anatomy

1. Blood supply of Upper Limb
Part 2
Forearm & hand
Dr M Idris Siddiqui

4. In the Hand
• In the hand, the ulnar and radial arteries
interconnect to form two arches, from which
branches to the digits emerge.
• Radial artery – contributes mainly to supply of
the thumb and the lateral side of the index
finger
• Ulnar artery – contributes mainly to the
supply of the rest of the digits, and the medial
side of the index finger

9. The ulnar
artery

10. The ulnar artery
• BEGINNING
• Opposite the neck of the radius, around
1 cm below the bend of the elbow.
• END
• It ends into superficial and deep branches
in the palm.

13. The ulnar artery
• COURSE
• In upper 1/3 rd of forearm, It runs downwards and
the medial side obliquely.
• In lower 2/3 rd , it runs The course is vertical.
• It goes into the palm by passing in front of flexor
retinaculum lateral to the ulnar nerve and the
pisiform bone.
• The superficial branch is the continuation of the
artery as superficial palmar arch.

14. The ulnar artery
• It lies on 3 structures throughout its
course.
a) In the cubital fossa:
• it lie on brachialis.
b) In the wrist:
• it lies on flexor retinaculum .
c) Between these two structures:
• it lies on flexor digitorum profundus.

15. The ulnar artery
• In the upper & oblque part, it is located
deep to the muscles which arise from
medial epicondyle(common flexor origin).
• In the lower & vertical part, it is
overlapped by flexor carpi ulnaris.
–It ends up being superficial and is located
between the tendons of flexor carpi ulnaris
and flexor digitorum superficialis.

16. The ulnar artery
• Two nerves in the forearm:
• The median nerve is located medial to the artery
in cubital fossa which passes between two heads
of pronator teres then crosses in front of the
artery.
• The ulnar nerve is has 3 relations with ulnar artery.
–At elbow: they are separated by a wide space.
–In upper 1/3rd of forearm the artery runs
obliquely to come nearer to the nerve.
–In lower 1/3rd nerve lies on medial side of
artery.

18. The ulnar artery
• Anterior:
• The upper part of the ulnar artery is covered up by
superficial muscles of the forearm, viz.
– Pronator teres.
– Flexor carpi radialis.
– Palmaris longus.
– Flexor digitorum superficialis.
• The lower part of the ulnar artery is covered merely
by the skin and superficial and deep fasciae.

19. The ulnar artery
• Posterior:
• Only the origin of ulnar artery is
located on brachialis, while in the
remaining whole part of its course it
is located on flexor digitorum
profundus.

20. The ulnar artery
•Medial:
–Ulnar nerve.
–Flexor carpi ulnaris.
•Lateral:
–Flexor digitorum superficialis.

22. The ulnar artery
BRANCHES
1. Muscular branches to neighboring muscles.
2. Anterior and posterior ulnar collateral (recurrent)
arteries, which join the arterial anastomosis(with branches
of brachial artery) around the elbow joint.
3. Common interosseous artery, which stems from the upper
part of the ulnar artery and after a very short course at the
upper border of interosseous membrane, it splits into
– anterior (larger)and posterior interosseous (smaller)arteries.
4. Anterior and posterior ulnar carpal branches, which join
the formation of anterior and posterior carpal arches.
5. Terminal branches are two, the larger superficial branch
continues as the superficial palmar arch, while the smaller
deep branch takes part in the deep palmar arch.

24. The ulnar artery
• CLINICAL SIGNIFICANCE
• Aberrant ulnar artery: In about 3% of human
beings, the ulnar artery may arise high in the arm
and passes superficial to the flexor muscles of the
forearm and is called superficial ulnar artery.
• This variation ought to always be kept in mind while
taking out blood samples or giving intravenous
injections, since if superficial ulnar artery is
mistaken for a vein it may be damaged and produce
bleeding.

27. RADIAL ARTERY
Smaller of the two of the terminal
branches of brachial artery

28. RADIAL ARTERY
• It is the main artery in the human forearm.
• The smaller of the two terminal branches of
brachial artery.
• It starts from the brachial artery at roughly
the neck of the radius in cubital fossa and
runs along the lateral aspect of the forearm.
• It e ds i the pal e o i g the deep
palmar ar h

30. RADIAL ARTERY

31. RADIAL ARTERY
• It descends in the lateral part of the front of
the forearm.
• It lies on muscles which are attached to front
of the radius.
• At the lower end of the radius it leaves the
front of forearm & turns backwards round the
lateral border of the wrist, below the styloid
process of the radius.
• Here pulsation can be felt in the anatomical
snuff box.

32. RADIAL ARTERY
• Its upper part lies between brachiordialis (laterally)
& pronator teres(medially) overlapped by
brachioradialis.
• In middle third of the forearm: Only one nerve
related to artery is the radial nerve that lies along
lateral side of artery.
• Lower down, the radial artery becomes superficial
& lies between brachiordialis (laterally) and flexor
carpi radialis (medially)

35. RADIAL ARTERY
• The radial artery leaves the forearm by
winding around the lateral aspect of
the wrist to reach the anatomical
snuff-box on the posterior surface of
the hand.

36. RADIAL ARTERY
• Relations in hand:
• The radial artery lies first between 1st dorsal
interosseous & adductor pollicis. Here it gives
two branches:
–Radialis indicis artery.
–Princeps pollicis artery.
• After that the radial artery passes through
adductor pollicis to become the deep palmar
arch.

38. RADIAL ARTERY
• ANTERIOR
• The upper part of the radial artery
is overlapped by brachioradialis.
• It s lower part is covered only by
the skin, and superficial and deep
fasciae.

40. RADIAL ARTERY
• POSTERIOR
• The radial artery from above to downward is
located on the following structures:
– Biceps tendon.
– Supinator.
– Pronator teres.
– Flexor digitorum superficialis.
• These structures together create the bed of the
radial artery.
• The radial artery is quite superficial as compared to
the ulnar artery.

42. RADIAL ARTERY
• BRANCHES IN THE FOREARM
1. Muscular branches to the lateral muscles of the
forearm.
2. Radial recurrent artery originates in the cubital
fossa and takes part in the formation of arterial
anastomose around the elbow joint.
3. Palmar carpal branch, originates near the wrist and
anastomosis with the palmar carpal branch of
the ulnar artery.
4. Superficial palmar branch originates just above the
wrist and enters the palm of the hand by passing in
front of the flexor retinaculum. It joins the terminal
part of the ulnar artery to finish the superficial palmar
arch.

43. The anatomical snuffbox
also known as the radial fossa

44. The anatomical snuffbox
• The anatomical snuffbox (also known as the
radial fossa), is a triangular depression found
on the lateral aspect of the dorsum of the
hand. It is located at the level of the carpal
bones, and best seen when the thumb is
extended.
–In the past, this depression was used to hold
snuff (ground tobacco) before inhaling via the
nose – he e it as gi e the a e s uff o .

46. Borders
• The snuffbox is triangula:
1. Ulnar (medial) border: Tendon of the extensor
pollicis longus.
2. Radial (lateral) border: Tendons of the abductor
pollicis longus and extensor pollicis brevis.
3. Proximal border: Styloid process of the radius.
• Floor: Carpal bones; scaphoid and trapezium.
• Roof: Skin.
• Note: The terms medial and lateral are used in the context of
the anatomical position, where the forearm is supinated.
• It is important to note that the tendons of the muscles form
the borders, not the muscles themselves.

48. Contents
1. The radial artery crosses the floor of the
anatomical snuffbox in an oblique manner. It runs
deep to the extensor tendons. The radial pulse can
be palpated in some individuals by placing two
fingers on the proximal portion of the anatomical
snuffbox.
2. Subcutaneously, terminal branches of
the superficial branch of the radial nerve run
across the roof of the anatomical snuffbox.
3. Also subcutaneously, the cephalic vein crosses the
anatomical snuffbox, having just arisen from
the dorsal venous network of the hand.

50. RADIAL ARTERY
• CLINICAL SIGNIFICANCE
• Evaluation of radial pulse: It is felt on the radial side
of the front of wrist where the radial artery is
located on the anterior surface of the distal end of
radius, and covered only by the skin and fascia
• Volk a s is he i o tra ture (is he i
compartment syndrome): The sudden complete
occlusion (example, because of tight plaster cast) or
laceration (because of supracondylar fracture of
the humerus) of the brachial artery can cause
paralysis of flexor muscles of the forearm because
of ischemia for a few hours.

51. Clinical Relevance
• Fractures of the Scaphoid
• In the anatomical snuffbox, the scaphoid and
the radius articulate to form part of the wrist joint. In
the event of a blow to the wrist (e.g falling on an
outstretched hand), the scaphoid takes most of the
force. If localised pain is reported in the anatomical
snuffbox, a fracture of the scaphoid is the most likely
cause.
• The scaphoid has a unique blood supply, which
runs distal to proximal. A fracture of the scaphoid can
disrupt the blood supply to the proximal portion – this
is an emergency. Failure to revascularise the scaphoid
can lead to avascular necrosis, and future arthritis for
the patient.

52. SUPERFICIAL PALMAR ARTERIAL ARCH
• The hand has high blood circulation.
The arteries of the hand are ending
portion of the ulnar and radial
arteries which, respectively in each
hand after going inside the palm
create superficial and deep palmar
arterial arches.

54. Superficial palmar arterial arch
• The superficial palmar arterial arch is the primary
extension of ulnar artery.
• It is superficial because it lies next to palmar
aponeurosis.
• It is superficial palmar division of the ulnar artery away
from flexor retinaculum.
• The convexity of arch is pointed towards the digits.
• The ulnar artery together with ulnar nerve gets into
the hand at the medial side of the wrist.
• The vessel is located among the palmaris brevis as well
as the flexor retinaculum and also lateral to the ulnar
nerve along with the pisiform bone.

55. Superficial palmar arterial arch
• The arch is terminated laterally
through anastomosing along with one
of the following divisions of the radial
artery:
–Superficial palmar division of the radial
artery (most common).
–Radialis indicis artery.
–Princeps pollicis artery.

56. Superficial palmar arterial arch
• BRANCHES
• Three common palmar digital arteries reach the
interdigital clefts among the fingers then each split
within two proper digital arteries that supply their
adjacent parts. In the inter-digital clefts, they are
connected by the palmar metacarpal arteries.
• One proper digital artery travels to and circulates
the medial part of the little finger.
• Cutaneous branches: towards the palm, which
circulate the skin along with superficial fascia of the
palm.

57. Superficial palmar arterial arch
RELATIONS
• SUPERFICIAL
–Palmar aponeurosis
• DEEP:
–Long flexor tendons of FDS and FDP.
–Lumbricals
–Digital branches of the median as well as ulnar
nerves

58. CLINICAL SIGNIFICANCE
• LACERATION (WOUNDS)
• The lacerated injuries of palmar arterial arches
generally cause excessive and uncontrollable
bleeding. One of the most effective techniques is
the compression of brachial artery in opposition
to humerus in order to control the bleeding. Due to
attachments of these arches together with the
palmar as well as dorsal carpal arches, the ligation
or clamping of the radial artery or ulnar artery or
both of these proximal towards wrist cannot control
the bleeding.

59. DEEP PALMAR ARCH
• It is formed by the radial artery with the
deep palmar division of the ulnar artery.
• It lies immediately distal to the bases of
metacarpal bones(nearer to the wrist
than superficial palmar arch).
• It is concave to the wrist and in this
concavity lies the deep branch of the
ulnar nerve.

62. DEEP PALMAR ARCH
RELATIONS
• DEEP
–Proximal portion of shafts of the
metacarpals.
–Interosseous muscles.
• SUPERFICIAL
–Long flexor tendons of the fingers.
–Lumbricals.

63. BRANCHES
1. Three palmar metacarpal arteries, which connect
the common palmar digital arteries, the divisions
of the superficial palmar arch.
2. Three perforating arteries, which travel through
the 2nd, 3rd, and 4th interosseous spaces in order
to anastomose along with dorsal metacarpal
arteries.
3. Recurrent branches run proximally facing carpus
towards end inside the palmar carpal arch.

64. CLINICAL SIGNIFICANCE
• The lacerated wounds of palmar arterial arches
generally create excessive and uncontrollable
bleeding.
• One of the most efficient procedures in order to
subdue the bleeding is the confinement of brachial
artery opposed to humerus.
• Due to the attachments of these arches together
with the palmar and dorsal carpal arches the
ligation or clamping of the radial artery or ulnar
artery or both of these proximal towards wrist
cannot subdue the bleeding.