Download Flexor Region of Forearm

M1 – Anatomy
Flexor Region of the Forearm
Dr. Simpson
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Upper Extremity
The Forearm:
Continuing with our
central theme that
structure is everything
Courtesy of the
Anatomy Department
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Supinator
Radial Artery
Brachial
Plexus
Pronator
Teres
Axillary
Artery
Teres Minor
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Non-Exhaustive List:
Upper limb
Does not
include blood
supply, nerves,
functions, or
attachments.
Nor does this
list include any
leg stuff that
starts next
week.
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Undergraduate Academic Record
Estimated Functional Capacity of Average
School of Medicine Class
50
40
30
MCV Students
20
10
0
0
5
10
15
20
All Students
6
50
40
30
MCV Students
20
10
Actual Performance
School of Medicine Class
0
0
5
10
15
20
All Students
Undergraduate Academic Record
Undergraduate Academic Record
Estimated Functional Capacity of Average
School of Medicine Class
50
40
30
20
10
0
0
5
10
15
20
All Students
7
Stay Current:
•It’s ok to spend long hours studying gross.
•Study and move on.
Do not study what you know,
concentrate on stuff you do not know.
•Pick a resource that works, don’t try to use them all
•Ignore the book unless desperate (or very, very
lonely).
•Lecture notes, dissector, head to toe
•Work as a team
•Participate in the dissections
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Axillary Artery
1. Supreme Thoracic
2. Thoracoacromial
2.Lateral Thoracic
3. Anterior humeral
circumflex
3. Posterior humeral
circumflex
3. Subscapular
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Neurovascular Considerations
Axillary
Brachial
Deep Profunda
Radial
Ulnar
Common Interosseus
Posterior
Anterior
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Brachial
Deep Profunda
Superior & Inferior Ulnar
Collaterals
Radial Collateral
Radial
Ulnar
Middle Collateral
Common Interosseus
Posterior
Anterior
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Osteology
•Carpals
•Metacarpals
•Proximal Phalanges
•Middle Phalanges
•Distal Phalanges
Thumb has no middle phalanges
Sesamoid=“sesame” small bones
within tendon or ligament that
develop in sites of “friction.”
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Carpals: 4 proximal, 4 distal
Proximal: Scaphoid, Lunate, Triquetral, Pisiform
Mnemonic = Some, Lovers, Try, Positions….
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Carpals: 4 proximal, 4 distal
Osteology
Distal: Trapezium*, Trapezoid*, Capitate, Hamate,
*M.D.= TrapeziuM TrapezoiD & trapezium is at the thumb
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Mnemonic = That, They, Can’t, Handle
!
Osteology
Carpal bones are
arranged into a
transverse arch with a
palmar concavity,
maintained partly by
the intrinsic shape of
the carpals and partly
by the flexor
retinaculum.
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Flexor Retinaculum
Medial
pisiform & hamate
Lateral
scaphoid & trapezium
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Radiocarpal joints
mediate flexion,
extension, abduction,
adduction &
circumduction
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Lunate
Displacement:
Most severe of carpal
instabilities.
The lunate is wedgeshaped, a blow to
palm may dislocate
lunate to the
posterior, capitate
may fall into space
vacated by lunate.
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Lunate Dislocation
Stage IV Lunate Dislocation
•Associated with trans-scaphoid fracture
•Involves all intercarpal joints & most
of the major carpal ligaments
•Volar dislocation and forward rotation
of lunate
•Capitate drops into space vacated by
lunate
•Triangular appearance of lunate
on frontal projection
•Concave distal surface of lunate
comes to face anteriorly
•Capitate and all other carpal bones lie
posterior to lunate on lateral radiograph
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Anterior Forearm
Organized
into two
(almost, but
not nearly
three) layers
of muscle.
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Medial Epicondyle
Pronator Teres
Flexor carpi radialis
Palmaris longus
Flexor carpi ulnaris
Flexor digitorum superficialis
***
Flexor digitorum profundus
Flexor pollicis longus
Pronator Quadratus
Ulna
Radius
*** Ulnar artery and nerve separate the
superficial and deep anterior compartments
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Medial Epicondyle
Pronator Teres
Flexor carpi radialis
Palmaris longus
Flexor carpi ulnaris
Flexor digitorum superficialis
***
Flexor digitorum profundus
Flexor pollicis longus
Pronator Quadratus
Ulna
Radius
*** Ulnar artery and nerve separate the
superficial and deep anterior compartments
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Superficial Group:
Medial Epicondyle
4 and 1*
•Pronator Teres
•Flexor Carpi Radialis
•Palmaris Longus
•Flexor Carpi Ulnaris
•*Flexor Digitorum
Superficialis
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Pronator Teres
Two Heads
•Origin:
Medial epicondyle
and Ulna
•Insertion:
Radius
Flexes elbow and
pronates forearm
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Flexor Carpi radialis
Origin:
Medial epicondyle
Insertion:
2nd Metacarpal
some on 3rd
Wrist flexion and
weak abduction
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Palmaris longus
Origin:
Medial
Epicondyle
Insertion:
Palmar
aponeurosis
Wrist flexion
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Palmaris longus
Origin:
Medial
Epicondyle
Insertion:
Palmar
aponeurosis
Wrist flexion
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Flexor Carpi Ulnaris
Origin:
Medial epicondyle
& ulna
Insertion:
Pisiform, hamate
fifth metacarpal
Wrist flexion and
adduction
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Flexor Digitorum
Superficialis
Origin:
Medial epicondyle,
coronoid process of ulna
& the radius
•Insertion:
middle phalanges of ulnar
4 digits
•Actions
Flexes proximal
interphalangeal joints and
contributes to wrist flexion
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Median Nerve
Leaves the antecubital fossa
by passing between the
superficial and deep heads of
the pronator teres, function
may be compromised if
trapped between the two
heads. Damage to median
nerve proximal to elbow
results in loss of active
pronation.
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Ulnar Nerve
Passes with ulnar
collateral artery behind
the medial epicondyle to
enter forearm. Passes
between the two origins
of the flexor carpi
ulnaris* at the medial
epicondyle and the ulna
*and innervates
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Deep Muscles
Flexor Digitorum Profundus
•Origin:
Ulna
•Insertion:
Distal phalanx of all four digits
Flexion of distal
interphalangeal joints
and joints proximal
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Page 5
Deep Muscles
Flexor Pollicis Longus
•Origin:
Radius
•Insertion:
Distal phalanx of thumb
Flexion of thumb & proximal
joints
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Page 5
Pronator Quadratus
•Origin:
Distal Ulna
•Insertion:
Radius
Primary pronator
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Medial Epicondyle
Pronator Teres
Flexor carpi radialis
Palmaris longus
Flexor carpi ulnaris
Flexor digitorum superficialis
***
Flexor digitorum profundus
Flexor pollicis longus
Pronator Quadratus
Ulna
Radius
*** Ulnar artery and nerve separate the
superficial and deep anterior compartments
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Passage of the deep
flexor digitorum
tendon to the distal
phalanx through the
flexor digitorum
superficialis tendon.
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Neurovascular Relationships
Ulnar artery running with the ulnar
nerve to separate superficial from
deep compartment
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C5
Superior Trunk
C6
C7
Middle Trunk
Ulnar Nerve of
the Anterior
Compartment
C8
Inferior Trunk
Ulnar Nerve
Medial Cord
T1
•Flexor carpi ulnaris
•Aspects of flexor
digitorum profundus
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C5
Superior Trunk
Lateral Cord
Musculocutaneous
C6
C7
Median Nerve
Middle Trunk
•All Forearm flexors except:
•Not flexor carpi ulnaris
•Aspects of flexor
digitorium profundus.
C8
Inferior Trunk
Medial Cord
T1
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Pronator teres
Radial nerve
Posterior cord
Ulna
Bicep
Ulnar artery
Axillary artery
Radius
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