pass anterior to the flexor retinaculum
(from medial to lateral side):
* ulnar n.
* ulnar a.
*tendon of palmaris longus m.
Structures that pass beneath to the flexor retinaculum pass the carpal tunnel (from medial to lateral side):
* tendons of flexor digitorum superficialis and profundus
*median n.
*tendon of flexor pollicis longus m.
Anatomical snuffbox (visible, when the
thumb is fully extended):
Anteriorly (laterally) bounded by 2 muscles:
• extensor pollicis brevis (EPB)
• abductor pollicis longus (APL)
Posteriorly (medially) bounded by 1 muscle:
• extensor pollicis longus (EPL)
The radial artery lies in the floor of the snuff box.
Anatomical snuffbox
EPB
APL
EPL
AXILLARY A.
(SHOULDER REGION)
DEEP BRACHIAL A. =
profunda brachi
(POSTERIOR COMPARTMENT)
BRACHIAL A
(ANTERIOR COMPARTMENT)
CUBITAL FOSSA
INTEROSSEOUS AA
(ANTERIOR AND POSTERIOR
RADIAL A
(ANTERIOR COMPARTMENT)
COMPARTMENTS)
ULNAR A
(ANTERIOR COMPARTMENT)
ARTERIAL ARCHES
(HAND)
Which artery in the forearm is often used to palpate an arterial pulse?
Radial artery (remember the thumb point)
Superficial palmar arch
is formed mainly by the
ULNAR ARTERY
Deep palmar arch is
formed mainly by the
RADIAL ARTERY
CEPHALIC VEIN
BASILIC VEIN
MEDIAN CUBITAL
VEIN
Where is the common place for venipuncture?
Cutaneous innervation of the upper limb
Branch of median nerve
=
Dinner fork deformity
Questions of the day!
1. Which muscle of the forearm has a double innervation?
1. Flexor digitorum profundus
2. Loss of pronation of the hand suggests a lesion of which
nerve?
2. Median
3. Numbness to the skin on the lateral half of the palm of the
hand would be caused by a lesion to which nerve?
- Median