The Origin, Course and Distribution of Arteries to the Thumb, with Special Reference to the So-Called A

Okajimas Fol. anat. jap., 46: 123-137, 1969

The Origin, Course and Distribution of Arteries to the Thumb, with Special Reference to the So-Called A. princeps pollicis

Takuro Murakami, Kenichi Takaya and Hiromu Outi

Department of Anatomy, Okayama University Medical School Okayama, Japan

The arteries of the thumb have been studied by numerous authors in their various aspects. However, their true disposition, especially their course in relation to the muscles, has not yet been fully demonstrated. Neither the classical works of T a n d 1 e r (1897) and A d a chi (1928), nor the comprehensive study of Coleman and Anson (1961) seems to give us sufficient informations. This is partly due to the considerable variability of the arteries ; namely in their origin, course and branching. Furthermore, varying nomen- clatures (e. g. Baum 1907) have caused conspicuous confusions and made our understanding rather difficult. The present study, planned to elucidate these conditions, is hoped to contribute to a better understanding of the arteries of the thumb. The materials consisted of 90 hands* of the Japanese adult cadavers, most of which were injected with lead oxide suspension.

The morphology of the thenar muscles and their nomenclature As the relations of the arteries to the thumb muscles are essential for a correct understanding of their course, we start with the morphology of the muscles. Here too, some confusions of nomenclature are found. Thus, the deep head of M. flexor pollicis brevis, which inserts into the radial sesamoid bone and its vicinity together with the superficial head, is sometimes regarded as a part of the oblique

* The results obtained in 44 out of these 90 cases were read before the Associated Meeting of the Kinki and Chugoku-Shikoku Associations of Anatomists (cf. M u r a- k ami et al., 1966). 123 124 T. Murakami, K. Takaya and H. Outi

head of M. adductor pollicis. In the present report, we adopt the nomenclature of Frobse and Frankel (1908). Namely, the flexor inserts into the radial side of the thumb, and the adductor into the ulnar side. However, according to some authors (F lemming 1887 ; D a y and Napier 1961), these two muscles may have, in some cases, accessory insertions, i. e. the flexor inserting into the ulnar and the adductor into the radial side. We dissected the hands carefully in this respect. The oblique head of the adductor and the deep head of the flexor brevis were commonly fused with each other in their proximal part, and the two muscles were discriminated only by their insertions. Sometimes we found in their muscle belly some cleavages, that did not lead to the boundary in the insertion. But a careful comparison of various conditions of the whole series observed, has led us to the conclusion that those cleavages, diverse in position and distinction from case to case, cannot be regarded as a consistent boundary of the two muscles. We, therefore, identify these muscles always by the insertion. Since the proposal of H e n 1 e (1871), the existence in man of the palmar interosseous muscle of the thumb (sometimes called the deep head of the flexor pollicis brevis)** has been widely accepted, although the description differs somewhat among authors. According to the previous authors, the muscle should be a fairly independent bundle, which originates from the first metacarpal bone and inserts into the extensor aponeurosis of the thumb. Indeed, in our materials, the adductor pollicis muscle had a small muscle slip, which, as the most dorsal and medial part of the muscle, originated from the shaft and the base of the first metacarpal bone and the tendinous arch, under which the first palmar metacarpal artery arose from the radial artery. However, as the muscle slip was completely fused to the dorsal aspect of the adductor muscle, we could not identify it as an independent muscle. The only criterion possible to discriminate the muscle bundle may be the course of the first palmar metacarpal artery. In the present paper we provisionally call that muscle bundle which originates radial to the artery "palmar interosseaus- like bundle" of the adductor pollicis.

** A detailed study of this muscle will be reported by one of the present authors (M urakam i, in preparation). Arteries to the thumb 125

General pattern of the arteries of the thumb and the so-called "A. princeps pollicis "

As in the case of other fingers, the proper digital arteries (Aa. digitales propriae) of the thumb are well developed only on the palmar side, while the dorsal digital arteries are very minute except in rare cases. Two palmar arteries, Aa. radialis and ulnaris pollicis, run along the radial and ulnar margins respectively, and have in front of the shaft of the proximal phalanx under the tendon sheath of the flexor pollicis longus muscle a transverse anastomosis, sometimes of a considerable caliber. Their main source, however, is very variable from case to case. In most cases, a branch from the superficial palmar arch divides into two twigs, one of which (A. marginalis

Fig. 1. Various patterns of the arteries to the thumb. In a) the first palmar metacarpal artery is fully developed (normal, type Ia) . In b) the branches of the superficial palmar arch are unusually developed. In c) one of the branches of the first dorsal metacarpal artery constitutes the princeps pollicis artery (type VIIb) . And d) shows type Ib. 1: the first palmar metacarpal artery 2: the radial terminal branch 3: the ulnar terminal branch 4: the radial circumflex (perforating) branch 5: the ulnar circumflex (perforating) branch 6: a branch of the first dorsal metacarpal artery 7: the first common palmar digital artery 8: A. marginalis palmaris radialis 9: A. radialis pollicis 10: A. ulnaris pollicis 11: the proximal transverse anastomosis 12: A. radialis indicis 13: the radial terminal branch of the second palmar metacarpal artery . 126 T. Murakami, K. Takaya and H. Outi palmaris radialis, often called A. radialis anastomoses with A. radialis pollicis. The other twig (A. digitalis palmaris communis I) bifurcates again and anastomoses with A. ulnaris pollicis and A. radialis indicis (Fig. 1, c) ; when the branch of the first palmar metacarpal artery to the index finger is well-developed, the twig seams to join the latter branch (Fig. 1, a). But usually the contribu- tion of these superficial arteries is not remarkable, sometimes almost wanting ; on the contrary, a deep artery, the first palmar metacarpal artery (A. metacarpea palmaris I), offers normally the principal supply of the palmar digital arteries of the thumb (Fig. 1, a). This is one of the terminal branches of the radial artery. It descends distally between the first metacarpal bone and the adductor pollicis muscle, and reaches to the level of the neck of the first metacarpal bone between the adductor and the short flexor and under the tendon of the long flexor. Then, it divides into two terminal branches. The radial terminal branch, joined by A. marginalis palmaris radialis, continues to A. radialis pollicis the ulnar one, after it has gained superficial position and received a branch of the first common palmar digital artery, continues to A. ulnaris pollicis. In some cases, when the first palmar inetacarpal artery is fully developed, it appears that the ulnar terminal branch anastomoses with or supplies A. radialis indicis (Fig. 1, a). Sometimes the first palmar metacarpal artery is weak or almost wanting and substituted by a dorsal artery with an unusual course. The term " A. princeps pollicis" has been used with different meanings. Sometimes it is quite the same as the first palmar metacarpal artery in the strict sense, and sometimes it means, regardless of the origin and course, the largest source of the palmar arteries of the thumb other than the branches of the superficial palmar arch. For the sake of convenience we follow this wider definition.

The first palmar metacarpal artery

This artery, often called the princeps pollicis artery, accurately corresponds to the palmar metacarpal arteries of the other fingers (more strictly, to the " deep " group of these arteries, M u r aka m i 1969) in its origin, course and branching, as Tan d I e r (1897) and Coleman and Anson (1961) pointed out. Therefore, we adopt the above designation ***. *** Sometimes the designation is applied also to arteries of various origin (our princeps pollicis artery). Arteries to the thumb 127

The radial artery reaches the proximal end of the first intermetacarpal space, with a few exceptions (in 6 out of 90 cases), where its main flow penetrates the proximal end of the second intermetacarpal space. There it pierces a cleft between the heads of the first dorsal interosseous muscle and then, giving off the first palmar metacarpal artery, passes under the thin tendinous arch of the adductor pollicis, which spans between the bases of the first and second metacarpal bones, to build up the deep palmar arch. It runs medially piercing those bundles of the adductor that originates from the second metacarpal bone. The first palmar metacarpal artery originates as one of the terminal branches of the radial artery, as the latter passes through the tendinous arch of the adductor. In the above-mentioned exceptional cases likewise we found always a smaller branch, which took the normal course of the deep palmar arch and gave rise to the first palmar metacarpal artery. The artery descends distally along the ulnar-palmar surface of the first metacarpal bone under the cover of the "palmar interosseous-like bundle" of the adductor pollicis, and reaches between the adductor and the short flexor . In its course, the artery sends off some muscular twigs and a nutrient branch to the metacarpal bone (usually in its proximal half). At the level of the neck of the metacarpal bone it has two circumflex branches (Figs. 1 and 2), which correspond to the distal perforating branches of the other fingers. The ulnar circumflex branch runs dorsally under the tendon of the adductor and anastomoses with a branch of the dorsal metacarpal artery . As will be mentioned later, it may serve as a route of the princeps pollicis artery of unusual course. When such cases and minute remnants are taken into consideration, the branch exists in all the cases . The radial circumflex branch is never lacking. It arises directly from the first palmar metacarpal artery or from the radial terminal branch , runs radially between the insertions of the opponens pollicis and the flexor pollicis brevis muscles, and anastomoses with a branch of the dorsal arteries on the back of the metacarpal bone. As mentioned previously, the first palmar metacarpal artery divides into two terminal branches under the tendon of the flexor pollicis longus muscle. The radial and the ulnar terminal branches become superficial by passing either side of the tendon of the flexor pollicis longus. We observed one exceptional case in which the ulnar terminal branch pierced a small bundle of the radial margin of the oblique head of the adductor. Normally, the radial terminal branch 128 T. Murakami, K. Takaya and H. Outi

Fig. 2. The distal branchesof the first palmar metacarpalartery (the ulnar circumflex branch is not shown.). 1: the first palmar metacarpalartery 2: the radial terminalbranch 3: the ulnar terminal branch 4: A. radialis indicis 5: the radial circumflex branch 6: the branch of the superficial palmar arch Abd: the abductorpollicis brevis muscle Add: the adductorpollicis muscle D: the first dorsal interosseous muscle : the flexorpollicis brevis muscle L: the first lumbricalmuscle Opp: the opponenspollicis muscle T: the tendon sheath of the flexorpollicis longus muscle offers the principal supply to A. radialis pollicis, and the ulnar one to A. ulnaris pollicis and/or A. radialis indicis (See the preceding sec- tion). When they are poorly developed, they only join the digital arteries derived from the superficial palmar arch or from the dorsal metacarpal artery (Fig. 1, b and c). The terminal branches also supply some minute branches to the palmar aspect of the meta- carpophalangeal joint of the thumb. According to A d a c hi (1928), only in less than one-third of the cases the superficial arteries offer the largest source of A. radialis Arteries to the thumb 129 pollicis and A. ulnaris pollicis, while Nagai (1955) reported more frequent participation of the superficial ones, especially A. ulnaris pollicis of superficial origin being rather normal. We could not take exact statistics of this relationship, but our figures are practically the same as those of A d a c h i. The difference between the results of A d a chi and the present authors and Nagai seems to lie, at least in part, in the point that the former considered only the largest artery, while the latter took all the " main " arteries, because Naga i's results show a far greater number of cases having two main sources (especially with A. ulnaris pollicis, as many as 43%). The first palmar metacarpal artery was never wanting completely. Although its size varies considerably and its proximal segment is absent in most cases of type b (See below) of the princeps pollicis artery, the distal segment, i. e. distal to the ulnar circumflex branch, is detectable in all the cases examined. In type a, the distal segment, at least, is well- or somewhat well-developed and constitutes a part of the princeps pollicis artery. The distal segment is small in type b, where the largest artery runs dorsal to the tendon of the adductor pollicis. In the extreme cases, too, where the artery is small and the terminal branches are reduced to minute twigs sup- plying only the proximal part of the thumb, the radial circumflex branch is always retained as the only significant branch. In the cases of types II-VII (Fig. 4), in which the princeps pollicis artery arises before the radial artery pierces the adductor pollicis muscle and runs dorsal to the "palmar interosseous-like bundle " or the first dorsal interosseous muscle, the proximal segment af the first palmar metacarpal artery is either a small branch running the full course (type a) or anastomosing with more prominent distal segment (type b) or completely absent. In the latter , too, some muscle branches arise at the very beginning of the deep palmar arch. These might be a sort of remnants of the artery, although exact judgement cannot be made in individual cases .

Dorsal arteries of the first interosseous space As is well known, the descending arteries on the back of the hand are " intermetacarpal " in their position, although they are generally named the dorsal " metacarpal " arteries. It is commonly said that the first dorsal metacarpal artery is given off as the radial artery pierces the first dorsal interosseous muscle , and soon bifurcates into two small branches which run distally on the back of the muscle . 130 T. Murakami, K. Takaya and H. Outi

We investigated these branches in 62 hands. It has been con-. firmed that these radial and ulnar branches more often arise in dependently and run along the origin of the radial head of the first dorsal interosseous muscle and along the boundary of the two heads of this muscle, respectively. They may be faint vessels, which cannot be distinguished from insignificant muscle branches. But, in the. typical and better developed cases they always anastomose at the level of the neck of the metacarpal bones with the distal perforating (circumflex) branches of the first and the second palmar metacarpal arteries, a disposition also typical of other dorsal metacarpal arteries. We have found such typical forms of the radial and ulnar branches in 30 and 48 out of the 62 hands respectively. The ulnar branch, when unusually developed, may reach the palmar side of the distal part of the second metacarpal bone by way of the distal perforating branch between the first dorsal interosseous muscle and the second metacarpal bone (2 out of the 90 cases examined). The radial branch or its proximal segment may be developed to serve as the route of the

Fig. 3. The branches of the first dorsal metacarpal artery. In this rare case three branches all exist and the intermediate branch, unusually developed, supplies mainly the radial side of the index finger. The princeps pollicis artery is of type Ia. 1-3 : the radial, intermediate and ulnar branches of the first dorsal metacarpal artery 4: A. radialis indicis, mainly supplied by the first dorsal metacarpal artery 5 and 6: the branches running on the back of the first metacarpal bone (See text) 7: A. ulnaris pollicis, mainly supplied by the first palmar metacarpal artery. Abdl : the abductor pollicis longus muscle Ebr : the extensor pollicis brevis muscle El: the extensor pollicis longus muscle Arteries to the thumb 131 princeps pollicis artery (in all the types V, VI and VIIa and some of type VIIb, See below). Besides these radial and ulnar branches, we sometimes found between them a third branch, the " intermediate " branch. In rare cases there existed all of the three branches (Fig. 3). When the intermediate branch is well developed (14 out of the 62 cases), it passes over the first dorsal interosseous muscle as far as the distal free border of the adductor pollicis muscle and anastomoses with the palmar digital arteries of the thumb and index finger. It constitutes the princeps pollicis artery of type VIIb (See below). This intermediate branch has not been recognized by the previous authors, but at least some of the unusually large branches of the dorsal metacarpal artery, which they saw, might be supposed to correspond to it. Coleman and Anson (1961) observed a small artery to the thumb running distally on the back of the first metacarpal bone (83%). According to our observations, such an artery can be of two different origins : one arising from the radial artery at the radial border of the wrist palmar or dorsal to the tendon of the abductor pollicis longus muscle and running along the radial border of the abductor pollicis brevis, and the other arising from the radial artery between the tendons of the extensor pollicis brevis and longus muscles (Fig. 3). Absence of both arteries is rather rare.

A. princeps pollicis, its origin and course As mentioned previously, we call A. princeps pollicis the largest source of the palmar arteries of the thumb other than the branches of the superficial palmar arch, i. e. the largest branch of the deep palmar and the dorsal arteries to the palmar aspect of the thumb. Most frequently, the first palmar metacarpal artery (in the strict sense) itself constitutes the princeps pollicis artery (type Ia, See below). This type is considered normal, but occurs only in about one half of the cases. The other cases show complicated variations. A d a c hi (1928) classified these various variations by its relation to the adductor pollicis muscle into two categories : A. metacarpea volaris (palmaris) I and A. metacarpea dorsalis I . The former makes its palmar appearance under the tendon of the flexor pollicis longus and lies palmar to the tendon of the adductor , while the latter passes from dorsal over the distal free border of the adductor to the palmar side of the thumb. His simple classification, convenient for the clear settlement of the complicated disposition of the artery, has been 132 T. Murakami, K. Takaya and H. Outi followed by many later authors. However, it cannot offer a full information of the true disposition of the princeps pollicis artery, because in this classification a considerable variability of its origin and proximal course is utterly neglected. For this reason, we have tried the following classification.

Fig. 4. Types of the princeps pollicis artery (See text).

As to the course of the distal segment, distal to the level of the ulnar circumflex branch, we follow A d a c h is classification and name his A. metacarpea volaris I as type a, and his A. metacarpea dorsalis I as type b. As will be seen below, the palmar or dorsal course of the distal segment of the artery does not neccessarily agree with the Arteries to the thumb 133 palmar or dorsal course of the proximal segment. In not a few cases an artery coursing palmar in the proximal segment continues to the dorsal artery, or vice versa. For this alteration of the course serves the ulnar circumflex branch, an anastomosing branch of the first palmar metacarpal artery with the dorsal artery. As to the origin and proximal course of the princeps pollicis artery, we have found three major (I, II, VII) and four intermediate, rather anomalous (III, IV, V, VI) types, as seen in Fig. 4 and Table 1.

Table 1. Types of the princeps pollicis artery (See text). Types of the distal segment of the princeps pollicis artery

Type I: The proximal segment of the artery is identical with the first palmar metacarpal artery (56 hands). Thus, it runs along the first metacarpal bone under the cover of the " palmar interosseous-like bundle ". We found type Ia, the normal type, in 42 hands, and type Ib in 14 hands. Type II: The artery arises from the radial artery, after the latter has pierced between the heads of the first dorsal interosseous muscle, and runs distally between the radial head of the first dorsal interosseous muscle and the adductor pollicis muscle, especially its palmar interosseous-like bundle" (four hands). In our materials, three hands of type IIa and one hand of type IIb were found . The proximal segment of the princeps pollicis artery in this type II co- incides in its course between the palmar and dorsal interosseous muscles with the "palmar intermetacarpal" arteries (M u r a k am i 1969) of the other fingers. Moreover, according to him, the palmar intermetacarpal arteries are divided into " superficial " and " deep " ones. In type Ha, the artery runs directly along the first metacarpal bone and is considered as the " deep " palmar intermetacarpal artery 134 T. Murakami, K. Takaya and H. Outi of the first interosseous space, while the princeps pollicis artery of type IIb which runs a little away from the bone might correspond to the " superficial " palmar intermetacarpal artery. Although in some cases of the other types, too, an insignificant twig is found under the origin of the radial head, the occurrence of the deep palmar intermetacarpal artery is rare in the thumb. On the other hand, a twig which takes the course of the superficial palmar intermetacarpal artery of the first interosseous space is found rather frequently. We found, besides the case of type IIb, three cases of fairly well- developed ones, which ran on the dorsal surface of the adductor pollicis and anastomosed at the free distal border of the muscle with the palmar digital arteries of the thumb and index finger. This superficial palmar intermetacarpal artery might correspond to " Aa. intermetacarpeae dorsales-- profundae " of Yamamoto (1937) and K i t a g a w a (1952), although they did not see the relation of the artery to the muscles, as they studied by the stereoradiogram and the corrosion method respectively. Type VII : The artery arises from the radial artery, before the latter passes between the heads of the first dorsal interosseous muscle, and runs distally on the back of the muscle (10 hands). Arteries of this origin and course are considered as an unusually developed type of a branch of A. metacarpea dorsalis I. We have found type VIIa in one hand and type VIIb in nine hands. The proximal (dorsal) segment of the artery of VIIa corresponded to the radial branch of the first dorsal metacarpal artery in its position. In type VIIb, the princeps pollicis artery took frequently a course somewhat away from the first metacarpal bone, a course which corresponds to that of the intermediate branch of the first dorsal metacarpal artery. Although a strict discrimination could not be always made, we interpret the artery as the radial branch in 2 and as the intermediate branch in 6 out of the 9 cases of type VIIb, one case being undetermined. Types III, IV, V and VI : These types are intermediate between types II and VII. In types III and IV, the artery arises from the radial artery before the latter pierces the adductor pollicis muscle, and on the palmar aspect of the radial head of the first dorsal interosseous muscle it pierces a small muscle bundle. Then, in type III, the artery passes through the palmar interosseous-like bundle to reach between the first metacarpal bone and the adductor muscle (four hands), while, in type IV, it runs between the radial head and the palmar interosseous-like bundle (three hands). In our materials we Arteries to the thumb 135 found three hands of type Ma and one hand of IIIb. All the cases of type IV were of IVa. In types V and VI, the artery arises from the radial artery immediately before the latter passes through the heads of the first dorsal interosseous muscle. It runs distally some distance along the first metacarpal bone, and then pierces the origin of the radial head of the muscle from the back to appear on the palmar aspect of the radial head. Then, in type V, the,artery pierces the "palmar interosseous-like bundle " and reaches between the first metacarpal bone and the adductor muscle (five hands), while, in type VI, it runs between the radial head and the palmar interosseous-like bundle (eight hands). All the five hands of the type V were of Va, while, in type VI, VIa and VIb were found in seven and one hands respectively. The dorsal segment of the princeps pollicis artery in types V and VI is always considered as a well-developed radial branch of the first dorsal metacarpal artery. It may send a small branch further distally on the back of the radial head.

• Summary

Ninety hands of the Japanese adult cadavers were examined to clarify the complicated variations of the arteries to the thumb . 1. Various patterns of the arteries can be considered as the results of the alterations that some of the normally existing small arteries or their branches are unusually well developed , the others being reduced in return (Fig. 1). 2. The princeps pollicis artery (the largest branch to the palmar aspect of the thumb arising from the deep palmar or the dorsal arteries) takes various courses both in its proximal and distal seg- ments. a) The proximal courses are classified into seven types (Fig . 4 and Tab. 1). In three major types, the artery runs between the first metacarpal bone and the adductor pollicis muscle palmar to the palmar interosseous-like bundle of the latter muscle (type I), between the adductor or its palmar interosseous-like bundle and the first dorsal interosseous muscle (type II), or on the back of the latter muscle (type VII). The other four types (III, IV, Vand VI) are rather anomalous and have a character intermediate between types II and VII. b) In the distal segment the artery runs palmar (type a) or dorsal (type b) to the tendon of the adductor pollicis muscle . 136 T. Murakami, K. Takaya and H. Outi

-c) Type Ia , which occurred in 42 of 90 hands, is considered as normal. The artery of this origin and course is nothing but the first palmar metacarpal artery itself. 3. The first palmar metacarpal artery has been called variously. It completely corresponds in the course and branching to the palmar metacarpal arteries of the other fingers (more strictly, to the " deep" group of these arteries, Mu r a k a m i 1969). After it has given off two circumflex (perforating) branches at the neck of the first metacarpal bone, it divides into two terminal branches, which supply the radial side of the thumb and the adjacent sides of the thumb and index finger (Fig. 2). The ulnar circumflex branch may serve as the route of the princeps pollicis artery of variant courses. 4. Also in the first interosseous space may occur the superficial and the deep palmar intermetacarpal arteries (M u r a k a m i 1969), which, when developed, may constitute the princeps pollicis artery of type II. 5. The dorsal metacarpal artery (Fig. 3) may have three branches. The radial or intermediate branches, when developed, may constitute the princeps pollicis artery of type VII.

Literature Ada c h i, B. (1928): Das Arteriensystem der Japaner, Bd. I. S. 382-428. Maruzen, Kyoto. B a u m, H. (1907): Die Benennung der Hand- und Fussarterien des Menschen und Haussaugetiere. Anat. Anz. 31 : 428-448. Colema n, S.S. and A n s o n, B.J. (1961) : Arterial patterns in the hand based upon a study of 650 specimens. Surg. Gynecol. Obstet. 113: 408-424. D a y, M. H. and N a p i e r, J. R. (1961): The two heads of Flexor pollicis brevis. J. Anat. 95 : 123-130. Edward s, E. A. (1960): Organization of the small arteries of the hand and digits. Amer. J. Surg. 99 : 837-846. Flemmin g, W. (1887) : Ober den Flexor brevis pollicis und hallucis des Menschen. Anat Anz. 2: 68-77. Fr ohs e, F. und Franke 1, M. (1908): Die Muskeln des menschlichen Armes. S. 209-239.Gustav Fischer, Jena. F u k u y a m a, U. (1938): Ober die Arterien der oberen Extremitat bei den Nord- chinesen. III. Mitteilung : Arterien der Hand. (Japanischer Text, mit Zusam- menfassung im Deutschen) J. Orient. Med. 29: 903-926. G r u b e r, W. (1864): Zur Anatomie der Arteria radialis. Arch. Anat. Physiol. wiss. Med. 1864: 434-455. H a y a s h i, M. (1952) : On the arterial system of the Japanese twin fetuses. III. Hand arteries. (Japanese text) Soutaitaiji no Kaibogakuteki Kenkyu 20 : 233-262. H e n 1e, J. (1871): Handbuch der Muskellehre des Menschen. Zweite Auflage S. 239- 249. Friedrich Vieweg und Sohn, Braunschweig. Arteries to the thumb 137

K i tag a w a, Y. (1932): A study of the arteries of the palm and back of the hand of Japanese by corrosion method. (Japanese text) Tokyo Jikei Ikadaigaku Kaibo- gyoseki 8. K o i z u m 1, K. (1932) : Fri la arteriaj anastomozoj inter mandorso kaj manplato. (japanlingva teksto kun esperanta resumo) Tokyo Igakkwai Z. 46 : 1530-1533. (1935) : A statistical study of the muscles, arteries and nerves of the hand, with special reference to their interrelationships of anomalies. (Japanese text) J. Nippon Med. School 6: 229-261. Kraus e, W. (1876) : Handbuch der Gefasslehre des Menschen von J. Henle. Zweite Auflage S. 143-157. Friedrich Vieweg und Sohn, Braunschweig. M o r i, Y. (1941) : Ober die Arterien der oberen Extremitaten der japanischen Feten. III. Handarterien. (Japanischer Text, mit Zusammenfassung im Deutschen) Kaibei. Z. 17: 428-454. M u r a k am i, T., T a k a y a, K. and 0 u t i, H. (1966) : On the palmar interosseous muscle of the thumb and the princeps pollicis artery. (Abstract in Japanese) Kaibo. Z. 41 (2, Suppl.). MN r a k a m i, T. (1969) : On the position and course of the deep palmar arteries, with special reverence to the so-called palmar metacarpal arteries. Okajimas Fol. anat. jap. 46(4). (in press) Murakam i, T.: On the palmar interosseous muscle of the thumb, with special reference to its relationships to the nerves and arteries. (in preparation) Naga i, S. (1955) : On the arteries and nerves of the hand. (Japanese text) Kuma- moto Daigaku Kaibogyoseki 17 : 428-454. T a n d 1e r, J. (1897) : Zur Anatomie der Arterien der Hand. Anat. H. 7: 263-282. Yamamot o, H. (1939) : Anatomisch-stereoskopische Röntgenuntersuchungen iiber die Hand- und Fingerarterien der Japaner. (Japanischer Text, mit Zusammen- fassung im Deutschen) KaibO. Z. 13: 837-980.