2. HAND
•The hand is the manual part of the upper limb
distal to the forearm. The wrist is located at the
junction of the forearm and hand.
•The hand is designed and purposely
positioned to allow for free motion, power
grasping, precision handling, and pinching.
3. DIGITS
• The digits are numbered from one to
five, beginning with the thumb: digit 1
is the thumb; digit 2, the index finger;
digit 3, the middle finger; digit 4, the
ring finger; and digit 5, the little finger
• The normally universal digital formula
in terms of the relative lengths of each
digit is 3>4>2>5>1
• Another digit formula for the whites
• 3>4=2>5>1 19% Caucasians
• 3>2>4>5>1> 33% Caucasians
• axial line: Pass through the capitate
through the metacarpal the 3rd digit.
4. The palm
• Furrows and ridges increase
the surface area and increase
the force of gripping.
• Sebaceous gland is absent
but sweat glands are present.
• Furrow and ridges are
arranged into arches whorls.
5. THE INTRINSIC MUSCLES OF THE HAND
•The intrinsic muscles of the
hand serve the function of
adjusting the hand during
gripping and also for carrying
out fined skilled movements.
There are twenty muscles in
the hand, they are as follow:
6. INTRINSIC MUSCLES
•ALL THE INTRINSIC
MUSCLES ARE
SUPPLIED BY C8 &
T1 SPINAL
SEGMENTS
THROUGH MEDIAN
& ULNAR NERVES
7. INTRINSIC MUSCLES…….
• THENAR MUSCLES:
1. Abductor pollicis brevis
2. Flexor pollicis brevis
3. Opponens pollicis
4. *Adductor pollicis
• HYPOTHENAR MUSCLES:
1. Abductor digiti minimi
2. Flexor digiti minimi
3. Opponens digiti minimi
4. *Palmaris Brevis
FOUR LUMBRICALS
FOUR PALMAR INTEROSSEI
FOUR DORSAL INTEROSSEI
9. Thenar eminence:
•There are three muscles that form
the thenar eminence with a common
origin from the flexor retinaculum.
The thenar muscles are supplied by
the Median Nerve
•The fourth muscle that is related to
the thenar muscles is the adductor
pollicis which have a different origin.
Thenar eminence:
10. ABDUCTOR POLLICI BREVIS
• Origin: Flexor retinaculum, tubercle of
scaphoid and tubercle of trapezium.
• Insertion: Is inserted into the radial side
of the base of the proximal phalanx of the
thumb.
• Action: Abduction and medial rotation of
the thumb at the metacarpophalangeal joint
and carpometacarpal joint.
11. FLEXOR POLLICIS BREVIS:
• It is related to the ulnar side of abductor
pollicis brevis.
• Origin: It arises by a superficial head from
the flexor retinaculum and the tubercle of
trapezium and by a deep head from the
trapezoid and capitate, sometimes this head is
absent in some individuals.
• Insertion: It is inserted into the radial side
of the base of proximal phalanx.
• Nerve Supply: Superficial head is supplied
by the median nerve and the deep head by the
deep branch of ulnar nerve.
• Action: Flexion of the thumb at the
proximal phalanx.
12. OPPONENS POLLICIS:
• It lies deep to the flexor pollicis brevis
and abductor pollicis brevis muscles.
• Origin: It arises from the tubercle of
trapezium and flexor retinaculum.
• Insertion: Lateral half of the palmar
surface of the 1st metacarpal bone.
• Nerve Supply: Median nerve
• Action: Opposition of the thumb.
13. ADDUCTOR POLLICIS:
• Origin: It arises by means of two heads,
an oblique head which arises from the
capitate bone and the base of the 2nd and
3rd metacarpal bones and a transverse
head which arises from the palmar aspect
of the 3rd metacarpal bone.
• Insertion: Medial side of the base of the
proximal phalanx of the thumb
• Nerve Supply: Deep branch of the ulnar
nerve (C8T1)
• Action: The muscle adducts the thumb.
The movement is forceful in gripping.
14.
15. HYPOTHENAR EMINENCE
• It is the muscles that lie on
the ulnar side of the palm
similar to the thenar muscle.
They are four in number
and include:
16. ABDUCTOR DIGITI MINIMI
• This is the most medial of the group.
• Origin: It arises from the pisiform bone and
the tendon of flexor carpi ulnaris proximally
and from the pisohamate ligament distally.
• Insertion: Ulnar side of the base of the
proximal phalanx of the little finger.
• Nerve Supply: Deep branch of ulnar nerve.
• Action: Abduction of little finger at the
metacarpophalangeal joint.
17. FLEXOR DIGITI MINIMI BREVIS
• Origin: Arises from the hook of
hamate bone and flexor retinaculum.
• Insertion: Ulnar side of the base of the
proximal phalanx of the little finger.
• Nerve Supply: Deep branch of ulnar
nerve (C8 T1).
• Action: Flexion of the little finger at
the metacarpophalangeal joint.
18. OPPONENS DIGITI MINIMI
• Origin: It arises from the flexor
retinaculum and hook of hamate.
• Insertion: Medial surface of the
shaft of the 5th metacarpal bone.
• Nerve Supply: Deep branch of
ulnar nerve (C8 T1).
• Action: Flexes of 5th metacarpal and
rotate it laterally.
19. LUMBRICAL MUSCLES
• These are four small wormlike muscles.
• Origin: The 1st lumbrical arises from the
radial side of the tendon for the index finger.
The 2nd lumbrical arises from the radial side of
the tendon for the middle finger. The 3rd
lumbrical arises from the contiguous sides of
the tendon of the middle and ring finger. The 4th
lumbrical arises from the contiguous side of the
tendon for the ring and little finger.
20. Insertion: The tendons of the 1st, 2nd, 3rd,
and 4th lumbrical pass backward on the
radial side of the 2nd, 3rd, 4th, and 5th
metacarpophalangeal joints respectively.
They are inserted into the dorsal expansion
of the corresponding digits.
Nerve Supply:
1. The 1st and 2nd lumbrical muscles by the
median nerve (C8, T1).
2. The 3rd and 4th lumbrical muscles by the
deep branch of ulnar nerve.
Action: The lumbrical muscles flex the
metacarpophalangeal joints and extend the
interphalangeal joints of the digit into
which they are inserted.
21. INTEROSSEOUS MUSCLE
• They are of two groups, the
palmar and dorsal interossei.
The former are small and arises
from only one metacarpal bone
while the latter are large and
arise from the adjacent
metacarpal bone of the space in
which they lie.
• It is easy to recall the action of
the interosseous by a
appreciating their format “PAD
and DAB”.
22. PALMAR INTEROSSEI
• They are numbered from lateral to medial side.
• Origin:
The 1st palmar interosseous muscle arises from
the medial side of the base of the 1st
metacarpal bone.
The 2nd palmar interosseous arises from the
medial half of the palmar aspect of the shaft of
the 2nd metacarpal.
The 3rd palmar interosseous arises from the
lateral part of the palmar surface of the shaft of
the 4th metacarpal bone.
The 4th palmar interosseous from the lateral
part of the palmar aspect of the shaft of the 5th
metacarpal bone.
23. Insertion: Each muscle is inserted into the
dorsal digital expansion of its own digit. It
may also be attached to the base of the
proximal phalanx of the same digit.
1.1st palmar interosseous muscle inserts
into the medial side of the thumb.
2.2nd palmar interosseous muscle inserts
into the medial side of the index finger.
3.3rd palmar interosseous muscle inserts
into the lateral side of the fourth digit.
4.4th palmar interosseous muscle inserts
into the lateral side of the 5th digit.
24. The middle finger does not receive the
insertion of the palmar interossei.
Nerve Supply: They are all supplied
by the deep branch of the ulnar nerve.
ACTION: They adduct (PAD) the
digit to which they are attached
toward the middle finger. In addition
they flex the digit at the
metacarpophalangeal joints and
extend it at the interphalangeal joints.
25. THE DORSAL INTEROSSEI
• They are also four in number and placed
between the metacarpal bones and are
numbered from lateral to medial.
• Origin:
i. 1st dorsal interosseous muscle arises
from the shaft of the 1st and 2nd
metacarpal.
ii.2nd dorsal interosseous muscle arises
from the shaft of the 2nd and 3rd
metacarpal.
iii.3rd dorsal interosseous muscle arises
from the shaft of the 3rd and 4th
metacarpal.
iv.4th dorsal interosseous muscle arises
from the shaft of the 4th and 5th
metacarpal.
26. It should be noted that the
middle finger receives two
dorsal interossei muscles on
either side and that the 1st and
5th digit do not receive any
insertion.
Action: All dorsal interossei
abduct the digit away from the
line of the middle finger.
Nerve supply: By the deep
branch of the ulnar nerve.
27. APPLIED ANATOMY
• Paralysis of the intrinsic
muscle of the hand due to
damage to the Ulna nerve
produces claw hand in
which there is
hyperextension at the
metacarpophalangeal joint
and flexion at the
interphalangeal joint. The
effect is opposite to the
action of the lumbricals and
interossei.
• Median nerve damage result
in Ape hand deformity and
hand of Benediction
28. ANATOMICAL SNUFF BOX
• It is a depression found at the root
of the thumb especially when the
thumb is fully extended.
• It is bounded lateral by the
extensor pollicis brevis and
abductor pollicis longus and
medial by the extensor pollicis
longus,
• the floor is formed by the
scaphoid and trapezium
• above is the styloid process of the
radius and
• below is the base of the 1st
metacarpal bone.
29. It contents include
the Radial artery,
Cephalic vein and
Cutaneous branch of
the radial nerve
31. SUPERFICIAL PALMAR ARCH
• FORMATION:
1. Direct continuation of ulnar artery
(mainly)
2. Superficial branch of radial artery
• SITE: between palmar aponeurosis & long
flexor tendons
• BRANCHES: digital branches to the medial
three & half fingers
• N.B.: Radial artery gives 2 branches that
supplies the lateral one & half fingers:
1. Radialis indicis: supplies lateral side of
index
2. Princeps pollicis: supplies both sides of
thumb
32. DEEP PALMAR ARCH
• FORMATION:
1. Direct continuation of
radial artery (mainly)
2. Deep branch of ulnar
artery
• SITE: between long flexor
tendons & metacarpal
bones
• BRANCHES:
1. Branches sharing in
anastomosis around wrist
joint
2. Articular & muscular
branches
33. MEDIAN NERVE
In the hand it gives up muscular branches
that supply most of the thenar muscles, three
proper palmar digital nerves; two of which
supply the thumb and one supplies the lateral
part of the index finger,
Two common digital nerves each dividing
into two digital nerves which supply the
medial border of the index finger, both sides
of the middle finger and the lateral border of
the ring finger.
It also sends a communicating branch that
connects with the ulna nerve. It also
supplies the 1st & 2nd lumbricals.
34. •Superficial palmar branch of the
median nerve. It supplies the
skin over the thenar
compartment.
•The two nerves for the thumb
may have a common origin.
•The various digital branches of
the median nerve supply palmar
skin of the lateral 3½ digits, the
nail beds and skin on the dorsal
aspect of the middle and distal
phalanges of the same digits.
35. APPLIED ANATOMY
• . In the hand there is paralysis of the thenar
muscles which leads to ape hand formation
• LACERATION AT THE WRIST
• Superficial laceration around the anterior
surface of the wrist by a sharp object can cause
damage to the superficial palmar branch of the
median nerve, in this case only loss of skin
sensation at the lateral aspect of the palm is felt.
There can also be deep cut which can lacerate
the superficial palmar branch and the deeply
placed median nerve. This will result to ape
hand deformity, loss of opposition and loss of
skin sensation over the lateral aspect of the
palm.
36. ULNAR NERVE
• It passes superficial to the flexor
retinaculum to enter the palm, and at the
vicinity of the hook of hamate it divides
into its terminal branches, a superficial
branch and a deep branch.
a. In the hand, the superficial terminal branch hooks
around at hook of hamate to supply the palmaris
brevis and ends by supplying the skin over the
hypothenar eminence.
b. The deep branch supply all the hypothenar
muscles all the interosseous muscles (both
palmar and dorsal interossei), the adductor
pollicis, the deep head of flexor pollicis brevis
and ulnar two lumbricals.
• The ulnar nerve also sends a communicating branch
that communicates with the median nerve. Other
branches include the palmar digital nerves that supply
the ulnar 1½fingers.
37. APPLIED ANATOMY
•In the hand paralysis of the
intrinsic muscle leads to claw
hand deformity, in this defect
there will be flexion at the
digiti minimi’s interphalangeal
joints while the
metacarpophalangeal joint
becomes hyper extended.
38. Wartenberg Sign is
considered positive if small
finger drifts away into
abduction from other fingers,
indicating an injury to the
ulnar nerve. This due to the
unopposed action of extensor
digiti minimi that is innervated
by the radial nerve.
40. RADIAL NERVE
•The superficial terminal
branch is the continuation of
the radial nerve; it is
cutaneous in its supply.
•It runs along the lateral border
of the forearm up to the
dorsum of the arm were it
supply its lateral 2½ half.
• It also supplies the proximal
part of the dorsum of the
radial 2½ fingers.
