257
J. Anat. (1979), 129, 2, pp. 257-260 With 5 figures Printed in Great Britain
Arterial segmentation in the spleen of the sheep (Ovis aries) S. C. GUPTA, C. D. GUPTA AND S. B. GUPTA
Departments of Anatomy and Physiology, S.N. Medical College, Agra (U.P.), India
(Accepted 26 July 1978) INTRODUCTION
Segmentation in the sheep lung (Bressou & Vladutiu, 1939; Hare, 1955) and liver (Heath, 1968) has been studied, but no information is available concerning the segments in the sheep spleen. The present paper reports our observations on arterial segmentation in the sheep spleen based on corrosion casts of the splenic artery and its tree. MATERIALS AND METHOD
Forty fresh sheep spleens from the slaughterhouse were used. The corrosion casts of the splenic artery and its tree were prepared by injecting a red coloured solution of butyl butyrate in acetone (Gupta, Gupta, Arora & Singh, 1976). RESULTS
In 28 specimens (70 %), the splenic artery divided into two primary divisions, a right and a left, just after its entrance into the spleen. There were no anastomoses between the branches of these two primary divisions (Fig. 1). The avascular plane was parallel to the long axis of the spleen. In these 28 spleens (70 %) there were thus two arterial segments - a right and a left (Fig. 2). The segments were often of unequal size. In 1 case (2-5 %) the splenic artery divided into parietal and visceral primary divisions instead of right and left. Anastomoses were not seen between the branches of these two main divisions, the avascular plane being oblique to the long axis of the spleen. The branches of the visceral division alone supplied the cranial half of the visceral surface of the spleen: the caudal half of this surface received branches from both divisions. The parietal surface of the spleen was entirely supplied by branches of the parietal division. (In view of the respective distribution of the two branches to the visceral and parietal surfaces, the terms parietal and visceral have been used). (Fig. 3). Thus this spleen showed two segments arranged as in Figure 4. In 11 specimens (27 5 %) the artery ramified irregularly after its entrance into the spleen, and no arterial segmentation was discernible (Fig. 5). DISCUSSION
Table 1 compares the arterial segments in the sheep spleen with those of man,
buffalo, dog and goat. The present observations on the sheep confirm that the arterial arrangement in the 0021-8782/79/2828-6350 $02.00 © 1979 Anat. Soc. G.B. & I. I'7
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S. C. GUPTA, C. D. GUPTA AND S. B. GUPTA
VS.
PS
4~~~~~~
Fig. 1. Two primary divisions of the splenic artery, a right and a left (visceral aspect). x 0-75. Fig. 2. Two arterial segments, a right (RS) and a left (LS) (visceral aspect). Fig. 3. Two primary divisions of the splenic artery, a parietal and a visceral (side view). x 0-75. Fig. 4. Two arterial segments exposed on the visceral surface, namely a visceral (VS) and a parietal (PS): and one on the parietal surface, namely a parietal (PS) (side view). Fig. 5. A splenic artery with irregular intrasplenic ramification (visceral aspect). x 0-75.
Segmentation in the sheep spleen
259
Table 1. Comparison of arterial segtnents in the spleen of sheep, man, buffalo, dog and goat Species
Specimens , studied (n)
Number of arterial segments k
Three
Two
8 cases (16 %) Superior, middle and inferior
Human (Gupta et al. 1976)
50
42 cases (84 %) Superior and inferior
Buffalo (Gupta et al. 1978 a)
44
Dog (Gupta et al. 1978b)
40
41 cases (93-18 %) 3 cases (6-82 %) Dorsal and Dorsal, interventral mediate and ventral 39 cases (97 5 %) Dorsal and ventral
Goat (Gupta et al. 1978 c)
50
Sheep (Present study)
40
37 cases (74 %) Right and left
Absence of arterial segments
5 cases (10 %)
Hilar, right and left
28 cases (70 %) Right and left 1 case (2-5 %) Visceral and
Position of the splenic hilum A longitudinal fissure on the visceral surface of the spleen Close to the upper third of its anterior border
1 case (2-5 %) 8 cases (16 %) 11 cases (27-5 %)
A longitudinal fissure on the visceral surface of the spleen Near the cranial angle of the spleen Near the cranial
angle of the spleen
parietal
mammalian spleen is generally segmental. However, absence of arterial segmentation is more common in the sheep than in the goat and dog. All human and buffalo spleens examined showed segmentation. Table 1 gives the variation in the position of the arterial segments in different species. This variation is perhaps associated with the position of the hilum. Clausen (1958) and Gutierrez-Cubillos (1969) reported two to four arterial segments in the human spleen. However, in our study of the human spleen (Gupta et al. 1976) no specimen showed more than three segments. SUMMARY
Forty corrosion casts of the splenic artery and its tree were used to study segmentation in the sheep spleen. Twenty eight spleens (70 %) had two arterial segments, a right and a left. One spleen (2-5 %O) had a visceral and a parietal segment. Eleven spleens (27-5 %) showed no arterial segmentation, the artery ramifying irregularly. REFERENCES BRESSOU, C. & VLADUTIU, 0. (1939). Cited by Hare, W. C. D. (1955). CLAUSEN, E. (1958). Cited by F. Goldby and R. J. Harrison (1961). In Recent Advances in Anatomy, 2nd ed., p. 392. London: J. & A. Churchill Ltd. GUPTA, C. D., GUPTA, S. C., ARORA, A. K. & SINGH, P. J. (1976). Vascular segments in the human
spleen. Journal of Anatomy 121, 613-616. GUPTA, S. C., GUPTA, C. D., ARORA, A. K. & GUPTA, S. B. (1978a). Vascular segments in the buffalo (Bubalus bubalis) spleen. A study by corrosion cast. Anatomischer Anzeiger 143, 493-495. GUPTA, S. C., GUPTA, C. D. & GUPTA, S. B. (1978 b). Segmentation in the dog spleen - A study by corrosion cast. Acta anatomica 101, 380-382. :7-2
S. C. GUPTA, C. D. GUPTA AND S. B. GUPTA 260 GUPTA, S. C., GUPTA, C. D. & GUPTA, S. B. (1978 c). Arterial segmentation in the goat (Capra hircus) spleen - A study by corrosion cast. Acta anatomica 102, 102-104. GUTIERREZ-CUBILLOS, C. (1969). Segmentation of the spleen (segmentation esplenica). Revista espanola de las enfermedades del aparato digestivo y la nutricion 29, 341-350. HARE, W. C. D. (1955). The broncho-pulmonary segments in the sheep. Journal of Anatomy 89, 387-402. HEATH, T. (1968). Origin and distribution of portal blood in the sheep. American Journal of Anatomy 122, 95-106.
J. Anat. (1979), 129, 2, pp. 257-260 With 5 figures Printed in Great Britain
Arterial segmentation in the spleen of the sheep (Ovis aries) S. C. GUPTA, C. D. GUPTA AND S. B. GUPTA
Departments of Anatomy and Physiology, S.N. Medical College, Agra (U.P.), India
(Accepted 26 July 1978) INTRODUCTION
Segmentation in the sheep lung (Bressou & Vladutiu, 1939; Hare, 1955) and liver (Heath, 1968) has been studied, but no information is available concerning the segments in the sheep spleen. The present paper reports our observations on arterial segmentation in the sheep spleen based on corrosion casts of the splenic artery and its tree. MATERIALS AND METHOD
Forty fresh sheep spleens from the slaughterhouse were used. The corrosion casts of the splenic artery and its tree were prepared by injecting a red coloured solution of butyl butyrate in acetone (Gupta, Gupta, Arora & Singh, 1976). RESULTS
In 28 specimens (70 %), the splenic artery divided into two primary divisions, a right and a left, just after its entrance into the spleen. There were no anastomoses between the branches of these two primary divisions (Fig. 1). The avascular plane was parallel to the long axis of the spleen. In these 28 spleens (70 %) there were thus two arterial segments - a right and a left (Fig. 2). The segments were often of unequal size. In 1 case (2-5 %) the splenic artery divided into parietal and visceral primary divisions instead of right and left. Anastomoses were not seen between the branches of these two main divisions, the avascular plane being oblique to the long axis of the spleen. The branches of the visceral division alone supplied the cranial half of the visceral surface of the spleen: the caudal half of this surface received branches from both divisions. The parietal surface of the spleen was entirely supplied by branches of the parietal division. (In view of the respective distribution of the two branches to the visceral and parietal surfaces, the terms parietal and visceral have been used). (Fig. 3). Thus this spleen showed two segments arranged as in Figure 4. In 11 specimens (27 5 %) the artery ramified irregularly after its entrance into the spleen, and no arterial segmentation was discernible (Fig. 5). DISCUSSION
Table 1 compares the arterial segments in the sheep spleen with those of man,
buffalo, dog and goat. The present observations on the sheep confirm that the arterial arrangement in the 0021-8782/79/2828-6350 $02.00 © 1979 Anat. Soc. G.B. & I. I'7
ANA I29
258
S. C. GUPTA, C. D. GUPTA AND S. B. GUPTA
VS.
PS
4~~~~~~
Fig. 1. Two primary divisions of the splenic artery, a right and a left (visceral aspect). x 0-75. Fig. 2. Two arterial segments, a right (RS) and a left (LS) (visceral aspect). Fig. 3. Two primary divisions of the splenic artery, a parietal and a visceral (side view). x 0-75. Fig. 4. Two arterial segments exposed on the visceral surface, namely a visceral (VS) and a parietal (PS): and one on the parietal surface, namely a parietal (PS) (side view). Fig. 5. A splenic artery with irregular intrasplenic ramification (visceral aspect). x 0-75.
Segmentation in the sheep spleen
259
Table 1. Comparison of arterial segtnents in the spleen of sheep, man, buffalo, dog and goat Species
Specimens , studied (n)
Number of arterial segments k
Three
Two
8 cases (16 %) Superior, middle and inferior
Human (Gupta et al. 1976)
50
42 cases (84 %) Superior and inferior
Buffalo (Gupta et al. 1978 a)
44
Dog (Gupta et al. 1978b)
40
41 cases (93-18 %) 3 cases (6-82 %) Dorsal and Dorsal, interventral mediate and ventral 39 cases (97 5 %) Dorsal and ventral
Goat (Gupta et al. 1978 c)
50
Sheep (Present study)
40
37 cases (74 %) Right and left
Absence of arterial segments
5 cases (10 %)
Hilar, right and left
28 cases (70 %) Right and left 1 case (2-5 %) Visceral and
Position of the splenic hilum A longitudinal fissure on the visceral surface of the spleen Close to the upper third of its anterior border
1 case (2-5 %) 8 cases (16 %) 11 cases (27-5 %)
A longitudinal fissure on the visceral surface of the spleen Near the cranial angle of the spleen Near the cranial
angle of the spleen
parietal
mammalian spleen is generally segmental. However, absence of arterial segmentation is more common in the sheep than in the goat and dog. All human and buffalo spleens examined showed segmentation. Table 1 gives the variation in the position of the arterial segments in different species. This variation is perhaps associated with the position of the hilum. Clausen (1958) and Gutierrez-Cubillos (1969) reported two to four arterial segments in the human spleen. However, in our study of the human spleen (Gupta et al. 1976) no specimen showed more than three segments. SUMMARY
Forty corrosion casts of the splenic artery and its tree were used to study segmentation in the sheep spleen. Twenty eight spleens (70 %) had two arterial segments, a right and a left. One spleen (2-5 %O) had a visceral and a parietal segment. Eleven spleens (27-5 %) showed no arterial segmentation, the artery ramifying irregularly. REFERENCES BRESSOU, C. & VLADUTIU, 0. (1939). Cited by Hare, W. C. D. (1955). CLAUSEN, E. (1958). Cited by F. Goldby and R. J. Harrison (1961). In Recent Advances in Anatomy, 2nd ed., p. 392. London: J. & A. Churchill Ltd. GUPTA, C. D., GUPTA, S. C., ARORA, A. K. & SINGH, P. J. (1976). Vascular segments in the human
spleen. Journal of Anatomy 121, 613-616. GUPTA, S. C., GUPTA, C. D., ARORA, A. K. & GUPTA, S. B. (1978a). Vascular segments in the buffalo (Bubalus bubalis) spleen. A study by corrosion cast. Anatomischer Anzeiger 143, 493-495. GUPTA, S. C., GUPTA, C. D. & GUPTA, S. B. (1978 b). Segmentation in the dog spleen - A study by corrosion cast. Acta anatomica 101, 380-382. :7-2
S. C. GUPTA, C. D. GUPTA AND S. B. GUPTA 260 GUPTA, S. C., GUPTA, C. D. & GUPTA, S. B. (1978 c). Arterial segmentation in the goat (Capra hircus) spleen - A study by corrosion cast. Acta anatomica 102, 102-104. GUTIERREZ-CUBILLOS, C. (1969). Segmentation of the spleen (segmentation esplenica). Revista espanola de las enfermedades del aparato digestivo y la nutricion 29, 341-350. HARE, W. C. D. (1955). The broncho-pulmonary segments in the sheep. Journal of Anatomy 89, 387-402. HEATH, T. (1968). Origin and distribution of portal blood in the sheep. American Journal of Anatomy 122, 95-106.
