1. Assistant professor Dr. Alaa A. Alharba Orthopedic &Hand Surgeon
Wrist & Hand Anatomy 3
Assistant professor
Dr. Alaa A. Alharba
Orthopedic &Hand Surgeon

2. Small Muscles of the Hand
Lumbrical muscles (4).
Palmar interossei muscles (4).
Dorsal inerossei muscles (4).
Short muscles of the thumb ( thenar muscles (3) + adductor pollicis).
Short muscles of the little finger (hypothenar muscles (3) .

3. Lumbrical muscles: Origin: tendons of flexor digitorum profundus.
Insertion: extensor expansion of medial four fingers.
Nerve supply: median nerve(lat.2) and deep branch of ulnar nerve (med.2).
Function: flex the MCP joints & extend the IP joints of medial four fingers.

4. Palmar interossei muscles
Origin: first, second, fourth, and fifth metacarpal bones.
Insertion: proximal phalanges of thumb, index, ring, and little fingers and extensor expansion of each finger.
Nerve supply: deep branch of ulnar nerve.
Function: adduct the fingers toward center of third finger and flex the MCP joints & extend the IP joints.

5. Dorsal interossei muscles
Origin: contiguous sides of metacarpal bones.
Insertion: proximal phalanges of index, middle, and ring fingers and dorsal extensor expansion.
Nerve supply: deep branch of ulnar nerve.
Function: abduct the fingers from center of third finger and flex the MCP joints & extend the IP joints.

6. Short muscles of the thumb:
1.Adductor pollicis:
Origin: Oblique head: 2nd & 3rd metacarpals. Transverse head: 3rd metacarpal
Insertion: base of proximal phalanx of thumb.
Nerve supply: deep branch of ulnar N
Function: adduction of the thumb.
2. Thenar eminence :
i.Abductor pollicis brevis.
ii.Flexor pollicis brevis
iii.Opponens pollicis

7. Short muscles of little finger:
Hypothenar eminence:
Abductor digiti minimi
Flexor digiti minimi
Opponens digiti minimi

8. Blood Supply of the Palm
Arteries:
Ulnar artery: it enters the palm anterior to the flexor retin. on the lat. Side of the ulnar N. It gives a deep branch and then continue as the Superficial palmar arch. This arch curves laterally deep to the aponeurosis and in front of long flexor tendons, it is completed laterally by one of the branches of the radial artery.

9. 2. Radial artery: it enters the palm from the dorsum of the hand between the 1st and 2nd metacarpal bones and curve medially and continues as Deep palmar arch. This arch run deep to long flexor tendons and in front of metacarpals and interossei, then completed medially by joining the deep branch of the ulnar artery.
Radial a. also gives two branches in the palm: Radialis indicis a. for index finger and Princeps pollicis a. for thumb.
Veins of the Palm:
The superficial and deep palmar arches are accompanied by superficial and deep palmar venous arches

10. Blood supply of the Dorsum of the Hand
Radial artery
It enters the dorsum of the hand deep to the tendon of the extensor pollicis longus and gives branches take part in the anastomosis around the wrist.
Dorsal Venous Arch:
It lies in the subcutaneous tissue proximal to the MCP joints and drains on the lateral side into the cephalic vein and, on the medial side into the basilic vein. The greater part of the blood from the whole hand drains into this arch.

11. Lymph Drainage of the Hand:
The lymph from the medial side of the hand ascends in the vessels that accompany the basilic vein, they drain into the supratrochlear nodes. The lymph from the lateral side of the hand ascends in vessels that accompany the cephalic vein, they drain into the infraclavicular nodes, and some drain into the lateral axillary nodes.

12. Nerves of the Palm
Median Nerve: it enters the palm deep to the flexor retin. through the carpal tunnel and then immediately divides into medial & lateral branches.
Other branches:
Muscular branch (Recurrent branch): supplies muscles of thenar eminence.
Cutaneous branches supply the palmar aspect of the lateral three and half fingers.
Palmar cutaneous branch given off in the front of the forearm and enter the palm in front of the flexor retin. and supplies the skin over the thenar eminence.

13. Ulnar Nerve:
it enters the palm anterior to the flexor retin. and as it crosses the retin. it divides into a superficial and a deep terminal branch.
Superficial branch: supplies the little finger and medial side of ring finger by sensation.
Deep branch: gives muscular branch supplies muscles of hypothenar eminence, adductor pollicis, palmar & dorsal inerossei, and medial two lumbricals.

14. Fascial Spaces of the Palm
Are potential spaces filled with loose Connective tissue.Their boundaries are clinically important because they limit the spread of infection in the palm.

15. 2 1
From the medial border of aponeurosis a fibrous septum passes backward and is attached to the anterior border of the fifth metacarpal bone. From the lateral border, a second fibrous septum passes obliquely backward to the anterior border of the third metacarpal bone. This second septum divides the palm into1. the thenar space and2. midpalmar space.

16. These spaces are closed off proximally from the forearm by the walls of the carpal tunnel.
1)Thenar space: it lies lateral to the septum and contains the first lumbrical muscle.
2)Midpalmar space: it lies medial to the septum and contains the second, third, and fourth lumbrical muscles. 2 1

17. Pulp Space of the Fingers:
The deep fascia of the pulp of each finger fuses with the periosteum of the terminal phalanx just distal to the insertion of the long flexor tendons and closes off a fascial compartment known as the pulp space

18. Pulp Space of the Fingers:
Each pulp-space is subdivided by the presence of numerous septa, which pass from the deep fascia to the periosteum. Through the pulp space, which is filled with fat, runs the terminal branch of the digital artery that supplies the diaphysis of the terminal phalanx. The epiphysis of the distal phalanx receives its blood supply proximal to the pulp space.

19. Fibrous Flexor Sheath:
The anterior surface of each finger, from the head of metacarpal to the base of distal phalanx, is provided with a strong fibrous sheath that is attached to the sides of the phalanges. The fibrous sheath form a blind tunnel in which the flexor tendons lie. It is opened proximally and closed distally. It is thick over the phalanges but thin and lax over the joints. The fibrous flexor sheath of the thumb contains the FPL tendon , while the sheath of other fingers contain the tendons of FDS & FDP.

20. Synovial Flexor Sheath:
as they enter the fingers. In the hand the tendons of FDS and FDP have a common synovial sheath (sometimes called ulnar bursa). The medial side of this sheath extends distally without interruption on the tendons of little finger. The lateral part of the sheath stop at the level of middle of the palm and the long flexor tendons of the index, middle, and ring fingers acquire a digital synovial sheaths
The FPL has its own synovial sheath that passes into the thumb( sometimes called radial bursa).
These sheaths allow long tendons to move smoothly beneath the flexor retinaculum and fibrous flexor sheaths.